/*
 * Copyright (C) 2006 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.view;

import static android.view.Display.INVALID_DISPLAY;
import static android.view.View.PFLAG_DRAW_ANIMATION;
import static android.view.WindowCallbacks.RESIZE_MODE_DOCKED_DIVIDER;
import static android.view.WindowCallbacks.RESIZE_MODE_FREEFORM;
import static android.view.WindowManager.LayoutParams.LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS;
import static android.view.WindowManager.LayoutParams.PRIVATE_FLAG_FORCE_DECOR_VIEW_VISIBILITY;
import static android.view.WindowManager.LayoutParams.TYPE_INPUT_METHOD;
import static android.view.WindowManager.LayoutParams.TYPE_STATUS_BAR_PANEL;
import static android.view.WindowManager.LayoutParams.TYPE_VOLUME_OVERLAY;

import android.Manifest;
import android.animation.LayoutTransition;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.ActivityManager;
import android.app.ActivityThread;
import android.app.ResourcesManager;
import android.content.ClipData;
import android.content.ClipDescription;
import android.content.Context;
import android.content.pm.ActivityInfo;
import android.content.pm.PackageManager;
import android.content.res.CompatibilityInfo;
import android.content.res.Configuration;
import android.content.res.Resources;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.PixelFormat;
import android.graphics.Point;
import android.graphics.PointF;
import android.graphics.PorterDuff;
import android.graphics.Rect;
import android.graphics.Region;
import android.graphics.drawable.AnimatedVectorDrawable;
import android.graphics.drawable.Drawable;
import android.hardware.display.DisplayManager;
import android.hardware.display.DisplayManager.DisplayListener;
import android.hardware.input.InputManager;
import android.media.AudioManager;
import android.os.Binder;
import android.os.Build;
import android.os.Bundle;
import android.os.Debug;
import android.os.Handler;
import android.os.Looper;
import android.os.Message;
import android.os.ParcelFileDescriptor;
import android.os.Process;
import android.os.RemoteException;
import android.os.SystemClock;
import android.os.SystemProperties;
import android.os.Trace;
import android.util.AndroidRuntimeException;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.LongArray;
import android.util.MergedConfiguration;
import android.util.Slog;
import android.util.SparseArray;
import android.util.TimeUtils;
import android.util.TypedValue;
import android.view.Surface.OutOfResourcesException;
import android.view.ThreadedRenderer.FrameDrawingCallback;
import android.view.View.AttachInfo;
import android.view.View.FocusDirection;
import android.view.View.MeasureSpec;
import android.view.WindowManager.LayoutParams.SoftInputModeFlags;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityManager;
import android.view.accessibility.AccessibilityManager.AccessibilityStateChangeListener;
import android.view.accessibility.AccessibilityManager.HighTextContrastChangeListener;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.accessibility.AccessibilityNodeInfo.AccessibilityAction;
import android.view.accessibility.AccessibilityNodeProvider;
import android.view.accessibility.AccessibilityWindowInfo;
import android.view.accessibility.IAccessibilityInteractionConnection;
import android.view.accessibility.IAccessibilityInteractionConnectionCallback;
import android.view.animation.AccelerateDecelerateInterpolator;
import android.view.animation.Interpolator;
import android.view.autofill.AutofillManager;
import android.view.inputmethod.InputMethodManager;
import android.widget.Scroller;

import com.android.internal.R;
import com.android.internal.annotations.GuardedBy;
import com.android.internal.os.IResultReceiver;
import com.android.internal.os.SomeArgs;
import com.android.internal.policy.PhoneFallbackEventHandler;
import com.android.internal.util.Preconditions;
import com.android.internal.view.BaseSurfaceHolder;
import com.android.internal.view.RootViewSurfaceTaker;
import com.android.internal.view.SurfaceCallbackHelper;

import java.io.FileDescriptor;
import java.io.IOException;
import java.io.OutputStream;
import java.io.PrintWriter;
import java.lang.ref.WeakReference;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.LinkedList;
import java.util.Queue;
import java.util.concurrent.CountDownLatch;

The top of a view hierarchy, implementing the needed protocol between View and the WindowManager. This is for the most part an internal implementation detail of WindowManagerGlobal. {@hide} /**
 * The top of a view hierarchy, implementing the needed protocol between View
 * and the WindowManager.  This is for the most part an internal implementation
 * detail of {@link WindowManagerGlobal}.
 *
 * {@hide}
 */
@SuppressWarnings({"EmptyCatchBlock", "PointlessBooleanExpression"})
public final class ViewRootImpl implements ViewParent,
        View.AttachInfo.Callbacks, ThreadedRenderer.DrawCallbacks {
    private static final String TAG = "ViewRootImpl";
    private static final boolean DBG = false;
    private static final boolean LOCAL_LOGV = false;
    
@noinspection
PointlessBooleanExpression/** @noinspection PointlessBooleanExpression*/
    private static final boolean DEBUG_DRAW = false || LOCAL_LOGV;
    private static final boolean DEBUG_LAYOUT = false || LOCAL_LOGV;
    private static final boolean DEBUG_DIALOG = false || LOCAL_LOGV;
    private static final boolean DEBUG_INPUT_RESIZE = false || LOCAL_LOGV;
    private static final boolean DEBUG_ORIENTATION = false || LOCAL_LOGV;
    private static final boolean DEBUG_TRACKBALL = false || LOCAL_LOGV;
    private static final boolean DEBUG_IMF = false || LOCAL_LOGV;
    private static final boolean DEBUG_CONFIGURATION = false || LOCAL_LOGV;
    private static final boolean DEBUG_FPS = false;
    private static final boolean DEBUG_INPUT_STAGES = false || LOCAL_LOGV;
    private static final boolean DEBUG_KEEP_SCREEN_ON = false || LOCAL_LOGV;

    
Set to false if we do not want to use the multi threaded renderer even though
threaded renderer (aka hardware renderering) is used. Note that by disabling
this, WindowCallbacks will not fire.
/**
     * Set to false if we do not want to use the multi threaded renderer even though
     * threaded renderer (aka hardware renderering) is used. Note that by disabling
     * this, WindowCallbacks will not fire.
     */
    private static final boolean MT_RENDERER_AVAILABLE = true;

    
Set this system property to true to force the view hierarchy to render
at 60 Hz. This can be used to measure the potential framerate.
/**
     * Set this system property to true to force the view hierarchy to render
     * at 60 Hz. This can be used to measure the potential framerate.
     */
    private static final String PROPERTY_PROFILE_RENDERING = "viewroot.profile_rendering";

    // properties used by emulator to determine display shape
    public static final String PROPERTY_EMULATOR_WIN_OUTSET_BOTTOM_PX =
            "ro.emu.win_outset_bottom_px";

    
Maximum time we allow the user to roll the trackball enough to generate
a key event, before resetting the counters.
/**
     * Maximum time we allow the user to roll the trackball enough to generate
     * a key event, before resetting the counters.
     */
    static final int MAX_TRACKBALL_DELAY = 250;

    static final ThreadLocal<HandlerActionQueue> sRunQueues = new ThreadLocal<HandlerActionQueue>();

    static final ArrayList<Runnable> sFirstDrawHandlers = new ArrayList();
    static boolean sFirstDrawComplete = false;

    private FrameDrawingCallback mNextRtFrameCallback;

    
Callback for notifying about global configuration changes.
/**
     * Callback for notifying about global configuration changes.
     */
    public interface ConfigChangedCallback {

        
Notifies about global config change. /** Notifies about global config change. */
        void onConfigurationChanged(Configuration globalConfig);
    }

    private static final ArrayList<ConfigChangedCallback> sConfigCallbacks = new ArrayList<>();

    
Callback for notifying activities about override configuration changes.
/**
     * Callback for notifying activities about override configuration changes.
     */
    public interface ActivityConfigCallback {

        
Notifies about override config change and/or move to different display.
Params:
overrideConfig – New override config to apply to activity.
newDisplayId – New display id, Display.INVALID_DISPLAY if not changed./**
         * Notifies about override config change and/or move to different display.
         * @param overrideConfig New override config to apply to activity.
         * @param newDisplayId New display id, {@link Display#INVALID_DISPLAY} if not changed.
         */
        void onConfigurationChanged(Configuration overrideConfig, int newDisplayId);
    }

    
Callback used to notify corresponding activity about override configuration change and make
sure that all resources are set correctly before updating the ViewRootImpl's internal state.
/**
     * Callback used to notify corresponding activity about override configuration change and make
     * sure that all resources are set correctly before updating the ViewRootImpl's internal state.
     */
    private ActivityConfigCallback mActivityConfigCallback;

    
Used when configuration change first updates the config of corresponding activity. In that case we receive a call back from ActivityThread and this flag is used to preserve the initial value. 
See Also:
performConfigurationChange(MergedConfiguration, boolean, int, int)/**
     * Used when configuration change first updates the config of corresponding activity.
     * In that case we receive a call back from {@link ActivityThread} and this flag is used to
     * preserve the initial value.
     *
     * @see #performConfigurationChange(Configuration, Configuration, boolean, int)
     */
    private boolean mForceNextConfigUpdate;

    
Signals that compatibility booleans have been initialized according to
target SDK versions.
/**
     * Signals that compatibility booleans have been initialized according to
     * target SDK versions.
     */
    private static boolean sCompatibilityDone = false;

    
Always assign focus if a focusable View is available.
/**
     * Always assign focus if a focusable View is available.
     */
    private static boolean sAlwaysAssignFocus;

    
This list must only be modified by the main thread, so a lock is only needed when changing
the list or when accessing the list from a non-main thread.
/**
     * This list must only be modified by the main thread, so a lock is only needed when changing
     * the list or when accessing the list from a non-main thread.
     */
    @GuardedBy("mWindowCallbacks")
    final ArrayList<WindowCallbacks> mWindowCallbacks = new ArrayList<>();
    final Context mContext;
    final IWindowSession mWindowSession;
    @NonNull Display mDisplay;
    final DisplayManager mDisplayManager;
    final String mBasePackageName;

    final int[] mTmpLocation = new int[2];

    final TypedValue mTmpValue = new TypedValue();

    final Thread mThread;

    final WindowLeaked mLocation;

    public final WindowManager.LayoutParams mWindowAttributes = new WindowManager.LayoutParams();

    final W mWindow;

    final int mTargetSdkVersion;

    int mSeq;

    View mView;

    View mAccessibilityFocusedHost;
    AccessibilityNodeInfo mAccessibilityFocusedVirtualView;

    // True if the window currently has pointer capture enabled.
    boolean mPointerCapture;

    int mViewVisibility;
    boolean mAppVisible = true;
    // For recents to freeform transition we need to keep drawing after the app receives information
    // that it became invisible. This will ignore that information and depend on the decor view
    // visibility to control drawing. The decor view visibility will get adjusted when the app get
    // stopped and that's when the app will stop drawing further frames.
    private boolean mForceDecorViewVisibility = false;
    // Used for tracking app visibility updates separately in case we get double change. This will
    // make sure that we always call relayout for the corresponding window.
    private boolean mAppVisibilityChanged;
    int mOrigWindowType = -1;

    
Whether the window had focus during the most recent traversal. /** Whether the window had focus during the most recent traversal. */
    boolean mHadWindowFocus;

    
Whether the window lost focus during a previous traversal and has not
yet gained it back. Used to determine whether a WINDOW_STATE_CHANGE
accessibility events should be sent during traversal.
/**
     * Whether the window lost focus during a previous traversal and has not
     * yet gained it back. Used to determine whether a WINDOW_STATE_CHANGE
     * accessibility events should be sent during traversal.
     */
    boolean mLostWindowFocus;

    // Set to true if the owner of this window is in the stopped state,
    // so the window should no longer be active.
    boolean mStopped = false;

    // Set to true if the owner of this window is in ambient mode,
    // which means it won't receive input events.
    boolean mIsAmbientMode = false;

    // Set to true to stop input during an Activity Transition.
    boolean mPausedForTransition = false;

    boolean mLastInCompatMode = false;

    SurfaceHolder.Callback2 mSurfaceHolderCallback;
    BaseSurfaceHolder mSurfaceHolder;
    boolean mIsCreating;
    boolean mDrawingAllowed;

    final Region mTransparentRegion;
    final Region mPreviousTransparentRegion;

    int mWidth;
    int mHeight;
    Rect mDirty;
    public boolean mIsAnimating;

    private boolean mUseMTRenderer;
    private boolean mDragResizing;
    private boolean mInvalidateRootRequested;
    private int mResizeMode;
    private int mCanvasOffsetX;
    private int mCanvasOffsetY;
    private boolean mActivityRelaunched;

    CompatibilityInfo.Translator mTranslator;

    final View.AttachInfo mAttachInfo;
    InputChannel mInputChannel;
    InputQueue.Callback mInputQueueCallback;
    InputQueue mInputQueue;
    FallbackEventHandler mFallbackEventHandler;
    Choreographer mChoreographer;

    final Rect mTempRect; // used in the transaction to not thrash the heap.
    final Rect mVisRect; // used to retrieve visible rect of focused view.

    // This is used to reduce the race between window focus changes being dispatched from
    // the window manager and input events coming through the input system.
    @GuardedBy("this")
    boolean mWindowFocusChanged;
    @GuardedBy("this")
    boolean mUpcomingWindowFocus;
    @GuardedBy("this")
    boolean mUpcomingInTouchMode;

    public boolean mTraversalScheduled;
    int mTraversalBarrier;
    boolean mWillDrawSoon;
    
Set to true while in performTraversals for detecting when die(true) is called from internal
callbacks such as onMeasure, onPreDraw, onDraw and deferring doDie() until later. /** Set to true while in performTraversals for detecting when die(true) is called from internal
     * callbacks such as onMeasure, onPreDraw, onDraw and deferring doDie() until later. */
    boolean mIsInTraversal;
    boolean mApplyInsetsRequested;
    boolean mLayoutRequested;
    boolean mFirst;
    boolean mReportNextDraw;
    boolean mFullRedrawNeeded;
    boolean mNewSurfaceNeeded;
    boolean mHasHadWindowFocus;
    boolean mLastWasImTarget;
    boolean mForceNextWindowRelayout;
    CountDownLatch mWindowDrawCountDown;

    boolean mIsDrawing;
    int mLastSystemUiVisibility;
    int mClientWindowLayoutFlags;
    boolean mLastOverscanRequested;

    // Pool of queued input events.
    private static final int MAX_QUEUED_INPUT_EVENT_POOL_SIZE = 10;
    private QueuedInputEvent mQueuedInputEventPool;
    private int mQueuedInputEventPoolSize;

    /* Input event queue.
     * Pending input events are input events waiting to be delivered to the input stages
     * and handled by the application.
     */
    QueuedInputEvent mPendingInputEventHead;
    QueuedInputEvent mPendingInputEventTail;
    int mPendingInputEventCount;
    boolean mProcessInputEventsScheduled;
    boolean mUnbufferedInputDispatch;
    String mPendingInputEventQueueLengthCounterName = "pq";

    InputStage mFirstInputStage;
    InputStage mFirstPostImeInputStage;
    InputStage mSyntheticInputStage;

    private final UnhandledKeyManager mUnhandledKeyManager = new UnhandledKeyManager();

    boolean mWindowAttributesChanged = false;
    int mWindowAttributesChangesFlag = 0;

    // These can be accessed by any thread, must be protected with a lock.
    // Surface can never be reassigned or cleared (use Surface.clear()).
    public final Surface mSurface = new Surface();

    boolean mAdded;
    boolean mAddedTouchMode;

    // These are accessed by multiple threads.
    final Rect mWinFrame; // frame given by window manager.

    final Rect mPendingOverscanInsets = new Rect();
    final Rect mPendingVisibleInsets = new Rect();
    final Rect mPendingStableInsets = new Rect();
    final Rect mPendingContentInsets = new Rect();
    final Rect mPendingOutsets = new Rect();
    final Rect mPendingBackDropFrame = new Rect();
    final DisplayCutout.ParcelableWrapper mPendingDisplayCutout =
            new DisplayCutout.ParcelableWrapper(DisplayCutout.NO_CUTOUT);
    boolean mPendingAlwaysConsumeNavBar;
    final ViewTreeObserver.InternalInsetsInfo mLastGivenInsets
            = new ViewTreeObserver.InternalInsetsInfo();

    final Rect mDispatchContentInsets = new Rect();
    final Rect mDispatchStableInsets = new Rect();
    DisplayCutout mDispatchDisplayCutout = DisplayCutout.NO_CUTOUT;

    private WindowInsets mLastWindowInsets;

    
Last applied configuration obtained from resources. /** Last applied configuration obtained from resources. */
    private final Configuration mLastConfigurationFromResources = new Configuration();
    
Last configuration reported from WM or via MSG_UPDATE_CONFIGURATION. /** Last configuration reported from WM or via {@link #MSG_UPDATE_CONFIGURATION}. */
    private final MergedConfiguration mLastReportedMergedConfiguration = new MergedConfiguration();
    
Configurations waiting to be applied. /** Configurations waiting to be applied. */
    private final MergedConfiguration mPendingMergedConfiguration = new MergedConfiguration();

    boolean mScrollMayChange;
    @SoftInputModeFlags
    int mSoftInputMode;
    WeakReference<View> mLastScrolledFocus;
    int mScrollY;
    int mCurScrollY;
    Scroller mScroller;
    static final Interpolator mResizeInterpolator = new AccelerateDecelerateInterpolator();
    private ArrayList<LayoutTransition> mPendingTransitions;

    final ViewConfiguration mViewConfiguration;

    /* Drag/drop */
    ClipDescription mDragDescription;
    View mCurrentDragView;
    volatile Object mLocalDragState;
    final PointF mDragPoint = new PointF();
    final PointF mLastTouchPoint = new PointF();
    int mLastTouchSource;

    private boolean mProfileRendering;
    private Choreographer.FrameCallback mRenderProfiler;
    private boolean mRenderProfilingEnabled;

    // Variables to track frames per second, enabled via DEBUG_FPS flag
    private long mFpsStartTime = -1;
    private long mFpsPrevTime = -1;
    private int mFpsNumFrames;

    private int mPointerIconType = PointerIcon.TYPE_NOT_SPECIFIED;
    private PointerIcon mCustomPointerIcon = null;

    
see playSoundEffect(int) /**
     * see {@link #playSoundEffect(int)}
     */
    AudioManager mAudioManager;

    final AccessibilityManager mAccessibilityManager;

    AccessibilityInteractionController mAccessibilityInteractionController;

    final AccessibilityInteractionConnectionManager mAccessibilityInteractionConnectionManager =
            new AccessibilityInteractionConnectionManager();
    final HighContrastTextManager mHighContrastTextManager;

    SendWindowContentChangedAccessibilityEvent mSendWindowContentChangedAccessibilityEvent;

    HashSet<View> mTempHashSet;

    private final int mDensity;
    private final int mNoncompatDensity;

    private boolean mInLayout = false;
    ArrayList<View> mLayoutRequesters = new ArrayList<View>();
    boolean mHandlingLayoutInLayoutRequest = false;

    private int mViewLayoutDirectionInitial;

    
Set to true once doDie() has been called. /** Set to true once doDie() has been called. */
    private boolean mRemoved;

    private boolean mNeedsRendererSetup;

    
Consistency verifier for debugging purposes.
/**
     * Consistency verifier for debugging purposes.
     */
    protected final InputEventConsistencyVerifier mInputEventConsistencyVerifier =
            InputEventConsistencyVerifier.isInstrumentationEnabled() ?
                    new InputEventConsistencyVerifier(this, 0) : null;

    static final class SystemUiVisibilityInfo {
        int seq;
        int globalVisibility;
        int localValue;
        int localChanges;
    }

    private String mTag = TAG;

    public ViewRootImpl(Context context, Display display) {
        mContext = context;
        mWindowSession = WindowManagerGlobal.getWindowSession();
        mDisplay = display;
        mBasePackageName = context.getBasePackageName();
        mThread = Thread.currentThread();
        mLocation = new WindowLeaked(null);
        mLocation.fillInStackTrace();
        mWidth = -1;
        mHeight = -1;
        mDirty = new Rect();
        mTempRect = new Rect();
        mVisRect = new Rect();
        mWinFrame = new Rect();
        mWindow = new W(this);
        mTargetSdkVersion = context.getApplicationInfo().targetSdkVersion;
        mViewVisibility = View.GONE;
        mTransparentRegion = new Region();
        mPreviousTransparentRegion = new Region();
        mFirst = true; // true for the first time the view is added
        mAdded = false;
        mAttachInfo = new View.AttachInfo(mWindowSession, mWindow, display, this, mHandler, this,
                context);
        mAccessibilityManager = AccessibilityManager.getInstance(context);
        mAccessibilityManager.addAccessibilityStateChangeListener(
                mAccessibilityInteractionConnectionManager, mHandler);
        mHighContrastTextManager = new HighContrastTextManager();
        mAccessibilityManager.addHighTextContrastStateChangeListener(
                mHighContrastTextManager, mHandler);
        mViewConfiguration = ViewConfiguration.get(context);
        mDensity = context.getResources().getDisplayMetrics().densityDpi;
        mNoncompatDensity = context.getResources().getDisplayMetrics().noncompatDensityDpi;
        mFallbackEventHandler = new PhoneFallbackEventHandler(context);
        mChoreographer = Choreographer.getInstance();
        mDisplayManager = (DisplayManager)context.getSystemService(Context.DISPLAY_SERVICE);

        if (!sCompatibilityDone) {
            sAlwaysAssignFocus = mTargetSdkVersion < Build.VERSION_CODES.P;

            sCompatibilityDone = true;
        }

        loadSystemProperties();
    }

    public static void addFirstDrawHandler(Runnable callback) {
        synchronized (sFirstDrawHandlers) {
            if (!sFirstDrawComplete) {
                sFirstDrawHandlers.add(callback);
            }
        }
    }

    
Add static config callback to be notified about global config changes. /** Add static config callback to be notified about global config changes. */
    public static void addConfigCallback(ConfigChangedCallback callback) {
        synchronized (sConfigCallbacks) {
            sConfigCallbacks.add(callback);
        }
    }

    
Add activity config callback to be notified about override config changes. /** Add activity config callback to be notified about override config changes. */
    public void setActivityConfigCallback(ActivityConfigCallback callback) {
        mActivityConfigCallback = callback;
    }

    public void addWindowCallbacks(WindowCallbacks callback) {
        synchronized (mWindowCallbacks) {
            mWindowCallbacks.add(callback);
        }
    }

    public void removeWindowCallbacks(WindowCallbacks callback) {
        synchronized (mWindowCallbacks) {
            mWindowCallbacks.remove(callback);
        }
    }

    public void reportDrawFinish() {
        if (mWindowDrawCountDown != null) {
            mWindowDrawCountDown.countDown();
        }
    }

    // FIXME for perf testing only
    private boolean mProfile = false;

    
Call this to profile the next traversal call.
FIXME for perf testing only. Remove eventually
/**
     * Call this to profile the next traversal call.
     * FIXME for perf testing only. Remove eventually
     */
    public void profile() {
        mProfile = true;
    }

    
Indicates whether we are in touch mode. Calling this method triggers an IPC
call and should be avoided whenever possible.
Returns:
True, if the device is in touch mode, false otherwise.
@hide
/**
     * Indicates whether we are in touch mode. Calling this method triggers an IPC
     * call and should be avoided whenever possible.
     *
     * @return True, if the device is in touch mode, false otherwise.
     *
     * @hide
     */
    static boolean isInTouchMode() {
        IWindowSession windowSession = WindowManagerGlobal.peekWindowSession();
        if (windowSession != null) {
            try {
                return windowSession.getInTouchMode();
            } catch (RemoteException e) {
            }
        }
        return false;
    }

    
Notifies us that our child has been rebuilt, following
a window preservation operation. In these cases we
keep the same DecorView, but the activity controlling it
is a different instance, and we need to update our
callbacks.
@hide
/**
     * Notifies us that our child has been rebuilt, following
     * a window preservation operation. In these cases we
     * keep the same DecorView, but the activity controlling it
     * is a different instance, and we need to update our
     * callbacks.
     *
     * @hide
     */
    public void notifyChildRebuilt() {
        if (mView instanceof RootViewSurfaceTaker) {
            if (mSurfaceHolderCallback != null) {
                mSurfaceHolder.removeCallback(mSurfaceHolderCallback);
            }

            mSurfaceHolderCallback =
                ((RootViewSurfaceTaker)mView).willYouTakeTheSurface();

            if (mSurfaceHolderCallback != null) {
                mSurfaceHolder = new TakenSurfaceHolder();
                mSurfaceHolder.setFormat(PixelFormat.UNKNOWN);
                mSurfaceHolder.addCallback(mSurfaceHolderCallback);
            } else {
                mSurfaceHolder = null;
            }

            mInputQueueCallback =
                ((RootViewSurfaceTaker)mView).willYouTakeTheInputQueue();
            if (mInputQueueCallback != null) {
                mInputQueueCallback.onInputQueueCreated(mInputQueue);
            }
        }
    }

    
We have one child
/**
     * We have one child
     */
    public void setView(View view, WindowManager.LayoutParams attrs, View panelParentView) {
        synchronized (this) {
            if (mView == null) {
                mView = view;

                mAttachInfo.mDisplayState = mDisplay.getState();
                mDisplayManager.registerDisplayListener(mDisplayListener, mHandler);

                mViewLayoutDirectionInitial = mView.getRawLayoutDirection();
                mFallbackEventHandler.setView(view);
                mWindowAttributes.copyFrom(attrs);
                if (mWindowAttributes.packageName == null) {
                    mWindowAttributes.packageName = mBasePackageName;
                }
                attrs = mWindowAttributes;
                setTag();

                if (DEBUG_KEEP_SCREEN_ON && (mClientWindowLayoutFlags
                        & WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) != 0
                        && (attrs.flags&WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) == 0) {
                    Slog.d(mTag, "setView: FLAG_KEEP_SCREEN_ON changed from true to false!");
                }
                // Keep track of the actual window flags supplied by the client.
                mClientWindowLayoutFlags = attrs.flags;

                setAccessibilityFocus(null, null);

                if (view instanceof RootViewSurfaceTaker) {
                    mSurfaceHolderCallback =
                            ((RootViewSurfaceTaker)view).willYouTakeTheSurface();
                    if (mSurfaceHolderCallback != null) {
                        mSurfaceHolder = new TakenSurfaceHolder();
                        mSurfaceHolder.setFormat(PixelFormat.UNKNOWN);
                        mSurfaceHolder.addCallback(mSurfaceHolderCallback);
                    }
                }

                // Compute surface insets required to draw at specified Z value.
                // TODO: Use real shadow insets for a constant max Z.
                if (!attrs.hasManualSurfaceInsets) {
                    attrs.setSurfaceInsets(view, false /*manual*/, true /*preservePrevious*/);
                }

                CompatibilityInfo compatibilityInfo =
                        mDisplay.getDisplayAdjustments().getCompatibilityInfo();
                mTranslator = compatibilityInfo.getTranslator();

                // If the application owns the surface, don't enable hardware acceleration
                if (mSurfaceHolder == null) {
                    // While this is supposed to enable only, it can effectively disable
                    // the acceleration too.
                    enableHardwareAcceleration(attrs);
                    final boolean useMTRenderer = MT_RENDERER_AVAILABLE
                            && mAttachInfo.mThreadedRenderer != null;
                    if (mUseMTRenderer != useMTRenderer) {
                        // Shouldn't be resizing, as it's done only in window setup,
                        // but end just in case.
                        endDragResizing();
                        mUseMTRenderer = useMTRenderer;
                    }
                }

                boolean restore = false;
                if (mTranslator != null) {
                    mSurface.setCompatibilityTranslator(mTranslator);
                    restore = true;
                    attrs.backup();
                    mTranslator.translateWindowLayout(attrs);
                }
                if (DEBUG_LAYOUT) Log.d(mTag, "WindowLayout in setView:" + attrs);

                if (!compatibilityInfo.supportsScreen()) {
                    attrs.privateFlags |= WindowManager.LayoutParams.PRIVATE_FLAG_COMPATIBLE_WINDOW;
                    mLastInCompatMode = true;
                }

                mSoftInputMode = attrs.softInputMode;
                mWindowAttributesChanged = true;
                mWindowAttributesChangesFlag = WindowManager.LayoutParams.EVERYTHING_CHANGED;
                mAttachInfo.mRootView = view;
                mAttachInfo.mScalingRequired = mTranslator != null;
                mAttachInfo.mApplicationScale =
                        mTranslator == null ? 1.0f : mTranslator.applicationScale;
                if (panelParentView != null) {
                    mAttachInfo.mPanelParentWindowToken
                            = panelParentView.getApplicationWindowToken();
                }
                mAdded = true;
                int res; /* = WindowManagerImpl.ADD_OKAY; */

                // Schedule the first layout -before- adding to the window
                // manager, to make sure we do the relayout before receiving
                // any other events from the system.
                requestLayout();
                if ((mWindowAttributes.inputFeatures
                        & WindowManager.LayoutParams.INPUT_FEATURE_NO_INPUT_CHANNEL) == 0) {
                    mInputChannel = new InputChannel();
                }
                mForceDecorViewVisibility = (mWindowAttributes.privateFlags
                        & PRIVATE_FLAG_FORCE_DECOR_VIEW_VISIBILITY) != 0;
                try {
                    mOrigWindowType = mWindowAttributes.type;
                    mAttachInfo.mRecomputeGlobalAttributes = true;
                    collectViewAttributes();
                    res = mWindowSession.addToDisplay(mWindow, mSeq, mWindowAttributes,
                            getHostVisibility(), mDisplay.getDisplayId(), mWinFrame,
                            mAttachInfo.mContentInsets, mAttachInfo.mStableInsets,
                            mAttachInfo.mOutsets, mAttachInfo.mDisplayCutout, mInputChannel);
                } catch (RemoteException e) {
                    mAdded = false;
                    mView = null;
                    mAttachInfo.mRootView = null;
                    mInputChannel = null;
                    mFallbackEventHandler.setView(null);
                    unscheduleTraversals();
                    setAccessibilityFocus(null, null);
                    throw new RuntimeException("Adding window failed", e);
                } finally {
                    if (restore) {
                        attrs.restore();
                    }
                }

                if (mTranslator != null) {
                    mTranslator.translateRectInScreenToAppWindow(mAttachInfo.mContentInsets);
                }
                mPendingOverscanInsets.set(0, 0, 0, 0);
                mPendingContentInsets.set(mAttachInfo.mContentInsets);
                mPendingStableInsets.set(mAttachInfo.mStableInsets);
                mPendingDisplayCutout.set(mAttachInfo.mDisplayCutout);
                mPendingVisibleInsets.set(0, 0, 0, 0);
                mAttachInfo.mAlwaysConsumeNavBar =
                        (res & WindowManagerGlobal.ADD_FLAG_ALWAYS_CONSUME_NAV_BAR) != 0;
                mPendingAlwaysConsumeNavBar = mAttachInfo.mAlwaysConsumeNavBar;
                if (DEBUG_LAYOUT) Log.v(mTag, "Added window " + mWindow);
                if (res < WindowManagerGlobal.ADD_OKAY) {
                    mAttachInfo.mRootView = null;
                    mAdded = false;
                    mFallbackEventHandler.setView(null);
                    unscheduleTraversals();
                    setAccessibilityFocus(null, null);
                    switch (res) {
                        case WindowManagerGlobal.ADD_BAD_APP_TOKEN:
                        case WindowManagerGlobal.ADD_BAD_SUBWINDOW_TOKEN:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- token " + attrs.token
                                    + " is not valid; is your activity running?");
                        case WindowManagerGlobal.ADD_NOT_APP_TOKEN:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- token " + attrs.token
                                    + " is not for an application");
                        case WindowManagerGlobal.ADD_APP_EXITING:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- app for token " + attrs.token
                                    + " is exiting");
                        case WindowManagerGlobal.ADD_DUPLICATE_ADD:
                            throw new WindowManager.BadTokenException(
                                    "Unable to add window -- window " + mWindow
                                    + " has already been added");
                        case WindowManagerGlobal.ADD_STARTING_NOT_NEEDED:
                            // Silently ignore -- we would have just removed it
                            // right away, anyway.
                            return;
                        case WindowManagerGlobal.ADD_MULTIPLE_SINGLETON:
                            throw new WindowManager.BadTokenException("Unable to add window "
                                    + mWindow + " -- another window of type "
                                    + mWindowAttributes.type + " already exists");
                        case WindowManagerGlobal.ADD_PERMISSION_DENIED:
                            throw new WindowManager.BadTokenException("Unable to add window "
                                    + mWindow + " -- permission denied for window type "
                                    + mWindowAttributes.type);
                        case WindowManagerGlobal.ADD_INVALID_DISPLAY:
                            throw new WindowManager.InvalidDisplayException("Unable to add window "
                                    + mWindow + " -- the specified display can not be found");
                        case WindowManagerGlobal.ADD_INVALID_TYPE:
                            throw new WindowManager.InvalidDisplayException("Unable to add window "
                                    + mWindow + " -- the specified window type "
                                    + mWindowAttributes.type + " is not valid");
                    }
                    throw new RuntimeException(
                            "Unable to add window -- unknown error code " + res);
                }

                if (view instanceof RootViewSurfaceTaker) {
                    mInputQueueCallback =
                        ((RootViewSurfaceTaker)view).willYouTakeTheInputQueue();
                }
                if (mInputChannel != null) {
                    if (mInputQueueCallback != null) {
                        mInputQueue = new InputQueue();
                        mInputQueueCallback.onInputQueueCreated(mInputQueue);
                    }
                    mInputEventReceiver = new WindowInputEventReceiver(mInputChannel,
                            Looper.myLooper());
                }

                view.assignParent(this);
                mAddedTouchMode = (res & WindowManagerGlobal.ADD_FLAG_IN_TOUCH_MODE) != 0;
                mAppVisible = (res & WindowManagerGlobal.ADD_FLAG_APP_VISIBLE) != 0;

                if (mAccessibilityManager.isEnabled()) {
                    mAccessibilityInteractionConnectionManager.ensureConnection();
                }

                if (view.getImportantForAccessibility() == View.IMPORTANT_FOR_ACCESSIBILITY_AUTO) {
                    view.setImportantForAccessibility(View.IMPORTANT_FOR_ACCESSIBILITY_YES);
                }

                // Set up the input pipeline.
                CharSequence counterSuffix = attrs.getTitle();
                mSyntheticInputStage = new SyntheticInputStage();
                InputStage viewPostImeStage = new ViewPostImeInputStage(mSyntheticInputStage);
                InputStage nativePostImeStage = new NativePostImeInputStage(viewPostImeStage,
                        "aq:native-post-ime:" + counterSuffix);
                InputStage earlyPostImeStage = new EarlyPostImeInputStage(nativePostImeStage);
                InputStage imeStage = new ImeInputStage(earlyPostImeStage,
                        "aq:ime:" + counterSuffix);
                InputStage viewPreImeStage = new ViewPreImeInputStage(imeStage);
                InputStage nativePreImeStage = new NativePreImeInputStage(viewPreImeStage,
                        "aq:native-pre-ime:" + counterSuffix);

                mFirstInputStage = nativePreImeStage;
                mFirstPostImeInputStage = earlyPostImeStage;
                mPendingInputEventQueueLengthCounterName = "aq:pending:" + counterSuffix;
            }
        }
    }

    private void setTag() {
        final String[] split = mWindowAttributes.getTitle().toString().split("\\.");
        if (split.length > 0) {
            mTag = TAG + "[" + split[split.length - 1] + "]";
        }
    }

    
Whether the window is in local focus mode or not /** Whether the window is in local focus mode or not */
    private boolean isInLocalFocusMode() {
        return (mWindowAttributes.flags & WindowManager.LayoutParams.FLAG_LOCAL_FOCUS_MODE) != 0;
    }

    public int getWindowFlags() {
        return mWindowAttributes.flags;
    }

    public int getDisplayId() {
        return mDisplay.getDisplayId();
    }

    public CharSequence getTitle() {
        return mWindowAttributes.getTitle();
    }

    
Returns:
the width of the root view. Note that this will return -1 until the first layout traversal, when the width is set.
@hide
/**
     * @return the width of the root view. Note that this will return {@code -1} until the first
     *         layout traversal, when the width is set.
     *
     * @hide
     */
    public int getWidth() {
        return mWidth;
    }

    
Returns:
the height of the root view. Note that this will return -1 until the first layout traversal, when the height is set.
@hide
/**
     * @return the height of the root view. Note that this will return {@code -1} until the first
     *         layout traversal, when the height is set.
     *
     * @hide
     */
    public int getHeight() {
        return mHeight;
    }

    void destroyHardwareResources() {
        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.destroyHardwareResources(mView);
            mAttachInfo.mThreadedRenderer.destroy();
        }
    }

    public void detachFunctor(long functor) {
        if (mAttachInfo.mThreadedRenderer != null) {
            // Fence so that any pending invokeFunctor() messages will be processed
            // before we return from detachFunctor.
            mAttachInfo.mThreadedRenderer.stopDrawing();
        }
    }

    
Schedules the functor for execution in either kModeProcess or
kModeProcessNoContext, depending on whether or not there is an EGLContext.
Params:
functor – The native functor to invoke
waitForCompletion – If true, this will not return until the functor
                         has invoked. If false, the functor may be invoked
                         asynchronously./**
     * Schedules the functor for execution in either kModeProcess or
     * kModeProcessNoContext, depending on whether or not there is an EGLContext.
     *
     * @param functor The native functor to invoke
     * @param waitForCompletion If true, this will not return until the functor
     *                          has invoked. If false, the functor may be invoked
     *                          asynchronously.
     */
    public static void invokeFunctor(long functor, boolean waitForCompletion) {
        ThreadedRenderer.invokeFunctor(functor, waitForCompletion);
    }

    public void registerAnimatingRenderNode(RenderNode animator) {
        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.registerAnimatingRenderNode(animator);
        } else {
            if (mAttachInfo.mPendingAnimatingRenderNodes == null) {
                mAttachInfo.mPendingAnimatingRenderNodes = new ArrayList<RenderNode>();
            }
            mAttachInfo.mPendingAnimatingRenderNodes.add(animator);
        }
    }

    public void registerVectorDrawableAnimator(
            AnimatedVectorDrawable.VectorDrawableAnimatorRT animator) {
        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.registerVectorDrawableAnimator(animator);
        }
    }

    
Registers a callback to be executed when the next frame is being drawn on RenderThread. This
callback will be executed on a RenderThread worker thread, and only used for the next frame
and thus it will only fire once.
Params:
callback – The callback to register./**
     * Registers a callback to be executed when the next frame is being drawn on RenderThread. This
     * callback will be executed on a RenderThread worker thread, and only used for the next frame
     * and thus it will only fire once.
     *
     * @param callback The callback to register.
     */
    public void registerRtFrameCallback(FrameDrawingCallback callback) {
        mNextRtFrameCallback = callback;
    }

    private void enableHardwareAcceleration(WindowManager.LayoutParams attrs) {
        mAttachInfo.mHardwareAccelerated = false;
        mAttachInfo.mHardwareAccelerationRequested = false;

        // Don't enable hardware acceleration when the application is in compatibility mode
        if (mTranslator != null) return;

        // Try to enable hardware acceleration if requested
        final boolean hardwareAccelerated =
                (attrs.flags & WindowManager.LayoutParams.FLAG_HARDWARE_ACCELERATED) != 0;

        if (hardwareAccelerated) {
            if (!ThreadedRenderer.isAvailable()) {
                return;
            }

            // Persistent processes (including the system) should not do
            // accelerated rendering on low-end devices.  In that case,
            // sRendererDisabled will be set.  In addition, the system process
            // itself should never do accelerated rendering.  In that case, both
            // sRendererDisabled and sSystemRendererDisabled are set.  When
            // sSystemRendererDisabled is set, PRIVATE_FLAG_FORCE_HARDWARE_ACCELERATED
            // can be used by code on the system process to escape that and enable
            // HW accelerated drawing.  (This is basically for the lock screen.)

            final boolean fakeHwAccelerated = (attrs.privateFlags &
                    WindowManager.LayoutParams.PRIVATE_FLAG_FAKE_HARDWARE_ACCELERATED) != 0;
            final boolean forceHwAccelerated = (attrs.privateFlags &
                    WindowManager.LayoutParams.PRIVATE_FLAG_FORCE_HARDWARE_ACCELERATED) != 0;

            if (fakeHwAccelerated) {
                // This is exclusively for the preview windows the window manager
                // shows for launching applications, so they will look more like
                // the app being launched.
                mAttachInfo.mHardwareAccelerationRequested = true;
            } else if (!ThreadedRenderer.sRendererDisabled
                    || (ThreadedRenderer.sSystemRendererDisabled && forceHwAccelerated)) {
                if (mAttachInfo.mThreadedRenderer != null) {
                    mAttachInfo.mThreadedRenderer.destroy();
                }

                final Rect insets = attrs.surfaceInsets;
                final boolean hasSurfaceInsets = insets.left != 0 || insets.right != 0
                        || insets.top != 0 || insets.bottom != 0;
                final boolean translucent = attrs.format != PixelFormat.OPAQUE || hasSurfaceInsets;
                final boolean wideGamut =
                        mContext.getResources().getConfiguration().isScreenWideColorGamut()
                        && attrs.getColorMode() == ActivityInfo.COLOR_MODE_WIDE_COLOR_GAMUT;

                mAttachInfo.mThreadedRenderer = ThreadedRenderer.create(mContext, translucent,
                        attrs.getTitle().toString());
                mAttachInfo.mThreadedRenderer.setWideGamut(wideGamut);
                if (mAttachInfo.mThreadedRenderer != null) {
                    mAttachInfo.mHardwareAccelerated =
                            mAttachInfo.mHardwareAccelerationRequested = true;
                }
            }
        }
    }

    public View getView() {
        return mView;
    }

    final WindowLeaked getLocation() {
        return mLocation;
    }

    void setLayoutParams(WindowManager.LayoutParams attrs, boolean newView) {
        synchronized (this) {
            final int oldInsetLeft = mWindowAttributes.surfaceInsets.left;
            final int oldInsetTop = mWindowAttributes.surfaceInsets.top;
            final int oldInsetRight = mWindowAttributes.surfaceInsets.right;
            final int oldInsetBottom = mWindowAttributes.surfaceInsets.bottom;
            final int oldSoftInputMode = mWindowAttributes.softInputMode;
            final boolean oldHasManualSurfaceInsets = mWindowAttributes.hasManualSurfaceInsets;

            if (DEBUG_KEEP_SCREEN_ON && (mClientWindowLayoutFlags
                    & WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) != 0
                    && (attrs.flags&WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON) == 0) {
                Slog.d(mTag, "setLayoutParams: FLAG_KEEP_SCREEN_ON from true to false!");
            }

            // Keep track of the actual window flags supplied by the client.
            mClientWindowLayoutFlags = attrs.flags;

            // Preserve compatible window flag if exists.
            final int compatibleWindowFlag = mWindowAttributes.privateFlags
                    & WindowManager.LayoutParams.PRIVATE_FLAG_COMPATIBLE_WINDOW;

            // Transfer over system UI visibility values as they carry current state.
            attrs.systemUiVisibility = mWindowAttributes.systemUiVisibility;
            attrs.subtreeSystemUiVisibility = mWindowAttributes.subtreeSystemUiVisibility;

            mWindowAttributesChangesFlag = mWindowAttributes.copyFrom(attrs);
            if ((mWindowAttributesChangesFlag
                    & WindowManager.LayoutParams.TRANSLUCENT_FLAGS_CHANGED) != 0) {
                // Recompute system ui visibility.
                mAttachInfo.mRecomputeGlobalAttributes = true;
            }
            if ((mWindowAttributesChangesFlag
                    & WindowManager.LayoutParams.LAYOUT_CHANGED) != 0) {
                // Request to update light center.
                mAttachInfo.mNeedsUpdateLightCenter = true;
            }
            if (mWindowAttributes.packageName == null) {
                mWindowAttributes.packageName = mBasePackageName;
            }
            mWindowAttributes.privateFlags |= compatibleWindowFlag;

            if (mWindowAttributes.preservePreviousSurfaceInsets) {
                // Restore old surface insets.
                mWindowAttributes.surfaceInsets.set(
                        oldInsetLeft, oldInsetTop, oldInsetRight, oldInsetBottom);
                mWindowAttributes.hasManualSurfaceInsets = oldHasManualSurfaceInsets;
            } else if (mWindowAttributes.surfaceInsets.left != oldInsetLeft
                    || mWindowAttributes.surfaceInsets.top != oldInsetTop
                    || mWindowAttributes.surfaceInsets.right != oldInsetRight
                    || mWindowAttributes.surfaceInsets.bottom != oldInsetBottom) {
                mNeedsRendererSetup = true;
            }

            applyKeepScreenOnFlag(mWindowAttributes);

            if (newView) {
                mSoftInputMode = attrs.softInputMode;
                requestLayout();
            }

            // Don't lose the mode we last auto-computed.
            if ((attrs.softInputMode & WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST)
                    == WindowManager.LayoutParams.SOFT_INPUT_ADJUST_UNSPECIFIED) {
                mWindowAttributes.softInputMode = (mWindowAttributes.softInputMode
                        & ~WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST)
                        | (oldSoftInputMode & WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST);
            }

            mWindowAttributesChanged = true;
            scheduleTraversals();
        }
    }

    void handleAppVisibility(boolean visible) {
        if (mAppVisible != visible) {
            mAppVisible = visible;
            mAppVisibilityChanged = true;
            scheduleTraversals();
            if (!mAppVisible) {
                WindowManagerGlobal.trimForeground();
            }
        }
    }

    void handleGetNewSurface() {
        mNewSurfaceNeeded = true;
        mFullRedrawNeeded = true;
        scheduleTraversals();
    }

    private final DisplayListener mDisplayListener = new DisplayListener() {
        @Override
        public void onDisplayChanged(int displayId) {
            if (mView != null && mDisplay.getDisplayId() == displayId) {
                final int oldDisplayState = mAttachInfo.mDisplayState;
                final int newDisplayState = mDisplay.getState();
                if (oldDisplayState != newDisplayState) {
                    mAttachInfo.mDisplayState = newDisplayState;
                    pokeDrawLockIfNeeded();
                    if (oldDisplayState != Display.STATE_UNKNOWN) {
                        final int oldScreenState = toViewScreenState(oldDisplayState);
                        final int newScreenState = toViewScreenState(newDisplayState);
                        if (oldScreenState != newScreenState) {
                            mView.dispatchScreenStateChanged(newScreenState);
                        }
                        if (oldDisplayState == Display.STATE_OFF) {
                            // Draw was suppressed so we need to for it to happen here.
                            mFullRedrawNeeded = true;
                            scheduleTraversals();
                        }
                    }
                }
            }
        }

        @Override
        public void onDisplayRemoved(int displayId) {
        }

        @Override
        public void onDisplayAdded(int displayId) {
        }

        private int toViewScreenState(int displayState) {
            return displayState == Display.STATE_OFF ?
                    View.SCREEN_STATE_OFF : View.SCREEN_STATE_ON;
        }
    };

    
Notify about move to a different display.
Params:
displayId – The id of the display where this view root is moved to.
config – Configuration of the resources on new display after move.
@hide
/**
     * Notify about move to a different display.
     * @param displayId The id of the display where this view root is moved to.
     * @param config Configuration of the resources on new display after move.
     *
     * @hide
     */
    public void onMovedToDisplay(int displayId, Configuration config) {
        if (mDisplay.getDisplayId() == displayId) {
            return;
        }

        // Get new instance of display based on current display adjustments. It may be updated later
        // if moving between the displays also involved a configuration change.
        mDisplay = ResourcesManager.getInstance().getAdjustedDisplay(displayId,
            mView.getResources());
        mAttachInfo.mDisplayState = mDisplay.getState();
        // Internal state updated, now notify the view hierarchy.
        mView.dispatchMovedToDisplay(mDisplay, config);
    }

    void pokeDrawLockIfNeeded() {
        final int displayState = mAttachInfo.mDisplayState;
        if (mView != null && mAdded && mTraversalScheduled
                && (displayState == Display.STATE_DOZE
                        || displayState == Display.STATE_DOZE_SUSPEND)) {
            try {
                mWindowSession.pokeDrawLock(mWindow);
            } catch (RemoteException ex) {
                // System server died, oh well.
            }
        }
    }

    @Override
    public void requestFitSystemWindows() {
        checkThread();
        mApplyInsetsRequested = true;
        scheduleTraversals();
    }

    @Override
    public void requestLayout() {
        if (!mHandlingLayoutInLayoutRequest) {
            checkThread();
            mLayoutRequested = true;
            scheduleTraversals();
        }
    }

    @Override
    public boolean isLayoutRequested() {
        return mLayoutRequested;
    }

    @Override
    public void onDescendantInvalidated(@NonNull View child, @NonNull View descendant) {
        if ((descendant.mPrivateFlags & PFLAG_DRAW_ANIMATION) != 0) {
            mIsAnimating = true;
        }
        invalidate();
    }

    void invalidate() {
        mDirty.set(0, 0, mWidth, mHeight);
        if (!mWillDrawSoon) {
            scheduleTraversals();
        }
    }

    void invalidateWorld(View view) {
        view.invalidate();
        if (view instanceof ViewGroup) {
            ViewGroup parent = (ViewGroup) view;
            for (int i = 0; i < parent.getChildCount(); i++) {
                invalidateWorld(parent.getChildAt(i));
            }
        }
    }

    @Override
    public void invalidateChild(View child, Rect dirty) {
        invalidateChildInParent(null, dirty);
    }

    @Override
    public ViewParent invalidateChildInParent(int[] location, Rect dirty) {
        checkThread();
        if (DEBUG_DRAW) Log.v(mTag, "Invalidate child: " + dirty);

        if (dirty == null) {
            invalidate();
            return null;
        } else if (dirty.isEmpty() && !mIsAnimating) {
            return null;
        }

        if (mCurScrollY != 0 || mTranslator != null) {
            mTempRect.set(dirty);
            dirty = mTempRect;
            if (mCurScrollY != 0) {
                dirty.offset(0, -mCurScrollY);
            }
            if (mTranslator != null) {
                mTranslator.translateRectInAppWindowToScreen(dirty);
            }
            if (mAttachInfo.mScalingRequired) {
                dirty.inset(-1, -1);
            }
        }

        invalidateRectOnScreen(dirty);

        return null;
    }

    private void invalidateRectOnScreen(Rect dirty) {
        final Rect localDirty = mDirty;
        if (!localDirty.isEmpty() && !localDirty.contains(dirty)) {
            mAttachInfo.mSetIgnoreDirtyState = true;
            mAttachInfo.mIgnoreDirtyState = true;
        }

        // Add the new dirty rect to the current one
        localDirty.union(dirty.left, dirty.top, dirty.right, dirty.bottom);
        // Intersect with the bounds of the window to skip
        // updates that lie outside of the visible region
        final float appScale = mAttachInfo.mApplicationScale;
        final boolean intersected = localDirty.intersect(0, 0,
                (int) (mWidth * appScale + 0.5f), (int) (mHeight * appScale + 0.5f));
        if (!intersected) {
            localDirty.setEmpty();
        }
        if (!mWillDrawSoon && (intersected || mIsAnimating)) {
            scheduleTraversals();
        }
    }

    public void setIsAmbientMode(boolean ambient) {
        mIsAmbientMode = ambient;
    }

    interface WindowStoppedCallback {
        public void windowStopped(boolean stopped);
    }
    private final ArrayList<WindowStoppedCallback> mWindowStoppedCallbacks =  new ArrayList<>();

    void addWindowStoppedCallback(WindowStoppedCallback c) {
        mWindowStoppedCallbacks.add(c);
    }

    void removeWindowStoppedCallback(WindowStoppedCallback c) {
        mWindowStoppedCallbacks.remove(c);
    }

    void setWindowStopped(boolean stopped) {
        if (mStopped != stopped) {
            mStopped = stopped;
            final ThreadedRenderer renderer = mAttachInfo.mThreadedRenderer;
            if (renderer != null) {
                if (DEBUG_DRAW) Log.d(mTag, "WindowStopped on " + getTitle() + " set to " + mStopped);
                renderer.setStopped(mStopped);
            }
            if (!mStopped) {
                scheduleTraversals();
            } else {
                if (renderer != null) {
                    renderer.destroyHardwareResources(mView);
                }
            }

            for (int i = 0; i < mWindowStoppedCallbacks.size(); i++) {
                mWindowStoppedCallbacks.get(i).windowStopped(stopped);
            }

            if (mStopped) {
                mSurface.release();
            }
        }
    }

    
Block the input events during an Activity Transition. The KEYCODE_BACK event is allowed
through to allow quick reversal of the Activity Transition.
Params:
paused – true to pause, false to resume./**
     * Block the input events during an Activity Transition. The KEYCODE_BACK event is allowed
     * through to allow quick reversal of the Activity Transition.
     *
     * @param paused true to pause, false to resume.
     */
    public void setPausedForTransition(boolean paused) {
        mPausedForTransition = paused;
    }

    @Override
    public ViewParent getParent() {
        return null;
    }

    @Override
    public boolean getChildVisibleRect(View child, Rect r, android.graphics.Point offset) {
        if (child != mView) {
            throw new RuntimeException("child is not mine, honest!");
        }
        // Note: don't apply scroll offset, because we want to know its
        // visibility in the virtual canvas being given to the view hierarchy.
        return r.intersect(0, 0, mWidth, mHeight);
    }

    @Override
    public void bringChildToFront(View child) {
    }

    int getHostVisibility() {
        return (mAppVisible || mForceDecorViewVisibility) ? mView.getVisibility() : View.GONE;
    }

    
Add LayoutTransition to the list of transitions to be started in the next traversal.
This list will be cleared after the transitions on the list are start()'ed. These
transitionsa re added by LayoutTransition itself when it sets up animations. The setup
happens during the layout phase of traversal, which we want to complete before any of the
animations are started (because those animations may side-effect properties that layout
depends upon, like the bounding rectangles of the affected views). So we add the transition
to the list and it is started just prior to starting the drawing phase of traversal.
Params:
transition – The LayoutTransition to be started on the next traversal.
@hide
/**
     * Add LayoutTransition to the list of transitions to be started in the next traversal.
     * This list will be cleared after the transitions on the list are start()'ed. These
     * transitionsa re added by LayoutTransition itself when it sets up animations. The setup
     * happens during the layout phase of traversal, which we want to complete before any of the
     * animations are started (because those animations may side-effect properties that layout
     * depends upon, like the bounding rectangles of the affected views). So we add the transition
     * to the list and it is started just prior to starting the drawing phase of traversal.
     *
     * @param transition The LayoutTransition to be started on the next traversal.
     *
     * @hide
     */
    public void requestTransitionStart(LayoutTransition transition) {
        if (mPendingTransitions == null || !mPendingTransitions.contains(transition)) {
            if (mPendingTransitions == null) {
                 mPendingTransitions = new ArrayList<LayoutTransition>();
            }
            mPendingTransitions.add(transition);
        }
    }

    
Notifies the HardwareRenderer that a new frame will be coming soon. Currently only ThreadedRenderer cares about this, and uses this knowledge to adjust the scheduling of off-thread animations /**
     * Notifies the HardwareRenderer that a new frame will be coming soon.
     * Currently only {@link ThreadedRenderer} cares about this, and uses
     * this knowledge to adjust the scheduling of off-thread animations
     */
    void notifyRendererOfFramePending() {
        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.notifyFramePending();
        }
    }

    void scheduleTraversals() {
        if (!mTraversalScheduled) {
            mTraversalScheduled = true;
            mTraversalBarrier = mHandler.getLooper().getQueue().postSyncBarrier();
            mChoreographer.postCallback(
                    Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null);
            if (!mUnbufferedInputDispatch) {
                scheduleConsumeBatchedInput();
            }
            notifyRendererOfFramePending();
            pokeDrawLockIfNeeded();
        }
    }

    void unscheduleTraversals() {
        if (mTraversalScheduled) {
            mTraversalScheduled = false;
            mHandler.getLooper().getQueue().removeSyncBarrier(mTraversalBarrier);
            mChoreographer.removeCallbacks(
                    Choreographer.CALLBACK_TRAVERSAL, mTraversalRunnable, null);
        }
    }

    void doTraversal() {
        if (mTraversalScheduled) {
            mTraversalScheduled = false;
            mHandler.getLooper().getQueue().removeSyncBarrier(mTraversalBarrier);

            if (mProfile) {
                Debug.startMethodTracing("ViewAncestor");
            }

            performTraversals();

            if (mProfile) {
                Debug.stopMethodTracing();
                mProfile = false;
            }
        }
    }

    private void applyKeepScreenOnFlag(WindowManager.LayoutParams params) {
        // Update window's global keep screen on flag: if a view has requested
        // that the screen be kept on, then it is always set; otherwise, it is
        // set to whatever the client last requested for the global state.
        if (mAttachInfo.mKeepScreenOn) {
            params.flags |= WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON;
        } else {
            params.flags = (params.flags&~WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON)
                    | (mClientWindowLayoutFlags&WindowManager.LayoutParams.FLAG_KEEP_SCREEN_ON);
        }
    }

    private boolean collectViewAttributes() {
        if (mAttachInfo.mRecomputeGlobalAttributes) {
            //Log.i(mTag, "Computing view hierarchy attributes!");
            mAttachInfo.mRecomputeGlobalAttributes = false;
            boolean oldScreenOn = mAttachInfo.mKeepScreenOn;
            mAttachInfo.mKeepScreenOn = false;
            mAttachInfo.mSystemUiVisibility = 0;
            mAttachInfo.mHasSystemUiListeners = false;
            mView.dispatchCollectViewAttributes(mAttachInfo, 0);
            mAttachInfo.mSystemUiVisibility &= ~mAttachInfo.mDisabledSystemUiVisibility;
            WindowManager.LayoutParams params = mWindowAttributes;
            mAttachInfo.mSystemUiVisibility |= getImpliedSystemUiVisibility(params);
            if (mAttachInfo.mKeepScreenOn != oldScreenOn
                    || mAttachInfo.mSystemUiVisibility != params.subtreeSystemUiVisibility
                    || mAttachInfo.mHasSystemUiListeners != params.hasSystemUiListeners) {
                applyKeepScreenOnFlag(params);
                params.subtreeSystemUiVisibility = mAttachInfo.mSystemUiVisibility;
                params.hasSystemUiListeners = mAttachInfo.mHasSystemUiListeners;
                mView.dispatchWindowSystemUiVisiblityChanged(mAttachInfo.mSystemUiVisibility);
                return true;
            }
        }
        return false;
    }

    private int getImpliedSystemUiVisibility(WindowManager.LayoutParams params) {
        int vis = 0;
        // Translucent decor window flags imply stable system ui visibility.
        if ((params.flags & WindowManager.LayoutParams.FLAG_TRANSLUCENT_STATUS) != 0) {
            vis |= View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_FULLSCREEN;
        }
        if ((params.flags & WindowManager.LayoutParams.FLAG_TRANSLUCENT_NAVIGATION) != 0) {
            vis |= View.SYSTEM_UI_FLAG_LAYOUT_STABLE | View.SYSTEM_UI_FLAG_LAYOUT_HIDE_NAVIGATION;
        }
        return vis;
    }

    private boolean measureHierarchy(final View host, final WindowManager.LayoutParams lp,
            final Resources res, final int desiredWindowWidth, final int desiredWindowHeight) {
        int childWidthMeasureSpec;
        int childHeightMeasureSpec;
        boolean windowSizeMayChange = false;

        if (DEBUG_ORIENTATION || DEBUG_LAYOUT) Log.v(mTag,
                "Measuring " + host + " in display " + desiredWindowWidth
                + "x" + desiredWindowHeight + "...");

        boolean goodMeasure = false;
        if (lp.width == ViewGroup.LayoutParams.WRAP_CONTENT) {
            // On large screens, we don't want to allow dialogs to just
            // stretch to fill the entire width of the screen to display
            // one line of text.  First try doing the layout at a smaller
            // size to see if it will fit.
            final DisplayMetrics packageMetrics = res.getDisplayMetrics();
            res.getValue(com.android.internal.R.dimen.config_prefDialogWidth, mTmpValue, true);
            int baseSize = 0;
            if (mTmpValue.type == TypedValue.TYPE_DIMENSION) {
                baseSize = (int)mTmpValue.getDimension(packageMetrics);
            }
            if (DEBUG_DIALOG) Log.v(mTag, "Window " + mView + ": baseSize=" + baseSize
                    + ", desiredWindowWidth=" + desiredWindowWidth);
            if (baseSize != 0 && desiredWindowWidth > baseSize) {
                childWidthMeasureSpec = getRootMeasureSpec(baseSize, lp.width);
                childHeightMeasureSpec = getRootMeasureSpec(desiredWindowHeight, lp.height);
                performMeasure(childWidthMeasureSpec, childHeightMeasureSpec);
                if (DEBUG_DIALOG) Log.v(mTag, "Window " + mView + ": measured ("
                        + host.getMeasuredWidth() + "," + host.getMeasuredHeight()
                        + ") from width spec: " + MeasureSpec.toString(childWidthMeasureSpec)
                        + " and height spec: " + MeasureSpec.toString(childHeightMeasureSpec));
                if ((host.getMeasuredWidthAndState()&View.MEASURED_STATE_TOO_SMALL) == 0) {
                    goodMeasure = true;
                } else {
                    // Didn't fit in that size... try expanding a bit.
                    baseSize = (baseSize+desiredWindowWidth)/2;
                    if (DEBUG_DIALOG) Log.v(mTag, "Window " + mView + ": next baseSize="
                            + baseSize);
                    childWidthMeasureSpec = getRootMeasureSpec(baseSize, lp.width);
                    performMeasure(childWidthMeasureSpec, childHeightMeasureSpec);
                    if (DEBUG_DIALOG) Log.v(mTag, "Window " + mView + ": measured ("
                            + host.getMeasuredWidth() + "," + host.getMeasuredHeight() + ")");
                    if ((host.getMeasuredWidthAndState()&View.MEASURED_STATE_TOO_SMALL) == 0) {
                        if (DEBUG_DIALOG) Log.v(mTag, "Good!");
                        goodMeasure = true;
                    }
                }
            }
        }

        if (!goodMeasure) {
            childWidthMeasureSpec = getRootMeasureSpec(desiredWindowWidth, lp.width);
            childHeightMeasureSpec = getRootMeasureSpec(desiredWindowHeight, lp.height);
            performMeasure(childWidthMeasureSpec, childHeightMeasureSpec);
            if (mWidth != host.getMeasuredWidth() || mHeight != host.getMeasuredHeight()) {
                windowSizeMayChange = true;
            }
        }

        if (DBG) {
            System.out.println("======================================");
            System.out.println("performTraversals -- after measure");
            host.debug();
        }

        return windowSizeMayChange;
    }

    
Modifies the input matrix such that it maps view-local coordinates to
on-screen coordinates.
Params:
m – input matrix to modify/**
     * Modifies the input matrix such that it maps view-local coordinates to
     * on-screen coordinates.
     *
     * @param m input matrix to modify
     */
    void transformMatrixToGlobal(Matrix m) {
        m.preTranslate(mAttachInfo.mWindowLeft, mAttachInfo.mWindowTop);
    }

    
Modifies the input matrix such that it maps on-screen coordinates to
view-local coordinates.
Params:
m – input matrix to modify/**
     * Modifies the input matrix such that it maps on-screen coordinates to
     * view-local coordinates.
     *
     * @param m input matrix to modify
     */
    void transformMatrixToLocal(Matrix m) {
        m.postTranslate(-mAttachInfo.mWindowLeft, -mAttachInfo.mWindowTop);
    }

    /* package */ WindowInsets getWindowInsets(boolean forceConstruct) {
        if (mLastWindowInsets == null || forceConstruct) {
            mDispatchContentInsets.set(mAttachInfo.mContentInsets);
            mDispatchStableInsets.set(mAttachInfo.mStableInsets);
            mDispatchDisplayCutout = mAttachInfo.mDisplayCutout.get();

            Rect contentInsets = mDispatchContentInsets;
            Rect stableInsets = mDispatchStableInsets;
            DisplayCutout displayCutout = mDispatchDisplayCutout;
            // For dispatch we preserve old logic, but for direct requests from Views we allow to
            // immediately use pending insets.
            if (!forceConstruct
                    && (!mPendingContentInsets.equals(contentInsets) ||
                        !mPendingStableInsets.equals(stableInsets) ||
                        !mPendingDisplayCutout.get().equals(displayCutout))) {
                contentInsets = mPendingContentInsets;
                stableInsets = mPendingStableInsets;
                displayCutout = mPendingDisplayCutout.get();
            }
            Rect outsets = mAttachInfo.mOutsets;
            if (outsets.left > 0 || outsets.top > 0 || outsets.right > 0 || outsets.bottom > 0) {
                contentInsets = new Rect(contentInsets.left + outsets.left,
                        contentInsets.top + outsets.top, contentInsets.right + outsets.right,
                        contentInsets.bottom + outsets.bottom);
            }
            contentInsets = ensureInsetsNonNegative(contentInsets, "content");
            stableInsets = ensureInsetsNonNegative(stableInsets, "stable");
            mLastWindowInsets = new WindowInsets(contentInsets,
                    null /* windowDecorInsets */, stableInsets,
                    mContext.getResources().getConfiguration().isScreenRound(),
                    mAttachInfo.mAlwaysConsumeNavBar, displayCutout);
        }
        return mLastWindowInsets;
    }

    private Rect ensureInsetsNonNegative(Rect insets, String kind) {
        if (insets.left < 0  || insets.top < 0  || insets.right < 0  || insets.bottom < 0) {
            return new Rect(Math.max(0, insets.left),
                    Math.max(0, insets.top),
                    Math.max(0, insets.right),
                    Math.max(0, insets.bottom));
        }
        return insets;
    }

    void dispatchApplyInsets(View host) {
        WindowInsets insets = getWindowInsets(true /* forceConstruct */);
        final boolean dispatchCutout = (mWindowAttributes.layoutInDisplayCutoutMode
                == LAYOUT_IN_DISPLAY_CUTOUT_MODE_ALWAYS);
        if (!dispatchCutout) {
            // Window is either not laid out in cutout or the status bar inset takes care of
            // clearing the cutout, so we don't need to dispatch the cutout to the hierarchy.
            insets = insets.consumeDisplayCutout();
        }
        host.dispatchApplyWindowInsets(insets);
    }

    private static boolean shouldUseDisplaySize(final WindowManager.LayoutParams lp) {
        return lp.type == TYPE_STATUS_BAR_PANEL
                || lp.type == TYPE_INPUT_METHOD
                || lp.type == TYPE_VOLUME_OVERLAY;
    }

    private int dipToPx(int dip) {
        final DisplayMetrics displayMetrics = mContext.getResources().getDisplayMetrics();
        return (int) (displayMetrics.density * dip + 0.5f);
    }

    private void performTraversals() {
        // cache mView since it is used so much below...
        final View host = mView;

        if (DBG) {
            System.out.println("======================================");
            System.out.println("performTraversals");
            host.debug();
        }

        if (host == null || !mAdded)
            return;

        mIsInTraversal = true;
        mWillDrawSoon = true;
        boolean windowSizeMayChange = false;
        boolean newSurface = false;
        boolean surfaceChanged = false;
        WindowManager.LayoutParams lp = mWindowAttributes;

        int desiredWindowWidth;
        int desiredWindowHeight;

        final int viewVisibility = getHostVisibility();
        final boolean viewVisibilityChanged = !mFirst
                && (mViewVisibility != viewVisibility || mNewSurfaceNeeded
                // Also check for possible double visibility update, which will make current
                // viewVisibility value equal to mViewVisibility and we may miss it.
                || mAppVisibilityChanged);
        mAppVisibilityChanged = false;
        final boolean viewUserVisibilityChanged = !mFirst &&
                ((mViewVisibility == View.VISIBLE) != (viewVisibility == View.VISIBLE));

        WindowManager.LayoutParams params = null;
        if (mWindowAttributesChanged) {
            mWindowAttributesChanged = false;
            surfaceChanged = true;
            params = lp;
        }
        CompatibilityInfo compatibilityInfo =
                mDisplay.getDisplayAdjustments().getCompatibilityInfo();
        if (compatibilityInfo.supportsScreen() == mLastInCompatMode) {
            params = lp;
            mFullRedrawNeeded = true;
            mLayoutRequested = true;
            if (mLastInCompatMode) {
                params.privateFlags &= ~WindowManager.LayoutParams.PRIVATE_FLAG_COMPATIBLE_WINDOW;
                mLastInCompatMode = false;
            } else {
                params.privateFlags |= WindowManager.LayoutParams.PRIVATE_FLAG_COMPATIBLE_WINDOW;
                mLastInCompatMode = true;
            }
        }

        mWindowAttributesChangesFlag = 0;

        Rect frame = mWinFrame;
        if (mFirst) {
            mFullRedrawNeeded = true;
            mLayoutRequested = true;

            final Configuration config = mContext.getResources().getConfiguration();
            if (shouldUseDisplaySize(lp)) {
                // NOTE -- system code, won't try to do compat mode.
                Point size = new Point();
                mDisplay.getRealSize(size);
                desiredWindowWidth = size.x;
                desiredWindowHeight = size.y;
            } else {
                desiredWindowWidth = mWinFrame.width();
                desiredWindowHeight = mWinFrame.height();
            }

            // We used to use the following condition to choose 32 bits drawing caches:
            // PixelFormat.hasAlpha(lp.format) || lp.format == PixelFormat.RGBX_8888
            // However, windows are now always 32 bits by default, so choose 32 bits
            mAttachInfo.mUse32BitDrawingCache = true;
            mAttachInfo.mHasWindowFocus = false;
            mAttachInfo.mWindowVisibility = viewVisibility;
            mAttachInfo.mRecomputeGlobalAttributes = false;
            mLastConfigurationFromResources.setTo(config);
            mLastSystemUiVisibility = mAttachInfo.mSystemUiVisibility;
            // Set the layout direction if it has not been set before (inherit is the default)
            if (mViewLayoutDirectionInitial == View.LAYOUT_DIRECTION_INHERIT) {
                host.setLayoutDirection(config.getLayoutDirection());
            }
            host.dispatchAttachedToWindow(mAttachInfo, 0);
            mAttachInfo.mTreeObserver.dispatchOnWindowAttachedChange(true);
            dispatchApplyInsets(host);
        } else {
            desiredWindowWidth = frame.width();
            desiredWindowHeight = frame.height();
            if (desiredWindowWidth != mWidth || desiredWindowHeight != mHeight) {
                if (DEBUG_ORIENTATION) Log.v(mTag, "View " + host + " resized to: " + frame);
                mFullRedrawNeeded = true;
                mLayoutRequested = true;
                windowSizeMayChange = true;
            }
        }

        if (viewVisibilityChanged) {
            mAttachInfo.mWindowVisibility = viewVisibility;
            host.dispatchWindowVisibilityChanged(viewVisibility);
            if (viewUserVisibilityChanged) {
                host.dispatchVisibilityAggregated(viewVisibility == View.VISIBLE);
            }
            if (viewVisibility != View.VISIBLE || mNewSurfaceNeeded) {
                endDragResizing();
                destroyHardwareResources();
            }
            if (viewVisibility == View.GONE) {
                // After making a window gone, we will count it as being
                // shown for the first time the next time it gets focus.
                mHasHadWindowFocus = false;
            }
        }

        // Non-visible windows can't hold accessibility focus.
        if (mAttachInfo.mWindowVisibility != View.VISIBLE) {
            host.clearAccessibilityFocus();
        }

        // Execute enqueued actions on every traversal in case a detached view enqueued an action
        getRunQueue().executeActions(mAttachInfo.mHandler);

        boolean insetsChanged = false;

        boolean layoutRequested = mLayoutRequested && (!mStopped || mReportNextDraw);
        if (layoutRequested) {

            final Resources res = mView.getContext().getResources();

            if (mFirst) {
                // make sure touch mode code executes by setting cached value
                // to opposite of the added touch mode.
                mAttachInfo.mInTouchMode = !mAddedTouchMode;
                ensureTouchModeLocally(mAddedTouchMode);
            } else {
                if (!mPendingOverscanInsets.equals(mAttachInfo.mOverscanInsets)) {
                    insetsChanged = true;
                }
                if (!mPendingContentInsets.equals(mAttachInfo.mContentInsets)) {
                    insetsChanged = true;
                }
                if (!mPendingStableInsets.equals(mAttachInfo.mStableInsets)) {
                    insetsChanged = true;
                }
                if (!mPendingDisplayCutout.equals(mAttachInfo.mDisplayCutout)) {
                    insetsChanged = true;
                }
                if (!mPendingVisibleInsets.equals(mAttachInfo.mVisibleInsets)) {
                    mAttachInfo.mVisibleInsets.set(mPendingVisibleInsets);
                    if (DEBUG_LAYOUT) Log.v(mTag, "Visible insets changing to: "
                            + mAttachInfo.mVisibleInsets);
                }
                if (!mPendingOutsets.equals(mAttachInfo.mOutsets)) {
                    insetsChanged = true;
                }
                if (mPendingAlwaysConsumeNavBar != mAttachInfo.mAlwaysConsumeNavBar) {
                    insetsChanged = true;
                }
                if (lp.width == ViewGroup.LayoutParams.WRAP_CONTENT
                        || lp.height == ViewGroup.LayoutParams.WRAP_CONTENT) {
                    windowSizeMayChange = true;

                    if (shouldUseDisplaySize(lp)) {
                        // NOTE -- system code, won't try to do compat mode.
                        Point size = new Point();
                        mDisplay.getRealSize(size);
                        desiredWindowWidth = size.x;
                        desiredWindowHeight = size.y;
                    } else {
                        Configuration config = res.getConfiguration();
                        desiredWindowWidth = dipToPx(config.screenWidthDp);
                        desiredWindowHeight = dipToPx(config.screenHeightDp);
                    }
                }
            }

            // Ask host how big it wants to be
            windowSizeMayChange |= measureHierarchy(host, lp, res,
                    desiredWindowWidth, desiredWindowHeight);
        }

        if (collectViewAttributes()) {
            params = lp;
        }
        if (mAttachInfo.mForceReportNewAttributes) {
            mAttachInfo.mForceReportNewAttributes = false;
            params = lp;
        }

        if (mFirst || mAttachInfo.mViewVisibilityChanged) {
            mAttachInfo.mViewVisibilityChanged = false;
            int resizeMode = mSoftInputMode &
                    WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST;
            // If we are in auto resize mode, then we need to determine
            // what mode to use now.
            if (resizeMode == WindowManager.LayoutParams.SOFT_INPUT_ADJUST_UNSPECIFIED) {
                final int N = mAttachInfo.mScrollContainers.size();
                for (int i=0; i<N; i++) {
                    if (mAttachInfo.mScrollContainers.get(i).isShown()) {
                        resizeMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_RESIZE;
                    }
                }
                if (resizeMode == 0) {
                    resizeMode = WindowManager.LayoutParams.SOFT_INPUT_ADJUST_PAN;
                }
                if ((lp.softInputMode &
                        WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST) != resizeMode) {
                    lp.softInputMode = (lp.softInputMode &
                            ~WindowManager.LayoutParams.SOFT_INPUT_MASK_ADJUST) |
                            resizeMode;
                    params = lp;
                }
            }
        }

        if (params != null) {
            if ((host.mPrivateFlags & View.PFLAG_REQUEST_TRANSPARENT_REGIONS) != 0) {
                if (!PixelFormat.formatHasAlpha(params.format)) {
                    params.format = PixelFormat.TRANSLUCENT;
                }
            }
            mAttachInfo.mOverscanRequested = (params.flags
                    & WindowManager.LayoutParams.FLAG_LAYOUT_IN_OVERSCAN) != 0;
        }

        if (mApplyInsetsRequested) {
            mApplyInsetsRequested = false;
            mLastOverscanRequested = mAttachInfo.mOverscanRequested;
            dispatchApplyInsets(host);
            if (mLayoutRequested) {
                // Short-circuit catching a new layout request here, so
                // we don't need to go through two layout passes when things
                // change due to fitting system windows, which can happen a lot.
                windowSizeMayChange |= measureHierarchy(host, lp,
                        mView.getContext().getResources(),
                        desiredWindowWidth, desiredWindowHeight);
            }
        }

        if (layoutRequested) {
            // Clear this now, so that if anything requests a layout in the
            // rest of this function we will catch it and re-run a full
            // layout pass.
            mLayoutRequested = false;
        }

        boolean windowShouldResize = layoutRequested && windowSizeMayChange
            && ((mWidth != host.getMeasuredWidth() || mHeight != host.getMeasuredHeight())
                || (lp.width == ViewGroup.LayoutParams.WRAP_CONTENT &&
                        frame.width() < desiredWindowWidth && frame.width() != mWidth)
                || (lp.height == ViewGroup.LayoutParams.WRAP_CONTENT &&
                        frame.height() < desiredWindowHeight && frame.height() != mHeight));
        windowShouldResize |= mDragResizing && mResizeMode == RESIZE_MODE_FREEFORM;

        // If the activity was just relaunched, it might have unfrozen the task bounds (while
        // relaunching), so we need to force a call into window manager to pick up the latest
        // bounds.
        windowShouldResize |= mActivityRelaunched;

        // Determine whether to compute insets.
        // If there are no inset listeners remaining then we may still need to compute
        // insets in case the old insets were non-empty and must be reset.
        final boolean computesInternalInsets =
                mAttachInfo.mTreeObserver.hasComputeInternalInsetsListeners()
                || mAttachInfo.mHasNonEmptyGivenInternalInsets;

        boolean insetsPending = false;
        int relayoutResult = 0;
        boolean updatedConfiguration = false;

        final int surfaceGenerationId = mSurface.getGenerationId();

        final boolean isViewVisible = viewVisibility == View.VISIBLE;
        final boolean windowRelayoutWasForced = mForceNextWindowRelayout;
        if (mFirst || windowShouldResize || insetsChanged ||
                viewVisibilityChanged || params != null || mForceNextWindowRelayout) {
            mForceNextWindowRelayout = false;

            if (isViewVisible) {
                // If this window is giving internal insets to the window
                // manager, and it is being added or changing its visibility,
                // then we want to first give the window manager "fake"
                // insets to cause it to effectively ignore the content of
                // the window during layout.  This avoids it briefly causing
                // other windows to resize/move based on the raw frame of the
                // window, waiting until we can finish laying out this window
                // and get back to the window manager with the ultimately
                // computed insets.
                insetsPending = computesInternalInsets && (mFirst || viewVisibilityChanged);
            }

            if (mSurfaceHolder != null) {
                mSurfaceHolder.mSurfaceLock.lock();
                mDrawingAllowed = true;
            }

            boolean hwInitialized = false;
            boolean contentInsetsChanged = false;
            boolean hadSurface = mSurface.isValid();

            try {
                if (DEBUG_LAYOUT) {
                    Log.i(mTag, "host=w:" + host.getMeasuredWidth() + ", h:" +
                            host.getMeasuredHeight() + ", params=" + params);
                }

                if (mAttachInfo.mThreadedRenderer != null) {
                    // relayoutWindow may decide to destroy mSurface. As that decision
                    // happens in WindowManager service, we need to be defensive here
                    // and stop using the surface in case it gets destroyed.
                    if (mAttachInfo.mThreadedRenderer.pauseSurface(mSurface)) {
                        // Animations were running so we need to push a frame
                        // to resume them
                        mDirty.set(0, 0, mWidth, mHeight);
                    }
                    mChoreographer.mFrameInfo.addFlags(FrameInfo.FLAG_WINDOW_LAYOUT_CHANGED);
                }
                relayoutResult = relayoutWindow(params, viewVisibility, insetsPending);

                if (DEBUG_LAYOUT) Log.v(mTag, "relayout: frame=" + frame.toShortString()
                        + " overscan=" + mPendingOverscanInsets.toShortString()
                        + " content=" + mPendingContentInsets.toShortString()
                        + " visible=" + mPendingVisibleInsets.toShortString()
                        + " stable=" + mPendingStableInsets.toShortString()
                        + " cutout=" + mPendingDisplayCutout.get().toString()
                        + " outsets=" + mPendingOutsets.toShortString()
                        + " surface=" + mSurface);

                // If the pending {@link MergedConfiguration} handed back from
                // {@link #relayoutWindow} does not match the one last reported,
                // WindowManagerService has reported back a frame from a configuration not yet
                // handled by the client. In this case, we need to accept the configuration so we
                // do not lay out and draw with the wrong configuration.
                if (!mPendingMergedConfiguration.equals(mLastReportedMergedConfiguration)) {
                    if (DEBUG_CONFIGURATION) Log.v(mTag, "Visible with new config: "
                            + mPendingMergedConfiguration.getMergedConfiguration());
                    performConfigurationChange(mPendingMergedConfiguration, !mFirst,
                            INVALID_DISPLAY /* same display */);
                    updatedConfiguration = true;
                }

                final boolean overscanInsetsChanged = !mPendingOverscanInsets.equals(
                        mAttachInfo.mOverscanInsets);
                contentInsetsChanged = !mPendingContentInsets.equals(
                        mAttachInfo.mContentInsets);
                final boolean visibleInsetsChanged = !mPendingVisibleInsets.equals(
                        mAttachInfo.mVisibleInsets);
                final boolean stableInsetsChanged = !mPendingStableInsets.equals(
                        mAttachInfo.mStableInsets);
                final boolean cutoutChanged = !mPendingDisplayCutout.equals(
                        mAttachInfo.mDisplayCutout);
                final boolean outsetsChanged = !mPendingOutsets.equals(mAttachInfo.mOutsets);
                final boolean surfaceSizeChanged = (relayoutResult
                        & WindowManagerGlobal.RELAYOUT_RES_SURFACE_RESIZED) != 0;
                surfaceChanged |= surfaceSizeChanged;
                final boolean alwaysConsumeNavBarChanged =
                        mPendingAlwaysConsumeNavBar != mAttachInfo.mAlwaysConsumeNavBar;
                if (contentInsetsChanged) {
                    mAttachInfo.mContentInsets.set(mPendingContentInsets);
                    if (DEBUG_LAYOUT) Log.v(mTag, "Content insets changing to: "
                            + mAttachInfo.mContentInsets);
                }
                if (overscanInsetsChanged) {
                    mAttachInfo.mOverscanInsets.set(mPendingOverscanInsets);
                    if (DEBUG_LAYOUT) Log.v(mTag, "Overscan insets changing to: "
                            + mAttachInfo.mOverscanInsets);
                    // Need to relayout with content insets.
                    contentInsetsChanged = true;
                }
                if (stableInsetsChanged) {
                    mAttachInfo.mStableInsets.set(mPendingStableInsets);
                    if (DEBUG_LAYOUT) Log.v(mTag, "Decor insets changing to: "
                            + mAttachInfo.mStableInsets);
                    // Need to relayout with content insets.
                    contentInsetsChanged = true;
                }
                if (cutoutChanged) {
                    mAttachInfo.mDisplayCutout.set(mPendingDisplayCutout);
                    if (DEBUG_LAYOUT) {
                        Log.v(mTag, "DisplayCutout changing to: " + mAttachInfo.mDisplayCutout);
                    }
                    // Need to relayout with content insets.
                    contentInsetsChanged = true;
                }
                if (alwaysConsumeNavBarChanged) {
                    mAttachInfo.mAlwaysConsumeNavBar = mPendingAlwaysConsumeNavBar;
                    contentInsetsChanged = true;
                }
                if (contentInsetsChanged || mLastSystemUiVisibility !=
                        mAttachInfo.mSystemUiVisibility || mApplyInsetsRequested
                        || mLastOverscanRequested != mAttachInfo.mOverscanRequested
                        || outsetsChanged) {
                    mLastSystemUiVisibility = mAttachInfo.mSystemUiVisibility;
                    mLastOverscanRequested = mAttachInfo.mOverscanRequested;
                    mAttachInfo.mOutsets.set(mPendingOutsets);
                    mApplyInsetsRequested = false;
                    dispatchApplyInsets(host);
                }
                if (visibleInsetsChanged) {
                    mAttachInfo.mVisibleInsets.set(mPendingVisibleInsets);
                    if (DEBUG_LAYOUT) Log.v(mTag, "Visible insets changing to: "
                            + mAttachInfo.mVisibleInsets);
                }

                if (!hadSurface) {
                    if (mSurface.isValid()) {
                        // If we are creating a new surface, then we need to
                        // completely redraw it.  Also, when we get to the
                        // point of drawing it we will hold off and schedule
                        // a new traversal instead.  This is so we can tell the
                        // window manager about all of the windows being displayed
                        // before actually drawing them, so it can display then
                        // all at once.
                        newSurface = true;
                        mFullRedrawNeeded = true;
                        mPreviousTransparentRegion.setEmpty();

                        // Only initialize up-front if transparent regions are not
                        // requested, otherwise defer to see if the entire window
                        // will be transparent
                        if (mAttachInfo.mThreadedRenderer != null) {
                            try {
                                hwInitialized = mAttachInfo.mThreadedRenderer.initialize(
                                        mSurface);
                                if (hwInitialized && (host.mPrivateFlags
                                        & View.PFLAG_REQUEST_TRANSPARENT_REGIONS) == 0) {
                                    // Don't pre-allocate if transparent regions
                                    // are requested as they may not be needed
                                    mAttachInfo.mThreadedRenderer.allocateBuffers(mSurface);
                                }
                            } catch (OutOfResourcesException e) {
                                handleOutOfResourcesException(e);
                                return;
                            }
                        }
                    }
                } else if (!mSurface.isValid()) {
                    // If the surface has been removed, then reset the scroll
                    // positions.
                    if (mLastScrolledFocus != null) {
                        mLastScrolledFocus.clear();
                    }
                    mScrollY = mCurScrollY = 0;
                    if (mView instanceof RootViewSurfaceTaker) {
                        ((RootViewSurfaceTaker) mView).onRootViewScrollYChanged(mCurScrollY);
                    }
                    if (mScroller != null) {
                        mScroller.abortAnimation();
                    }
                    // Our surface is gone
                    if (mAttachInfo.mThreadedRenderer != null &&
                            mAttachInfo.mThreadedRenderer.isEnabled()) {
                        mAttachInfo.mThreadedRenderer.destroy();
                    }
                } else if ((surfaceGenerationId != mSurface.getGenerationId()
                        || surfaceSizeChanged || windowRelayoutWasForced)
                        && mSurfaceHolder == null
                        && mAttachInfo.mThreadedRenderer != null) {
                    mFullRedrawNeeded = true;
                    try {
                        // Need to do updateSurface (which leads to CanvasContext::setSurface and
                        // re-create the EGLSurface) if either the Surface changed (as indicated by
                        // generation id), or WindowManager changed the surface size. The latter is
                        // because on some chips, changing the consumer side's BufferQueue size may
                        // not take effect immediately unless we create a new EGLSurface.
                        // Note that frame size change doesn't always imply surface size change (eg.
                        // drag resizing uses fullscreen surface), need to check surfaceSizeChanged
                        // flag from WindowManager.
                        mAttachInfo.mThreadedRenderer.updateSurface(mSurface);
                    } catch (OutOfResourcesException e) {
                        handleOutOfResourcesException(e);
                        return;
                    }
                }

                final boolean freeformResizing = (relayoutResult
                        & WindowManagerGlobal.RELAYOUT_RES_DRAG_RESIZING_FREEFORM) != 0;
                final boolean dockedResizing = (relayoutResult
                        & WindowManagerGlobal.RELAYOUT_RES_DRAG_RESIZING_DOCKED) != 0;
                final boolean dragResizing = freeformResizing || dockedResizing;
                if (mDragResizing != dragResizing) {
                    if (dragResizing) {
                        mResizeMode = freeformResizing
                                ? RESIZE_MODE_FREEFORM
                                : RESIZE_MODE_DOCKED_DIVIDER;
                        // TODO: Need cutout?
                        startDragResizing(mPendingBackDropFrame,
                                mWinFrame.equals(mPendingBackDropFrame), mPendingVisibleInsets,
                                mPendingStableInsets, mResizeMode);
                    } else {
                        // We shouldn't come here, but if we come we should end the resize.
                        endDragResizing();
                    }
                }
                if (!mUseMTRenderer) {
                    if (dragResizing) {
                        mCanvasOffsetX = mWinFrame.left;
                        mCanvasOffsetY = mWinFrame.top;
                    } else {
                        mCanvasOffsetX = mCanvasOffsetY = 0;
                    }
                }
            } catch (RemoteException e) {
            }

            if (DEBUG_ORIENTATION) Log.v(
                    TAG, "Relayout returned: frame=" + frame + ", surface=" + mSurface);

            mAttachInfo.mWindowLeft = frame.left;
            mAttachInfo.mWindowTop = frame.top;

            // !!FIXME!! This next section handles the case where we did not get the
            // window size we asked for. We should avoid this by getting a maximum size from
            // the window session beforehand.
            if (mWidth != frame.width() || mHeight != frame.height()) {
                mWidth = frame.width();
                mHeight = frame.height();
            }

            if (mSurfaceHolder != null) {
                // The app owns the surface; tell it about what is going on.
                if (mSurface.isValid()) {
                    // XXX .copyFrom() doesn't work!
                    //mSurfaceHolder.mSurface.copyFrom(mSurface);
                    mSurfaceHolder.mSurface = mSurface;
                }
                mSurfaceHolder.setSurfaceFrameSize(mWidth, mHeight);
                mSurfaceHolder.mSurfaceLock.unlock();
                if (mSurface.isValid()) {
                    if (!hadSurface) {
                        mSurfaceHolder.ungetCallbacks();

                        mIsCreating = true;
                        SurfaceHolder.Callback callbacks[] = mSurfaceHolder.getCallbacks();
                        if (callbacks != null) {
                            for (SurfaceHolder.Callback c : callbacks) {
                                c.surfaceCreated(mSurfaceHolder);
                            }
                        }
                        surfaceChanged = true;
                    }
                    if (surfaceChanged || surfaceGenerationId != mSurface.getGenerationId()) {
                        SurfaceHolder.Callback callbacks[] = mSurfaceHolder.getCallbacks();
                        if (callbacks != null) {
                            for (SurfaceHolder.Callback c : callbacks) {
                                c.surfaceChanged(mSurfaceHolder, lp.format,
                                        mWidth, mHeight);
                            }
                        }
                    }
                    mIsCreating = false;
                } else if (hadSurface) {
                    mSurfaceHolder.ungetCallbacks();
                    SurfaceHolder.Callback callbacks[] = mSurfaceHolder.getCallbacks();
                    if (callbacks != null) {
                        for (SurfaceHolder.Callback c : callbacks) {
                            c.surfaceDestroyed(mSurfaceHolder);
                        }
                    }
                    mSurfaceHolder.mSurfaceLock.lock();
                    try {
                        mSurfaceHolder.mSurface = new Surface();
                    } finally {
                        mSurfaceHolder.mSurfaceLock.unlock();
                    }
                }
            }

            final ThreadedRenderer threadedRenderer = mAttachInfo.mThreadedRenderer;
            if (threadedRenderer != null && threadedRenderer.isEnabled()) {
                if (hwInitialized
                        || mWidth != threadedRenderer.getWidth()
                        || mHeight != threadedRenderer.getHeight()
                        || mNeedsRendererSetup) {
                    threadedRenderer.setup(mWidth, mHeight, mAttachInfo,
                            mWindowAttributes.surfaceInsets);
                    mNeedsRendererSetup = false;
                }
            }

            if (!mStopped || mReportNextDraw) {
                boolean focusChangedDueToTouchMode = ensureTouchModeLocally(
                        (relayoutResult&WindowManagerGlobal.RELAYOUT_RES_IN_TOUCH_MODE) != 0);
                if (focusChangedDueToTouchMode || mWidth != host.getMeasuredWidth()
                        || mHeight != host.getMeasuredHeight() || contentInsetsChanged ||
                        updatedConfiguration) {
                    int childWidthMeasureSpec = getRootMeasureSpec(mWidth, lp.width);
                    int childHeightMeasureSpec = getRootMeasureSpec(mHeight, lp.height);

                    if (DEBUG_LAYOUT) Log.v(mTag, "Ooops, something changed!  mWidth="
                            + mWidth + " measuredWidth=" + host.getMeasuredWidth()
                            + " mHeight=" + mHeight
                            + " measuredHeight=" + host.getMeasuredHeight()
                            + " coveredInsetsChanged=" + contentInsetsChanged);

                     // Ask host how big it wants to be
                    performMeasure(childWidthMeasureSpec, childHeightMeasureSpec);

                    // Implementation of weights from WindowManager.LayoutParams
                    // We just grow the dimensions as needed and re-measure if
                    // needs be
                    int width = host.getMeasuredWidth();
                    int height = host.getMeasuredHeight();
                    boolean measureAgain = false;

                    if (lp.horizontalWeight > 0.0f) {
                        width += (int) ((mWidth - width) * lp.horizontalWeight);
                        childWidthMeasureSpec = MeasureSpec.makeMeasureSpec(width,
                                MeasureSpec.EXACTLY);
                        measureAgain = true;
                    }
                    if (lp.verticalWeight > 0.0f) {
                        height += (int) ((mHeight - height) * lp.verticalWeight);
                        childHeightMeasureSpec = MeasureSpec.makeMeasureSpec(height,
                                MeasureSpec.EXACTLY);
                        measureAgain = true;
                    }

                    if (measureAgain) {
                        if (DEBUG_LAYOUT) Log.v(mTag,
                                "And hey let's measure once more: width=" + width
                                + " height=" + height);
                        performMeasure(childWidthMeasureSpec, childHeightMeasureSpec);
                    }

                    layoutRequested = true;
                }
            }
        } else {
            // Not the first pass and no window/insets/visibility change but the window
            // may have moved and we need check that and if so to update the left and right
            // in the attach info. We translate only the window frame since on window move
            // the window manager tells us only for the new frame but the insets are the
            // same and we do not want to translate them more than once.
            maybeHandleWindowMove(frame);
        }

        final boolean didLayout = layoutRequested && (!mStopped || mReportNextDraw);
        boolean triggerGlobalLayoutListener = didLayout
                || mAttachInfo.mRecomputeGlobalAttributes;
        if (didLayout) {
            performLayout(lp, mWidth, mHeight);

            // By this point all views have been sized and positioned
            // We can compute the transparent area

            if ((host.mPrivateFlags & View.PFLAG_REQUEST_TRANSPARENT_REGIONS) != 0) {
                // start out transparent
                // TODO: AVOID THAT CALL BY CACHING THE RESULT?
                host.getLocationInWindow(mTmpLocation);
                mTransparentRegion.set(mTmpLocation[0], mTmpLocation[1],
                        mTmpLocation[0] + host.mRight - host.mLeft,
                        mTmpLocation[1] + host.mBottom - host.mTop);

                host.gatherTransparentRegion(mTransparentRegion);
                if (mTranslator != null) {
                    mTranslator.translateRegionInWindowToScreen(mTransparentRegion);
                }

                if (!mTransparentRegion.equals(mPreviousTransparentRegion)) {
                    mPreviousTransparentRegion.set(mTransparentRegion);
                    mFullRedrawNeeded = true;
                    // reconfigure window manager
                    try {
                        mWindowSession.setTransparentRegion(mWindow, mTransparentRegion);
                    } catch (RemoteException e) {
                    }
                }
            }

            if (DBG) {
                System.out.println("======================================");
                System.out.println("performTraversals -- after setFrame");
                host.debug();
            }
        }

        if (triggerGlobalLayoutListener) {
            mAttachInfo.mRecomputeGlobalAttributes = false;
            mAttachInfo.mTreeObserver.dispatchOnGlobalLayout();
        }

        if (computesInternalInsets) {
            // Clear the original insets.
            final ViewTreeObserver.InternalInsetsInfo insets = mAttachInfo.mGivenInternalInsets;
            insets.reset();

            // Compute new insets in place.
            mAttachInfo.mTreeObserver.dispatchOnComputeInternalInsets(insets);
            mAttachInfo.mHasNonEmptyGivenInternalInsets = !insets.isEmpty();

            // Tell the window manager.
            if (insetsPending || !mLastGivenInsets.equals(insets)) {
                mLastGivenInsets.set(insets);

                // Translate insets to screen coordinates if needed.
                final Rect contentInsets;
                final Rect visibleInsets;
                final Region touchableRegion;
                if (mTranslator != null) {
                    contentInsets = mTranslator.getTranslatedContentInsets(insets.contentInsets);
                    visibleInsets = mTranslator.getTranslatedVisibleInsets(insets.visibleInsets);
                    touchableRegion = mTranslator.getTranslatedTouchableArea(insets.touchableRegion);
                } else {
                    contentInsets = insets.contentInsets;
                    visibleInsets = insets.visibleInsets;
                    touchableRegion = insets.touchableRegion;
                }

                try {
                    mWindowSession.setInsets(mWindow, insets.mTouchableInsets,
                            contentInsets, visibleInsets, touchableRegion);
                } catch (RemoteException e) {
                }
            }
        }

        if (mFirst) {
            if (sAlwaysAssignFocus || !isInTouchMode()) {
                // handle first focus request
                if (DEBUG_INPUT_RESIZE) {
                    Log.v(mTag, "First: mView.hasFocus()=" + mView.hasFocus());
                }
                if (mView != null) {
                    if (!mView.hasFocus()) {
                        mView.restoreDefaultFocus();
                        if (DEBUG_INPUT_RESIZE) {
                            Log.v(mTag, "First: requested focused view=" + mView.findFocus());
                        }
                    } else {
                        if (DEBUG_INPUT_RESIZE) {
                            Log.v(mTag, "First: existing focused view=" + mView.findFocus());
                        }
                    }
                }
            } else {
                // Some views (like ScrollView) won't hand focus to descendants that aren't within
                // their viewport. Before layout, there's a good change these views are size 0
                // which means no children can get focus. After layout, this view now has size, but
                // is not guaranteed to hand-off focus to a focusable child (specifically, the edge-
                // case where the child has a size prior to layout and thus won't trigger
                // focusableViewAvailable).
                View focused = mView.findFocus();
                if (focused instanceof ViewGroup
                        && ((ViewGroup) focused).getDescendantFocusability()
                                == ViewGroup.FOCUS_AFTER_DESCENDANTS) {
                    focused.restoreDefaultFocus();
                }
            }
        }

        final boolean changedVisibility = (viewVisibilityChanged || mFirst) && isViewVisible;
        final boolean hasWindowFocus = mAttachInfo.mHasWindowFocus && isViewVisible;
        final boolean regainedFocus = hasWindowFocus && mLostWindowFocus;
        if (regainedFocus) {
            mLostWindowFocus = false;
        } else if (!hasWindowFocus && mHadWindowFocus) {
            mLostWindowFocus = true;
        }

        if (changedVisibility || regainedFocus) {
            // Toasts are presented as notifications - don't present them as windows as well
            boolean isToast = (mWindowAttributes == null) ? false
                    : (mWindowAttributes.type == WindowManager.LayoutParams.TYPE_TOAST);
            if (!isToast) {
                host.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
            }
        }

        mFirst = false;
        mWillDrawSoon = false;
        mNewSurfaceNeeded = false;
        mActivityRelaunched = false;
        mViewVisibility = viewVisibility;
        mHadWindowFocus = hasWindowFocus;

        if (hasWindowFocus && !isInLocalFocusMode()) {
            final boolean imTarget = WindowManager.LayoutParams
                    .mayUseInputMethod(mWindowAttributes.flags);
            if (imTarget != mLastWasImTarget) {
                mLastWasImTarget = imTarget;
                InputMethodManager imm = InputMethodManager.peekInstance();
                if (imm != null && imTarget) {
                    imm.onPreWindowFocus(mView, hasWindowFocus);
                    imm.onPostWindowFocus(mView, mView.findFocus(),
                            mWindowAttributes.softInputMode,
                            !mHasHadWindowFocus, mWindowAttributes.flags);
                }
            }
        }

        // Remember if we must report the next draw.
        if ((relayoutResult & WindowManagerGlobal.RELAYOUT_RES_FIRST_TIME) != 0) {
            reportNextDraw();
        }

        boolean cancelDraw = mAttachInfo.mTreeObserver.dispatchOnPreDraw() || !isViewVisible;

        if (!cancelDraw && !newSurface) {
            if (mPendingTransitions != null && mPendingTransitions.size() > 0) {
                for (int i = 0; i < mPendingTransitions.size(); ++i) {
                    mPendingTransitions.get(i).startChangingAnimations();
                }
                mPendingTransitions.clear();
            }

            performDraw();
        } else {
            if (isViewVisible) {
                // Try again
                scheduleTraversals();
            } else if (mPendingTransitions != null && mPendingTransitions.size() > 0) {
                for (int i = 0; i < mPendingTransitions.size(); ++i) {
                    mPendingTransitions.get(i).endChangingAnimations();
                }
                mPendingTransitions.clear();
            }
        }

        mIsInTraversal = false;
    }

    private void maybeHandleWindowMove(Rect frame) {

        // TODO: Well, we are checking whether the frame has changed similarly
        // to how this is done for the insets. This is however incorrect since
        // the insets and the frame are translated. For example, the old frame
        // was (1, 1 - 1, 1) and was translated to say (2, 2 - 2, 2), now the new
        // reported frame is (2, 2 - 2, 2) which implies no change but this is not
        // true since we are comparing a not translated value to a translated one.
        // This scenario is rare but we may want to fix that.

        final boolean windowMoved = mAttachInfo.mWindowLeft != frame.left
                || mAttachInfo.mWindowTop != frame.top;
        if (windowMoved) {
            if (mTranslator != null) {
                mTranslator.translateRectInScreenToAppWinFrame(frame);
            }
            mAttachInfo.mWindowLeft = frame.left;
            mAttachInfo.mWindowTop = frame.top;
        }
        if (windowMoved || mAttachInfo.mNeedsUpdateLightCenter) {
            // Update the light position for the new offsets.
            if (mAttachInfo.mThreadedRenderer != null) {
                mAttachInfo.mThreadedRenderer.setLightCenter(mAttachInfo);
            }
            mAttachInfo.mNeedsUpdateLightCenter = false;
        }
    }

    private void handleWindowFocusChanged() {
        final boolean hasWindowFocus;
        final boolean inTouchMode;
        synchronized (this) {
            if (!mWindowFocusChanged) {
                return;
            }
            mWindowFocusChanged = false;
            hasWindowFocus = mUpcomingWindowFocus;
            inTouchMode = mUpcomingInTouchMode;
        }

        if (mAdded) {
            profileRendering(hasWindowFocus);

            if (hasWindowFocus) {
                ensureTouchModeLocally(inTouchMode);
                if (mAttachInfo.mThreadedRenderer != null && mSurface.isValid()) {
                    mFullRedrawNeeded = true;
                    try {
                        final WindowManager.LayoutParams lp = mWindowAttributes;
                        final Rect surfaceInsets = lp != null ? lp.surfaceInsets : null;
                        mAttachInfo.mThreadedRenderer.initializeIfNeeded(
                                mWidth, mHeight, mAttachInfo, mSurface, surfaceInsets);
                    } catch (OutOfResourcesException e) {
                        Log.e(mTag, "OutOfResourcesException locking surface", e);
                        try {
                            if (!mWindowSession.outOfMemory(mWindow)) {
                                Slog.w(mTag, "No processes killed for memory;"
                                        + " killing self");
                                Process.killProcess(Process.myPid());
                            }
                        } catch (RemoteException ex) {
                        }
                        // Retry in a bit.
                        mHandler.sendMessageDelayed(mHandler.obtainMessage(
                                MSG_WINDOW_FOCUS_CHANGED), 500);
                        return;
                    }
                }
            }

            mAttachInfo.mHasWindowFocus = hasWindowFocus;

            mLastWasImTarget = WindowManager.LayoutParams
                    .mayUseInputMethod(mWindowAttributes.flags);

            InputMethodManager imm = InputMethodManager.peekInstance();
            if (imm != null && mLastWasImTarget && !isInLocalFocusMode()) {
                imm.onPreWindowFocus(mView, hasWindowFocus);
            }
            if (mView != null) {
                mAttachInfo.mKeyDispatchState.reset();
                mView.dispatchWindowFocusChanged(hasWindowFocus);
                mAttachInfo.mTreeObserver.dispatchOnWindowFocusChange(hasWindowFocus);

                if (mAttachInfo.mTooltipHost != null) {
                    mAttachInfo.mTooltipHost.hideTooltip();
                }
            }

            // Note: must be done after the focus change callbacks,
            // so all of the view state is set up correctly.
            if (hasWindowFocus) {
                if (imm != null && mLastWasImTarget && !isInLocalFocusMode()) {
                    imm.onPostWindowFocus(mView, mView.findFocus(),
                            mWindowAttributes.softInputMode,
                            !mHasHadWindowFocus, mWindowAttributes.flags);
                }
                // Clear the forward bit.  We can just do this directly, since
                // the window manager doesn't care about it.
                mWindowAttributes.softInputMode &=
                        ~WindowManager.LayoutParams.SOFT_INPUT_IS_FORWARD_NAVIGATION;
                ((WindowManager.LayoutParams) mView.getLayoutParams())
                        .softInputMode &=
                        ~WindowManager.LayoutParams
                                .SOFT_INPUT_IS_FORWARD_NAVIGATION;
                mHasHadWindowFocus = true;

                // Refocusing a window that has a focused view should fire a
                // focus event for the view since the global focused view changed.
                fireAccessibilityFocusEventIfHasFocusedNode();
            } else {
                if (mPointerCapture) {
                    handlePointerCaptureChanged(false);
                }
            }
        }
        mFirstInputStage.onWindowFocusChanged(hasWindowFocus);
    }

    private void fireAccessibilityFocusEventIfHasFocusedNode() {
        if (!AccessibilityManager.getInstance(mContext).isEnabled()) {
            return;
        }
        final View focusedView = mView.findFocus();
        if (focusedView == null) {
            return;
        }
        final AccessibilityNodeProvider provider = focusedView.getAccessibilityNodeProvider();
        if (provider == null) {
            focusedView.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
        } else {
            final AccessibilityNodeInfo focusedNode = findFocusedVirtualNode(provider);
            if (focusedNode != null) {
                final int virtualId = AccessibilityNodeInfo.getVirtualDescendantId(
                        focusedNode.getSourceNodeId());
                // This is a best effort since clearing and setting the focus via the
                // provider APIs could have side effects. We don't have a provider API
                // similar to that on View to ask a given event to be fired.
                final AccessibilityEvent event = AccessibilityEvent.obtain(
                        AccessibilityEvent.TYPE_VIEW_FOCUSED);
                event.setSource(focusedView, virtualId);
                event.setPackageName(focusedNode.getPackageName());
                event.setChecked(focusedNode.isChecked());
                event.setContentDescription(focusedNode.getContentDescription());
                event.setPassword(focusedNode.isPassword());
                event.getText().add(focusedNode.getText());
                event.setEnabled(focusedNode.isEnabled());
                focusedView.getParent().requestSendAccessibilityEvent(focusedView, event);
                focusedNode.recycle();
            }
        }
    }

    private AccessibilityNodeInfo findFocusedVirtualNode(AccessibilityNodeProvider provider) {
        AccessibilityNodeInfo focusedNode = provider.findFocus(
                AccessibilityNodeInfo.FOCUS_INPUT);
        if (focusedNode != null) {
            return focusedNode;
        }

        if (!mContext.isAutofillCompatibilityEnabled()) {
            return null;
        }

        // Unfortunately some provider implementations don't properly
        // implement AccessibilityNodeProvider#findFocus
        AccessibilityNodeInfo current = provider.createAccessibilityNodeInfo(
                AccessibilityNodeProvider.HOST_VIEW_ID);
        if (current.isFocused()) {
            return current;
        }

        final Queue<AccessibilityNodeInfo> fringe = new LinkedList<>();
        fringe.offer(current);

        while (!fringe.isEmpty()) {
            current = fringe.poll();
            final LongArray childNodeIds = current.getChildNodeIds();
            if (childNodeIds== null || childNodeIds.size() <= 0) {
                continue;
            }
            final int childCount = childNodeIds.size();
            for (int i = 0; i < childCount; i++) {
                final int virtualId = AccessibilityNodeInfo.getVirtualDescendantId(
                        childNodeIds.get(i));
                final AccessibilityNodeInfo child = provider.createAccessibilityNodeInfo(virtualId);
                if (child != null) {
                    if (child.isFocused()) {
                        return child;
                    }
                    fringe.offer(child);
                }
            }
            current.recycle();
        }

        return null;
    }

    private void handleOutOfResourcesException(Surface.OutOfResourcesException e) {
        Log.e(mTag, "OutOfResourcesException initializing HW surface", e);
        try {
            if (!mWindowSession.outOfMemory(mWindow) &&
                    Process.myUid() != Process.SYSTEM_UID) {
                Slog.w(mTag, "No processes killed for memory; killing self");
                Process.killProcess(Process.myPid());
            }
        } catch (RemoteException ex) {
        }
        mLayoutRequested = true;    // ask wm for a new surface next time.
    }

    private void performMeasure(int childWidthMeasureSpec, int childHeightMeasureSpec) {
        if (mView == null) {
            return;
        }
        Trace.traceBegin(Trace.TRACE_TAG_VIEW, "measure");
        try {
            mView.measure(childWidthMeasureSpec, childHeightMeasureSpec);
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_VIEW);
        }
    }

    
Called by View.isInLayout() to determine whether the view hierarchy is currently undergoing a layout pass. 
Returns:
whether the view hierarchy is currently undergoing a layout pass/**
     * Called by {@link android.view.View#isInLayout()} to determine whether the view hierarchy
     * is currently undergoing a layout pass.
     *
     * @return whether the view hierarchy is currently undergoing a layout pass
     */
    boolean isInLayout() {
        return mInLayout;
    }

    
Called by View.requestLayout() if the view hierarchy is currently undergoing a layout pass. requestLayout() should not generally be called during layout, unless the container hierarchy knows what it is doing (i.e., it is fine as long as all children in that container hierarchy are measured and laid out at the end of the layout pass for that container). If requestLayout() is called anyway, we handle it correctly by registering all requesters during a frame as it proceeds. At the end of the frame, we check all of those views to see if any still have pending layout requests, which indicates that they were not correctly handled by their container hierarchy. If that is the case, we clear all such flags in the tree, to remove the buggy flag state that leads to blank containers, and force a second request/measure/layout pass in this frame. If more requestLayout() calls are received during that second layout pass, we post those requests to the next frame to avoid possible infinite loops. 
The return value from this method indicates whether the request should proceed
(if it is a request during the first layout pass) or should be skipped and posted to the
next frame (if it is a request during the second layout pass).
Params:
view – the view that requested the layout.
Returns:
true if request should proceed, false otherwise./**
     * Called by {@link android.view.View#requestLayout()} if the view hierarchy is currently
     * undergoing a layout pass. requestLayout() should not generally be called during layout,
     * unless the container hierarchy knows what it is doing (i.e., it is fine as long as
     * all children in that container hierarchy are measured and laid out at the end of the layout
     * pass for that container). If requestLayout() is called anyway, we handle it correctly
     * by registering all requesters during a frame as it proceeds. At the end of the frame,
     * we check all of those views to see if any still have pending layout requests, which
     * indicates that they were not correctly handled by their container hierarchy. If that is
     * the case, we clear all such flags in the tree, to remove the buggy flag state that leads
     * to blank containers, and force a second request/measure/layout pass in this frame. If
     * more requestLayout() calls are received during that second layout pass, we post those
     * requests to the next frame to avoid possible infinite loops.
     *
     * <p>The return value from this method indicates whether the request should proceed
     * (if it is a request during the first layout pass) or should be skipped and posted to the
     * next frame (if it is a request during the second layout pass).</p>
     *
     * @param view the view that requested the layout.
     *
     * @return true if request should proceed, false otherwise.
     */
    boolean requestLayoutDuringLayout(final View view) {
        if (view.mParent == null || view.mAttachInfo == null) {
            // Would not normally trigger another layout, so just let it pass through as usual
            return true;
        }
        if (!mLayoutRequesters.contains(view)) {
            mLayoutRequesters.add(view);
        }
        if (!mHandlingLayoutInLayoutRequest) {
            // Let the request proceed normally; it will be processed in a second layout pass
            // if necessary
            return true;
        } else {
            // Don't let the request proceed during the second layout pass.
            // It will post to the next frame instead.
            return false;
        }
    }

    private void performLayout(WindowManager.LayoutParams lp, int desiredWindowWidth,
            int desiredWindowHeight) {
        mLayoutRequested = false;
        mScrollMayChange = true;
        mInLayout = true;

        final View host = mView;
        if (host == null) {
            return;
        }
        if (DEBUG_ORIENTATION || DEBUG_LAYOUT) {
            Log.v(mTag, "Laying out " + host + " to (" +
                    host.getMeasuredWidth() + ", " + host.getMeasuredHeight() + ")");
        }

        Trace.traceBegin(Trace.TRACE_TAG_VIEW, "layout");
        try {
            host.layout(0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());

            mInLayout = false;
            int numViewsRequestingLayout = mLayoutRequesters.size();
            if (numViewsRequestingLayout > 0) {
                // requestLayout() was called during layout.
                // If no layout-request flags are set on the requesting views, there is no problem.
                // If some requests are still pending, then we need to clear those flags and do
                // a full request/measure/layout pass to handle this situation.
                ArrayList<View> validLayoutRequesters = getValidLayoutRequesters(mLayoutRequesters,
                        false);
                if (validLayoutRequesters != null) {
                    // Set this flag to indicate that any further requests are happening during
                    // the second pass, which may result in posting those requests to the next
                    // frame instead
                    mHandlingLayoutInLayoutRequest = true;

                    // Process fresh layout requests, then measure and layout
                    int numValidRequests = validLayoutRequesters.size();
                    for (int i = 0; i < numValidRequests; ++i) {
                        final View view = validLayoutRequesters.get(i);
                        Log.w("View", "requestLayout() improperly called by " + view +
                                " during layout: running second layout pass");
                        view.requestLayout();
                    }
                    measureHierarchy(host, lp, mView.getContext().getResources(),
                            desiredWindowWidth, desiredWindowHeight);
                    mInLayout = true;
                    host.layout(0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());

                    mHandlingLayoutInLayoutRequest = false;

                    // Check the valid requests again, this time without checking/clearing the
                    // layout flags, since requests happening during the second pass get noop'd
                    validLayoutRequesters = getValidLayoutRequesters(mLayoutRequesters, true);
                    if (validLayoutRequesters != null) {
                        final ArrayList<View> finalRequesters = validLayoutRequesters;
                        // Post second-pass requests to the next frame
                        getRunQueue().post(new Runnable() {
                            @Override
                            public void run() {
                                int numValidRequests = finalRequesters.size();
                                for (int i = 0; i < numValidRequests; ++i) {
                                    final View view = finalRequesters.get(i);
                                    Log.w("View", "requestLayout() improperly called by " + view +
                                            " during second layout pass: posting in next frame");
                                    view.requestLayout();
                                }
                            }
                        });
                    }
                }

            }
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_VIEW);
        }
        mInLayout = false;
    }

    
This method is called during layout when there have been calls to requestLayout() during
layout. It walks through the list of views that requested layout to determine which ones
still need it, based on visibility in the hierarchy and whether they have already been
handled (as is usually the case with ListView children).
Params:
layoutRequesters – The list of views that requested layout during layout
secondLayoutRequests – Whether the requests were issued during the second layout pass.
If so, the FORCE_LAYOUT flag was not set on requesters.
Returns:
A list of the actual views that still need to be laid out./**
     * This method is called during layout when there have been calls to requestLayout() during
     * layout. It walks through the list of views that requested layout to determine which ones
     * still need it, based on visibility in the hierarchy and whether they have already been
     * handled (as is usually the case with ListView children).
     *
     * @param layoutRequesters The list of views that requested layout during layout
     * @param secondLayoutRequests Whether the requests were issued during the second layout pass.
     * If so, the FORCE_LAYOUT flag was not set on requesters.
     * @return A list of the actual views that still need to be laid out.
     */
    private ArrayList<View> getValidLayoutRequesters(ArrayList<View> layoutRequesters,
            boolean secondLayoutRequests) {

        int numViewsRequestingLayout = layoutRequesters.size();
        ArrayList<View> validLayoutRequesters = null;
        for (int i = 0; i < numViewsRequestingLayout; ++i) {
            View view = layoutRequesters.get(i);
            if (view != null && view.mAttachInfo != null && view.mParent != null &&
                    (secondLayoutRequests || (view.mPrivateFlags & View.PFLAG_FORCE_LAYOUT) ==
                            View.PFLAG_FORCE_LAYOUT)) {
                boolean gone = false;
                View parent = view;
                // Only trigger new requests for views in a non-GONE hierarchy
                while (parent != null) {
                    if ((parent.mViewFlags & View.VISIBILITY_MASK) == View.GONE) {
                        gone = true;
                        break;
                    }
                    if (parent.mParent instanceof View) {
                        parent = (View) parent.mParent;
                    } else {
                        parent = null;
                    }
                }
                if (!gone) {
                    if (validLayoutRequesters == null) {
                        validLayoutRequesters = new ArrayList<View>();
                    }
                    validLayoutRequesters.add(view);
                }
            }
        }
        if (!secondLayoutRequests) {
            // If we're checking the layout flags, then we need to clean them up also
            for (int i = 0; i < numViewsRequestingLayout; ++i) {
                View view = layoutRequesters.get(i);
                while (view != null &&
                        (view.mPrivateFlags & View.PFLAG_FORCE_LAYOUT) != 0) {
                    view.mPrivateFlags &= ~View.PFLAG_FORCE_LAYOUT;
                    if (view.mParent instanceof View) {
                        view = (View) view.mParent;
                    } else {
                        view = null;
                    }
                }
            }
        }
        layoutRequesters.clear();
        return validLayoutRequesters;
    }

    @Override
    public void requestTransparentRegion(View child) {
        // the test below should not fail unless someone is messing with us
        checkThread();
        if (mView == child) {
            mView.mPrivateFlags |= View.PFLAG_REQUEST_TRANSPARENT_REGIONS;
            // Need to make sure we re-evaluate the window attributes next
            // time around, to ensure the window has the correct format.
            mWindowAttributesChanged = true;
            mWindowAttributesChangesFlag = 0;
            requestLayout();
        }
    }

    
Figures out the measure spec for the root view in a window based on it's
layout params.
Params:
windowSize – 
           The available width or height of the window
rootDimension – 
           The layout params for one dimension (width or height) of the
           window.
Returns:
The measure spec to use to measure the root view./**
     * Figures out the measure spec for the root view in a window based on it's
     * layout params.
     *
     * @param windowSize
     *            The available width or height of the window
     *
     * @param rootDimension
     *            The layout params for one dimension (width or height) of the
     *            window.
     *
     * @return The measure spec to use to measure the root view.
     */
    private static int getRootMeasureSpec(int windowSize, int rootDimension) {
        int measureSpec;
        switch (rootDimension) {

        case ViewGroup.LayoutParams.MATCH_PARENT:
            // Window can't resize. Force root view to be windowSize.
            measureSpec = MeasureSpec.makeMeasureSpec(windowSize, MeasureSpec.EXACTLY);
            break;
        case ViewGroup.LayoutParams.WRAP_CONTENT:
            // Window can resize. Set max size for root view.
            measureSpec = MeasureSpec.makeMeasureSpec(windowSize, MeasureSpec.AT_MOST);
            break;
        default:
            // Window wants to be an exact size. Force root view to be that size.
            measureSpec = MeasureSpec.makeMeasureSpec(rootDimension, MeasureSpec.EXACTLY);
            break;
        }
        return measureSpec;
    }

    int mHardwareXOffset;
    int mHardwareYOffset;

    @Override
    public void onPreDraw(DisplayListCanvas canvas) {
        // If mCurScrollY is not 0 then this influences the hardwareYOffset. The end result is we
        // can apply offsets that are not handled by anything else, resulting in underdraw as
        // the View is shifted (thus shifting the window background) exposing unpainted
        // content. To handle this with minimal glitches we just clear to BLACK if the window
        // is opaque. If it's not opaque then HWUI already internally does a glClear to
        // transparent, so there's no risk of underdraw on non-opaque surfaces.
        if (mCurScrollY != 0 && mHardwareYOffset != 0 && mAttachInfo.mThreadedRenderer.isOpaque()) {
            canvas.drawColor(Color.BLACK);
        }
        canvas.translate(-mHardwareXOffset, -mHardwareYOffset);
    }

    @Override
    public void onPostDraw(DisplayListCanvas canvas) {
        drawAccessibilityFocusedDrawableIfNeeded(canvas);
        if (mUseMTRenderer) {
            for (int i = mWindowCallbacks.size() - 1; i >= 0; i--) {
                mWindowCallbacks.get(i).onPostDraw(canvas);
            }
        }
    }

    
@hide
/**
     * @hide
     */
    void outputDisplayList(View view) {
        view.mRenderNode.output();
        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.serializeDisplayListTree();
        }
    }

    
See Also:
PROPERTY_PROFILE_RENDERING/**
     * @see #PROPERTY_PROFILE_RENDERING
     */
    private void profileRendering(boolean enabled) {
        if (mProfileRendering) {
            mRenderProfilingEnabled = enabled;

            if (mRenderProfiler != null) {
                mChoreographer.removeFrameCallback(mRenderProfiler);
            }
            if (mRenderProfilingEnabled) {
                if (mRenderProfiler == null) {
                    mRenderProfiler = new Choreographer.FrameCallback() {
                        @Override
                        public void doFrame(long frameTimeNanos) {
                            mDirty.set(0, 0, mWidth, mHeight);
                            scheduleTraversals();
                            if (mRenderProfilingEnabled) {
                                mChoreographer.postFrameCallback(mRenderProfiler);
                            }
                        }
                    };
                }
                mChoreographer.postFrameCallback(mRenderProfiler);
            } else {
                mRenderProfiler = null;
            }
        }
    }

    
Called from draw() when DEBUG_FPS is enabled
/**
     * Called from draw() when DEBUG_FPS is enabled
     */
    private void trackFPS() {
        // Tracks frames per second drawn. First value in a series of draws may be bogus
        // because it down not account for the intervening idle time
        long nowTime = System.currentTimeMillis();
        if (mFpsStartTime < 0) {
            mFpsStartTime = mFpsPrevTime = nowTime;
            mFpsNumFrames = 0;
        } else {
            ++mFpsNumFrames;
            String thisHash = Integer.toHexString(System.identityHashCode(this));
            long frameTime = nowTime - mFpsPrevTime;
            long totalTime = nowTime - mFpsStartTime;
            Log.v(mTag, "0x" + thisHash + "\tFrame time:\t" + frameTime);
            mFpsPrevTime = nowTime;
            if (totalTime > 1000) {
                float fps = (float) mFpsNumFrames * 1000 / totalTime;
                Log.v(mTag, "0x" + thisHash + "\tFPS:\t" + fps);
                mFpsStartTime = nowTime;
                mFpsNumFrames = 0;
            }
        }
    }

    
A count of the number of calls to pendingDrawFinished we
require to notify the WM drawing is complete.
/**
     * A count of the number of calls to pendingDrawFinished we
     * require to notify the WM drawing is complete.
     */
    int mDrawsNeededToReport = 0;

    
Delay notifying WM of draw finished until
a balanced call to pendingDrawFinished.
/**
     * Delay notifying WM of draw finished until
     * a balanced call to pendingDrawFinished.
     */
    void drawPending() {
        mDrawsNeededToReport++;
    }

    void pendingDrawFinished() {
        if (mDrawsNeededToReport == 0) {
            throw new RuntimeException("Unbalanced drawPending/pendingDrawFinished calls");
        }
        mDrawsNeededToReport--;
        if (mDrawsNeededToReport == 0) {
            reportDrawFinished();
        }
    }

    private void postDrawFinished() {
        mHandler.sendEmptyMessage(MSG_DRAW_FINISHED);
    }

    private void reportDrawFinished() {
        try {
            mDrawsNeededToReport = 0;
            mWindowSession.finishDrawing(mWindow);
        } catch (RemoteException e) {
            // Have fun!
        }
    }

    private void performDraw() {
        if (mAttachInfo.mDisplayState == Display.STATE_OFF && !mReportNextDraw) {
            return;
        } else if (mView == null) {
            return;
        }

        final boolean fullRedrawNeeded = mFullRedrawNeeded || mReportNextDraw;
        mFullRedrawNeeded = false;

        mIsDrawing = true;
        Trace.traceBegin(Trace.TRACE_TAG_VIEW, "draw");

        boolean usingAsyncReport = false;
        if (mReportNextDraw && mAttachInfo.mThreadedRenderer != null
                && mAttachInfo.mThreadedRenderer.isEnabled()) {
            usingAsyncReport = true;
            mAttachInfo.mThreadedRenderer.setFrameCompleteCallback((long frameNr) -> {
                // TODO: Use the frame number
                pendingDrawFinished();
            });
        }

        try {
            boolean canUseAsync = draw(fullRedrawNeeded);
            if (usingAsyncReport && !canUseAsync) {
                mAttachInfo.mThreadedRenderer.setFrameCompleteCallback(null);
                usingAsyncReport = false;
            }
        } finally {
            mIsDrawing = false;
            Trace.traceEnd(Trace.TRACE_TAG_VIEW);
        }

        // For whatever reason we didn't create a HardwareRenderer, end any
        // hardware animations that are now dangling
        if (mAttachInfo.mPendingAnimatingRenderNodes != null) {
            final int count = mAttachInfo.mPendingAnimatingRenderNodes.size();
            for (int i = 0; i < count; i++) {
                mAttachInfo.mPendingAnimatingRenderNodes.get(i).endAllAnimators();
            }
            mAttachInfo.mPendingAnimatingRenderNodes.clear();
        }

        if (mReportNextDraw) {
            mReportNextDraw = false;

            // if we're using multi-thread renderer, wait for the window frame draws
            if (mWindowDrawCountDown != null) {
                try {
                    mWindowDrawCountDown.await();
                } catch (InterruptedException e) {
                    Log.e(mTag, "Window redraw count down interrupted!");
                }
                mWindowDrawCountDown = null;
            }

            if (mAttachInfo.mThreadedRenderer != null) {
                mAttachInfo.mThreadedRenderer.setStopped(mStopped);
            }

            if (LOCAL_LOGV) {
                Log.v(mTag, "FINISHED DRAWING: " + mWindowAttributes.getTitle());
            }

            if (mSurfaceHolder != null && mSurface.isValid()) {
                SurfaceCallbackHelper sch = new SurfaceCallbackHelper(this::postDrawFinished);
                SurfaceHolder.Callback callbacks[] = mSurfaceHolder.getCallbacks();

                sch.dispatchSurfaceRedrawNeededAsync(mSurfaceHolder, callbacks);
            } else if (!usingAsyncReport) {
                if (mAttachInfo.mThreadedRenderer != null) {
                    mAttachInfo.mThreadedRenderer.fence();
                }
                pendingDrawFinished();
            }
        }
    }

    private boolean draw(boolean fullRedrawNeeded) {
        Surface surface = mSurface;
        if (!surface.isValid()) {
            return false;
        }

        if (DEBUG_FPS) {
            trackFPS();
        }

        if (!sFirstDrawComplete) {
            synchronized (sFirstDrawHandlers) {
                sFirstDrawComplete = true;
                final int count = sFirstDrawHandlers.size();
                for (int i = 0; i< count; i++) {
                    mHandler.post(sFirstDrawHandlers.get(i));
                }
            }
        }

        scrollToRectOrFocus(null, false);

        if (mAttachInfo.mViewScrollChanged) {
            mAttachInfo.mViewScrollChanged = false;
            mAttachInfo.mTreeObserver.dispatchOnScrollChanged();
        }

        boolean animating = mScroller != null && mScroller.computeScrollOffset();
        final int curScrollY;
        if (animating) {
            curScrollY = mScroller.getCurrY();
        } else {
            curScrollY = mScrollY;
        }
        if (mCurScrollY != curScrollY) {
            mCurScrollY = curScrollY;
            fullRedrawNeeded = true;
            if (mView instanceof RootViewSurfaceTaker) {
                ((RootViewSurfaceTaker) mView).onRootViewScrollYChanged(mCurScrollY);
            }
        }

        final float appScale = mAttachInfo.mApplicationScale;
        final boolean scalingRequired = mAttachInfo.mScalingRequired;

        final Rect dirty = mDirty;
        if (mSurfaceHolder != null) {
            // The app owns the surface, we won't draw.
            dirty.setEmpty();
            if (animating && mScroller != null) {
                mScroller.abortAnimation();
            }
            return false;
        }

        if (fullRedrawNeeded) {
            mAttachInfo.mIgnoreDirtyState = true;
            dirty.set(0, 0, (int) (mWidth * appScale + 0.5f), (int) (mHeight * appScale + 0.5f));
        }

        if (DEBUG_ORIENTATION || DEBUG_DRAW) {
            Log.v(mTag, "Draw " + mView + "/"
                    + mWindowAttributes.getTitle()
                    + ": dirty={" + dirty.left + "," + dirty.top
                    + "," + dirty.right + "," + dirty.bottom + "} surface="
                    + surface + " surface.isValid()=" + surface.isValid() + ", appScale:" +
                    appScale + ", width=" + mWidth + ", height=" + mHeight);
        }

        mAttachInfo.mTreeObserver.dispatchOnDraw();

        int xOffset = -mCanvasOffsetX;
        int yOffset = -mCanvasOffsetY + curScrollY;
        final WindowManager.LayoutParams params = mWindowAttributes;
        final Rect surfaceInsets = params != null ? params.surfaceInsets : null;
        if (surfaceInsets != null) {
            xOffset -= surfaceInsets.left;
            yOffset -= surfaceInsets.top;

            // Offset dirty rect for surface insets.
            dirty.offset(surfaceInsets.left, surfaceInsets.right);
        }

        boolean accessibilityFocusDirty = false;
        final Drawable drawable = mAttachInfo.mAccessibilityFocusDrawable;
        if (drawable != null) {
            final Rect bounds = mAttachInfo.mTmpInvalRect;
            final boolean hasFocus = getAccessibilityFocusedRect(bounds);
            if (!hasFocus) {
                bounds.setEmpty();
            }
            if (!bounds.equals(drawable.getBounds())) {
                accessibilityFocusDirty = true;
            }
        }

        mAttachInfo.mDrawingTime =
                mChoreographer.getFrameTimeNanos() / TimeUtils.NANOS_PER_MS;

        boolean useAsyncReport = false;
        if (!dirty.isEmpty() || mIsAnimating || accessibilityFocusDirty) {
            if (mAttachInfo.mThreadedRenderer != null && mAttachInfo.mThreadedRenderer.isEnabled()) {
                // If accessibility focus moved, always invalidate the root.
                boolean invalidateRoot = accessibilityFocusDirty || mInvalidateRootRequested;
                mInvalidateRootRequested = false;

                // Draw with hardware renderer.
                mIsAnimating = false;

                if (mHardwareYOffset != yOffset || mHardwareXOffset != xOffset) {
                    mHardwareYOffset = yOffset;
                    mHardwareXOffset = xOffset;
                    invalidateRoot = true;
                }

                if (invalidateRoot) {
                    mAttachInfo.mThreadedRenderer.invalidateRoot();
                }

                dirty.setEmpty();

                // Stage the content drawn size now. It will be transferred to the renderer
                // shortly before the draw commands get send to the renderer.
                final boolean updated = updateContentDrawBounds();

                if (mReportNextDraw) {
                    // report next draw overrides setStopped()
                    // This value is re-sync'd to the value of mStopped
                    // in the handling of mReportNextDraw post-draw.
                    mAttachInfo.mThreadedRenderer.setStopped(false);
                }

                if (updated) {
                    requestDrawWindow();
                }

                useAsyncReport = true;

                // draw(...) might invoke post-draw, which might register the next callback already.
                final FrameDrawingCallback callback = mNextRtFrameCallback;
                mNextRtFrameCallback = null;
                mAttachInfo.mThreadedRenderer.draw(mView, mAttachInfo, this, callback);
            } else {
                // If we get here with a disabled & requested hardware renderer, something went
                // wrong (an invalidate posted right before we destroyed the hardware surface
                // for instance) so we should just bail out. Locking the surface with software
                // rendering at this point would lock it forever and prevent hardware renderer
                // from doing its job when it comes back.
                // Before we request a new frame we must however attempt to reinitiliaze the
                // hardware renderer if it's in requested state. This would happen after an
                // eglTerminate() for instance.
                if (mAttachInfo.mThreadedRenderer != null &&
                        !mAttachInfo.mThreadedRenderer.isEnabled() &&
                        mAttachInfo.mThreadedRenderer.isRequested() &&
                        mSurface.isValid()) {

                    try {
                        mAttachInfo.mThreadedRenderer.initializeIfNeeded(
                                mWidth, mHeight, mAttachInfo, mSurface, surfaceInsets);
                    } catch (OutOfResourcesException e) {
                        handleOutOfResourcesException(e);
                        return false;
                    }

                    mFullRedrawNeeded = true;
                    scheduleTraversals();
                    return false;
                }

                if (!drawSoftware(surface, mAttachInfo, xOffset, yOffset,
                        scalingRequired, dirty, surfaceInsets)) {
                    return false;
                }
            }
        }

        if (animating) {
            mFullRedrawNeeded = true;
            scheduleTraversals();
        }
        return useAsyncReport;
    }

    
Returns:
true if drawing was successful, false if an error occurred/**
     * @return true if drawing was successful, false if an error occurred
     */
    private boolean drawSoftware(Surface surface, AttachInfo attachInfo, int xoff, int yoff,
            boolean scalingRequired, Rect dirty, Rect surfaceInsets) {

        // Draw with software renderer.
        final Canvas canvas;

        // We already have the offset of surfaceInsets in xoff, yoff and dirty region,
        // therefore we need to add it back when moving the dirty region.
        int dirtyXOffset = xoff;
        int dirtyYOffset = yoff;
        if (surfaceInsets != null) {
            dirtyXOffset += surfaceInsets.left;
            dirtyYOffset += surfaceInsets.top;
        }

        try {
            dirty.offset(-dirtyXOffset, -dirtyYOffset);
            final int left = dirty.left;
            final int top = dirty.top;
            final int right = dirty.right;
            final int bottom = dirty.bottom;

            canvas = mSurface.lockCanvas(dirty);

            // The dirty rectangle can be modified by Surface.lockCanvas()
            //noinspection ConstantConditions
            if (left != dirty.left || top != dirty.top || right != dirty.right
                    || bottom != dirty.bottom) {
                attachInfo.mIgnoreDirtyState = true;
            }

            // TODO: Do this in native
            canvas.setDensity(mDensity);
        } catch (Surface.OutOfResourcesException e) {
            handleOutOfResourcesException(e);
            return false;
        } catch (IllegalArgumentException e) {
            Log.e(mTag, "Could not lock surface", e);
            // Don't assume this is due to out of memory, it could be
            // something else, and if it is something else then we could
            // kill stuff (or ourself) for no reason.
            mLayoutRequested = true;    // ask wm for a new surface next time.
            return false;
        } finally {
            dirty.offset(dirtyXOffset, dirtyYOffset);  // Reset to the original value.
        }

        try {
            if (DEBUG_ORIENTATION || DEBUG_DRAW) {
                Log.v(mTag, "Surface " + surface + " drawing to bitmap w="
                        + canvas.getWidth() + ", h=" + canvas.getHeight());
                //canvas.drawARGB(255, 255, 0, 0);
            }

            // If this bitmap's format includes an alpha channel, we
            // need to clear it before drawing so that the child will
            // properly re-composite its drawing on a transparent
            // background. This automatically respects the clip/dirty region
            // or
            // If we are applying an offset, we need to clear the area
            // where the offset doesn't appear to avoid having garbage
            // left in the blank areas.
            if (!canvas.isOpaque() || yoff != 0 || xoff != 0) {
                canvas.drawColor(0, PorterDuff.Mode.CLEAR);
            }

            dirty.setEmpty();
            mIsAnimating = false;
            mView.mPrivateFlags |= View.PFLAG_DRAWN;

            if (DEBUG_DRAW) {
                Context cxt = mView.getContext();
                Log.i(mTag, "Drawing: package:" + cxt.getPackageName() +
                        ", metrics=" + cxt.getResources().getDisplayMetrics() +
                        ", compatibilityInfo=" + cxt.getResources().getCompatibilityInfo());
            }
            try {
                canvas.translate(-xoff, -yoff);
                if (mTranslator != null) {
                    mTranslator.translateCanvas(canvas);
                }
                canvas.setScreenDensity(scalingRequired ? mNoncompatDensity : 0);
                attachInfo.mSetIgnoreDirtyState = false;

                mView.draw(canvas);

                drawAccessibilityFocusedDrawableIfNeeded(canvas);
            } finally {
                if (!attachInfo.mSetIgnoreDirtyState) {
                    // Only clear the flag if it was not set during the mView.draw() call
                    attachInfo.mIgnoreDirtyState = false;
                }
            }
        } finally {
            try {
                surface.unlockCanvasAndPost(canvas);
            } catch (IllegalArgumentException e) {
                Log.e(mTag, "Could not unlock surface", e);
                mLayoutRequested = true;    // ask wm for a new surface next time.
                //noinspection ReturnInsideFinallyBlock
                return false;
            }

            if (LOCAL_LOGV) {
                Log.v(mTag, "Surface " + surface + " unlockCanvasAndPost");
            }
        }
        return true;
    }

    
We want to draw a highlight around the current accessibility focused.
Since adding a style for all possible view is not a viable option we
have this specialized drawing method.
Note: We are doing this here to be able to draw the highlight for
      virtual views in addition to real ones.
Params:
canvas – The canvas on which to draw./**
     * We want to draw a highlight around the current accessibility focused.
     * Since adding a style for all possible view is not a viable option we
     * have this specialized drawing method.
     *
     * Note: We are doing this here to be able to draw the highlight for
     *       virtual views in addition to real ones.
     *
     * @param canvas The canvas on which to draw.
     */
    private void drawAccessibilityFocusedDrawableIfNeeded(Canvas canvas) {
        final Rect bounds = mAttachInfo.mTmpInvalRect;
        if (getAccessibilityFocusedRect(bounds)) {
            final Drawable drawable = getAccessibilityFocusedDrawable();
            if (drawable != null) {
                drawable.setBounds(bounds);
                drawable.draw(canvas);
            }
        } else if (mAttachInfo.mAccessibilityFocusDrawable != null) {
            mAttachInfo.mAccessibilityFocusDrawable.setBounds(0, 0, 0, 0);
        }
    }

    private boolean getAccessibilityFocusedRect(Rect bounds) {
        final AccessibilityManager manager = AccessibilityManager.getInstance(mView.mContext);
        if (!manager.isEnabled() || !manager.isTouchExplorationEnabled()) {
            return false;
        }

        final View host = mAccessibilityFocusedHost;
        if (host == null || host.mAttachInfo == null) {
            return false;
        }

        final AccessibilityNodeProvider provider = host.getAccessibilityNodeProvider();
        if (provider == null) {
            host.getBoundsOnScreen(bounds, true);
        } else if (mAccessibilityFocusedVirtualView != null) {
            mAccessibilityFocusedVirtualView.getBoundsInScreen(bounds);
        } else {
            return false;
        }

        // Transform the rect into window-relative coordinates.
        final AttachInfo attachInfo = mAttachInfo;
        bounds.offset(0, attachInfo.mViewRootImpl.mScrollY);
        bounds.offset(-attachInfo.mWindowLeft, -attachInfo.mWindowTop);
        if (!bounds.intersect(0, 0, attachInfo.mViewRootImpl.mWidth,
                attachInfo.mViewRootImpl.mHeight)) {
            // If no intersection, set bounds to empty.
            bounds.setEmpty();
        }
        return !bounds.isEmpty();
    }

    private Drawable getAccessibilityFocusedDrawable() {
        // Lazily load the accessibility focus drawable.
        if (mAttachInfo.mAccessibilityFocusDrawable == null) {
            final TypedValue value = new TypedValue();
            final boolean resolved = mView.mContext.getTheme().resolveAttribute(
                    R.attr.accessibilityFocusedDrawable, value, true);
            if (resolved) {
                mAttachInfo.mAccessibilityFocusDrawable =
                        mView.mContext.getDrawable(value.resourceId);
            }
        }
        return mAttachInfo.mAccessibilityFocusDrawable;
    }

    
Requests that the root render node is invalidated next time we perform a draw, such that WindowCallbacks.onPostDraw gets called. /**
     * Requests that the root render node is invalidated next time we perform a draw, such that
     * {@link WindowCallbacks#onPostDraw} gets called.
     */
    public void requestInvalidateRootRenderNode() {
        mInvalidateRootRequested = true;
    }

    boolean scrollToRectOrFocus(Rect rectangle, boolean immediate) {
        final Rect ci = mAttachInfo.mContentInsets;
        final Rect vi = mAttachInfo.mVisibleInsets;
        int scrollY = 0;
        boolean handled = false;

        if (vi.left > ci.left || vi.top > ci.top
                || vi.right > ci.right || vi.bottom > ci.bottom) {
            // We'll assume that we aren't going to change the scroll
            // offset, since we want to avoid that unless it is actually
            // going to make the focus visible...  otherwise we scroll
            // all over the place.
            scrollY = mScrollY;
            // We can be called for two different situations: during a draw,
            // to update the scroll position if the focus has changed (in which
            // case 'rectangle' is null), or in response to a
            // requestChildRectangleOnScreen() call (in which case 'rectangle'
            // is non-null and we just want to scroll to whatever that
            // rectangle is).
            final View focus = mView.findFocus();
            if (focus == null) {
                return false;
            }
            View lastScrolledFocus = (mLastScrolledFocus != null) ? mLastScrolledFocus.get() : null;
            if (focus != lastScrolledFocus) {
                // If the focus has changed, then ignore any requests to scroll
                // to a rectangle; first we want to make sure the entire focus
                // view is visible.
                rectangle = null;
            }
            if (DEBUG_INPUT_RESIZE) Log.v(mTag, "Eval scroll: focus=" + focus
                    + " rectangle=" + rectangle + " ci=" + ci
                    + " vi=" + vi);
            if (focus == lastScrolledFocus && !mScrollMayChange && rectangle == null) {
                // Optimization: if the focus hasn't changed since last
                // time, and no layout has happened, then just leave things
                // as they are.
                if (DEBUG_INPUT_RESIZE) Log.v(mTag, "Keeping scroll y="
                        + mScrollY + " vi=" + vi.toShortString());
            } else {
                // We need to determine if the currently focused view is
                // within the visible part of the window and, if not, apply
                // a pan so it can be seen.
                mLastScrolledFocus = new WeakReference<View>(focus);
                mScrollMayChange = false;
                if (DEBUG_INPUT_RESIZE) Log.v(mTag, "Need to scroll?");
                // Try to find the rectangle from the focus view.
                if (focus.getGlobalVisibleRect(mVisRect, null)) {
                    if (DEBUG_INPUT_RESIZE) Log.v(mTag, "Root w="
                            + mView.getWidth() + " h=" + mView.getHeight()
                            + " ci=" + ci.toShortString()
                            + " vi=" + vi.toShortString());
                    if (rectangle == null) {
                        focus.getFocusedRect(mTempRect);
                        if (DEBUG_INPUT_RESIZE) Log.v(mTag, "Focus " + focus
                                + ": focusRect=" + mTempRect.toShortString());
                        if (mView instanceof ViewGroup) {
                            ((ViewGroup) mView).offsetDescendantRectToMyCoords(
                                    focus, mTempRect);
                        }
                        if (DEBUG_INPUT_RESIZE) Log.v(mTag,
                                "Focus in window: focusRect="
                                + mTempRect.toShortString()
                                + " visRect=" + mVisRect.toShortString());
                    } else {
                        mTempRect.set(rectangle);
                        if (DEBUG_INPUT_RESIZE) Log.v(mTag,
                                "Request scroll to rect: "
                                + mTempRect.toShortString()
                                + " visRect=" + mVisRect.toShortString());
                    }
                    if (mTempRect.intersect(mVisRect)) {
                        if (DEBUG_INPUT_RESIZE) Log.v(mTag,
                                "Focus window visible rect: "
                                + mTempRect.toShortString());
                        if (mTempRect.height() >
                                (mView.getHeight()-vi.top-vi.bottom)) {
                            // If the focus simply is not going to fit, then
                            // best is probably just to leave things as-is.
                            if (DEBUG_INPUT_RESIZE) Log.v(mTag,
                                    "Too tall; leaving scrollY=" + scrollY);
                        }
                        // Next, check whether top or bottom is covered based on the non-scrolled
                        // position, and calculate new scrollY (or set it to 0).
                        // We can't keep using mScrollY here. For example mScrollY is non-zero
                        // due to IME, then IME goes away. The current value of mScrollY leaves top
                        // and bottom both visible, but we still need to scroll it back to 0.
                        else if (mTempRect.top < vi.top) {
                            scrollY = mTempRect.top - vi.top;
                            if (DEBUG_INPUT_RESIZE) Log.v(mTag,
                                    "Top covered; scrollY=" + scrollY);
                        } else if (mTempRect.bottom > (mView.getHeight()-vi.bottom)) {
                            scrollY = mTempRect.bottom - (mView.getHeight()-vi.bottom);
                            if (DEBUG_INPUT_RESIZE) Log.v(mTag,
                                    "Bottom covered; scrollY=" + scrollY);
                        } else {
                            scrollY = 0;
                        }
                        handled = true;
                    }
                }
            }
        }

        if (scrollY != mScrollY) {
            if (DEBUG_INPUT_RESIZE) Log.v(mTag, "Pan scroll changed: old="
                    + mScrollY + " , new=" + scrollY);
            if (!immediate) {
                if (mScroller == null) {
                    mScroller = new Scroller(mView.getContext());
                }
                mScroller.startScroll(0, mScrollY, 0, scrollY-mScrollY);
            } else if (mScroller != null) {
                mScroller.abortAnimation();
            }
            mScrollY = scrollY;
        }

        return handled;
    }

    
@hide
/**
     * @hide
     */
    public View getAccessibilityFocusedHost() {
        return mAccessibilityFocusedHost;
    }

    
@hide
/**
     * @hide
     */
    public AccessibilityNodeInfo getAccessibilityFocusedVirtualView() {
        return mAccessibilityFocusedVirtualView;
    }

    void setAccessibilityFocus(View view, AccessibilityNodeInfo node) {
        // If we have a virtual view with accessibility focus we need
        // to clear the focus and invalidate the virtual view bounds.
        if (mAccessibilityFocusedVirtualView != null) {

            AccessibilityNodeInfo focusNode = mAccessibilityFocusedVirtualView;
            View focusHost = mAccessibilityFocusedHost;

            // Wipe the state of the current accessibility focus since
            // the call into the provider to clear accessibility focus
            // will fire an accessibility event which will end up calling
            // this method and we want to have clean state when this
            // invocation happens.
            mAccessibilityFocusedHost = null;
            mAccessibilityFocusedVirtualView = null;

            // Clear accessibility focus on the host after clearing state since
            // this method may be reentrant.
            focusHost.clearAccessibilityFocusNoCallbacks(
                    AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);

            AccessibilityNodeProvider provider = focusHost.getAccessibilityNodeProvider();
            if (provider != null) {
                // Invalidate the area of the cleared accessibility focus.
                focusNode.getBoundsInParent(mTempRect);
                focusHost.invalidate(mTempRect);
                // Clear accessibility focus in the virtual node.
                final int virtualNodeId = AccessibilityNodeInfo.getVirtualDescendantId(
                        focusNode.getSourceNodeId());
                provider.performAction(virtualNodeId,
                        AccessibilityNodeInfo.ACTION_CLEAR_ACCESSIBILITY_FOCUS, null);
            }
            focusNode.recycle();
        }
        if ((mAccessibilityFocusedHost != null) && (mAccessibilityFocusedHost != view))  {
            // Clear accessibility focus in the view.
            mAccessibilityFocusedHost.clearAccessibilityFocusNoCallbacks(
                    AccessibilityNodeInfo.ACTION_ACCESSIBILITY_FOCUS);
        }

        // Set the new focus host and node.
        mAccessibilityFocusedHost = view;
        mAccessibilityFocusedVirtualView = node;

        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.invalidateRoot();
        }
    }

    boolean hasPointerCapture() {
        return mPointerCapture;
    }

    void requestPointerCapture(boolean enabled) {
        if (mPointerCapture == enabled) {
            return;
        }
        InputManager.getInstance().requestPointerCapture(mAttachInfo.mWindowToken, enabled);
    }

    private void handlePointerCaptureChanged(boolean hasCapture) {
        if (mPointerCapture == hasCapture) {
            return;
        }
        mPointerCapture = hasCapture;
        if (mView != null) {
            mView.dispatchPointerCaptureChanged(hasCapture);
        }
    }

    @Override
    public void requestChildFocus(View child, View focused) {
        if (DEBUG_INPUT_RESIZE) {
            Log.v(mTag, "Request child focus: focus now " + focused);
        }
        checkThread();
        scheduleTraversals();
    }

    @Override
    public void clearChildFocus(View child) {
        if (DEBUG_INPUT_RESIZE) {
            Log.v(mTag, "Clearing child focus");
        }
        checkThread();
        scheduleTraversals();
    }

    @Override
    public ViewParent getParentForAccessibility() {
        return null;
    }

    @Override
    public void focusableViewAvailable(View v) {
        checkThread();
        if (mView != null) {
            if (!mView.hasFocus()) {
                if (sAlwaysAssignFocus || !mAttachInfo.mInTouchMode) {
                    v.requestFocus();
                }
            } else {
                // the one case where will transfer focus away from the current one
                // is if the current view is a view group that prefers to give focus
                // to its children first AND the view is a descendant of it.
                View focused = mView.findFocus();
                if (focused instanceof ViewGroup) {
                    ViewGroup group = (ViewGroup) focused;
                    if (group.getDescendantFocusability() == ViewGroup.FOCUS_AFTER_DESCENDANTS
                            && isViewDescendantOf(v, focused)) {
                        v.requestFocus();
                    }
                }
            }
        }
    }

    @Override
    public void recomputeViewAttributes(View child) {
        checkThread();
        if (mView == child) {
            mAttachInfo.mRecomputeGlobalAttributes = true;
            if (!mWillDrawSoon) {
                scheduleTraversals();
            }
        }
    }

    void dispatchDetachedFromWindow() {
        mFirstInputStage.onDetachedFromWindow();
        if (mView != null && mView.mAttachInfo != null) {
            mAttachInfo.mTreeObserver.dispatchOnWindowAttachedChange(false);
            mView.dispatchDetachedFromWindow();
        }

        mAccessibilityInteractionConnectionManager.ensureNoConnection();
        mAccessibilityManager.removeAccessibilityStateChangeListener(
                mAccessibilityInteractionConnectionManager);
        mAccessibilityManager.removeHighTextContrastStateChangeListener(
                mHighContrastTextManager);
        removeSendWindowContentChangedCallback();

        destroyHardwareRenderer();

        setAccessibilityFocus(null, null);

        mView.assignParent(null);
        mView = null;
        mAttachInfo.mRootView = null;

        mSurface.release();

        if (mInputQueueCallback != null && mInputQueue != null) {
            mInputQueueCallback.onInputQueueDestroyed(mInputQueue);
            mInputQueue.dispose();
            mInputQueueCallback = null;
            mInputQueue = null;
        }
        if (mInputEventReceiver != null) {
            mInputEventReceiver.dispose();
            mInputEventReceiver = null;
        }
        try {
            mWindowSession.remove(mWindow);
        } catch (RemoteException e) {
        }

        // Dispose the input channel after removing the window so the Window Manager
        // doesn't interpret the input channel being closed as an abnormal termination.
        if (mInputChannel != null) {
            mInputChannel.dispose();
            mInputChannel = null;
        }

        mDisplayManager.unregisterDisplayListener(mDisplayListener);

        unscheduleTraversals();
    }

    
Notifies all callbacks that configuration and/or display has changed and updates internal
state.
Params:
mergedConfiguration – New global and override config in MergedConfiguration container.
force – Flag indicating if we should force apply the config.
newDisplayId – Id of new display if moved, Display.INVALID_DISPLAY if not changed./**
     * Notifies all callbacks that configuration and/or display has changed and updates internal
     * state.
     * @param mergedConfiguration New global and override config in {@link MergedConfiguration}
     *                            container.
     * @param force Flag indicating if we should force apply the config.
     * @param newDisplayId Id of new display if moved, {@link Display#INVALID_DISPLAY} if not
     *                     changed.
     */
    private void performConfigurationChange(MergedConfiguration mergedConfiguration, boolean force,
            int newDisplayId) {
        if (mergedConfiguration == null) {
            throw new IllegalArgumentException("No merged config provided.");
        }

        Configuration globalConfig = mergedConfiguration.getGlobalConfiguration();
        final Configuration overrideConfig = mergedConfiguration.getOverrideConfiguration();
        if (DEBUG_CONFIGURATION) Log.v(mTag,
                "Applying new config to window " + mWindowAttributes.getTitle()
                        + ", globalConfig: " + globalConfig
                        + ", overrideConfig: " + overrideConfig);

        final CompatibilityInfo ci = mDisplay.getDisplayAdjustments().getCompatibilityInfo();
        if (!ci.equals(CompatibilityInfo.DEFAULT_COMPATIBILITY_INFO)) {
            globalConfig = new Configuration(globalConfig);
            ci.applyToConfiguration(mNoncompatDensity, globalConfig);
        }

        synchronized (sConfigCallbacks) {
            for (int i=sConfigCallbacks.size()-1; i>=0; i--) {
                sConfigCallbacks.get(i).onConfigurationChanged(globalConfig);
            }
        }

        mLastReportedMergedConfiguration.setConfiguration(globalConfig, overrideConfig);

        mForceNextConfigUpdate = force;
        if (mActivityConfigCallback != null) {
            // An activity callback is set - notify it about override configuration update.
            // This basically initiates a round trip to ActivityThread and back, which will ensure
            // that corresponding activity and resources are updated before updating inner state of
            // ViewRootImpl. Eventually it will call #updateConfiguration().
            mActivityConfigCallback.onConfigurationChanged(overrideConfig, newDisplayId);
        } else {
            // There is no activity callback - update the configuration right away.
            updateConfiguration(newDisplayId);
        }
        mForceNextConfigUpdate = false;
    }

    
Update display and views if last applied merged configuration changed.
Params:
newDisplayId – Id of new display if moved, Display.INVALID_DISPLAY otherwise./**
     * Update display and views if last applied merged configuration changed.
     * @param newDisplayId Id of new display if moved, {@link Display#INVALID_DISPLAY} otherwise.
     */
    public void updateConfiguration(int newDisplayId) {
        if (mView == null) {
            return;
        }

        // At this point the resources have been updated to
        // have the most recent config, whatever that is.  Use
        // the one in them which may be newer.
        final Resources localResources = mView.getResources();
        final Configuration config = localResources.getConfiguration();

        // Handle move to display.
        if (newDisplayId != INVALID_DISPLAY) {
            onMovedToDisplay(newDisplayId, config);
        }

        // Handle configuration change.
        if (mForceNextConfigUpdate || mLastConfigurationFromResources.diff(config) != 0) {
            // Update the display with new DisplayAdjustments.
            mDisplay = ResourcesManager.getInstance().getAdjustedDisplay(
                    mDisplay.getDisplayId(), localResources);

            final int lastLayoutDirection = mLastConfigurationFromResources.getLayoutDirection();
            final int currentLayoutDirection = config.getLayoutDirection();
            mLastConfigurationFromResources.setTo(config);
            if (lastLayoutDirection != currentLayoutDirection
                    && mViewLayoutDirectionInitial == View.LAYOUT_DIRECTION_INHERIT) {
                mView.setLayoutDirection(currentLayoutDirection);
            }
            mView.dispatchConfigurationChanged(config);

            // We could have gotten this {@link Configuration} update after we called
            // {@link #performTraversals} with an older {@link Configuration}. As a result, our
            // window frame may be stale. We must ensure the next pass of {@link #performTraversals}
            // catches this.
            mForceNextWindowRelayout = true;
            requestLayout();
        }
    }

    
Return true if child is an ancestor of parent, (or equal to the parent).
/**
     * Return true if child is an ancestor of parent, (or equal to the parent).
     */
    public static boolean isViewDescendantOf(View child, View parent) {
        if (child == parent) {
            return true;
        }

        final ViewParent theParent = child.getParent();
        return (theParent instanceof ViewGroup) && isViewDescendantOf((View) theParent, parent);
    }

    private static void forceLayout(View view) {
        view.forceLayout();
        if (view instanceof ViewGroup) {
            ViewGroup group = (ViewGroup) view;
            final int count = group.getChildCount();
            for (int i = 0; i < count; i++) {
                forceLayout(group.getChildAt(i));
            }
        }
    }

    private final static int MSG_INVALIDATE = 1;
    private final static int MSG_INVALIDATE_RECT = 2;
    private final static int MSG_DIE = 3;
    private final static int MSG_RESIZED = 4;
    private final static int MSG_RESIZED_REPORT = 5;
    private final static int MSG_WINDOW_FOCUS_CHANGED = 6;
    private final static int MSG_DISPATCH_INPUT_EVENT = 7;
    private final static int MSG_DISPATCH_APP_VISIBILITY = 8;
    private final static int MSG_DISPATCH_GET_NEW_SURFACE = 9;
    private final static int MSG_DISPATCH_KEY_FROM_IME = 11;
    private final static int MSG_DISPATCH_KEY_FROM_AUTOFILL = 12;
    private final static int MSG_CHECK_FOCUS = 13;
    private final static int MSG_CLOSE_SYSTEM_DIALOGS = 14;
    private final static int MSG_DISPATCH_DRAG_EVENT = 15;
    private final static int MSG_DISPATCH_DRAG_LOCATION_EVENT = 16;
    private final static int MSG_DISPATCH_SYSTEM_UI_VISIBILITY = 17;
    private final static int MSG_UPDATE_CONFIGURATION = 18;
    private final static int MSG_PROCESS_INPUT_EVENTS = 19;
    private final static int MSG_CLEAR_ACCESSIBILITY_FOCUS_HOST = 21;
    private final static int MSG_INVALIDATE_WORLD = 22;
    private final static int MSG_WINDOW_MOVED = 23;
    private final static int MSG_SYNTHESIZE_INPUT_EVENT = 24;
    private final static int MSG_DISPATCH_WINDOW_SHOWN = 25;
    private final static int MSG_REQUEST_KEYBOARD_SHORTCUTS = 26;
    private final static int MSG_UPDATE_POINTER_ICON = 27;
    private final static int MSG_POINTER_CAPTURE_CHANGED = 28;
    private final static int MSG_DRAW_FINISHED = 29;

    final class ViewRootHandler extends Handler {
        @Override
        public String getMessageName(Message message) {
            switch (message.what) {
                case MSG_INVALIDATE:
                    return "MSG_INVALIDATE";
                case MSG_INVALIDATE_RECT:
                    return "MSG_INVALIDATE_RECT";
                case MSG_DIE:
                    return "MSG_DIE";
                case MSG_RESIZED:
                    return "MSG_RESIZED";
                case MSG_RESIZED_REPORT:
                    return "MSG_RESIZED_REPORT";
                case MSG_WINDOW_FOCUS_CHANGED:
                    return "MSG_WINDOW_FOCUS_CHANGED";
                case MSG_DISPATCH_INPUT_EVENT:
                    return "MSG_DISPATCH_INPUT_EVENT";
                case MSG_DISPATCH_APP_VISIBILITY:
                    return "MSG_DISPATCH_APP_VISIBILITY";
                case MSG_DISPATCH_GET_NEW_SURFACE:
                    return "MSG_DISPATCH_GET_NEW_SURFACE";
                case MSG_DISPATCH_KEY_FROM_IME:
                    return "MSG_DISPATCH_KEY_FROM_IME";
                case MSG_DISPATCH_KEY_FROM_AUTOFILL:
                    return "MSG_DISPATCH_KEY_FROM_AUTOFILL";
                case MSG_CHECK_FOCUS:
                    return "MSG_CHECK_FOCUS";
                case MSG_CLOSE_SYSTEM_DIALOGS:
                    return "MSG_CLOSE_SYSTEM_DIALOGS";
                case MSG_DISPATCH_DRAG_EVENT:
                    return "MSG_DISPATCH_DRAG_EVENT";
                case MSG_DISPATCH_DRAG_LOCATION_EVENT:
                    return "MSG_DISPATCH_DRAG_LOCATION_EVENT";
                case MSG_DISPATCH_SYSTEM_UI_VISIBILITY:
                    return "MSG_DISPATCH_SYSTEM_UI_VISIBILITY";
                case MSG_UPDATE_CONFIGURATION:
                    return "MSG_UPDATE_CONFIGURATION";
                case MSG_PROCESS_INPUT_EVENTS:
                    return "MSG_PROCESS_INPUT_EVENTS";
                case MSG_CLEAR_ACCESSIBILITY_FOCUS_HOST:
                    return "MSG_CLEAR_ACCESSIBILITY_FOCUS_HOST";
                case MSG_WINDOW_MOVED:
                    return "MSG_WINDOW_MOVED";
                case MSG_SYNTHESIZE_INPUT_EVENT:
                    return "MSG_SYNTHESIZE_INPUT_EVENT";
                case MSG_DISPATCH_WINDOW_SHOWN:
                    return "MSG_DISPATCH_WINDOW_SHOWN";
                case MSG_UPDATE_POINTER_ICON:
                    return "MSG_UPDATE_POINTER_ICON";
                case MSG_POINTER_CAPTURE_CHANGED:
                    return "MSG_POINTER_CAPTURE_CHANGED";
                case MSG_DRAW_FINISHED:
                    return "MSG_DRAW_FINISHED";
            }
            return super.getMessageName(message);
        }

        @Override
        public boolean sendMessageAtTime(Message msg, long uptimeMillis) {
            if (msg.what == MSG_REQUEST_KEYBOARD_SHORTCUTS && msg.obj == null) {
                // Debugging for b/27963013
                throw new NullPointerException(
                        "Attempted to call MSG_REQUEST_KEYBOARD_SHORTCUTS with null receiver:");
            }
            return super.sendMessageAtTime(msg, uptimeMillis);
        }

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_INVALIDATE:
                    ((View) msg.obj).invalidate();
                    break;
                case MSG_INVALIDATE_RECT:
                    final View.AttachInfo.InvalidateInfo info =
                            (View.AttachInfo.InvalidateInfo) msg.obj;
                    info.target.invalidate(info.left, info.top, info.right, info.bottom);
                    info.recycle();
                    break;
                case MSG_PROCESS_INPUT_EVENTS:
                    mProcessInputEventsScheduled = false;
                    doProcessInputEvents();
                    break;
                case MSG_DISPATCH_APP_VISIBILITY:
                    handleAppVisibility(msg.arg1 != 0);
                    break;
                case MSG_DISPATCH_GET_NEW_SURFACE:
                    handleGetNewSurface();
                    break;
                case MSG_RESIZED: {
                    // Recycled in the fall through...
                    SomeArgs args = (SomeArgs) msg.obj;
                    if (mWinFrame.equals(args.arg1)
                            && mPendingOverscanInsets.equals(args.arg5)
                            && mPendingContentInsets.equals(args.arg2)
                            && mPendingStableInsets.equals(args.arg6)
                            && mPendingDisplayCutout.get().equals(args.arg9)
                            && mPendingVisibleInsets.equals(args.arg3)
                            && mPendingOutsets.equals(args.arg7)
                            && mPendingBackDropFrame.equals(args.arg8)
                            && args.arg4 == null
                            && args.argi1 == 0
                            && mDisplay.getDisplayId() == args.argi3) {
                        break;
                    }
                } // fall through...
                case MSG_RESIZED_REPORT:
                    if (mAdded) {
                        SomeArgs args = (SomeArgs) msg.obj;

                        final int displayId = args.argi3;
                        MergedConfiguration mergedConfiguration = (MergedConfiguration) args.arg4;
                        final boolean displayChanged = mDisplay.getDisplayId() != displayId;

                        if (!mLastReportedMergedConfiguration.equals(mergedConfiguration)) {
                            // If configuration changed - notify about that and, maybe,
                            // about move to display.
                            performConfigurationChange(mergedConfiguration, false /* force */,
                                    displayChanged
                                            ? displayId : INVALID_DISPLAY /* same display */);
                        } else if (displayChanged) {
                            // Moved to display without config change - report last applied one.
                            onMovedToDisplay(displayId, mLastConfigurationFromResources);
                        }

                        final boolean framesChanged = !mWinFrame.equals(args.arg1)
                                || !mPendingOverscanInsets.equals(args.arg5)
                                || !mPendingContentInsets.equals(args.arg2)
                                || !mPendingStableInsets.equals(args.arg6)
                                || !mPendingDisplayCutout.get().equals(args.arg9)
                                || !mPendingVisibleInsets.equals(args.arg3)
                                || !mPendingOutsets.equals(args.arg7);

                        mWinFrame.set((Rect) args.arg1);
                        mPendingOverscanInsets.set((Rect) args.arg5);
                        mPendingContentInsets.set((Rect) args.arg2);
                        mPendingStableInsets.set((Rect) args.arg6);
                        mPendingDisplayCutout.set((DisplayCutout) args.arg9);
                        mPendingVisibleInsets.set((Rect) args.arg3);
                        mPendingOutsets.set((Rect) args.arg7);
                        mPendingBackDropFrame.set((Rect) args.arg8);
                        mForceNextWindowRelayout = args.argi1 != 0;
                        mPendingAlwaysConsumeNavBar = args.argi2 != 0;

                        args.recycle();

                        if (msg.what == MSG_RESIZED_REPORT) {
                            reportNextDraw();
                        }

                        if (mView != null && framesChanged) {
                            forceLayout(mView);
                        }
                        requestLayout();
                    }
                    break;
                case MSG_WINDOW_MOVED:
                    if (mAdded) {
                        final int w = mWinFrame.width();
                        final int h = mWinFrame.height();
                        final int l = msg.arg1;
                        final int t = msg.arg2;
                        mWinFrame.left = l;
                        mWinFrame.right = l + w;
                        mWinFrame.top = t;
                        mWinFrame.bottom = t + h;

                        mPendingBackDropFrame.set(mWinFrame);
                        maybeHandleWindowMove(mWinFrame);
                    }
                    break;
                case MSG_WINDOW_FOCUS_CHANGED: {
                    handleWindowFocusChanged();
                } break;
                case MSG_DIE:
                    doDie();
                    break;
                case MSG_DISPATCH_INPUT_EVENT: {
                    SomeArgs args = (SomeArgs) msg.obj;
                    InputEvent event = (InputEvent) args.arg1;
                    InputEventReceiver receiver = (InputEventReceiver) args.arg2;
                    enqueueInputEvent(event, receiver, 0, true);
                    args.recycle();
                } break;
                case MSG_SYNTHESIZE_INPUT_EVENT: {
                    InputEvent event = (InputEvent) msg.obj;
                    enqueueInputEvent(event, null, QueuedInputEvent.FLAG_UNHANDLED, true);
                } break;
                case MSG_DISPATCH_KEY_FROM_IME: {
                    if (LOCAL_LOGV) {
                        Log.v(TAG, "Dispatching key " + msg.obj + " from IME to " + mView);
                    }
                    KeyEvent event = (KeyEvent) msg.obj;
                    if ((event.getFlags() & KeyEvent.FLAG_FROM_SYSTEM) != 0) {
                        // The IME is trying to say this event is from the
                        // system!  Bad bad bad!
                        //noinspection UnusedAssignment
                        event = KeyEvent.changeFlags(event,
                                event.getFlags() & ~KeyEvent.FLAG_FROM_SYSTEM);
                    }
                    enqueueInputEvent(event, null, QueuedInputEvent.FLAG_DELIVER_POST_IME, true);
                } break;
                case MSG_DISPATCH_KEY_FROM_AUTOFILL: {
                    if (LOCAL_LOGV) {
                        Log.v(TAG, "Dispatching key " + msg.obj + " from Autofill to " + mView);
                    }
                    KeyEvent event = (KeyEvent) msg.obj;
                    enqueueInputEvent(event, null, 0, true);
                } break;
                case MSG_CHECK_FOCUS: {
                    InputMethodManager imm = InputMethodManager.peekInstance();
                    if (imm != null) {
                        imm.checkFocus();
                    }
                } break;
                case MSG_CLOSE_SYSTEM_DIALOGS: {
                    if (mView != null) {
                        mView.onCloseSystemDialogs((String) msg.obj);
                    }
                } break;
                case MSG_DISPATCH_DRAG_EVENT: {
                } // fall through
                case MSG_DISPATCH_DRAG_LOCATION_EVENT: {
                    DragEvent event = (DragEvent) msg.obj;
                    // only present when this app called startDrag()
                    event.mLocalState = mLocalDragState;
                    handleDragEvent(event);
                } break;
                case MSG_DISPATCH_SYSTEM_UI_VISIBILITY: {
                    handleDispatchSystemUiVisibilityChanged((SystemUiVisibilityInfo) msg.obj);
                } break;
                case MSG_UPDATE_CONFIGURATION: {
                    Configuration config = (Configuration) msg.obj;
                    if (config.isOtherSeqNewer(
                            mLastReportedMergedConfiguration.getMergedConfiguration())) {
                        // If we already have a newer merged config applied - use its global part.
                        config = mLastReportedMergedConfiguration.getGlobalConfiguration();
                    }

                    // Use the newer global config and last reported override config.
                    mPendingMergedConfiguration.setConfiguration(config,
                            mLastReportedMergedConfiguration.getOverrideConfiguration());

                    performConfigurationChange(mPendingMergedConfiguration, false /* force */,
                            INVALID_DISPLAY /* same display */);
                } break;
                case MSG_CLEAR_ACCESSIBILITY_FOCUS_HOST: {
                    setAccessibilityFocus(null, null);
                } break;
                case MSG_INVALIDATE_WORLD: {
                    if (mView != null) {
                        invalidateWorld(mView);
                    }
                } break;
                case MSG_DISPATCH_WINDOW_SHOWN: {
                    handleDispatchWindowShown();
                } break;
                case MSG_REQUEST_KEYBOARD_SHORTCUTS: {
                    final IResultReceiver receiver = (IResultReceiver) msg.obj;
                    final int deviceId = msg.arg1;
                    handleRequestKeyboardShortcuts(receiver, deviceId);
                } break;
                case MSG_UPDATE_POINTER_ICON: {
                    MotionEvent event = (MotionEvent) msg.obj;
                    resetPointerIcon(event);
                } break;
                case MSG_POINTER_CAPTURE_CHANGED: {
                    final boolean hasCapture = msg.arg1 != 0;
                    handlePointerCaptureChanged(hasCapture);
                } break;
                case MSG_DRAW_FINISHED: {
                    pendingDrawFinished();
                } break;
            }
        }
    }

    final ViewRootHandler mHandler = new ViewRootHandler();

    
Something in the current window tells us we need to change the touch mode.  For
example, we are not in touch mode, and the user touches the screen.
If the touch mode has changed, tell the window manager, and handle it locally.
Params:
inTouchMode – Whether we want to be in touch mode.
Returns:
True if the touch mode changed and focus changed was changed as a result/**
     * Something in the current window tells us we need to change the touch mode.  For
     * example, we are not in touch mode, and the user touches the screen.
     *
     * If the touch mode has changed, tell the window manager, and handle it locally.
     *
     * @param inTouchMode Whether we want to be in touch mode.
     * @return True if the touch mode changed and focus changed was changed as a result
     */
    boolean ensureTouchMode(boolean inTouchMode) {
        if (DBG) Log.d("touchmode", "ensureTouchMode(" + inTouchMode + "), current "
                + "touch mode is " + mAttachInfo.mInTouchMode);
        if (mAttachInfo.mInTouchMode == inTouchMode) return false;

        // tell the window manager
        try {
            mWindowSession.setInTouchMode(inTouchMode);
        } catch (RemoteException e) {
            throw new RuntimeException(e);
        }

        // handle the change
        return ensureTouchModeLocally(inTouchMode);
    }

    
Ensure that the touch mode for this window is set, and if it is changing,
take the appropriate action.
Params:
inTouchMode – Whether we want to be in touch mode.
Returns:
True if the touch mode changed and focus changed was changed as a result/**
     * Ensure that the touch mode for this window is set, and if it is changing,
     * take the appropriate action.
     * @param inTouchMode Whether we want to be in touch mode.
     * @return True if the touch mode changed and focus changed was changed as a result
     */
    private boolean ensureTouchModeLocally(boolean inTouchMode) {
        if (DBG) Log.d("touchmode", "ensureTouchModeLocally(" + inTouchMode + "), current "
                + "touch mode is " + mAttachInfo.mInTouchMode);

        if (mAttachInfo.mInTouchMode == inTouchMode) return false;

        mAttachInfo.mInTouchMode = inTouchMode;
        mAttachInfo.mTreeObserver.dispatchOnTouchModeChanged(inTouchMode);

        return (inTouchMode) ? enterTouchMode() : leaveTouchMode();
    }

    private boolean enterTouchMode() {
        if (mView != null && mView.hasFocus()) {
            // note: not relying on mFocusedView here because this could
            // be when the window is first being added, and mFocused isn't
            // set yet.
            final View focused = mView.findFocus();
            if (focused != null && !focused.isFocusableInTouchMode()) {
                final ViewGroup ancestorToTakeFocus = findAncestorToTakeFocusInTouchMode(focused);
                if (ancestorToTakeFocus != null) {
                    // there is an ancestor that wants focus after its
                    // descendants that is focusable in touch mode.. give it
                    // focus
                    return ancestorToTakeFocus.requestFocus();
                } else {
                    // There's nothing to focus. Clear and propagate through the
                    // hierarchy, but don't attempt to place new focus.
                    focused.clearFocusInternal(null, true, false);
                    return true;
                }
            }
        }
        return false;
    }

    
Find an ancestor of focused that wants focus after its descendants and is
focusable in touch mode.
Params:
focused – The currently focused view.
Returns:
An appropriate view, or null if no such view exists./**
     * Find an ancestor of focused that wants focus after its descendants and is
     * focusable in touch mode.
     * @param focused The currently focused view.
     * @return An appropriate view, or null if no such view exists.
     */
    private static ViewGroup findAncestorToTakeFocusInTouchMode(View focused) {
        ViewParent parent = focused.getParent();
        while (parent instanceof ViewGroup) {
            final ViewGroup vgParent = (ViewGroup) parent;
            if (vgParent.getDescendantFocusability() == ViewGroup.FOCUS_AFTER_DESCENDANTS
                    && vgParent.isFocusableInTouchMode()) {
                return vgParent;
            }
            if (vgParent.isRootNamespace()) {
                return null;
            } else {
                parent = vgParent.getParent();
            }
        }
        return null;
    }

    private boolean leaveTouchMode() {
        if (mView != null) {
            if (mView.hasFocus()) {
                View focusedView = mView.findFocus();
                if (!(focusedView instanceof ViewGroup)) {
                    // some view has focus, let it keep it
                    return false;
                } else if (((ViewGroup) focusedView).getDescendantFocusability() !=
                        ViewGroup.FOCUS_AFTER_DESCENDANTS) {
                    // some view group has focus, and doesn't prefer its children
                    // over itself for focus, so let them keep it.
                    return false;
                }
            }

            // find the best view to give focus to in this brave new non-touch-mode
            // world
            return mView.restoreDefaultFocus();
        }
        return false;
    }

    
Base class for implementing a stage in the chain of responsibility
for processing input events.
 Events are delivered to the stage by the deliver method. The stage then has the choice of finishing the event or forwarding it to the next stage. 
/**
     * Base class for implementing a stage in the chain of responsibility
     * for processing input events.
     * <p>
     * Events are delivered to the stage by the {@link #deliver} method.  The stage
     * then has the choice of finishing the event or forwarding it to the next stage.
     * </p>
     */
    abstract class InputStage {
        private final InputStage mNext;

        protected static final int FORWARD = 0;
        protected static final int FINISH_HANDLED = 1;
        protected static final int FINISH_NOT_HANDLED = 2;

        
Creates an input stage.
Params:
next – The next stage to which events should be forwarded./**
         * Creates an input stage.
         * @param next The next stage to which events should be forwarded.
         */
        public InputStage(InputStage next) {
            mNext = next;
        }

        
Delivers an event to be processed.
/**
         * Delivers an event to be processed.
         */
        public final void deliver(QueuedInputEvent q) {
            if ((q.mFlags & QueuedInputEvent.FLAG_FINISHED) != 0) {
                forward(q);
            } else if (shouldDropInputEvent(q)) {
                finish(q, false);
            } else {
                apply(q, onProcess(q));
            }
        }

        
Marks the the input event as finished then forwards it to the next stage.
/**
         * Marks the the input event as finished then forwards it to the next stage.
         */
        protected void finish(QueuedInputEvent q, boolean handled) {
            q.mFlags |= QueuedInputEvent.FLAG_FINISHED;
            if (handled) {
                q.mFlags |= QueuedInputEvent.FLAG_FINISHED_HANDLED;
            }
            forward(q);
        }

        
Forwards the event to the next stage.
/**
         * Forwards the event to the next stage.
         */
        protected void forward(QueuedInputEvent q) {
            onDeliverToNext(q);
        }

        
Applies a result code from onProcess to the specified event. /**
         * Applies a result code from {@link #onProcess} to the specified event.
         */
        protected void apply(QueuedInputEvent q, int result) {
            if (result == FORWARD) {
                forward(q);
            } else if (result == FINISH_HANDLED) {
                finish(q, true);
            } else if (result == FINISH_NOT_HANDLED) {
                finish(q, false);
            } else {
                throw new IllegalArgumentException("Invalid result: " + result);
            }
        }

        
Called when an event is ready to be processed.
Returns:
A result code indicating how the event was handled./**
         * Called when an event is ready to be processed.
         * @return A result code indicating how the event was handled.
         */
        protected int onProcess(QueuedInputEvent q) {
            return FORWARD;
        }

        
Called when an event is being delivered to the next stage.
/**
         * Called when an event is being delivered to the next stage.
         */
        protected void onDeliverToNext(QueuedInputEvent q) {
            if (DEBUG_INPUT_STAGES) {
                Log.v(mTag, "Done with " + getClass().getSimpleName() + ". " + q);
            }
            if (mNext != null) {
                mNext.deliver(q);
            } else {
                finishInputEvent(q);
            }
        }

        protected void onWindowFocusChanged(boolean hasWindowFocus) {
            if (mNext != null) {
                mNext.onWindowFocusChanged(hasWindowFocus);
            }
        }

        protected void onDetachedFromWindow() {
            if (mNext != null) {
                mNext.onDetachedFromWindow();
            }
        }

        protected boolean shouldDropInputEvent(QueuedInputEvent q) {
            if (mView == null || !mAdded) {
                Slog.w(mTag, "Dropping event due to root view being removed: " + q.mEvent);
                return true;
            } else if ((!mAttachInfo.mHasWindowFocus
                    && !q.mEvent.isFromSource(InputDevice.SOURCE_CLASS_POINTER)
                    && !isAutofillUiShowing()) || mStopped
                    || (mIsAmbientMode && !q.mEvent.isFromSource(InputDevice.SOURCE_CLASS_BUTTON))
                    || (mPausedForTransition && !isBack(q.mEvent))) {
                // This is a focus event and the window doesn't currently have input focus or
                // has stopped. This could be an event that came back from the previous stage
                // but the window has lost focus or stopped in the meantime.
                if (isTerminalInputEvent(q.mEvent)) {
                    // Don't drop terminal input events, however mark them as canceled.
                    q.mEvent.cancel();
                    Slog.w(mTag, "Cancelling event due to no window focus: " + q.mEvent);
                    return false;
                }

                // Drop non-terminal input events.
                Slog.w(mTag, "Dropping event due to no window focus: " + q.mEvent);
                return true;
            }
            return false;
        }

        void dump(String prefix, PrintWriter writer) {
            if (mNext != null) {
                mNext.dump(prefix, writer);
            }
        }

        private boolean isBack(InputEvent event) {
            if (event instanceof KeyEvent) {
                return ((KeyEvent) event).getKeyCode() == KeyEvent.KEYCODE_BACK;
            } else {
                return false;
            }
        }
    }

    
Base class for implementing an input pipeline stage that supports
asynchronous and out-of-order processing of input events.

In addition to what a normal input stage can do, an asynchronous
input stage may also defer an input event that has been delivered to it
and finish or forward it later.

/**
     * Base class for implementing an input pipeline stage that supports
     * asynchronous and out-of-order processing of input events.
     * <p>
     * In addition to what a normal input stage can do, an asynchronous
     * input stage may also defer an input event that has been delivered to it
     * and finish or forward it later.
     * </p>
     */
    abstract class AsyncInputStage extends InputStage {
        private final String mTraceCounter;

        private QueuedInputEvent mQueueHead;
        private QueuedInputEvent mQueueTail;
        private int mQueueLength;

        protected static final int DEFER = 3;

        
Creates an asynchronous input stage.
Params:
next – The next stage to which events should be forwarded.
traceCounter – The name of a counter to record the size of
the queue of pending events./**
         * Creates an asynchronous input stage.
         * @param next The next stage to which events should be forwarded.
         * @param traceCounter The name of a counter to record the size of
         * the queue of pending events.
         */
        public AsyncInputStage(InputStage next, String traceCounter) {
            super(next);
            mTraceCounter = traceCounter;
        }

        
Marks the event as deferred, which is to say that it will be handled asynchronously. The caller is responsible for calling forward or InputStage.finish later when it is done handling the event. /**
         * Marks the event as deferred, which is to say that it will be handled
         * asynchronously.  The caller is responsible for calling {@link #forward}
         * or {@link #finish} later when it is done handling the event.
         */
        protected void defer(QueuedInputEvent q) {
            q.mFlags |= QueuedInputEvent.FLAG_DEFERRED;
            enqueue(q);
        }

        @Override
        protected void forward(QueuedInputEvent q) {
            // Clear the deferred flag.
            q.mFlags &= ~QueuedInputEvent.FLAG_DEFERRED;

            // Fast path if the queue is empty.
            QueuedInputEvent curr = mQueueHead;
            if (curr == null) {
                super.forward(q);
                return;
            }

            // Determine whether the event must be serialized behind any others
            // before it can be delivered to the next stage.  This is done because
            // deferred events might be handled out of order by the stage.
            final int deviceId = q.mEvent.getDeviceId();
            QueuedInputEvent prev = null;
            boolean blocked = false;
            while (curr != null && curr != q) {
                if (!blocked && deviceId == curr.mEvent.getDeviceId()) {
                    blocked = true;
                }
                prev = curr;
                curr = curr.mNext;
            }

            // If the event is blocked, then leave it in the queue to be delivered later.
            // Note that the event might not yet be in the queue if it was not previously
            // deferred so we will enqueue it if needed.
            if (blocked) {
                if (curr == null) {
                    enqueue(q);
                }
                return;
            }

            // The event is not blocked.  Deliver it immediately.
            if (curr != null) {
                curr = curr.mNext;
                dequeue(q, prev);
            }
            super.forward(q);

            // Dequeuing this event may have unblocked successors.  Deliver them.
            while (curr != null) {
                if (deviceId == curr.mEvent.getDeviceId()) {
                    if ((curr.mFlags & QueuedInputEvent.FLAG_DEFERRED) != 0) {
                        break;
                    }
                    QueuedInputEvent next = curr.mNext;
                    dequeue(curr, prev);
                    super.forward(curr);
                    curr = next;
                } else {
                    prev = curr;
                    curr = curr.mNext;
                }
            }
        }

        @Override
        protected void apply(QueuedInputEvent q, int result) {
            if (result == DEFER) {
                defer(q);
            } else {
                super.apply(q, result);
            }
        }

        private void enqueue(QueuedInputEvent q) {
            if (mQueueTail == null) {
                mQueueHead = q;
                mQueueTail = q;
            } else {
                mQueueTail.mNext = q;
                mQueueTail = q;
            }

            mQueueLength += 1;
            Trace.traceCounter(Trace.TRACE_TAG_INPUT, mTraceCounter, mQueueLength);
        }

        private void dequeue(QueuedInputEvent q, QueuedInputEvent prev) {
            if (prev == null) {
                mQueueHead = q.mNext;
            } else {
                prev.mNext = q.mNext;
            }
            if (mQueueTail == q) {
                mQueueTail = prev;
            }
            q.mNext = null;

            mQueueLength -= 1;
            Trace.traceCounter(Trace.TRACE_TAG_INPUT, mTraceCounter, mQueueLength);
        }

        @Override
        void dump(String prefix, PrintWriter writer) {
            writer.print(prefix);
            writer.print(getClass().getName());
            writer.print(": mQueueLength=");
            writer.println(mQueueLength);

            super.dump(prefix, writer);
        }
    }

    
Delivers pre-ime input events to a native activity.
Does not support pointer events.
/**
     * Delivers pre-ime input events to a native activity.
     * Does not support pointer events.
     */
    final class NativePreImeInputStage extends AsyncInputStage
            implements InputQueue.FinishedInputEventCallback {
        public NativePreImeInputStage(InputStage next, String traceCounter) {
            super(next, traceCounter);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            if (mInputQueue != null && q.mEvent instanceof KeyEvent) {
                mInputQueue.sendInputEvent(q.mEvent, q, true, this);
                return DEFER;
            }
            return FORWARD;
        }

        @Override
        public void onFinishedInputEvent(Object token, boolean handled) {
            QueuedInputEvent q = (QueuedInputEvent)token;
            if (handled) {
                finish(q, true);
                return;
            }
            forward(q);
        }
    }

    
Delivers pre-ime input events to the view hierarchy.
Does not support pointer events.
/**
     * Delivers pre-ime input events to the view hierarchy.
     * Does not support pointer events.
     */
    final class ViewPreImeInputStage extends InputStage {
        public ViewPreImeInputStage(InputStage next) {
            super(next);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            if (q.mEvent instanceof KeyEvent) {
                return processKeyEvent(q);
            }
            return FORWARD;
        }

        private int processKeyEvent(QueuedInputEvent q) {
            final KeyEvent event = (KeyEvent)q.mEvent;
            if (mView.dispatchKeyEventPreIme(event)) {
                return FINISH_HANDLED;
            }
            return FORWARD;
        }
    }

    
Delivers input events to the ime.
Does not support pointer events.
/**
     * Delivers input events to the ime.
     * Does not support pointer events.
     */
    final class ImeInputStage extends AsyncInputStage
            implements InputMethodManager.FinishedInputEventCallback {
        public ImeInputStage(InputStage next, String traceCounter) {
            super(next, traceCounter);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            if (mLastWasImTarget && !isInLocalFocusMode()) {
                InputMethodManager imm = InputMethodManager.peekInstance();
                if (imm != null) {
                    final InputEvent event = q.mEvent;
                    if (DEBUG_IMF) Log.v(mTag, "Sending input event to IME: " + event);
                    int result = imm.dispatchInputEvent(event, q, this, mHandler);
                    if (result == InputMethodManager.DISPATCH_HANDLED) {
                        return FINISH_HANDLED;
                    } else if (result == InputMethodManager.DISPATCH_NOT_HANDLED) {
                        // The IME could not handle it, so skip along to the next InputStage
                        return FORWARD;
                    } else {
                        return DEFER; // callback will be invoked later
                    }
                }
            }
            return FORWARD;
        }

        @Override
        public void onFinishedInputEvent(Object token, boolean handled) {
            QueuedInputEvent q = (QueuedInputEvent)token;
            if (handled) {
                finish(q, true);
                return;
            }
            forward(q);
        }
    }

    
Performs early processing of post-ime input events.
/**
     * Performs early processing of post-ime input events.
     */
    final class EarlyPostImeInputStage extends InputStage {
        public EarlyPostImeInputStage(InputStage next) {
            super(next);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            if (q.mEvent instanceof KeyEvent) {
                return processKeyEvent(q);
            } else {
                final int source = q.mEvent.getSource();
                if ((source & InputDevice.SOURCE_CLASS_POINTER) != 0) {
                    return processPointerEvent(q);
                }
            }
            return FORWARD;
        }

        private int processKeyEvent(QueuedInputEvent q) {
            final KeyEvent event = (KeyEvent)q.mEvent;

            if (mAttachInfo.mTooltipHost != null) {
                mAttachInfo.mTooltipHost.handleTooltipKey(event);
            }

            // If the key's purpose is to exit touch mode then we consume it
            // and consider it handled.
            if (checkForLeavingTouchModeAndConsume(event)) {
                return FINISH_HANDLED;
            }

            // Make sure the fallback event policy sees all keys that will be
            // delivered to the view hierarchy.
            mFallbackEventHandler.preDispatchKeyEvent(event);
            return FORWARD;
        }

        private int processPointerEvent(QueuedInputEvent q) {
            final MotionEvent event = (MotionEvent)q.mEvent;

            // Translate the pointer event for compatibility, if needed.
            if (mTranslator != null) {
                mTranslator.translateEventInScreenToAppWindow(event);
            }

            // Enter touch mode on down or scroll, if it is coming from a touch screen device,
            // exit otherwise.
            final int action = event.getAction();
            if (action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_SCROLL) {
                ensureTouchMode(event.isFromSource(InputDevice.SOURCE_TOUCHSCREEN));
            }

            if (action == MotionEvent.ACTION_DOWN) {
                // Upon motion event within app window, close autofill ui.
                AutofillManager afm = getAutofillManager();
                if (afm != null) {
                    afm.requestHideFillUi();
                }
            }

            if (action == MotionEvent.ACTION_DOWN && mAttachInfo.mTooltipHost != null) {
                mAttachInfo.mTooltipHost.hideTooltip();
            }

            // Offset the scroll position.
            if (mCurScrollY != 0) {
                event.offsetLocation(0, mCurScrollY);
            }

            // Remember the touch position for possible drag-initiation.
            if (event.isTouchEvent()) {
                mLastTouchPoint.x = event.getRawX();
                mLastTouchPoint.y = event.getRawY();
                mLastTouchSource = event.getSource();
            }
            return FORWARD;
        }
    }

    
Delivers post-ime input events to a native activity.
/**
     * Delivers post-ime input events to a native activity.
     */
    final class NativePostImeInputStage extends AsyncInputStage
            implements InputQueue.FinishedInputEventCallback {
        public NativePostImeInputStage(InputStage next, String traceCounter) {
            super(next, traceCounter);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            if (mInputQueue != null) {
                mInputQueue.sendInputEvent(q.mEvent, q, false, this);
                return DEFER;
            }
            return FORWARD;
        }

        @Override
        public void onFinishedInputEvent(Object token, boolean handled) {
            QueuedInputEvent q = (QueuedInputEvent)token;
            if (handled) {
                finish(q, true);
                return;
            }
            forward(q);
        }
    }

    
Delivers post-ime input events to the view hierarchy.
/**
     * Delivers post-ime input events to the view hierarchy.
     */
    final class ViewPostImeInputStage extends InputStage {
        public ViewPostImeInputStage(InputStage next) {
            super(next);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            if (q.mEvent instanceof KeyEvent) {
                return processKeyEvent(q);
            } else {
                final int source = q.mEvent.getSource();
                if ((source & InputDevice.SOURCE_CLASS_POINTER) != 0) {
                    return processPointerEvent(q);
                } else if ((source & InputDevice.SOURCE_CLASS_TRACKBALL) != 0) {
                    return processTrackballEvent(q);
                } else {
                    return processGenericMotionEvent(q);
                }
            }
        }

        @Override
        protected void onDeliverToNext(QueuedInputEvent q) {
            if (mUnbufferedInputDispatch
                    && q.mEvent instanceof MotionEvent
                    && ((MotionEvent)q.mEvent).isTouchEvent()
                    && isTerminalInputEvent(q.mEvent)) {
                mUnbufferedInputDispatch = false;
                scheduleConsumeBatchedInput();
            }
            super.onDeliverToNext(q);
        }

        private boolean performFocusNavigation(KeyEvent event) {
            int direction = 0;
            switch (event.getKeyCode()) {
                case KeyEvent.KEYCODE_DPAD_LEFT:
                    if (event.hasNoModifiers()) {
                        direction = View.FOCUS_LEFT;
                    }
                    break;
                case KeyEvent.KEYCODE_DPAD_RIGHT:
                    if (event.hasNoModifiers()) {
                        direction = View.FOCUS_RIGHT;
                    }
                    break;
                case KeyEvent.KEYCODE_DPAD_UP:
                    if (event.hasNoModifiers()) {
                        direction = View.FOCUS_UP;
                    }
                    break;
                case KeyEvent.KEYCODE_DPAD_DOWN:
                    if (event.hasNoModifiers()) {
                        direction = View.FOCUS_DOWN;
                    }
                    break;
                case KeyEvent.KEYCODE_TAB:
                    if (event.hasNoModifiers()) {
                        direction = View.FOCUS_FORWARD;
                    } else if (event.hasModifiers(KeyEvent.META_SHIFT_ON)) {
                        direction = View.FOCUS_BACKWARD;
                    }
                    break;
            }
            if (direction != 0) {
                View focused = mView.findFocus();
                if (focused != null) {
                    View v = focused.focusSearch(direction);
                    if (v != null && v != focused) {
                        // do the math the get the interesting rect
                        // of previous focused into the coord system of
                        // newly focused view
                        focused.getFocusedRect(mTempRect);
                        if (mView instanceof ViewGroup) {
                            ((ViewGroup) mView).offsetDescendantRectToMyCoords(
                                    focused, mTempRect);
                            ((ViewGroup) mView).offsetRectIntoDescendantCoords(
                                    v, mTempRect);
                        }
                        if (v.requestFocus(direction, mTempRect)) {
                            playSoundEffect(SoundEffectConstants
                                    .getContantForFocusDirection(direction));
                            return true;
                        }
                    }

                    // Give the focused view a last chance to handle the dpad key.
                    if (mView.dispatchUnhandledMove(focused, direction)) {
                        return true;
                    }
                } else {
                    if (mView.restoreDefaultFocus()) {
                        return true;
                    }
                }
            }
            return false;
        }

        private boolean performKeyboardGroupNavigation(int direction) {
            final View focused = mView.findFocus();
            if (focused == null && mView.restoreDefaultFocus()) {
                return true;
            }
            View cluster = focused == null ? keyboardNavigationClusterSearch(null, direction)
                    : focused.keyboardNavigationClusterSearch(null, direction);

            // Since requestFocus only takes "real" focus directions (and therefore also
            // restoreFocusInCluster), convert forward/backward focus into FOCUS_DOWN.
            int realDirection = direction;
            if (direction == View.FOCUS_FORWARD || direction == View.FOCUS_BACKWARD) {
                realDirection = View.FOCUS_DOWN;
            }

            if (cluster != null && cluster.isRootNamespace()) {
                // the default cluster. Try to find a non-clustered view to focus.
                if (cluster.restoreFocusNotInCluster()) {
                    playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
                    return true;
                }
                // otherwise skip to next actual cluster
                cluster = keyboardNavigationClusterSearch(null, direction);
            }

            if (cluster != null && cluster.restoreFocusInCluster(realDirection)) {
                playSoundEffect(SoundEffectConstants.getContantForFocusDirection(direction));
                return true;
            }

            return false;
        }

        private int processKeyEvent(QueuedInputEvent q) {
            final KeyEvent event = (KeyEvent)q.mEvent;

            if (mUnhandledKeyManager.preViewDispatch(event)) {
                return FINISH_HANDLED;
            }

            // Deliver the key to the view hierarchy.
            if (mView.dispatchKeyEvent(event)) {
                return FINISH_HANDLED;
            }

            if (shouldDropInputEvent(q)) {
                return FINISH_NOT_HANDLED;
            }

            // This dispatch is for windows that don't have a Window.Callback. Otherwise,
            // the Window.Callback usually will have already called this (see
            // DecorView.superDispatchKeyEvent) leaving this call a no-op.
            if (mUnhandledKeyManager.dispatch(mView, event)) {
                return FINISH_HANDLED;
            }

            int groupNavigationDirection = 0;

            if (event.getAction() == KeyEvent.ACTION_DOWN
                    && event.getKeyCode() == KeyEvent.KEYCODE_TAB) {
                if (KeyEvent.metaStateHasModifiers(event.getMetaState(), KeyEvent.META_META_ON)) {
                    groupNavigationDirection = View.FOCUS_FORWARD;
                } else if (KeyEvent.metaStateHasModifiers(event.getMetaState(),
                        KeyEvent.META_META_ON | KeyEvent.META_SHIFT_ON)) {
                    groupNavigationDirection = View.FOCUS_BACKWARD;
                }
            }

            // If a modifier is held, try to interpret the key as a shortcut.
            if (event.getAction() == KeyEvent.ACTION_DOWN
                    && !KeyEvent.metaStateHasNoModifiers(event.getMetaState())
                    && event.getRepeatCount() == 0
                    && !KeyEvent.isModifierKey(event.getKeyCode())
                    && groupNavigationDirection == 0) {
                if (mView.dispatchKeyShortcutEvent(event)) {
                    return FINISH_HANDLED;
                }
                if (shouldDropInputEvent(q)) {
                    return FINISH_NOT_HANDLED;
                }
            }

            // Apply the fallback event policy.
            if (mFallbackEventHandler.dispatchKeyEvent(event)) {
                return FINISH_HANDLED;
            }
            if (shouldDropInputEvent(q)) {
                return FINISH_NOT_HANDLED;
            }

            // Handle automatic focus changes.
            if (event.getAction() == KeyEvent.ACTION_DOWN) {
                if (groupNavigationDirection != 0) {
                    if (performKeyboardGroupNavigation(groupNavigationDirection)) {
                        return FINISH_HANDLED;
                    }
                } else {
                    if (performFocusNavigation(event)) {
                        return FINISH_HANDLED;
                    }
                }
            }
            return FORWARD;
        }

        private int processPointerEvent(QueuedInputEvent q) {
            final MotionEvent event = (MotionEvent)q.mEvent;

            mAttachInfo.mUnbufferedDispatchRequested = false;
            mAttachInfo.mHandlingPointerEvent = true;
            boolean handled = mView.dispatchPointerEvent(event);
            maybeUpdatePointerIcon(event);
            maybeUpdateTooltip(event);
            mAttachInfo.mHandlingPointerEvent = false;
            if (mAttachInfo.mUnbufferedDispatchRequested && !mUnbufferedInputDispatch) {
                mUnbufferedInputDispatch = true;
                if (mConsumeBatchedInputScheduled) {
                    scheduleConsumeBatchedInputImmediately();
                }
            }
            return handled ? FINISH_HANDLED : FORWARD;
        }

        private void maybeUpdatePointerIcon(MotionEvent event) {
            if (event.getPointerCount() == 1 && event.isFromSource(InputDevice.SOURCE_MOUSE)) {
                if (event.getActionMasked() == MotionEvent.ACTION_HOVER_ENTER
                        || event.getActionMasked() == MotionEvent.ACTION_HOVER_EXIT) {
                    // Other apps or the window manager may change the icon type outside of
                    // this app, therefore the icon type has to be reset on enter/exit event.
                    mPointerIconType = PointerIcon.TYPE_NOT_SPECIFIED;
                }

                if (event.getActionMasked() != MotionEvent.ACTION_HOVER_EXIT) {
                    if (!updatePointerIcon(event) &&
                            event.getActionMasked() == MotionEvent.ACTION_HOVER_MOVE) {
                        mPointerIconType = PointerIcon.TYPE_NOT_SPECIFIED;
                    }
                }
            }
        }

        private int processTrackballEvent(QueuedInputEvent q) {
            final MotionEvent event = (MotionEvent)q.mEvent;

            if (event.isFromSource(InputDevice.SOURCE_MOUSE_RELATIVE)) {
                if (!hasPointerCapture() || mView.dispatchCapturedPointerEvent(event)) {
                    return FINISH_HANDLED;
                }
            }

            if (mView.dispatchTrackballEvent(event)) {
                return FINISH_HANDLED;
            }
            return FORWARD;
        }

        private int processGenericMotionEvent(QueuedInputEvent q) {
            final MotionEvent event = (MotionEvent)q.mEvent;

            // Deliver the event to the view.
            if (mView.dispatchGenericMotionEvent(event)) {
                return FINISH_HANDLED;
            }
            return FORWARD;
        }
    }

    private void resetPointerIcon(MotionEvent event) {
        mPointerIconType = PointerIcon.TYPE_NOT_SPECIFIED;
        updatePointerIcon(event);
    }

    private boolean updatePointerIcon(MotionEvent event) {
        final int pointerIndex = 0;
        final float x = event.getX(pointerIndex);
        final float y = event.getY(pointerIndex);
        if (mView == null) {
            // E.g. click outside a popup to dismiss it
            Slog.d(mTag, "updatePointerIcon called after view was removed");
            return false;
        }
        if (x < 0 || x >= mView.getWidth() || y < 0 || y >= mView.getHeight()) {
            // E.g. when moving window divider with mouse
            Slog.d(mTag, "updatePointerIcon called with position out of bounds");
            return false;
        }
        final PointerIcon pointerIcon = mView.onResolvePointerIcon(event, pointerIndex);
        final int pointerType = (pointerIcon != null) ?
                pointerIcon.getType() : PointerIcon.TYPE_DEFAULT;

        if (mPointerIconType != pointerType) {
            mPointerIconType = pointerType;
            mCustomPointerIcon = null;
            if (mPointerIconType != PointerIcon.TYPE_CUSTOM) {
                InputManager.getInstance().setPointerIconType(pointerType);
                return true;
            }
        }
        if (mPointerIconType == PointerIcon.TYPE_CUSTOM &&
                !pointerIcon.equals(mCustomPointerIcon)) {
            mCustomPointerIcon = pointerIcon;
            InputManager.getInstance().setCustomPointerIcon(mCustomPointerIcon);
        }
        return true;
    }

    private void maybeUpdateTooltip(MotionEvent event) {
        if (event.getPointerCount() != 1) {
            return;
        }
        final int action = event.getActionMasked();
        if (action != MotionEvent.ACTION_HOVER_ENTER
                && action != MotionEvent.ACTION_HOVER_MOVE
                && action != MotionEvent.ACTION_HOVER_EXIT) {
            return;
        }
        AccessibilityManager manager = AccessibilityManager.getInstance(mContext);
        if (manager.isEnabled() && manager.isTouchExplorationEnabled()) {
            return;
        }
        if (mView == null) {
            Slog.d(mTag, "maybeUpdateTooltip called after view was removed");
            return;
        }
        mView.dispatchTooltipHoverEvent(event);
    }

    
Performs synthesis of new input events from unhandled input events.
/**
     * Performs synthesis of new input events from unhandled input events.
     */
    final class SyntheticInputStage extends InputStage {
        private final SyntheticTrackballHandler mTrackball = new SyntheticTrackballHandler();
        private final SyntheticJoystickHandler mJoystick = new SyntheticJoystickHandler();
        private final SyntheticTouchNavigationHandler mTouchNavigation =
                new SyntheticTouchNavigationHandler();
        private final SyntheticKeyboardHandler mKeyboard = new SyntheticKeyboardHandler();

        public SyntheticInputStage() {
            super(null);
        }

        @Override
        protected int onProcess(QueuedInputEvent q) {
            q.mFlags |= QueuedInputEvent.FLAG_RESYNTHESIZED;
            if (q.mEvent instanceof MotionEvent) {
                final MotionEvent event = (MotionEvent)q.mEvent;
                final int source = event.getSource();
                if ((source & InputDevice.SOURCE_CLASS_TRACKBALL) != 0) {
                    mTrackball.process(event);
                    return FINISH_HANDLED;
                } else if ((source & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
                    mJoystick.process(event);
                    return FINISH_HANDLED;
                } else if ((source & InputDevice.SOURCE_TOUCH_NAVIGATION)
                        == InputDevice.SOURCE_TOUCH_NAVIGATION) {
                    mTouchNavigation.process(event);
                    return FINISH_HANDLED;
                }
            } else if ((q.mFlags & QueuedInputEvent.FLAG_UNHANDLED) != 0) {
                mKeyboard.process((KeyEvent)q.mEvent);
                return FINISH_HANDLED;
            }

            return FORWARD;
        }

        @Override
        protected void onDeliverToNext(QueuedInputEvent q) {
            if ((q.mFlags & QueuedInputEvent.FLAG_RESYNTHESIZED) == 0) {
                // Cancel related synthetic events if any prior stage has handled the event.
                if (q.mEvent instanceof MotionEvent) {
                    final MotionEvent event = (MotionEvent)q.mEvent;
                    final int source = event.getSource();
                    if ((source & InputDevice.SOURCE_CLASS_TRACKBALL) != 0) {
                        mTrackball.cancel();
                    } else if ((source & InputDevice.SOURCE_CLASS_JOYSTICK) != 0) {
                        mJoystick.cancel();
                    } else if ((source & InputDevice.SOURCE_TOUCH_NAVIGATION)
                            == InputDevice.SOURCE_TOUCH_NAVIGATION) {
                        mTouchNavigation.cancel(event);
                    }
                }
            }
            super.onDeliverToNext(q);
        }

        @Override
        protected void onWindowFocusChanged(boolean hasWindowFocus) {
            if (!hasWindowFocus) {
                mJoystick.cancel();
            }
        }

        @Override
        protected void onDetachedFromWindow() {
            mJoystick.cancel();
        }
    }

    
Creates dpad events from unhandled trackball movements.
/**
     * Creates dpad events from unhandled trackball movements.
     */
    final class SyntheticTrackballHandler {
        private final TrackballAxis mX = new TrackballAxis();
        private final TrackballAxis mY = new TrackballAxis();
        private long mLastTime;

        public void process(MotionEvent event) {
            // Translate the trackball event into DPAD keys and try to deliver those.
            long curTime = SystemClock.uptimeMillis();
            if ((mLastTime + MAX_TRACKBALL_DELAY) < curTime) {
                // It has been too long since the last movement,
                // so restart at the beginning.
                mX.reset(0);
                mY.reset(0);
                mLastTime = curTime;
            }

            final int action = event.getAction();
            final int metaState = event.getMetaState();
            switch (action) {
                case MotionEvent.ACTION_DOWN:
                    mX.reset(2);
                    mY.reset(2);
                    enqueueInputEvent(new KeyEvent(curTime, curTime,
                            KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_DPAD_CENTER, 0, metaState,
                            KeyCharacterMap.VIRTUAL_KEYBOARD, 0, KeyEvent.FLAG_FALLBACK,
                            InputDevice.SOURCE_KEYBOARD));
                    break;
                case MotionEvent.ACTION_UP:
                    mX.reset(2);
                    mY.reset(2);
                    enqueueInputEvent(new KeyEvent(curTime, curTime,
                            KeyEvent.ACTION_UP, KeyEvent.KEYCODE_DPAD_CENTER, 0, metaState,
                            KeyCharacterMap.VIRTUAL_KEYBOARD, 0, KeyEvent.FLAG_FALLBACK,
                            InputDevice.SOURCE_KEYBOARD));
                    break;
            }

            if (DEBUG_TRACKBALL) Log.v(mTag, "TB X=" + mX.position + " step="
                    + mX.step + " dir=" + mX.dir + " acc=" + mX.acceleration
                    + " move=" + event.getX()
                    + " / Y=" + mY.position + " step="
                    + mY.step + " dir=" + mY.dir + " acc=" + mY.acceleration
                    + " move=" + event.getY());
            final float xOff = mX.collect(event.getX(), event.getEventTime(), "X");
            final float yOff = mY.collect(event.getY(), event.getEventTime(), "Y");

            // Generate DPAD events based on the trackball movement.
            // We pick the axis that has moved the most as the direction of
            // the DPAD.  When we generate DPAD events for one axis, then the
            // other axis is reset -- we don't want to perform DPAD jumps due
            // to slight movements in the trackball when making major movements
            // along the other axis.
            int keycode = 0;
            int movement = 0;
            float accel = 1;
            if (xOff > yOff) {
                movement = mX.generate();
                if (movement != 0) {
                    keycode = movement > 0 ? KeyEvent.KEYCODE_DPAD_RIGHT
                            : KeyEvent.KEYCODE_DPAD_LEFT;
                    accel = mX.acceleration;
                    mY.reset(2);
                }
            } else if (yOff > 0) {
                movement = mY.generate();
                if (movement != 0) {
                    keycode = movement > 0 ? KeyEvent.KEYCODE_DPAD_DOWN
                            : KeyEvent.KEYCODE_DPAD_UP;
                    accel = mY.acceleration;
                    mX.reset(2);
                }
            }

            if (keycode != 0) {
                if (movement < 0) movement = -movement;
                int accelMovement = (int)(movement * accel);
                if (DEBUG_TRACKBALL) Log.v(mTag, "Move: movement=" + movement
                        + " accelMovement=" + accelMovement
                        + " accel=" + accel);
                if (accelMovement > movement) {
                    if (DEBUG_TRACKBALL) Log.v(mTag, "Delivering fake DPAD: "
                            + keycode);
                    movement--;
                    int repeatCount = accelMovement - movement;
                    enqueueInputEvent(new KeyEvent(curTime, curTime,
                            KeyEvent.ACTION_MULTIPLE, keycode, repeatCount, metaState,
                            KeyCharacterMap.VIRTUAL_KEYBOARD, 0, KeyEvent.FLAG_FALLBACK,
                            InputDevice.SOURCE_KEYBOARD));
                }
                while (movement > 0) {
                    if (DEBUG_TRACKBALL) Log.v(mTag, "Delivering fake DPAD: "
                            + keycode);
                    movement--;
                    curTime = SystemClock.uptimeMillis();
                    enqueueInputEvent(new KeyEvent(curTime, curTime,
                            KeyEvent.ACTION_DOWN, keycode, 0, metaState,
                            KeyCharacterMap.VIRTUAL_KEYBOARD, 0, KeyEvent.FLAG_FALLBACK,
                            InputDevice.SOURCE_KEYBOARD));
                    enqueueInputEvent(new KeyEvent(curTime, curTime,
                            KeyEvent.ACTION_UP, keycode, 0, metaState,
                            KeyCharacterMap.VIRTUAL_KEYBOARD, 0, KeyEvent.FLAG_FALLBACK,
                            InputDevice.SOURCE_KEYBOARD));
                }
                mLastTime = curTime;
            }
        }

        public void cancel() {
            mLastTime = Integer.MIN_VALUE;

            // If we reach this, we consumed a trackball event.
            // Because we will not translate the trackball event into a key event,
            // touch mode will not exit, so we exit touch mode here.
            if (mView != null && mAdded) {
                ensureTouchMode(false);
            }
        }
    }

    
Maintains state information for a single trackball axis, generating
discrete (DPAD) movements based on raw trackball motion.
/**
     * Maintains state information for a single trackball axis, generating
     * discrete (DPAD) movements based on raw trackball motion.
     */
    static final class TrackballAxis {
        
The maximum amount of acceleration we will apply.
/**
         * The maximum amount of acceleration we will apply.
         */
        static final float MAX_ACCELERATION = 20;

        
The maximum amount of time (in milliseconds) between events in order
for us to consider the user to be doing fast trackball movements,
and thus apply an acceleration.
/**
         * The maximum amount of time (in milliseconds) between events in order
         * for us to consider the user to be doing fast trackball movements,
         * and thus apply an acceleration.
         */
        static final long FAST_MOVE_TIME = 150;

        
Scaling factor to the time (in milliseconds) between events to how
much to multiple/divide the current acceleration.  When movement
is < FAST_MOVE_TIME this multiplies the acceleration; when >
FAST_MOVE_TIME it divides it.
/**
         * Scaling factor to the time (in milliseconds) between events to how
         * much to multiple/divide the current acceleration.  When movement
         * is < FAST_MOVE_TIME this multiplies the acceleration; when >
         * FAST_MOVE_TIME it divides it.
         */
        static final float ACCEL_MOVE_SCALING_FACTOR = (1.0f/40);

        static final float FIRST_MOVEMENT_THRESHOLD = 0.5f;
        static final float SECOND_CUMULATIVE_MOVEMENT_THRESHOLD = 2.0f;
        static final float SUBSEQUENT_INCREMENTAL_MOVEMENT_THRESHOLD = 1.0f;

        float position;
        float acceleration = 1;
        long lastMoveTime = 0;
        int step;
        int dir;
        int nonAccelMovement;

        void reset(int _step) {
            position = 0;
            acceleration = 1;
            lastMoveTime = 0;
            step = _step;
            dir = 0;
        }

        
Add trackball movement into the state.  If the direction of movement
has been reversed, the state is reset before adding the
movement (so that you don't have to compensate for any previously
collected movement before see the result of the movement in the
new direction).
Returns:
Returns the absolute value of the amount of movement
collected so far./**
         * Add trackball movement into the state.  If the direction of movement
         * has been reversed, the state is reset before adding the
         * movement (so that you don't have to compensate for any previously
         * collected movement before see the result of the movement in the
         * new direction).
         *
         * @return Returns the absolute value of the amount of movement
         * collected so far.
         */
        float collect(float off, long time, String axis) {
            long normTime;
            if (off > 0) {
                normTime = (long)(off * FAST_MOVE_TIME);
                if (dir < 0) {
                    if (DEBUG_TRACKBALL) Log.v(TAG, axis + " reversed to positive!");
                    position = 0;
                    step = 0;
                    acceleration = 1;
                    lastMoveTime = 0;
                }
                dir = 1;
            } else if (off < 0) {
                normTime = (long)((-off) * FAST_MOVE_TIME);
                if (dir > 0) {
                    if (DEBUG_TRACKBALL) Log.v(TAG, axis + " reversed to negative!");
                    position = 0;
                    step = 0;
                    acceleration = 1;
                    lastMoveTime = 0;
                }
                dir = -1;
            } else {
                normTime = 0;
            }

            // The number of milliseconds between each movement that is
            // considered "normal" and will not result in any acceleration
            // or deceleration, scaled by the offset we have here.
            if (normTime > 0) {
                long delta = time - lastMoveTime;
                lastMoveTime = time;
                float acc = acceleration;
                if (delta < normTime) {
                    // The user is scrolling rapidly, so increase acceleration.
                    float scale = (normTime-delta) * ACCEL_MOVE_SCALING_FACTOR;
                    if (scale > 1) acc *= scale;
                    if (DEBUG_TRACKBALL) Log.v(TAG, axis + " accelerate: off="
                            + off + " normTime=" + normTime + " delta=" + delta
                            + " scale=" + scale + " acc=" + acc);
                    acceleration = acc < MAX_ACCELERATION ? acc : MAX_ACCELERATION;
                } else {
                    // The user is scrolling slowly, so decrease acceleration.
                    float scale = (delta-normTime) * ACCEL_MOVE_SCALING_FACTOR;
                    if (scale > 1) acc /= scale;
                    if (DEBUG_TRACKBALL) Log.v(TAG, axis + " deccelerate: off="
                            + off + " normTime=" + normTime + " delta=" + delta
                            + " scale=" + scale + " acc=" + acc);
                    acceleration = acc > 1 ? acc : 1;
                }
            }
            position += off;
            return Math.abs(position);
        }

        
Generate the number of discrete movement events appropriate for
the currently collected trackball movement.
Returns:
Returns the number of discrete movements, either positive
or negative, or 0 if there is not enough trackball movement yet
for a discrete movement./**
         * Generate the number of discrete movement events appropriate for
         * the currently collected trackball movement.
         *
         * @return Returns the number of discrete movements, either positive
         * or negative, or 0 if there is not enough trackball movement yet
         * for a discrete movement.
         */
        int generate() {
            int movement = 0;
            nonAccelMovement = 0;
            do {
                final int dir = position >= 0 ? 1 : -1;
                switch (step) {
                    // If we are going to execute the first step, then we want
                    // to do this as soon as possible instead of waiting for
                    // a full movement, in order to make things look responsive.
                    case 0:
                        if (Math.abs(position) < FIRST_MOVEMENT_THRESHOLD) {
                            return movement;
                        }
                        movement += dir;
                        nonAccelMovement += dir;
                        step = 1;
                        break;
                    // If we have generated the first movement, then we need
                    // to wait for the second complete trackball motion before
                    // generating the second discrete movement.
                    case 1:
                        if (Math.abs(position) < SECOND_CUMULATIVE_MOVEMENT_THRESHOLD) {
                            return movement;
                        }
                        movement += dir;
                        nonAccelMovement += dir;
                        position -= SECOND_CUMULATIVE_MOVEMENT_THRESHOLD * dir;
                        step = 2;
                        break;
                    // After the first two, we generate discrete movements
                    // consistently with the trackball, applying an acceleration
                    // if the trackball is moving quickly.  This is a simple
                    // acceleration on top of what we already compute based
                    // on how quickly the wheel is being turned, to apply
                    // a longer increasing acceleration to continuous movement
                    // in one direction.
                    default:
                        if (Math.abs(position) < SUBSEQUENT_INCREMENTAL_MOVEMENT_THRESHOLD) {
                            return movement;
                        }
                        movement += dir;
                        position -= dir * SUBSEQUENT_INCREMENTAL_MOVEMENT_THRESHOLD;
                        float acc = acceleration;
                        acc *= 1.1f;
                        acceleration = acc < MAX_ACCELERATION ? acc : acceleration;
                        break;
                }
            } while (true);
        }
    }

    
Creates dpad events from unhandled joystick movements.
/**
     * Creates dpad events from unhandled joystick movements.
     */
    final class SyntheticJoystickHandler extends Handler {
        private final static int MSG_ENQUEUE_X_AXIS_KEY_REPEAT = 1;
        private final static int MSG_ENQUEUE_Y_AXIS_KEY_REPEAT = 2;

        private final JoystickAxesState mJoystickAxesState = new JoystickAxesState();
        private final SparseArray<KeyEvent> mDeviceKeyEvents = new SparseArray<>();

        public SyntheticJoystickHandler() {
            super(true);
        }

        @Override
        public void handleMessage(Message msg) {
            switch (msg.what) {
                case MSG_ENQUEUE_X_AXIS_KEY_REPEAT:
                case MSG_ENQUEUE_Y_AXIS_KEY_REPEAT: {
                    if (mAttachInfo.mHasWindowFocus) {
                        KeyEvent oldEvent = (KeyEvent) msg.obj;
                        KeyEvent e = KeyEvent.changeTimeRepeat(oldEvent,
                                SystemClock.uptimeMillis(), oldEvent.getRepeatCount() + 1);
                        enqueueInputEvent(e);
                        Message m = obtainMessage(msg.what, e);
                        m.setAsynchronous(true);
                        sendMessageDelayed(m, ViewConfiguration.getKeyRepeatDelay());
                    }
                } break;
            }
        }

        public void process(MotionEvent event) {
            switch(event.getActionMasked()) {
                case MotionEvent.ACTION_CANCEL:
                    cancel();
                    break;
                case MotionEvent.ACTION_MOVE:
                    update(event);
                    break;
                default:
                    Log.w(mTag, "Unexpected action: " + event.getActionMasked());
            }
        }

        private void cancel() {
            removeMessages(MSG_ENQUEUE_X_AXIS_KEY_REPEAT);
            removeMessages(MSG_ENQUEUE_Y_AXIS_KEY_REPEAT);
            for (int i = 0; i < mDeviceKeyEvents.size(); i++) {
                final KeyEvent keyEvent = mDeviceKeyEvents.valueAt(i);
                if (keyEvent != null) {
                    enqueueInputEvent(KeyEvent.changeTimeRepeat(keyEvent,
                            SystemClock.uptimeMillis(), 0));
                }
            }
            mDeviceKeyEvents.clear();
            mJoystickAxesState.resetState();
        }

        private void update(MotionEvent event) {
            final int historySize = event.getHistorySize();
            for (int h = 0; h < historySize; h++) {
                final long time = event.getHistoricalEventTime(h);
                mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_X,
                        event.getHistoricalAxisValue(MotionEvent.AXIS_X, 0, h));
                mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_Y,
                        event.getHistoricalAxisValue(MotionEvent.AXIS_Y, 0, h));
                mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_HAT_X,
                        event.getHistoricalAxisValue(MotionEvent.AXIS_HAT_X, 0, h));
                mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_HAT_Y,
                        event.getHistoricalAxisValue(MotionEvent.AXIS_HAT_Y, 0, h));
            }
            final long time = event.getEventTime();
            mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_X,
                    event.getAxisValue(MotionEvent.AXIS_X));
            mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_Y,
                    event.getAxisValue(MotionEvent.AXIS_Y));
            mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_HAT_X,
                    event.getAxisValue(MotionEvent.AXIS_HAT_X));
            mJoystickAxesState.updateStateForAxis(event, time, MotionEvent.AXIS_HAT_Y,
                    event.getAxisValue(MotionEvent.AXIS_HAT_Y));
        }

        final class JoystickAxesState {
            // State machine: from neutral state (no button press) can go into
            // button STATE_UP_OR_LEFT or STATE_DOWN_OR_RIGHT state, emitting an ACTION_DOWN event.
            // From STATE_UP_OR_LEFT or STATE_DOWN_OR_RIGHT state can go into neutral state,
            // emitting an ACTION_UP event.
            private static final int STATE_UP_OR_LEFT = -1;
            private static final int STATE_NEUTRAL = 0;
            private static final int STATE_DOWN_OR_RIGHT = 1;

            final int[] mAxisStatesHat = {STATE_NEUTRAL, STATE_NEUTRAL}; // {AXIS_HAT_X, AXIS_HAT_Y}
            final int[] mAxisStatesStick = {STATE_NEUTRAL, STATE_NEUTRAL}; // {AXIS_X, AXIS_Y}

            void resetState() {
                mAxisStatesHat[0] = STATE_NEUTRAL;
                mAxisStatesHat[1] = STATE_NEUTRAL;
                mAxisStatesStick[0] = STATE_NEUTRAL;
                mAxisStatesStick[1] = STATE_NEUTRAL;
            }

            void updateStateForAxis(MotionEvent event, long time, int axis, float value) {
                // Emit KeyEvent if necessary
                // axis can be AXIS_X, AXIS_Y, AXIS_HAT_X, AXIS_HAT_Y
                final int axisStateIndex;
                final int repeatMessage;
                if (isXAxis(axis)) {
                    axisStateIndex = 0;
                    repeatMessage = MSG_ENQUEUE_X_AXIS_KEY_REPEAT;
                } else if (isYAxis(axis)) {
                    axisStateIndex = 1;
                    repeatMessage = MSG_ENQUEUE_Y_AXIS_KEY_REPEAT;
                } else {
                    Log.e(mTag, "Unexpected axis " + axis + " in updateStateForAxis!");
                    return;
                }
                final int newState = joystickAxisValueToState(value);

                final int currentState;
                if (axis == MotionEvent.AXIS_X || axis == MotionEvent.AXIS_Y) {
                    currentState = mAxisStatesStick[axisStateIndex];
                } else {
                    currentState = mAxisStatesHat[axisStateIndex];
                }

                if (currentState == newState) {
                    return;
                }

                final int metaState = event.getMetaState();
                final int deviceId = event.getDeviceId();
                final int source = event.getSource();

                if (currentState == STATE_DOWN_OR_RIGHT || currentState == STATE_UP_OR_LEFT) {
                    // send a button release event
                    final int keyCode = joystickAxisAndStateToKeycode(axis, currentState);
                    if (keyCode != KeyEvent.KEYCODE_UNKNOWN) {
                        enqueueInputEvent(new KeyEvent(time, time, KeyEvent.ACTION_UP, keyCode,
                                0, metaState, deviceId, 0, KeyEvent.FLAG_FALLBACK, source));
                        // remove the corresponding pending UP event if focus lost/view detached
                        mDeviceKeyEvents.put(deviceId, null);
                    }
                    removeMessages(repeatMessage);
                }

                if (newState == STATE_DOWN_OR_RIGHT || newState == STATE_UP_OR_LEFT) {
                    // send a button down event
                    final int keyCode = joystickAxisAndStateToKeycode(axis, newState);
                    if (keyCode != KeyEvent.KEYCODE_UNKNOWN) {
                        KeyEvent keyEvent = new KeyEvent(time, time, KeyEvent.ACTION_DOWN, keyCode,
                                0, metaState, deviceId, 0, KeyEvent.FLAG_FALLBACK, source);
                        enqueueInputEvent(keyEvent);
                        Message m = obtainMessage(repeatMessage, keyEvent);
                        m.setAsynchronous(true);
                        sendMessageDelayed(m, ViewConfiguration.getKeyRepeatTimeout());
                        // store the corresponding ACTION_UP event so that it can be sent
                        // if focus is lost or root view is removed
                        mDeviceKeyEvents.put(deviceId,
                                new KeyEvent(time, time, KeyEvent.ACTION_UP, keyCode,
                                        0, metaState, deviceId, 0,
                                        KeyEvent.FLAG_FALLBACK | KeyEvent.FLAG_CANCELED,
                                        source));
                    }
                }
                if (axis == MotionEvent.AXIS_X || axis == MotionEvent.AXIS_Y) {
                    mAxisStatesStick[axisStateIndex] = newState;
                } else {
                    mAxisStatesHat[axisStateIndex] = newState;
                }
            }

            private boolean isXAxis(int axis) {
                return axis == MotionEvent.AXIS_X || axis == MotionEvent.AXIS_HAT_X;
            }
            private boolean isYAxis(int axis) {
                return axis == MotionEvent.AXIS_Y || axis == MotionEvent.AXIS_HAT_Y;
            }

            private int joystickAxisAndStateToKeycode(int axis, int state) {
                if (isXAxis(axis) && state == STATE_UP_OR_LEFT) {
                    return KeyEvent.KEYCODE_DPAD_LEFT;
                }
                if (isXAxis(axis) && state == STATE_DOWN_OR_RIGHT) {
                    return KeyEvent.KEYCODE_DPAD_RIGHT;
                }
                if (isYAxis(axis) && state == STATE_UP_OR_LEFT) {
                    return KeyEvent.KEYCODE_DPAD_UP;
                }
                if (isYAxis(axis) && state == STATE_DOWN_OR_RIGHT) {
                    return KeyEvent.KEYCODE_DPAD_DOWN;
                }
                Log.e(mTag, "Unknown axis " + axis + " or direction " + state);
                return KeyEvent.KEYCODE_UNKNOWN; // should never happen
            }

            private int joystickAxisValueToState(float value) {
                if (value >= 0.5f) {
                    return STATE_DOWN_OR_RIGHT;
                } else if (value <= -0.5f) {
                    return STATE_UP_OR_LEFT;
                } else {
                    return STATE_NEUTRAL;
                }
            }
        }
    }

    
Creates dpad events from unhandled touch navigation movements.
/**
     * Creates dpad events from unhandled touch navigation movements.
     */
    final class SyntheticTouchNavigationHandler extends Handler {
        private static final String LOCAL_TAG = "SyntheticTouchNavigationHandler";
        private static final boolean LOCAL_DEBUG = false;

        // Assumed nominal width and height in millimeters of a touch navigation pad,
        // if no resolution information is available from the input system.
        private static final float DEFAULT_WIDTH_MILLIMETERS = 48;
        private static final float DEFAULT_HEIGHT_MILLIMETERS = 48;

        /* TODO: These constants should eventually be moved to ViewConfiguration. */

        // The nominal distance traveled to move by one unit.
        private static final int TICK_DISTANCE_MILLIMETERS = 12;

        // Minimum and maximum fling velocity in ticks per second.
        // The minimum velocity should be set such that we perform enough ticks per
        // second that the fling appears to be fluid.  For example, if we set the minimum
        // to 2 ticks per second, then there may be up to half a second delay between the next
        // to last and last ticks which is noticeably discrete and jerky.  This value should
        // probably not be set to anything less than about 4.
        // If fling accuracy is a problem then consider tuning the tick distance instead.
        private static final float MIN_FLING_VELOCITY_TICKS_PER_SECOND = 6f;
        private static final float MAX_FLING_VELOCITY_TICKS_PER_SECOND = 20f;

        // Fling velocity decay factor applied after each new key is emitted.
        // This parameter controls the deceleration and overall duration of the fling.
        // The fling stops automatically when its velocity drops below the minimum
        // fling velocity defined above.
        private static final float FLING_TICK_DECAY = 0.8f;

        /* The input device that we are tracking. */

        private int mCurrentDeviceId = -1;
        private int mCurrentSource;
        private boolean mCurrentDeviceSupported;

        /* Configuration for the current input device. */

        // The scaled tick distance.  A movement of this amount should generally translate
        // into a single dpad event in a given direction.
        private float mConfigTickDistance;

        // The minimum and maximum scaled fling velocity.
        private float mConfigMinFlingVelocity;
        private float mConfigMaxFlingVelocity;

        /* Tracking state. */

        // The velocity tracker for detecting flings.
        private VelocityTracker mVelocityTracker;

        // The active pointer id, or -1 if none.
        private int mActivePointerId = -1;

        // Location where tracking started.
        private float mStartX;
        private float mStartY;

        // Most recently observed position.
        private float mLastX;
        private float mLastY;

        // Accumulated movement delta since the last direction key was sent.
        private float mAccumulatedX;
        private float mAccumulatedY;

        // Set to true if any movement was delivered to the app.
        // Implies that tap slop was exceeded.
        private boolean mConsumedMovement;

        // The most recently sent key down event.
        // The keycode remains set until the direction changes or a fling ends
        // so that repeated key events may be generated as required.
        private long mPendingKeyDownTime;
        private int mPendingKeyCode = KeyEvent.KEYCODE_UNKNOWN;
        private int mPendingKeyRepeatCount;
        private int mPendingKeyMetaState;

        // The current fling velocity while a fling is in progress.
        private boolean mFlinging;
        private float mFlingVelocity;

        public SyntheticTouchNavigationHandler() {
            super(true);
        }

        public void process(MotionEvent event) {
            // Update the current device information.
            final long time = event.getEventTime();
            final int deviceId = event.getDeviceId();
            final int source = event.getSource();
            if (mCurrentDeviceId != deviceId || mCurrentSource != source) {
                finishKeys(time);
                finishTracking(time);
                mCurrentDeviceId = deviceId;
                mCurrentSource = source;
                mCurrentDeviceSupported = false;
                InputDevice device = event.getDevice();
                if (device != null) {
                    // In order to support an input device, we must know certain
                    // characteristics about it, such as its size and resolution.
                    InputDevice.MotionRange xRange = device.getMotionRange(MotionEvent.AXIS_X);
                    InputDevice.MotionRange yRange = device.getMotionRange(MotionEvent.AXIS_Y);
                    if (xRange != null && yRange != null) {
                        mCurrentDeviceSupported = true;

                        // Infer the resolution if it not actually known.
                        float xRes = xRange.getResolution();
                        if (xRes <= 0) {
                            xRes = xRange.getRange() / DEFAULT_WIDTH_MILLIMETERS;
                        }
                        float yRes = yRange.getResolution();
                        if (yRes <= 0) {
                            yRes = yRange.getRange() / DEFAULT_HEIGHT_MILLIMETERS;
                        }
                        float nominalRes = (xRes + yRes) * 0.5f;

                        // Precompute all of the configuration thresholds we will need.
                        mConfigTickDistance = TICK_DISTANCE_MILLIMETERS * nominalRes;
                        mConfigMinFlingVelocity =
                                MIN_FLING_VELOCITY_TICKS_PER_SECOND * mConfigTickDistance;
                        mConfigMaxFlingVelocity =
                                MAX_FLING_VELOCITY_TICKS_PER_SECOND * mConfigTickDistance;

                        if (LOCAL_DEBUG) {
                            Log.d(LOCAL_TAG, "Configured device " + mCurrentDeviceId
                                    + " (" + Integer.toHexString(mCurrentSource) + "): "
                                    + ", mConfigTickDistance=" + mConfigTickDistance
                                    + ", mConfigMinFlingVelocity=" + mConfigMinFlingVelocity
                                    + ", mConfigMaxFlingVelocity=" + mConfigMaxFlingVelocity);
                        }
                    }
                }
            }
            if (!mCurrentDeviceSupported) {
                return;
            }

            // Handle the event.
            final int action = event.getActionMasked();
            switch (action) {
                case MotionEvent.ACTION_DOWN: {
                    boolean caughtFling = mFlinging;
                    finishKeys(time);
                    finishTracking(time);
                    mActivePointerId = event.getPointerId(0);
                    mVelocityTracker = VelocityTracker.obtain();
                    mVelocityTracker.addMovement(event);
                    mStartX = event.getX();
                    mStartY = event.getY();
                    mLastX = mStartX;
                    mLastY = mStartY;
                    mAccumulatedX = 0;
                    mAccumulatedY = 0;

                    // If we caught a fling, then pretend that the tap slop has already
                    // been exceeded to suppress taps whose only purpose is to stop the fling.
                    mConsumedMovement = caughtFling;
                    break;
                }

                case MotionEvent.ACTION_MOVE:
                case MotionEvent.ACTION_UP: {
                    if (mActivePointerId < 0) {
                        break;
                    }
                    final int index = event.findPointerIndex(mActivePointerId);
                    if (index < 0) {
                        finishKeys(time);
                        finishTracking(time);
                        break;
                    }

                    mVelocityTracker.addMovement(event);
                    final float x = event.getX(index);
                    final float y = event.getY(index);
                    mAccumulatedX += x - mLastX;
                    mAccumulatedY += y - mLastY;
                    mLastX = x;
                    mLastY = y;

                    // Consume any accumulated movement so far.
                    final int metaState = event.getMetaState();
                    consumeAccumulatedMovement(time, metaState);

                    // Detect taps and flings.
                    if (action == MotionEvent.ACTION_UP) {
                        if (mConsumedMovement && mPendingKeyCode != KeyEvent.KEYCODE_UNKNOWN) {
                            // It might be a fling.
                            mVelocityTracker.computeCurrentVelocity(1000, mConfigMaxFlingVelocity);
                            final float vx = mVelocityTracker.getXVelocity(mActivePointerId);
                            final float vy = mVelocityTracker.getYVelocity(mActivePointerId);
                            if (!startFling(time, vx, vy)) {
                                finishKeys(time);
                            }
                        }
                        finishTracking(time);
                    }
                    break;
                }

                case MotionEvent.ACTION_CANCEL: {
                    finishKeys(time);
                    finishTracking(time);
                    break;
                }
            }
        }

        public void cancel(MotionEvent event) {
            if (mCurrentDeviceId == event.getDeviceId()
                    && mCurrentSource == event.getSource()) {
                final long time = event.getEventTime();
                finishKeys(time);
                finishTracking(time);
            }
        }

        private void finishKeys(long time) {
            cancelFling();
            sendKeyUp(time);
        }

        private void finishTracking(long time) {
            if (mActivePointerId >= 0) {
                mActivePointerId = -1;
                mVelocityTracker.recycle();
                mVelocityTracker = null;
            }
        }

        private void consumeAccumulatedMovement(long time, int metaState) {
            final float absX = Math.abs(mAccumulatedX);
            final float absY = Math.abs(mAccumulatedY);
            if (absX >= absY) {
                if (absX >= mConfigTickDistance) {
                    mAccumulatedX = consumeAccumulatedMovement(time, metaState, mAccumulatedX,
                            KeyEvent.KEYCODE_DPAD_LEFT, KeyEvent.KEYCODE_DPAD_RIGHT);
                    mAccumulatedY = 0;
                    mConsumedMovement = true;
                }
            } else {
                if (absY >= mConfigTickDistance) {
                    mAccumulatedY = consumeAccumulatedMovement(time, metaState, mAccumulatedY,
                            KeyEvent.KEYCODE_DPAD_UP, KeyEvent.KEYCODE_DPAD_DOWN);
                    mAccumulatedX = 0;
                    mConsumedMovement = true;
                }
            }
        }

        private float consumeAccumulatedMovement(long time, int metaState,
                float accumulator, int negativeKeyCode, int positiveKeyCode) {
            while (accumulator <= -mConfigTickDistance) {
                sendKeyDownOrRepeat(time, negativeKeyCode, metaState);
                accumulator += mConfigTickDistance;
            }
            while (accumulator >= mConfigTickDistance) {
                sendKeyDownOrRepeat(time, positiveKeyCode, metaState);
                accumulator -= mConfigTickDistance;
            }
            return accumulator;
        }

        private void sendKeyDownOrRepeat(long time, int keyCode, int metaState) {
            if (mPendingKeyCode != keyCode) {
                sendKeyUp(time);
                mPendingKeyDownTime = time;
                mPendingKeyCode = keyCode;
                mPendingKeyRepeatCount = 0;
            } else {
                mPendingKeyRepeatCount += 1;
            }
            mPendingKeyMetaState = metaState;

            // Note: Normally we would pass FLAG_LONG_PRESS when the repeat count is 1
            // but it doesn't quite make sense when simulating the events in this way.
            if (LOCAL_DEBUG) {
                Log.d(LOCAL_TAG, "Sending key down: keyCode=" + mPendingKeyCode
                        + ", repeatCount=" + mPendingKeyRepeatCount
                        + ", metaState=" + Integer.toHexString(mPendingKeyMetaState));
            }
            enqueueInputEvent(new KeyEvent(mPendingKeyDownTime, time,
                    KeyEvent.ACTION_DOWN, mPendingKeyCode, mPendingKeyRepeatCount,
                    mPendingKeyMetaState, mCurrentDeviceId,
                    KeyEvent.FLAG_FALLBACK, mCurrentSource));
        }

        private void sendKeyUp(long time) {
            if (mPendingKeyCode != KeyEvent.KEYCODE_UNKNOWN) {
                if (LOCAL_DEBUG) {
                    Log.d(LOCAL_TAG, "Sending key up: keyCode=" + mPendingKeyCode
                            + ", metaState=" + Integer.toHexString(mPendingKeyMetaState));
                }
                enqueueInputEvent(new KeyEvent(mPendingKeyDownTime, time,
                        KeyEvent.ACTION_UP, mPendingKeyCode, 0, mPendingKeyMetaState,
                        mCurrentDeviceId, 0, KeyEvent.FLAG_FALLBACK,
                        mCurrentSource));
                mPendingKeyCode = KeyEvent.KEYCODE_UNKNOWN;
            }
        }

        private boolean startFling(long time, float vx, float vy) {
            if (LOCAL_DEBUG) {
                Log.d(LOCAL_TAG, "Considering fling: vx=" + vx + ", vy=" + vy
                        + ", min=" + mConfigMinFlingVelocity);
            }

            // Flings must be oriented in the same direction as the preceding movements.
            switch (mPendingKeyCode) {
                case KeyEvent.KEYCODE_DPAD_LEFT:
                    if (-vx >= mConfigMinFlingVelocity
                            && Math.abs(vy) < mConfigMinFlingVelocity) {
                        mFlingVelocity = -vx;
                        break;
                    }
                    return false;

                case KeyEvent.KEYCODE_DPAD_RIGHT:
                    if (vx >= mConfigMinFlingVelocity
                            && Math.abs(vy) < mConfigMinFlingVelocity) {
                        mFlingVelocity = vx;
                        break;
                    }
                    return false;

                case KeyEvent.KEYCODE_DPAD_UP:
                    if (-vy >= mConfigMinFlingVelocity
                            && Math.abs(vx) < mConfigMinFlingVelocity) {
                        mFlingVelocity = -vy;
                        break;
                    }
                    return false;

                case KeyEvent.KEYCODE_DPAD_DOWN:
                    if (vy >= mConfigMinFlingVelocity
                            && Math.abs(vx) < mConfigMinFlingVelocity) {
                        mFlingVelocity = vy;
                        break;
                    }
                    return false;
            }

            // Post the first fling event.
            mFlinging = postFling(time);
            return mFlinging;
        }

        private boolean postFling(long time) {
            // The idea here is to estimate the time when the pointer would have
            // traveled one tick distance unit given the current fling velocity.
            // This effect creates continuity of motion.
            if (mFlingVelocity >= mConfigMinFlingVelocity) {
                long delay = (long)(mConfigTickDistance / mFlingVelocity * 1000);
                postAtTime(mFlingRunnable, time + delay);
                if (LOCAL_DEBUG) {
                    Log.d(LOCAL_TAG, "Posted fling: velocity="
                            + mFlingVelocity + ", delay=" + delay
                            + ", keyCode=" + mPendingKeyCode);
                }
                return true;
            }
            return false;
        }

        private void cancelFling() {
            if (mFlinging) {
                removeCallbacks(mFlingRunnable);
                mFlinging = false;
            }
        }

        private final Runnable mFlingRunnable = new Runnable() {
            @Override
            public void run() {
                final long time = SystemClock.uptimeMillis();
                sendKeyDownOrRepeat(time, mPendingKeyCode, mPendingKeyMetaState);
                mFlingVelocity *= FLING_TICK_DECAY;
                if (!postFling(time)) {
                    mFlinging = false;
                    finishKeys(time);
                }
            }
        };
    }

    final class SyntheticKeyboardHandler {
        public void process(KeyEvent event) {
            if ((event.getFlags() & KeyEvent.FLAG_FALLBACK) != 0) {
                return;
            }

            final KeyCharacterMap kcm = event.getKeyCharacterMap();
            final int keyCode = event.getKeyCode();
            final int metaState = event.getMetaState();

            // Check for fallback actions specified by the key character map.
            KeyCharacterMap.FallbackAction fallbackAction =
                    kcm.getFallbackAction(keyCode, metaState);
            if (fallbackAction != null) {
                final int flags = event.getFlags() | KeyEvent.FLAG_FALLBACK;
                KeyEvent fallbackEvent = KeyEvent.obtain(
                        event.getDownTime(), event.getEventTime(),
                        event.getAction(), fallbackAction.keyCode,
                        event.getRepeatCount(), fallbackAction.metaState,
                        event.getDeviceId(), event.getScanCode(),
                        flags, event.getSource(), null);
                fallbackAction.recycle();
                enqueueInputEvent(fallbackEvent);
            }
        }
    }

    
Returns true if the key is used for keyboard navigation.
Params:
keyEvent – The key event.
Returns:
True if the key is used for keyboard navigation./**
     * Returns true if the key is used for keyboard navigation.
     * @param keyEvent The key event.
     * @return True if the key is used for keyboard navigation.
     */
    private static boolean isNavigationKey(KeyEvent keyEvent) {
        switch (keyEvent.getKeyCode()) {
        case KeyEvent.KEYCODE_DPAD_LEFT:
        case KeyEvent.KEYCODE_DPAD_RIGHT:
        case KeyEvent.KEYCODE_DPAD_UP:
        case KeyEvent.KEYCODE_DPAD_DOWN:
        case KeyEvent.KEYCODE_DPAD_CENTER:
        case KeyEvent.KEYCODE_PAGE_UP:
        case KeyEvent.KEYCODE_PAGE_DOWN:
        case KeyEvent.KEYCODE_MOVE_HOME:
        case KeyEvent.KEYCODE_MOVE_END:
        case KeyEvent.KEYCODE_TAB:
        case KeyEvent.KEYCODE_SPACE:
        case KeyEvent.KEYCODE_ENTER:
            return true;
        }
        return false;
    }

    
Returns true if the key is used for typing.
Params:
keyEvent – The key event.
Returns:
True if the key is used for typing./**
     * Returns true if the key is used for typing.
     * @param keyEvent The key event.
     * @return True if the key is used for typing.
     */
    private static boolean isTypingKey(KeyEvent keyEvent) {
        return keyEvent.getUnicodeChar() > 0;
    }

    
See if the key event means we should leave touch mode (and leave touch mode if so).
Params:
event – The key event.
Returns:
Whether this key event should be consumed (meaning the act of
  leaving touch mode alone is considered the event)./**
     * See if the key event means we should leave touch mode (and leave touch mode if so).
     * @param event The key event.
     * @return Whether this key event should be consumed (meaning the act of
     *   leaving touch mode alone is considered the event).
     */
    private boolean checkForLeavingTouchModeAndConsume(KeyEvent event) {
        // Only relevant in touch mode.
        if (!mAttachInfo.mInTouchMode) {
            return false;
        }

        // Only consider leaving touch mode on DOWN or MULTIPLE actions, never on UP.
        final int action = event.getAction();
        if (action != KeyEvent.ACTION_DOWN && action != KeyEvent.ACTION_MULTIPLE) {
            return false;
        }

        // Don't leave touch mode if the IME told us not to.
        if ((event.getFlags() & KeyEvent.FLAG_KEEP_TOUCH_MODE) != 0) {
            return false;
        }

        // If the key can be used for keyboard navigation then leave touch mode
        // and select a focused view if needed (in ensureTouchMode).
        // When a new focused view is selected, we consume the navigation key because
        // navigation doesn't make much sense unless a view already has focus so
        // the key's purpose is to set focus.
        if (isNavigationKey(event)) {
            return ensureTouchMode(false);
        }

        // If the key can be used for typing then leave touch mode
        // and select a focused view if needed (in ensureTouchMode).
        // Always allow the view to process the typing key.
        if (isTypingKey(event)) {
            ensureTouchMode(false);
            return false;
        }

        return false;
    }

    /* drag/drop */
    void setLocalDragState(Object obj) {
        mLocalDragState = obj;
    }

    private void handleDragEvent(DragEvent event) {
        // From the root, only drag start/end/location are dispatched.  entered/exited
        // are determined and dispatched by the viewgroup hierarchy, who then report
        // that back here for ultimate reporting back to the framework.
        if (mView != null && mAdded) {
            final int what = event.mAction;

            // Cache the drag description when the operation starts, then fill it in
            // on subsequent calls as a convenience
            if (what == DragEvent.ACTION_DRAG_STARTED) {
                mCurrentDragView = null;    // Start the current-recipient tracking
                mDragDescription = event.mClipDescription;
            } else {
                if (what == DragEvent.ACTION_DRAG_ENDED) {
                    mDragDescription = null;
                }
                event.mClipDescription = mDragDescription;
            }

            if (what == DragEvent.ACTION_DRAG_EXITED) {
                // A direct EXITED event means that the window manager knows we've just crossed
                // a window boundary, so the current drag target within this one must have
                // just been exited. Send the EXITED notification to the current drag view, if any.
                if (View.sCascadedDragDrop) {
                    mView.dispatchDragEnterExitInPreN(event);
                }
                setDragFocus(null, event);
            } else {
                // For events with a [screen] location, translate into window coordinates
                if ((what == DragEvent.ACTION_DRAG_LOCATION) || (what == DragEvent.ACTION_DROP)) {
                    mDragPoint.set(event.mX, event.mY);
                    if (mTranslator != null) {
                        mTranslator.translatePointInScreenToAppWindow(mDragPoint);
                    }

                    if (mCurScrollY != 0) {
                        mDragPoint.offset(0, mCurScrollY);
                    }

                    event.mX = mDragPoint.x;
                    event.mY = mDragPoint.y;
                }

                // Remember who the current drag target is pre-dispatch
                final View prevDragView = mCurrentDragView;

                if (what == DragEvent.ACTION_DROP && event.mClipData != null) {
                    event.mClipData.prepareToEnterProcess();
                }

                // Now dispatch the drag/drop event
                boolean result = mView.dispatchDragEvent(event);

                if (what == DragEvent.ACTION_DRAG_LOCATION && !event.mEventHandlerWasCalled) {
                    // If the LOCATION event wasn't delivered to any handler, no view now has a drag
                    // focus.
                    setDragFocus(null, event);
                }

                // If we changed apparent drag target, tell the OS about it
                if (prevDragView != mCurrentDragView) {
                    try {
                        if (prevDragView != null) {
                            mWindowSession.dragRecipientExited(mWindow);
                        }
                        if (mCurrentDragView != null) {
                            mWindowSession.dragRecipientEntered(mWindow);
                        }
                    } catch (RemoteException e) {
                        Slog.e(mTag, "Unable to note drag target change");
                    }
                }

                // Report the drop result when we're done
                if (what == DragEvent.ACTION_DROP) {
                    try {
                        Log.i(mTag, "Reporting drop result: " + result);
                        mWindowSession.reportDropResult(mWindow, result);
                    } catch (RemoteException e) {
                        Log.e(mTag, "Unable to report drop result");
                    }
                }

                // When the drag operation ends, reset drag-related state
                if (what == DragEvent.ACTION_DRAG_ENDED) {
                    mCurrentDragView = null;
                    setLocalDragState(null);
                    mAttachInfo.mDragToken = null;
                    if (mAttachInfo.mDragSurface != null) {
                        mAttachInfo.mDragSurface.release();
                        mAttachInfo.mDragSurface = null;
                    }
                }
            }
        }
        event.recycle();
    }

    public void handleDispatchSystemUiVisibilityChanged(SystemUiVisibilityInfo args) {
        if (mSeq != args.seq) {
            // The sequence has changed, so we need to update our value and make
            // sure to do a traversal afterward so the window manager is given our
            // most recent data.
            mSeq = args.seq;
            mAttachInfo.mForceReportNewAttributes = true;
            scheduleTraversals();
        }
        if (mView == null) return;
        if (args.localChanges != 0) {
            mView.updateLocalSystemUiVisibility(args.localValue, args.localChanges);
        }

        int visibility = args.globalVisibility&View.SYSTEM_UI_CLEARABLE_FLAGS;
        if (visibility != mAttachInfo.mGlobalSystemUiVisibility) {
            mAttachInfo.mGlobalSystemUiVisibility = visibility;
            mView.dispatchSystemUiVisibilityChanged(visibility);
        }
    }

    
Notify that the window title changed
/**
     * Notify that the window title changed
     */
    public void onWindowTitleChanged() {
        mAttachInfo.mForceReportNewAttributes = true;
    }

    public void handleDispatchWindowShown() {
        mAttachInfo.mTreeObserver.dispatchOnWindowShown();
    }

    public void handleRequestKeyboardShortcuts(IResultReceiver receiver, int deviceId) {
        Bundle data = new Bundle();
        ArrayList<KeyboardShortcutGroup> list = new ArrayList<>();
        if (mView != null) {
            mView.requestKeyboardShortcuts(list, deviceId);
        }
        data.putParcelableArrayList(WindowManager.PARCEL_KEY_SHORTCUTS_ARRAY, list);
        try {
            receiver.send(0, data);
        } catch (RemoteException e) {
        }
    }

    public void getLastTouchPoint(Point outLocation) {
        outLocation.x = (int) mLastTouchPoint.x;
        outLocation.y = (int) mLastTouchPoint.y;
    }

    public int getLastTouchSource() {
        return mLastTouchSource;
    }

    public void setDragFocus(View newDragTarget, DragEvent event) {
        if (mCurrentDragView != newDragTarget && !View.sCascadedDragDrop) {
            // Send EXITED and ENTERED notifications to the old and new drag focus views.

            final float tx = event.mX;
            final float ty = event.mY;
            final int action = event.mAction;
            final ClipData td = event.mClipData;
            // Position should not be available for ACTION_DRAG_ENTERED and ACTION_DRAG_EXITED.
            event.mX = 0;
            event.mY = 0;
            event.mClipData = null;

            if (mCurrentDragView != null) {
                event.mAction = DragEvent.ACTION_DRAG_EXITED;
                mCurrentDragView.callDragEventHandler(event);
            }

            if (newDragTarget != null) {
                event.mAction = DragEvent.ACTION_DRAG_ENTERED;
                newDragTarget.callDragEventHandler(event);
            }

            event.mAction = action;
            event.mX = tx;
            event.mY = ty;
            event.mClipData = td;
        }

        mCurrentDragView = newDragTarget;
    }

    private AudioManager getAudioManager() {
        if (mView == null) {
            throw new IllegalStateException("getAudioManager called when there is no mView");
        }
        if (mAudioManager == null) {
            mAudioManager = (AudioManager) mView.getContext().getSystemService(Context.AUDIO_SERVICE);
        }
        return mAudioManager;
    }

    private @Nullable AutofillManager getAutofillManager() {
        if (mView instanceof ViewGroup) {
            ViewGroup decorView = (ViewGroup) mView;
            if (decorView.getChildCount() > 0) {
                // We cannot use decorView's Context for querying AutofillManager: DecorView's
                // context is based on Application Context, it would allocate a different
                // AutofillManager instance.
                return decorView.getChildAt(0).getContext()
                        .getSystemService(AutofillManager.class);
            }
        }
        return null;
    }

    private boolean isAutofillUiShowing() {
        AutofillManager afm = getAutofillManager();
        if (afm == null) {
            return false;
        }
        return afm.isAutofillUiShowing();
    }

    public AccessibilityInteractionController getAccessibilityInteractionController() {
        if (mView == null) {
            throw new IllegalStateException("getAccessibilityInteractionController"
                    + " called when there is no mView");
        }
        if (mAccessibilityInteractionController == null) {
            mAccessibilityInteractionController = new AccessibilityInteractionController(this);
        }
        return mAccessibilityInteractionController;
    }

    private int relayoutWindow(WindowManager.LayoutParams params, int viewVisibility,
            boolean insetsPending) throws RemoteException {

        float appScale = mAttachInfo.mApplicationScale;
        boolean restore = false;
        if (params != null && mTranslator != null) {
            restore = true;
            params.backup();
            mTranslator.translateWindowLayout(params);
        }

        if (params != null) {
            if (DBG) Log.d(mTag, "WindowLayout in layoutWindow:" + params);

            if (mOrigWindowType != params.type) {
                // For compatibility with old apps, don't crash here.
                if (mTargetSdkVersion < Build.VERSION_CODES.ICE_CREAM_SANDWICH) {
                    Slog.w(mTag, "Window type can not be changed after "
                            + "the window is added; ignoring change of " + mView);
                    params.type = mOrigWindowType;
                }
            }
        }

        long frameNumber = -1;
        if (mSurface.isValid()) {
            frameNumber = mSurface.getNextFrameNumber();
        }

        int relayoutResult = mWindowSession.relayout(mWindow, mSeq, params,
                (int) (mView.getMeasuredWidth() * appScale + 0.5f),
                (int) (mView.getMeasuredHeight() * appScale + 0.5f), viewVisibility,
                insetsPending ? WindowManagerGlobal.RELAYOUT_INSETS_PENDING : 0, frameNumber,
                mWinFrame, mPendingOverscanInsets, mPendingContentInsets, mPendingVisibleInsets,
                mPendingStableInsets, mPendingOutsets, mPendingBackDropFrame, mPendingDisplayCutout,
                mPendingMergedConfiguration, mSurface);

        mPendingAlwaysConsumeNavBar =
                (relayoutResult & WindowManagerGlobal.RELAYOUT_RES_CONSUME_ALWAYS_NAV_BAR) != 0;

        if (restore) {
            params.restore();
        }

        if (mTranslator != null) {
            mTranslator.translateRectInScreenToAppWinFrame(mWinFrame);
            mTranslator.translateRectInScreenToAppWindow(mPendingOverscanInsets);
            mTranslator.translateRectInScreenToAppWindow(mPendingContentInsets);
            mTranslator.translateRectInScreenToAppWindow(mPendingVisibleInsets);
            mTranslator.translateRectInScreenToAppWindow(mPendingStableInsets);
        }
        return relayoutResult;
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public void playSoundEffect(int effectId) {
        checkThread();

        try {
            final AudioManager audioManager = getAudioManager();

            switch (effectId) {
                case SoundEffectConstants.CLICK:
                    audioManager.playSoundEffect(AudioManager.FX_KEY_CLICK);
                    return;
                case SoundEffectConstants.NAVIGATION_DOWN:
                    audioManager.playSoundEffect(AudioManager.FX_FOCUS_NAVIGATION_DOWN);
                    return;
                case SoundEffectConstants.NAVIGATION_LEFT:
                    audioManager.playSoundEffect(AudioManager.FX_FOCUS_NAVIGATION_LEFT);
                    return;
                case SoundEffectConstants.NAVIGATION_RIGHT:
                    audioManager.playSoundEffect(AudioManager.FX_FOCUS_NAVIGATION_RIGHT);
                    return;
                case SoundEffectConstants.NAVIGATION_UP:
                    audioManager.playSoundEffect(AudioManager.FX_FOCUS_NAVIGATION_UP);
                    return;
                default:
                    throw new IllegalArgumentException("unknown effect id " + effectId +
                            " not defined in " + SoundEffectConstants.class.getCanonicalName());
            }
        } catch (IllegalStateException e) {
            // Exception thrown by getAudioManager() when mView is null
            Log.e(mTag, "FATAL EXCEPTION when attempting to play sound effect: " + e);
            e.printStackTrace();
        }
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public boolean performHapticFeedback(int effectId, boolean always) {
        try {
            return mWindowSession.performHapticFeedback(mWindow, effectId, always);
        } catch (RemoteException e) {
            return false;
        }
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public View focusSearch(View focused, int direction) {
        checkThread();
        if (!(mView instanceof ViewGroup)) {
            return null;
        }
        return FocusFinder.getInstance().findNextFocus((ViewGroup) mView, focused, direction);
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    @Override
    public View keyboardNavigationClusterSearch(View currentCluster,
            @FocusDirection int direction) {
        checkThread();
        return FocusFinder.getInstance().findNextKeyboardNavigationCluster(
                mView, currentCluster, direction);
    }

    public void debug() {
        mView.debug();
    }

    public void dump(String prefix, FileDescriptor fd, PrintWriter writer, String[] args) {
        String innerPrefix = prefix + "  ";
        writer.print(prefix); writer.println("ViewRoot:");
        writer.print(innerPrefix); writer.print("mAdded="); writer.print(mAdded);
                writer.print(" mRemoved="); writer.println(mRemoved);
        writer.print(innerPrefix); writer.print("mConsumeBatchedInputScheduled=");
                writer.println(mConsumeBatchedInputScheduled);
        writer.print(innerPrefix); writer.print("mConsumeBatchedInputImmediatelyScheduled=");
                writer.println(mConsumeBatchedInputImmediatelyScheduled);
        writer.print(innerPrefix); writer.print("mPendingInputEventCount=");
                writer.println(mPendingInputEventCount);
        writer.print(innerPrefix); writer.print("mProcessInputEventsScheduled=");
                writer.println(mProcessInputEventsScheduled);
        writer.print(innerPrefix); writer.print("mTraversalScheduled=");
                writer.print(mTraversalScheduled);
        writer.print(innerPrefix); writer.print("mIsAmbientMode=");
                writer.print(mIsAmbientMode);
        if (mTraversalScheduled) {
            writer.print(" (barrier="); writer.print(mTraversalBarrier); writer.println(")");
        } else {
            writer.println();
        }
        mFirstInputStage.dump(innerPrefix, writer);

        mChoreographer.dump(prefix, writer);

        writer.print(prefix); writer.println("View Hierarchy:");
        dumpViewHierarchy(innerPrefix, writer, mView);
    }

    private void dumpViewHierarchy(String prefix, PrintWriter writer, View view) {
        writer.print(prefix);
        if (view == null) {
            writer.println("null");
            return;
        }
        writer.println(view.toString());
        if (!(view instanceof ViewGroup)) {
            return;
        }
        ViewGroup grp = (ViewGroup)view;
        final int N = grp.getChildCount();
        if (N <= 0) {
            return;
        }
        prefix = prefix + "  ";
        for (int i=0; i<N; i++) {
            dumpViewHierarchy(prefix, writer, grp.getChildAt(i));
        }
    }

    public void dumpGfxInfo(int[] info) {
        info[0] = info[1] = 0;
        if (mView != null) {
            getGfxInfo(mView, info);
        }
    }

    private static void getGfxInfo(View view, int[] info) {
        RenderNode renderNode = view.mRenderNode;
        info[0]++;
        if (renderNode != null) {
            info[1] += renderNode.getDebugSize();
        }

        if (view instanceof ViewGroup) {
            ViewGroup group = (ViewGroup) view;

            int count = group.getChildCount();
            for (int i = 0; i < count; i++) {
                getGfxInfo(group.getChildAt(i), info);
            }
        }
    }

    
Params:
immediate – True, do now if not in traversal. False, put on queue and do later.
Returns:
True, request has been queued. False, request has been completed./**
     * @param immediate True, do now if not in traversal. False, put on queue and do later.
     * @return True, request has been queued. False, request has been completed.
     */
    boolean die(boolean immediate) {
        // Make sure we do execute immediately if we are in the middle of a traversal or the damage
        // done by dispatchDetachedFromWindow will cause havoc on return.
        if (immediate && !mIsInTraversal) {
            doDie();
            return false;
        }

        if (!mIsDrawing) {
            destroyHardwareRenderer();
        } else {
            Log.e(mTag, "Attempting to destroy the window while drawing!\n" +
                    "  window=" + this + ", title=" + mWindowAttributes.getTitle());
        }
        mHandler.sendEmptyMessage(MSG_DIE);
        return true;
    }

    void doDie() {
        checkThread();
        if (LOCAL_LOGV) Log.v(mTag, "DIE in " + this + " of " + mSurface);
        synchronized (this) {
            if (mRemoved) {
                return;
            }
            mRemoved = true;
            if (mAdded) {
                dispatchDetachedFromWindow();
            }

            if (mAdded && !mFirst) {
                destroyHardwareRenderer();

                if (mView != null) {
                    int viewVisibility = mView.getVisibility();
                    boolean viewVisibilityChanged = mViewVisibility != viewVisibility;
                    if (mWindowAttributesChanged || viewVisibilityChanged) {
                        // If layout params have been changed, first give them
                        // to the window manager to make sure it has the correct
                        // animation info.
                        try {
                            if ((relayoutWindow(mWindowAttributes, viewVisibility, false)
                                    & WindowManagerGlobal.RELAYOUT_RES_FIRST_TIME) != 0) {
                                mWindowSession.finishDrawing(mWindow);
                            }
                        } catch (RemoteException e) {
                        }
                    }

                    mSurface.release();
                }
            }

            mAdded = false;
        }
        WindowManagerGlobal.getInstance().doRemoveView(this);
    }

    public void requestUpdateConfiguration(Configuration config) {
        Message msg = mHandler.obtainMessage(MSG_UPDATE_CONFIGURATION, config);
        mHandler.sendMessage(msg);
    }

    public void loadSystemProperties() {
        mHandler.post(new Runnable() {
            @Override
            public void run() {
                // Profiling
                mProfileRendering = SystemProperties.getBoolean(PROPERTY_PROFILE_RENDERING, false);
                profileRendering(mAttachInfo.mHasWindowFocus);

                // Hardware rendering
                if (mAttachInfo.mThreadedRenderer != null) {
                    if (mAttachInfo.mThreadedRenderer.loadSystemProperties()) {
                        invalidate();
                    }
                }

                // Layout debugging
                boolean layout = SystemProperties.getBoolean(View.DEBUG_LAYOUT_PROPERTY, false);
                if (layout != mAttachInfo.mDebugLayout) {
                    mAttachInfo.mDebugLayout = layout;
                    if (!mHandler.hasMessages(MSG_INVALIDATE_WORLD)) {
                        mHandler.sendEmptyMessageDelayed(MSG_INVALIDATE_WORLD, 200);
                    }
                }
            }
        });
    }

    private void destroyHardwareRenderer() {
        ThreadedRenderer hardwareRenderer = mAttachInfo.mThreadedRenderer;

        if (hardwareRenderer != null) {
            if (mView != null) {
                hardwareRenderer.destroyHardwareResources(mView);
            }
            hardwareRenderer.destroy();
            hardwareRenderer.setRequested(false);

            mAttachInfo.mThreadedRenderer = null;
            mAttachInfo.mHardwareAccelerated = false;
        }
    }

    private void dispatchResized(Rect frame, Rect overscanInsets, Rect contentInsets,
            Rect visibleInsets, Rect stableInsets, Rect outsets, boolean reportDraw,
            MergedConfiguration mergedConfiguration, Rect backDropFrame, boolean forceLayout,
            boolean alwaysConsumeNavBar, int displayId,
            DisplayCutout.ParcelableWrapper displayCutout) {
        if (DEBUG_LAYOUT) Log.v(mTag, "Resizing " + this + ": frame=" + frame.toShortString()
                + " contentInsets=" + contentInsets.toShortString()
                + " visibleInsets=" + visibleInsets.toShortString()
                + " reportDraw=" + reportDraw
                + " backDropFrame=" + backDropFrame);

        // Tell all listeners that we are resizing the window so that the chrome can get
        // updated as fast as possible on a separate thread,
        if (mDragResizing && mUseMTRenderer) {
            boolean fullscreen = frame.equals(backDropFrame);
            synchronized (mWindowCallbacks) {
                for (int i = mWindowCallbacks.size() - 1; i >= 0; i--) {
                    mWindowCallbacks.get(i).onWindowSizeIsChanging(backDropFrame, fullscreen,
                            visibleInsets, stableInsets);
                }
            }
        }

        Message msg = mHandler.obtainMessage(reportDraw ? MSG_RESIZED_REPORT : MSG_RESIZED);
        if (mTranslator != null) {
            mTranslator.translateRectInScreenToAppWindow(frame);
            mTranslator.translateRectInScreenToAppWindow(overscanInsets);
            mTranslator.translateRectInScreenToAppWindow(contentInsets);
            mTranslator.translateRectInScreenToAppWindow(visibleInsets);
        }
        SomeArgs args = SomeArgs.obtain();
        final boolean sameProcessCall = (Binder.getCallingPid() == android.os.Process.myPid());
        args.arg1 = sameProcessCall ? new Rect(frame) : frame;
        args.arg2 = sameProcessCall ? new Rect(contentInsets) : contentInsets;
        args.arg3 = sameProcessCall ? new Rect(visibleInsets) : visibleInsets;
        args.arg4 = sameProcessCall && mergedConfiguration != null
                ? new MergedConfiguration(mergedConfiguration) : mergedConfiguration;
        args.arg5 = sameProcessCall ? new Rect(overscanInsets) : overscanInsets;
        args.arg6 = sameProcessCall ? new Rect(stableInsets) : stableInsets;
        args.arg7 = sameProcessCall ? new Rect(outsets) : outsets;
        args.arg8 = sameProcessCall ? new Rect(backDropFrame) : backDropFrame;
        args.arg9 = displayCutout.get(); // DisplayCutout is immutable.
        args.argi1 = forceLayout ? 1 : 0;
        args.argi2 = alwaysConsumeNavBar ? 1 : 0;
        args.argi3 = displayId;
        msg.obj = args;
        mHandler.sendMessage(msg);
    }

    public void dispatchMoved(int newX, int newY) {
        if (DEBUG_LAYOUT) Log.v(mTag, "Window moved " + this + ": newX=" + newX + " newY=" + newY);
        if (mTranslator != null) {
            PointF point = new PointF(newX, newY);
            mTranslator.translatePointInScreenToAppWindow(point);
            newX = (int) (point.x + 0.5);
            newY = (int) (point.y + 0.5);
        }
        Message msg = mHandler.obtainMessage(MSG_WINDOW_MOVED, newX, newY);
        mHandler.sendMessage(msg);
    }

    
Represents a pending input event that is waiting in a queue. Input events are processed in serial order by the timestamp specified by InputEvent.getEventTimeNano(). In general, the input dispatcher delivers one input event to the application at a time and waits for the application to finish handling it before delivering the next one. However, because the application or IME can synthesize and inject multiple key events at a time without going through the input dispatcher, we end up needing a queue on the application's side. /**
     * Represents a pending input event that is waiting in a queue.
     *
     * Input events are processed in serial order by the timestamp specified by
     * {@link InputEvent#getEventTimeNano()}.  In general, the input dispatcher delivers
     * one input event to the application at a time and waits for the application
     * to finish handling it before delivering the next one.
     *
     * However, because the application or IME can synthesize and inject multiple
     * key events at a time without going through the input dispatcher, we end up
     * needing a queue on the application's side.
     */
    private static final class QueuedInputEvent {
        public static final int FLAG_DELIVER_POST_IME = 1 << 0;
        public static final int FLAG_DEFERRED = 1 << 1;
        public static final int FLAG_FINISHED = 1 << 2;
        public static final int FLAG_FINISHED_HANDLED = 1 << 3;
        public static final int FLAG_RESYNTHESIZED = 1 << 4;
        public static final int FLAG_UNHANDLED = 1 << 5;

        public QueuedInputEvent mNext;

        public InputEvent mEvent;
        public InputEventReceiver mReceiver;
        public int mFlags;

        public boolean shouldSkipIme() {
            if ((mFlags & FLAG_DELIVER_POST_IME) != 0) {
                return true;
            }
            return mEvent instanceof MotionEvent
                    && (mEvent.isFromSource(InputDevice.SOURCE_CLASS_POINTER)
                        || mEvent.isFromSource(InputDevice.SOURCE_ROTARY_ENCODER));
        }

        public boolean shouldSendToSynthesizer() {
            if ((mFlags & FLAG_UNHANDLED) != 0) {
                return true;
            }

            return false;
        }

        @Override
        public String toString() {
            StringBuilder sb = new StringBuilder("QueuedInputEvent{flags=");
            boolean hasPrevious = false;
            hasPrevious = flagToString("DELIVER_POST_IME", FLAG_DELIVER_POST_IME, hasPrevious, sb);
            hasPrevious = flagToString("DEFERRED", FLAG_DEFERRED, hasPrevious, sb);
            hasPrevious = flagToString("FINISHED", FLAG_FINISHED, hasPrevious, sb);
            hasPrevious = flagToString("FINISHED_HANDLED", FLAG_FINISHED_HANDLED, hasPrevious, sb);
            hasPrevious = flagToString("RESYNTHESIZED", FLAG_RESYNTHESIZED, hasPrevious, sb);
            hasPrevious = flagToString("UNHANDLED", FLAG_UNHANDLED, hasPrevious, sb);
            if (!hasPrevious) {
                sb.append("0");
            }
            sb.append(", hasNextQueuedEvent=" + (mEvent != null ? "true" : "false"));
            sb.append(", hasInputEventReceiver=" + (mReceiver != null ? "true" : "false"));
            sb.append(", mEvent=" + mEvent + "}");
            return sb.toString();
        }

        private boolean flagToString(String name, int flag,
                boolean hasPrevious, StringBuilder sb) {
            if ((mFlags & flag) != 0) {
                if (hasPrevious) {
                    sb.append("|");
                }
                sb.append(name);
                return true;
            }
            return hasPrevious;
        }
    }

    private QueuedInputEvent obtainQueuedInputEvent(InputEvent event,
            InputEventReceiver receiver, int flags) {
        QueuedInputEvent q = mQueuedInputEventPool;
        if (q != null) {
            mQueuedInputEventPoolSize -= 1;
            mQueuedInputEventPool = q.mNext;
            q.mNext = null;
        } else {
            q = new QueuedInputEvent();
        }

        q.mEvent = event;
        q.mReceiver = receiver;
        q.mFlags = flags;
        return q;
    }

    private void recycleQueuedInputEvent(QueuedInputEvent q) {
        q.mEvent = null;
        q.mReceiver = null;

        if (mQueuedInputEventPoolSize < MAX_QUEUED_INPUT_EVENT_POOL_SIZE) {
            mQueuedInputEventPoolSize += 1;
            q.mNext = mQueuedInputEventPool;
            mQueuedInputEventPool = q;
        }
    }

    void enqueueInputEvent(InputEvent event) {
        enqueueInputEvent(event, null, 0, false);
    }

    void enqueueInputEvent(InputEvent event,
            InputEventReceiver receiver, int flags, boolean processImmediately) {
        adjustInputEventForCompatibility(event);
        QueuedInputEvent q = obtainQueuedInputEvent(event, receiver, flags);

        // Always enqueue the input event in order, regardless of its time stamp.
        // We do this because the application or the IME may inject key events
        // in response to touch events and we want to ensure that the injected keys
        // are processed in the order they were received and we cannot trust that
        // the time stamp of injected events are monotonic.
        QueuedInputEvent last = mPendingInputEventTail;
        if (last == null) {
            mPendingInputEventHead = q;
            mPendingInputEventTail = q;
        } else {
            last.mNext = q;
            mPendingInputEventTail = q;
        }
        mPendingInputEventCount += 1;
        Trace.traceCounter(Trace.TRACE_TAG_INPUT, mPendingInputEventQueueLengthCounterName,
                mPendingInputEventCount);

        if (processImmediately) {
            doProcessInputEvents();
        } else {
            scheduleProcessInputEvents();
        }
    }

    private void scheduleProcessInputEvents() {
        if (!mProcessInputEventsScheduled) {
            mProcessInputEventsScheduled = true;
            Message msg = mHandler.obtainMessage(MSG_PROCESS_INPUT_EVENTS);
            msg.setAsynchronous(true);
            mHandler.sendMessage(msg);
        }
    }

    void doProcessInputEvents() {
        // Deliver all pending input events in the queue.
        while (mPendingInputEventHead != null) {
            QueuedInputEvent q = mPendingInputEventHead;
            mPendingInputEventHead = q.mNext;
            if (mPendingInputEventHead == null) {
                mPendingInputEventTail = null;
            }
            q.mNext = null;

            mPendingInputEventCount -= 1;
            Trace.traceCounter(Trace.TRACE_TAG_INPUT, mPendingInputEventQueueLengthCounterName,
                    mPendingInputEventCount);

            long eventTime = q.mEvent.getEventTimeNano();
            long oldestEventTime = eventTime;
            if (q.mEvent instanceof MotionEvent) {
                MotionEvent me = (MotionEvent)q.mEvent;
                if (me.getHistorySize() > 0) {
                    oldestEventTime = me.getHistoricalEventTimeNano(0);
                }
            }
            mChoreographer.mFrameInfo.updateInputEventTime(eventTime, oldestEventTime);

            deliverInputEvent(q);
        }

        // We are done processing all input events that we can process right now
        // so we can clear the pending flag immediately.
        if (mProcessInputEventsScheduled) {
            mProcessInputEventsScheduled = false;
            mHandler.removeMessages(MSG_PROCESS_INPUT_EVENTS);
        }
    }

    private void deliverInputEvent(QueuedInputEvent q) {
        Trace.asyncTraceBegin(Trace.TRACE_TAG_VIEW, "deliverInputEvent",
                q.mEvent.getSequenceNumber());
        if (mInputEventConsistencyVerifier != null) {
            mInputEventConsistencyVerifier.onInputEvent(q.mEvent, 0);
        }

        InputStage stage;
        if (q.shouldSendToSynthesizer()) {
            stage = mSyntheticInputStage;
        } else {
            stage = q.shouldSkipIme() ? mFirstPostImeInputStage : mFirstInputStage;
        }

        if (q.mEvent instanceof KeyEvent) {
            mUnhandledKeyManager.preDispatch((KeyEvent) q.mEvent);
        }

        if (stage != null) {
            handleWindowFocusChanged();
            stage.deliver(q);
        } else {
            finishInputEvent(q);
        }
    }

    private void finishInputEvent(QueuedInputEvent q) {
        Trace.asyncTraceEnd(Trace.TRACE_TAG_VIEW, "deliverInputEvent",
                q.mEvent.getSequenceNumber());

        if (q.mReceiver != null) {
            boolean handled = (q.mFlags & QueuedInputEvent.FLAG_FINISHED_HANDLED) != 0;
            q.mReceiver.finishInputEvent(q.mEvent, handled);
        } else {
            q.mEvent.recycleIfNeededAfterDispatch();
        }

        recycleQueuedInputEvent(q);
    }

    private void adjustInputEventForCompatibility(InputEvent e) {
        if (mTargetSdkVersion < Build.VERSION_CODES.M && e instanceof MotionEvent) {
            MotionEvent motion = (MotionEvent) e;
            final int mask =
                MotionEvent.BUTTON_STYLUS_PRIMARY | MotionEvent.BUTTON_STYLUS_SECONDARY;
            final int buttonState = motion.getButtonState();
            final int compatButtonState = (buttonState & mask) >> 4;
            if (compatButtonState != 0) {
                motion.setButtonState(buttonState | compatButtonState);
            }
        }
    }

    static boolean isTerminalInputEvent(InputEvent event) {
        if (event instanceof KeyEvent) {
            final KeyEvent keyEvent = (KeyEvent)event;
            return keyEvent.getAction() == KeyEvent.ACTION_UP;
        } else {
            final MotionEvent motionEvent = (MotionEvent)event;
            final int action = motionEvent.getAction();
            return action == MotionEvent.ACTION_UP
                    || action == MotionEvent.ACTION_CANCEL
                    || action == MotionEvent.ACTION_HOVER_EXIT;
        }
    }

    void scheduleConsumeBatchedInput() {
        if (!mConsumeBatchedInputScheduled) {
            mConsumeBatchedInputScheduled = true;
            mChoreographer.postCallback(Choreographer.CALLBACK_INPUT,
                    mConsumedBatchedInputRunnable, null);
        }
    }

    void unscheduleConsumeBatchedInput() {
        if (mConsumeBatchedInputScheduled) {
            mConsumeBatchedInputScheduled = false;
            mChoreographer.removeCallbacks(Choreographer.CALLBACK_INPUT,
                    mConsumedBatchedInputRunnable, null);
        }
    }

    void scheduleConsumeBatchedInputImmediately() {
        if (!mConsumeBatchedInputImmediatelyScheduled) {
            unscheduleConsumeBatchedInput();
            mConsumeBatchedInputImmediatelyScheduled = true;
            mHandler.post(mConsumeBatchedInputImmediatelyRunnable);
        }
    }

    void doConsumeBatchedInput(long frameTimeNanos) {
        if (mConsumeBatchedInputScheduled) {
            mConsumeBatchedInputScheduled = false;
            if (mInputEventReceiver != null) {
                if (mInputEventReceiver.consumeBatchedInputEvents(frameTimeNanos)
                        && frameTimeNanos != -1) {
                    // If we consumed a batch here, we want to go ahead and schedule the
                    // consumption of batched input events on the next frame. Otherwise, we would
                    // wait until we have more input events pending and might get starved by other
                    // things occurring in the process. If the frame time is -1, however, then
                    // we're in a non-batching mode, so there's no need to schedule this.
                    scheduleConsumeBatchedInput();
                }
            }
            doProcessInputEvents();
        }
    }

    final class TraversalRunnable implements Runnable {
        @Override
        public void run() {
            doTraversal();
        }
    }
    final TraversalRunnable mTraversalRunnable = new TraversalRunnable();

    final class WindowInputEventReceiver extends InputEventReceiver {
        public WindowInputEventReceiver(InputChannel inputChannel, Looper looper) {
            super(inputChannel, looper);
        }

        @Override
        public void onInputEvent(InputEvent event, int displayId) {
            enqueueInputEvent(event, this, 0, true);
        }

        @Override
        public void onBatchedInputEventPending() {
            if (mUnbufferedInputDispatch) {
                super.onBatchedInputEventPending();
            } else {
                scheduleConsumeBatchedInput();
            }
        }

        @Override
        public void dispose() {
            unscheduleConsumeBatchedInput();
            super.dispose();
        }
    }
    WindowInputEventReceiver mInputEventReceiver;

    final class ConsumeBatchedInputRunnable implements Runnable {
        @Override
        public void run() {
            doConsumeBatchedInput(mChoreographer.getFrameTimeNanos());
        }
    }
    final ConsumeBatchedInputRunnable mConsumedBatchedInputRunnable =
            new ConsumeBatchedInputRunnable();
    boolean mConsumeBatchedInputScheduled;

    final class ConsumeBatchedInputImmediatelyRunnable implements Runnable {
        @Override
        public void run() {
            doConsumeBatchedInput(-1);
        }
    }
    final ConsumeBatchedInputImmediatelyRunnable mConsumeBatchedInputImmediatelyRunnable =
            new ConsumeBatchedInputImmediatelyRunnable();
    boolean mConsumeBatchedInputImmediatelyScheduled;

    final class InvalidateOnAnimationRunnable implements Runnable {
        private boolean mPosted;
        private final ArrayList<View> mViews = new ArrayList<View>();
        private final ArrayList<AttachInfo.InvalidateInfo> mViewRects =
                new ArrayList<AttachInfo.InvalidateInfo>();
        private View[] mTempViews;
        private AttachInfo.InvalidateInfo[] mTempViewRects;

        public void addView(View view) {
            synchronized (this) {
                mViews.add(view);
                postIfNeededLocked();
            }
        }

        public void addViewRect(AttachInfo.InvalidateInfo info) {
            synchronized (this) {
                mViewRects.add(info);
                postIfNeededLocked();
            }
        }

        public void removeView(View view) {
            synchronized (this) {
                mViews.remove(view);

                for (int i = mViewRects.size(); i-- > 0; ) {
                    AttachInfo.InvalidateInfo info = mViewRects.get(i);
                    if (info.target == view) {
                        mViewRects.remove(i);
                        info.recycle();
                    }
                }

                if (mPosted && mViews.isEmpty() && mViewRects.isEmpty()) {
                    mChoreographer.removeCallbacks(Choreographer.CALLBACK_ANIMATION, this, null);
                    mPosted = false;
                }
            }
        }

        @Override
        public void run() {
            final int viewCount;
            final int viewRectCount;
            synchronized (this) {
                mPosted = false;

                viewCount = mViews.size();
                if (viewCount != 0) {
                    mTempViews = mViews.toArray(mTempViews != null
                            ? mTempViews : new View[viewCount]);
                    mViews.clear();
                }

                viewRectCount = mViewRects.size();
                if (viewRectCount != 0) {
                    mTempViewRects = mViewRects.toArray(mTempViewRects != null
                            ? mTempViewRects : new AttachInfo.InvalidateInfo[viewRectCount]);
                    mViewRects.clear();
                }
            }

            for (int i = 0; i < viewCount; i++) {
                mTempViews[i].invalidate();
                mTempViews[i] = null;
            }

            for (int i = 0; i < viewRectCount; i++) {
                final View.AttachInfo.InvalidateInfo info = mTempViewRects[i];
                info.target.invalidate(info.left, info.top, info.right, info.bottom);
                info.recycle();
            }
        }

        private void postIfNeededLocked() {
            if (!mPosted) {
                mChoreographer.postCallback(Choreographer.CALLBACK_ANIMATION, this, null);
                mPosted = true;
            }
        }
    }
    final InvalidateOnAnimationRunnable mInvalidateOnAnimationRunnable =
            new InvalidateOnAnimationRunnable();

    public void dispatchInvalidateDelayed(View view, long delayMilliseconds) {
        Message msg = mHandler.obtainMessage(MSG_INVALIDATE, view);
        mHandler.sendMessageDelayed(msg, delayMilliseconds);
    }

    public void dispatchInvalidateRectDelayed(AttachInfo.InvalidateInfo info,
            long delayMilliseconds) {
        final Message msg = mHandler.obtainMessage(MSG_INVALIDATE_RECT, info);
        mHandler.sendMessageDelayed(msg, delayMilliseconds);
    }

    public void dispatchInvalidateOnAnimation(View view) {
        mInvalidateOnAnimationRunnable.addView(view);
    }

    public void dispatchInvalidateRectOnAnimation(AttachInfo.InvalidateInfo info) {
        mInvalidateOnAnimationRunnable.addViewRect(info);
    }

    public void cancelInvalidate(View view) {
        mHandler.removeMessages(MSG_INVALIDATE, view);
        // fixme: might leak the AttachInfo.InvalidateInfo objects instead of returning
        // them to the pool
        mHandler.removeMessages(MSG_INVALIDATE_RECT, view);
        mInvalidateOnAnimationRunnable.removeView(view);
    }

    public void dispatchInputEvent(InputEvent event) {
        dispatchInputEvent(event, null);
    }

    public void dispatchInputEvent(InputEvent event, InputEventReceiver receiver) {
        SomeArgs args = SomeArgs.obtain();
        args.arg1 = event;
        args.arg2 = receiver;
        Message msg = mHandler.obtainMessage(MSG_DISPATCH_INPUT_EVENT, args);
        msg.setAsynchronous(true);
        mHandler.sendMessage(msg);
    }

    public void synthesizeInputEvent(InputEvent event) {
        Message msg = mHandler.obtainMessage(MSG_SYNTHESIZE_INPUT_EVENT, event);
        msg.setAsynchronous(true);
        mHandler.sendMessage(msg);
    }

    public void dispatchKeyFromIme(KeyEvent event) {
        Message msg = mHandler.obtainMessage(MSG_DISPATCH_KEY_FROM_IME, event);
        msg.setAsynchronous(true);
        mHandler.sendMessage(msg);
    }

    public void dispatchKeyFromAutofill(KeyEvent event) {
        Message msg = mHandler.obtainMessage(MSG_DISPATCH_KEY_FROM_AUTOFILL, event);
        msg.setAsynchronous(true);
        mHandler.sendMessage(msg);
    }

    
Reinject unhandled InputEvents in order to synthesize fallbacks events. Note that it is the responsibility of the caller of this API to recycle the InputEvent it passes in. /**
     * Reinject unhandled {@link InputEvent}s in order to synthesize fallbacks events.
     *
     * Note that it is the responsibility of the caller of this API to recycle the InputEvent it
     * passes in.
     */
    public void dispatchUnhandledInputEvent(InputEvent event) {
        if (event instanceof MotionEvent) {
            event = MotionEvent.obtain((MotionEvent) event);
        }
        synthesizeInputEvent(event);
    }

    public void dispatchAppVisibility(boolean visible) {
        Message msg = mHandler.obtainMessage(MSG_DISPATCH_APP_VISIBILITY);
        msg.arg1 = visible ? 1 : 0;
        mHandler.sendMessage(msg);
    }

    public void dispatchGetNewSurface() {
        Message msg = mHandler.obtainMessage(MSG_DISPATCH_GET_NEW_SURFACE);
        mHandler.sendMessage(msg);
    }

    public void windowFocusChanged(boolean hasFocus, boolean inTouchMode) {
        synchronized (this) {
            mWindowFocusChanged = true;
            mUpcomingWindowFocus = hasFocus;
            mUpcomingInTouchMode = inTouchMode;
        }
        Message msg = Message.obtain();
        msg.what = MSG_WINDOW_FOCUS_CHANGED;
        mHandler.sendMessage(msg);
    }

    public void dispatchWindowShown() {
        mHandler.sendEmptyMessage(MSG_DISPATCH_WINDOW_SHOWN);
    }

    public void dispatchCloseSystemDialogs(String reason) {
        Message msg = Message.obtain();
        msg.what = MSG_CLOSE_SYSTEM_DIALOGS;
        msg.obj = reason;
        mHandler.sendMessage(msg);
    }

    public void dispatchDragEvent(DragEvent event) {
        final int what;
        if (event.getAction() == DragEvent.ACTION_DRAG_LOCATION) {
            what = MSG_DISPATCH_DRAG_LOCATION_EVENT;
            mHandler.removeMessages(what);
        } else {
            what = MSG_DISPATCH_DRAG_EVENT;
        }
        Message msg = mHandler.obtainMessage(what, event);
        mHandler.sendMessage(msg);
    }

    public void updatePointerIcon(float x, float y) {
        final int what = MSG_UPDATE_POINTER_ICON;
        mHandler.removeMessages(what);
        final long now = SystemClock.uptimeMillis();
        final MotionEvent event = MotionEvent.obtain(
                0, now, MotionEvent.ACTION_HOVER_MOVE, x, y, 0);
        Message msg = mHandler.obtainMessage(what, event);
        mHandler.sendMessage(msg);
    }

    public void dispatchSystemUiVisibilityChanged(int seq, int globalVisibility,
            int localValue, int localChanges) {
        SystemUiVisibilityInfo args = new SystemUiVisibilityInfo();
        args.seq = seq;
        args.globalVisibility = globalVisibility;
        args.localValue = localValue;
        args.localChanges = localChanges;
        mHandler.sendMessage(mHandler.obtainMessage(MSG_DISPATCH_SYSTEM_UI_VISIBILITY, args));
    }

    public void dispatchCheckFocus() {
        if (!mHandler.hasMessages(MSG_CHECK_FOCUS)) {
            // This will result in a call to checkFocus() below.
            mHandler.sendEmptyMessage(MSG_CHECK_FOCUS);
        }
    }

    public void dispatchRequestKeyboardShortcuts(IResultReceiver receiver, int deviceId) {
        mHandler.obtainMessage(
                MSG_REQUEST_KEYBOARD_SHORTCUTS, deviceId, 0, receiver).sendToTarget();
    }

    public void dispatchPointerCaptureChanged(boolean on) {
        final int what = MSG_POINTER_CAPTURE_CHANGED;
        mHandler.removeMessages(what);
        Message msg = mHandler.obtainMessage(what);
        msg.arg1 = on ? 1 : 0;
        mHandler.sendMessage(msg);
    }

    
Post a callback to send a AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED event. This event is send at most once every ViewConfiguration.getSendRecurringAccessibilityEventsInterval(). /**
     * Post a callback to send a
     * {@link AccessibilityEvent#TYPE_WINDOW_CONTENT_CHANGED} event.
     * This event is send at most once every
     * {@link ViewConfiguration#getSendRecurringAccessibilityEventsInterval()}.
     */
    private void postSendWindowContentChangedCallback(View source, int changeType) {
        if (mSendWindowContentChangedAccessibilityEvent == null) {
            mSendWindowContentChangedAccessibilityEvent =
                new SendWindowContentChangedAccessibilityEvent();
        }
        mSendWindowContentChangedAccessibilityEvent.runOrPost(source, changeType);
    }

    
Remove a posted callback to send a AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED event. /**
     * Remove a posted callback to send a
     * {@link AccessibilityEvent#TYPE_WINDOW_CONTENT_CHANGED} event.
     */
    private void removeSendWindowContentChangedCallback() {
        if (mSendWindowContentChangedAccessibilityEvent != null) {
            mHandler.removeCallbacks(mSendWindowContentChangedAccessibilityEvent);
        }
    }

    @Override
    public boolean showContextMenuForChild(View originalView) {
        return false;
    }

    @Override
    public boolean showContextMenuForChild(View originalView, float x, float y) {
        return false;
    }

    @Override
    public ActionMode startActionModeForChild(View originalView, ActionMode.Callback callback) {
        return null;
    }

    @Override
    public ActionMode startActionModeForChild(
            View originalView, ActionMode.Callback callback, int type) {
        return null;
    }

    @Override
    public void createContextMenu(ContextMenu menu) {
    }

    @Override
    public void childDrawableStateChanged(View child) {
    }

    @Override
    public boolean requestSendAccessibilityEvent(View child, AccessibilityEvent event) {
        if (mView == null || mStopped || mPausedForTransition) {
            return false;
        }

        // Immediately flush pending content changed event (if any) to preserve event order
        if (event.getEventType() != AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED
                && mSendWindowContentChangedAccessibilityEvent != null
                && mSendWindowContentChangedAccessibilityEvent.mSource != null) {
            mSendWindowContentChangedAccessibilityEvent.removeCallbacksAndRun();
        }

        // Intercept accessibility focus events fired by virtual nodes to keep
        // track of accessibility focus position in such nodes.
        final int eventType = event.getEventType();
        switch (eventType) {
            case AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUSED: {
                final long sourceNodeId = event.getSourceNodeId();
                final int accessibilityViewId = AccessibilityNodeInfo.getAccessibilityViewId(
                        sourceNodeId);
                View source = mView.findViewByAccessibilityId(accessibilityViewId);
                if (source != null) {
                    AccessibilityNodeProvider provider = source.getAccessibilityNodeProvider();
                    if (provider != null) {
                        final int virtualNodeId = AccessibilityNodeInfo.getVirtualDescendantId(
                                sourceNodeId);
                        final AccessibilityNodeInfo node;
                        node = provider.createAccessibilityNodeInfo(virtualNodeId);
                        setAccessibilityFocus(source, node);
                    }
                }
            } break;
            case AccessibilityEvent.TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED: {
                final long sourceNodeId = event.getSourceNodeId();
                final int accessibilityViewId = AccessibilityNodeInfo.getAccessibilityViewId(
                        sourceNodeId);
                View source = mView.findViewByAccessibilityId(accessibilityViewId);
                if (source != null) {
                    AccessibilityNodeProvider provider = source.getAccessibilityNodeProvider();
                    if (provider != null) {
                        setAccessibilityFocus(null, null);
                    }
                }
            } break;


            case AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED: {
                handleWindowContentChangedEvent(event);
            } break;
        }
        mAccessibilityManager.sendAccessibilityEvent(event);
        return true;
    }

    
Updates the focused virtual view, when necessary, in response to a
content changed event.

This is necessary to get updated bounds after a position change.
Params:
event – an accessibility event of type AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED/**
     * Updates the focused virtual view, when necessary, in response to a
     * content changed event.
     * <p>
     * This is necessary to get updated bounds after a position change.
     *
     * @param event an accessibility event of type
     *              {@link AccessibilityEvent#TYPE_WINDOW_CONTENT_CHANGED}
     */
    private void handleWindowContentChangedEvent(AccessibilityEvent event) {
        final View focusedHost = mAccessibilityFocusedHost;
        if (focusedHost == null || mAccessibilityFocusedVirtualView == null) {
            // No virtual view focused, nothing to do here.
            return;
        }

        final AccessibilityNodeProvider provider = focusedHost.getAccessibilityNodeProvider();
        if (provider == null) {
            // Error state: virtual view with no provider. Clear focus.
            mAccessibilityFocusedHost = null;
            mAccessibilityFocusedVirtualView = null;
            focusedHost.clearAccessibilityFocusNoCallbacks(0);
            return;
        }

        // We only care about change types that may affect the bounds of the
        // focused virtual view.
        final int changes = event.getContentChangeTypes();
        if ((changes & AccessibilityEvent.CONTENT_CHANGE_TYPE_SUBTREE) == 0
                && changes != AccessibilityEvent.CONTENT_CHANGE_TYPE_UNDEFINED) {
            return;
        }

        final long eventSourceNodeId = event.getSourceNodeId();
        final int changedViewId = AccessibilityNodeInfo.getAccessibilityViewId(eventSourceNodeId);

        // Search up the tree for subtree containment.
        boolean hostInSubtree = false;
        View root = mAccessibilityFocusedHost;
        while (root != null && !hostInSubtree) {
            if (changedViewId == root.getAccessibilityViewId()) {
                hostInSubtree = true;
            } else {
                final ViewParent parent = root.getParent();
                if (parent instanceof View) {
                    root = (View) parent;
                } else {
                    root = null;
                }
            }
        }

        // We care only about changes in subtrees containing the host view.
        if (!hostInSubtree) {
            return;
        }

        final long focusedSourceNodeId = mAccessibilityFocusedVirtualView.getSourceNodeId();
        int focusedChildId = AccessibilityNodeInfo.getVirtualDescendantId(focusedSourceNodeId);

        // Refresh the node for the focused virtual view.
        final Rect oldBounds = mTempRect;
        mAccessibilityFocusedVirtualView.getBoundsInScreen(oldBounds);
        mAccessibilityFocusedVirtualView = provider.createAccessibilityNodeInfo(focusedChildId);
        if (mAccessibilityFocusedVirtualView == null) {
            // Error state: The node no longer exists. Clear focus.
            mAccessibilityFocusedHost = null;
            focusedHost.clearAccessibilityFocusNoCallbacks(0);

            // This will probably fail, but try to keep the provider's internal
            // state consistent by clearing focus.
            provider.performAction(focusedChildId,
                    AccessibilityAction.ACTION_CLEAR_ACCESSIBILITY_FOCUS.getId(), null);
            invalidateRectOnScreen(oldBounds);
        } else {
            // The node was refreshed, invalidate bounds if necessary.
            final Rect newBounds = mAccessibilityFocusedVirtualView.getBoundsInScreen();
            if (!oldBounds.equals(newBounds)) {
                oldBounds.union(newBounds);
                invalidateRectOnScreen(oldBounds);
            }
        }
    }

    @Override
    public void notifySubtreeAccessibilityStateChanged(View child, View source, int changeType) {
        postSendWindowContentChangedCallback(Preconditions.checkNotNull(source), changeType);
    }

    @Override
    public boolean canResolveLayoutDirection() {
        return true;
    }

    @Override
    public boolean isLayoutDirectionResolved() {
        return true;
    }

    @Override
    public int getLayoutDirection() {
        return View.LAYOUT_DIRECTION_RESOLVED_DEFAULT;
    }

    @Override
    public boolean canResolveTextDirection() {
        return true;
    }

    @Override
    public boolean isTextDirectionResolved() {
        return true;
    }

    @Override
    public int getTextDirection() {
        return View.TEXT_DIRECTION_RESOLVED_DEFAULT;
    }

    @Override
    public boolean canResolveTextAlignment() {
        return true;
    }

    @Override
    public boolean isTextAlignmentResolved() {
        return true;
    }

    @Override
    public int getTextAlignment() {
        return View.TEXT_ALIGNMENT_RESOLVED_DEFAULT;
    }

    private View getCommonPredecessor(View first, View second) {
        if (mTempHashSet == null) {
            mTempHashSet = new HashSet<View>();
        }
        HashSet<View> seen = mTempHashSet;
        seen.clear();
        View firstCurrent = first;
        while (firstCurrent != null) {
            seen.add(firstCurrent);
            ViewParent firstCurrentParent = firstCurrent.mParent;
            if (firstCurrentParent instanceof View) {
                firstCurrent = (View) firstCurrentParent;
            } else {
                firstCurrent = null;
            }
        }
        View secondCurrent = second;
        while (secondCurrent != null) {
            if (seen.contains(secondCurrent)) {
                seen.clear();
                return secondCurrent;
            }
            ViewParent secondCurrentParent = secondCurrent.mParent;
            if (secondCurrentParent instanceof View) {
                secondCurrent = (View) secondCurrentParent;
            } else {
                secondCurrent = null;
            }
        }
        seen.clear();
        return null;
    }

    void checkThread() {
        if (mThread != Thread.currentThread()) {
            throw new CalledFromWrongThreadException(
                    "Only the original thread that created a view hierarchy can touch its views.");
        }
    }

    @Override
    public void requestDisallowInterceptTouchEvent(boolean disallowIntercept) {
        // ViewAncestor never intercepts touch event, so this can be a no-op
    }

    @Override
    public boolean requestChildRectangleOnScreen(View child, Rect rectangle, boolean immediate) {
        if (rectangle == null) {
            return scrollToRectOrFocus(null, immediate);
        }
        rectangle.offset(child.getLeft() - child.getScrollX(),
                child.getTop() - child.getScrollY());
        final boolean scrolled = scrollToRectOrFocus(rectangle, immediate);
        mTempRect.set(rectangle);
        mTempRect.offset(0, -mCurScrollY);
        mTempRect.offset(mAttachInfo.mWindowLeft, mAttachInfo.mWindowTop);
        try {
            mWindowSession.onRectangleOnScreenRequested(mWindow, mTempRect);
        } catch (RemoteException re) {
            /* ignore */
        }
        return scrolled;
    }

    @Override
    public void childHasTransientStateChanged(View child, boolean hasTransientState) {
        // Do nothing.
    }

    @Override
    public boolean onStartNestedScroll(View child, View target, int nestedScrollAxes) {
        return false;
    }

    @Override
    public void onStopNestedScroll(View target) {
    }

    @Override
    public void onNestedScrollAccepted(View child, View target, int nestedScrollAxes) {
    }

    @Override
    public void onNestedScroll(View target, int dxConsumed, int dyConsumed,
            int dxUnconsumed, int dyUnconsumed) {
    }

    @Override
    public void onNestedPreScroll(View target, int dx, int dy, int[] consumed) {
    }

    @Override
    public boolean onNestedFling(View target, float velocityX, float velocityY, boolean consumed) {
        return false;
    }

    @Override
    public boolean onNestedPreFling(View target, float velocityX, float velocityY) {
        return false;
    }

    @Override
    public boolean onNestedPrePerformAccessibilityAction(View target, int action, Bundle args) {
        return false;
    }


    private void reportNextDraw() {
        if (mReportNextDraw == false) {
            drawPending();
        }
        mReportNextDraw = true;
    }

    
Force the window to report its next draw.

This method is only supposed to be used to speed up the interaction from SystemUI and window
manager when waiting for the first frame to be drawn when turning on the screen. DO NOT USE
unless you fully understand this interaction.
@hide
/**
     * Force the window to report its next draw.
     * <p>
     * This method is only supposed to be used to speed up the interaction from SystemUI and window
     * manager when waiting for the first frame to be drawn when turning on the screen. DO NOT USE
     * unless you fully understand this interaction.
     * @hide
     */
    public void setReportNextDraw() {
        reportNextDraw();
        invalidate();
    }

    void changeCanvasOpacity(boolean opaque) {
        Log.d(mTag, "changeCanvasOpacity: opaque=" + opaque);
        if (mAttachInfo.mThreadedRenderer != null) {
            mAttachInfo.mThreadedRenderer.setOpaque(opaque);
        }
    }

    
Dispatches a KeyEvent to all registered key fallback handlers.
Params:
event – 
Returns:
true if the event was handled, false otherwise./**
     * Dispatches a KeyEvent to all registered key fallback handlers.
     *
     * @param event
     * @return {@code true} if the event was handled, {@code false} otherwise.
     */
    public boolean dispatchUnhandledKeyEvent(KeyEvent event) {
        return mUnhandledKeyManager.dispatch(mView, event);
    }

    class TakenSurfaceHolder extends BaseSurfaceHolder {
        @Override
        public boolean onAllowLockCanvas() {
            return mDrawingAllowed;
        }

        @Override
        public void onRelayoutContainer() {
            // Not currently interesting -- from changing between fixed and layout size.
        }

        @Override
        public void setFormat(int format) {
            ((RootViewSurfaceTaker)mView).setSurfaceFormat(format);
        }

        @Override
        public void setType(int type) {
            ((RootViewSurfaceTaker)mView).setSurfaceType(type);
        }

        @Override
        public void onUpdateSurface() {
            // We take care of format and type changes on our own.
            throw new IllegalStateException("Shouldn't be here");
        }

        @Override
        public boolean isCreating() {
            return mIsCreating;
        }

        @Override
        public void setFixedSize(int width, int height) {
            throw new UnsupportedOperationException(
                    "Currently only support sizing from layout");
        }

        @Override
        public void setKeepScreenOn(boolean screenOn) {
            ((RootViewSurfaceTaker)mView).setSurfaceKeepScreenOn(screenOn);
        }
    }

    static class W extends IWindow.Stub {
        private final WeakReference<ViewRootImpl> mViewAncestor;
        private final IWindowSession mWindowSession;

        W(ViewRootImpl viewAncestor) {
            mViewAncestor = new WeakReference<ViewRootImpl>(viewAncestor);
            mWindowSession = viewAncestor.mWindowSession;
        }

        @Override
        public void resized(Rect frame, Rect overscanInsets, Rect contentInsets,
                Rect visibleInsets, Rect stableInsets, Rect outsets, boolean reportDraw,
                MergedConfiguration mergedConfiguration, Rect backDropFrame, boolean forceLayout,
                boolean alwaysConsumeNavBar, int displayId,
                DisplayCutout.ParcelableWrapper displayCutout) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchResized(frame, overscanInsets, contentInsets,
                        visibleInsets, stableInsets, outsets, reportDraw, mergedConfiguration,
                        backDropFrame, forceLayout, alwaysConsumeNavBar, displayId, displayCutout);
            }
        }

        @Override
        public void moved(int newX, int newY) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchMoved(newX, newY);
            }
        }

        @Override
        public void dispatchAppVisibility(boolean visible) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchAppVisibility(visible);
            }
        }

        @Override
        public void dispatchGetNewSurface() {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchGetNewSurface();
            }
        }

        @Override
        public void windowFocusChanged(boolean hasFocus, boolean inTouchMode) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.windowFocusChanged(hasFocus, inTouchMode);
            }
        }

        private static int checkCallingPermission(String permission) {
            try {
                return ActivityManager.getService().checkPermission(
                        permission, Binder.getCallingPid(), Binder.getCallingUid());
            } catch (RemoteException e) {
                return PackageManager.PERMISSION_DENIED;
            }
        }

        @Override
        public void executeCommand(String command, String parameters, ParcelFileDescriptor out) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                final View view = viewAncestor.mView;
                if (view != null) {
                    if (checkCallingPermission(Manifest.permission.DUMP) !=
                            PackageManager.PERMISSION_GRANTED) {
                        throw new SecurityException("Insufficient permissions to invoke"
                                + " executeCommand() from pid=" + Binder.getCallingPid()
                                + ", uid=" + Binder.getCallingUid());
                    }

                    OutputStream clientStream = null;
                    try {
                        clientStream = new ParcelFileDescriptor.AutoCloseOutputStream(out);
                        ViewDebug.dispatchCommand(view, command, parameters, clientStream);
                    } catch (IOException e) {
                        e.printStackTrace();
                    } finally {
                        if (clientStream != null) {
                            try {
                                clientStream.close();
                            } catch (IOException e) {
                                e.printStackTrace();
                            }
                        }
                    }
                }
            }
        }

        @Override
        public void closeSystemDialogs(String reason) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchCloseSystemDialogs(reason);
            }
        }

        @Override
        public void dispatchWallpaperOffsets(float x, float y, float xStep, float yStep,
                boolean sync) {
            if (sync) {
                try {
                    mWindowSession.wallpaperOffsetsComplete(asBinder());
                } catch (RemoteException e) {
                }
            }
        }

        @Override
        public void dispatchWallpaperCommand(String action, int x, int y,
                int z, Bundle extras, boolean sync) {
            if (sync) {
                try {
                    mWindowSession.wallpaperCommandComplete(asBinder(), null);
                } catch (RemoteException e) {
                }
            }
        }

        /* Drag/drop */
        @Override
        public void dispatchDragEvent(DragEvent event) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchDragEvent(event);
            }
        }

        @Override
        public void updatePointerIcon(float x, float y) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.updatePointerIcon(x, y);
            }
        }

        @Override
        public void dispatchSystemUiVisibilityChanged(int seq, int globalVisibility,
                int localValue, int localChanges) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchSystemUiVisibilityChanged(seq, globalVisibility,
                        localValue, localChanges);
            }
        }

        @Override
        public void dispatchWindowShown() {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchWindowShown();
            }
        }

        @Override
        public void requestAppKeyboardShortcuts(IResultReceiver receiver, int deviceId) {
            ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchRequestKeyboardShortcuts(receiver, deviceId);
            }
        }

        @Override
        public void dispatchPointerCaptureChanged(boolean hasCapture) {
            final ViewRootImpl viewAncestor = mViewAncestor.get();
            if (viewAncestor != null) {
                viewAncestor.dispatchPointerCaptureChanged(hasCapture);
            }
        }

    }

    public static final class CalledFromWrongThreadException extends AndroidRuntimeException {
        public CalledFromWrongThreadException(String msg) {
            super(msg);
        }
    }

    static HandlerActionQueue getRunQueue() {
        HandlerActionQueue rq = sRunQueues.get();
        if (rq != null) {
            return rq;
        }
        rq = new HandlerActionQueue();
        sRunQueues.set(rq);
        return rq;
    }

    
Start a drag resizing which will inform all listeners that a window resize is taking place.
/**
     * Start a drag resizing which will inform all listeners that a window resize is taking place.
     */
    private void startDragResizing(Rect initialBounds, boolean fullscreen, Rect systemInsets,
            Rect stableInsets, int resizeMode) {
        if (!mDragResizing) {
            mDragResizing = true;
            if (mUseMTRenderer) {
                for (int i = mWindowCallbacks.size() - 1; i >= 0; i--) {
                    mWindowCallbacks.get(i).onWindowDragResizeStart(
                            initialBounds, fullscreen, systemInsets, stableInsets, resizeMode);
                }
            }
            mFullRedrawNeeded = true;
        }
    }

    
End a drag resize which will inform all listeners that a window resize has ended.
/**
     * End a drag resize which will inform all listeners that a window resize has ended.
     */
    private void endDragResizing() {
        if (mDragResizing) {
            mDragResizing = false;
            if (mUseMTRenderer) {
                for (int i = mWindowCallbacks.size() - 1; i >= 0; i--) {
                    mWindowCallbacks.get(i).onWindowDragResizeEnd();
                }
            }
            mFullRedrawNeeded = true;
        }
    }

    private boolean updateContentDrawBounds() {
        boolean updated = false;
        if (mUseMTRenderer) {
            for (int i = mWindowCallbacks.size() - 1; i >= 0; i--) {
                updated |=
                        mWindowCallbacks.get(i).onContentDrawn(mWindowAttributes.surfaceInsets.left,
                                mWindowAttributes.surfaceInsets.top, mWidth, mHeight);
            }
        }
        return updated | (mDragResizing && mReportNextDraw);
    }

    private void requestDrawWindow() {
        if (!mUseMTRenderer) {
            return;
        }
        mWindowDrawCountDown = new CountDownLatch(mWindowCallbacks.size());
        for (int i = mWindowCallbacks.size() - 1; i >= 0; i--) {
            mWindowCallbacks.get(i).onRequestDraw(mReportNextDraw);
        }
    }

    
Tells this instance that its corresponding activity has just relaunched. In this case, we
need to force a relayout of the window to make sure we get the correct bounds from window
manager.
/**
     * Tells this instance that its corresponding activity has just relaunched. In this case, we
     * need to force a relayout of the window to make sure we get the correct bounds from window
     * manager.
     */
    public void reportActivityRelaunched() {
        mActivityRelaunched = true;
    }

    
Class for managing the accessibility interaction connection
based on the global accessibility state.
/**
     * Class for managing the accessibility interaction connection
     * based on the global accessibility state.
     */
    final class AccessibilityInteractionConnectionManager
            implements AccessibilityStateChangeListener {
        @Override
        public void onAccessibilityStateChanged(boolean enabled) {
            if (enabled) {
                ensureConnection();
                if (mAttachInfo.mHasWindowFocus && (mView != null)) {
                    mView.sendAccessibilityEvent(AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED);
                    View focusedView = mView.findFocus();
                    if (focusedView != null && focusedView != mView) {
                        focusedView.sendAccessibilityEvent(AccessibilityEvent.TYPE_VIEW_FOCUSED);
                    }
                }
            } else {
                ensureNoConnection();
                mHandler.obtainMessage(MSG_CLEAR_ACCESSIBILITY_FOCUS_HOST).sendToTarget();
            }
        }

        public void ensureConnection() {
            final boolean registered = mAttachInfo.mAccessibilityWindowId
                    != AccessibilityWindowInfo.UNDEFINED_WINDOW_ID;
            if (!registered) {
                mAttachInfo.mAccessibilityWindowId =
                        mAccessibilityManager.addAccessibilityInteractionConnection(mWindow,
                                mContext.getPackageName(),
                                new AccessibilityInteractionConnection(ViewRootImpl.this));
            }
        }

        public void ensureNoConnection() {
            final boolean registered = mAttachInfo.mAccessibilityWindowId
                    != AccessibilityWindowInfo.UNDEFINED_WINDOW_ID;
            if (registered) {
                mAttachInfo.mAccessibilityWindowId = AccessibilityWindowInfo.UNDEFINED_WINDOW_ID;
                mAccessibilityManager.removeAccessibilityInteractionConnection(mWindow);
            }
        }
    }

    final class HighContrastTextManager implements HighTextContrastChangeListener {
        HighContrastTextManager() {
            ThreadedRenderer.setHighContrastText(mAccessibilityManager.isHighTextContrastEnabled());
        }
        @Override
        public void onHighTextContrastStateChanged(boolean enabled) {
            ThreadedRenderer.setHighContrastText(enabled);

            // Destroy Displaylists so they can be recreated with high contrast recordings
            destroyHardwareResources();

            // Schedule redraw, which will rerecord + redraw all text
            invalidate();
        }
    }

    
This class is an interface this ViewAncestor provides to the
AccessibilityManagerService to the latter can interact with
the view hierarchy in this ViewAncestor.
/**
     * This class is an interface this ViewAncestor provides to the
     * AccessibilityManagerService to the latter can interact with
     * the view hierarchy in this ViewAncestor.
     */
    static final class AccessibilityInteractionConnection
            extends IAccessibilityInteractionConnection.Stub {
        private final WeakReference<ViewRootImpl> mViewRootImpl;

        AccessibilityInteractionConnection(ViewRootImpl viewRootImpl) {
            mViewRootImpl = new WeakReference<ViewRootImpl>(viewRootImpl);
        }

        @Override
        public void findAccessibilityNodeInfoByAccessibilityId(long accessibilityNodeId,
                Region interactiveRegion, int interactionId,
                IAccessibilityInteractionConnectionCallback callback, int flags,
                int interrogatingPid, long interrogatingTid, MagnificationSpec spec, Bundle args) {
            ViewRootImpl viewRootImpl = mViewRootImpl.get();
            if (viewRootImpl != null && viewRootImpl.mView != null) {
                viewRootImpl.getAccessibilityInteractionController()
                    .findAccessibilityNodeInfoByAccessibilityIdClientThread(accessibilityNodeId,
                            interactiveRegion, interactionId, callback, flags, interrogatingPid,
                            interrogatingTid, spec, args);
            } else {
                // We cannot make the call and notify the caller so it does not wait.
                try {
                    callback.setFindAccessibilityNodeInfosResult(null, interactionId);
                } catch (RemoteException re) {
                    /* best effort - ignore */
                }
            }
        }

        @Override
        public void performAccessibilityAction(long accessibilityNodeId, int action,
                Bundle arguments, int interactionId,
                IAccessibilityInteractionConnectionCallback callback, int flags,
                int interrogatingPid, long interrogatingTid) {
            ViewRootImpl viewRootImpl = mViewRootImpl.get();
            if (viewRootImpl != null && viewRootImpl.mView != null) {
                viewRootImpl.getAccessibilityInteractionController()
                    .performAccessibilityActionClientThread(accessibilityNodeId, action, arguments,
                            interactionId, callback, flags, interrogatingPid, interrogatingTid);
            } else {
                // We cannot make the call and notify the caller so it does not wait.
                try {
                    callback.setPerformAccessibilityActionResult(false, interactionId);
                } catch (RemoteException re) {
                    /* best effort - ignore */
                }
            }
        }

        @Override
        public void findAccessibilityNodeInfosByViewId(long accessibilityNodeId,
                String viewId, Region interactiveRegion, int interactionId,
                IAccessibilityInteractionConnectionCallback callback, int flags,
                int interrogatingPid, long interrogatingTid, MagnificationSpec spec) {
            ViewRootImpl viewRootImpl = mViewRootImpl.get();
            if (viewRootImpl != null && viewRootImpl.mView != null) {
                viewRootImpl.getAccessibilityInteractionController()
                    .findAccessibilityNodeInfosByViewIdClientThread(accessibilityNodeId,
                            viewId, interactiveRegion, interactionId, callback, flags,
                            interrogatingPid, interrogatingTid, spec);
            } else {
                // We cannot make the call and notify the caller so it does not wait.
                try {
                    callback.setFindAccessibilityNodeInfoResult(null, interactionId);
                } catch (RemoteException re) {
                    /* best effort - ignore */
                }
            }
        }

        @Override
        public void findAccessibilityNodeInfosByText(long accessibilityNodeId, String text,
                Region interactiveRegion, int interactionId,
                IAccessibilityInteractionConnectionCallback callback, int flags,
                int interrogatingPid, long interrogatingTid, MagnificationSpec spec) {
            ViewRootImpl viewRootImpl = mViewRootImpl.get();
            if (viewRootImpl != null && viewRootImpl.mView != null) {
                viewRootImpl.getAccessibilityInteractionController()
                    .findAccessibilityNodeInfosByTextClientThread(accessibilityNodeId, text,
                            interactiveRegion, interactionId, callback, flags, interrogatingPid,
                            interrogatingTid, spec);
            } else {
                // We cannot make the call and notify the caller so it does not wait.
                try {
                    callback.setFindAccessibilityNodeInfosResult(null, interactionId);
                } catch (RemoteException re) {
                    /* best effort - ignore */
                }
            }
        }

        @Override
        public void findFocus(long accessibilityNodeId, int focusType, Region interactiveRegion,
                int interactionId, IAccessibilityInteractionConnectionCallback callback, int flags,
                int interrogatingPid, long interrogatingTid, MagnificationSpec spec) {
            ViewRootImpl viewRootImpl = mViewRootImpl.get();
            if (viewRootImpl != null && viewRootImpl.mView != null) {
                viewRootImpl.getAccessibilityInteractionController()
                    .findFocusClientThread(accessibilityNodeId, focusType, interactiveRegion,
                            interactionId, callback, flags, interrogatingPid, interrogatingTid,
                            spec);
            } else {
                // We cannot make the call and notify the caller so it does not wait.
                try {
                    callback.setFindAccessibilityNodeInfoResult(null, interactionId);
                } catch (RemoteException re) {
                    /* best effort - ignore */
                }
            }
        }

        @Override
        public void focusSearch(long accessibilityNodeId, int direction, Region interactiveRegion,
                int interactionId, IAccessibilityInteractionConnectionCallback callback, int flags,
                int interrogatingPid, long interrogatingTid, MagnificationSpec spec) {
            ViewRootImpl viewRootImpl = mViewRootImpl.get();
            if (viewRootImpl != null && viewRootImpl.mView != null) {
                viewRootImpl.getAccessibilityInteractionController()
                    .focusSearchClientThread(accessibilityNodeId, direction, interactiveRegion,
                            interactionId, callback, flags, interrogatingPid, interrogatingTid,
                            spec);
            } else {
                // We cannot make the call and notify the caller so it does not wait.
                try {
                    callback.setFindAccessibilityNodeInfoResult(null, interactionId);
                } catch (RemoteException re) {
                    /* best effort - ignore */
                }
            }
        }
    }

    private class SendWindowContentChangedAccessibilityEvent implements Runnable {
        private int mChangeTypes = 0;

        public View mSource;
        public long mLastEventTimeMillis;
        
Override for AccessibilityEvent.originStackTrace to provide the stack trace of the original runOrPost call instead of one for sending the delayed event from a looper. /**
         * Override for {@link AccessibilityEvent#originStackTrace} to provide the stack trace
         * of the original {@link #runOrPost} call instead of one for sending the delayed event
         * from a looper.
         */
        public StackTraceElement[] mOrigin;

        @Override
        public void run() {
            // Protect against re-entrant code and attempt to do the right thing in the case that
            // we're multithreaded.
            View source = mSource;
            mSource = null;
            if (source == null) {
                Log.e(TAG, "Accessibility content change has no source");
                return;
            }
            // The accessibility may be turned off while we were waiting so check again.
            if (AccessibilityManager.getInstance(mContext).isEnabled()) {
                mLastEventTimeMillis = SystemClock.uptimeMillis();
                AccessibilityEvent event = AccessibilityEvent.obtain();
                event.setEventType(AccessibilityEvent.TYPE_WINDOW_CONTENT_CHANGED);
                event.setContentChangeTypes(mChangeTypes);
                if (AccessibilityEvent.DEBUG_ORIGIN) event.originStackTrace = mOrigin;
                source.sendAccessibilityEventUnchecked(event);
            } else {
                mLastEventTimeMillis = 0;
            }
            // In any case reset to initial state.
            source.resetSubtreeAccessibilityStateChanged();
            mChangeTypes = 0;
            if (AccessibilityEvent.DEBUG_ORIGIN) mOrigin = null;
        }

        public void runOrPost(View source, int changeType) {
            if (mHandler.getLooper() != Looper.myLooper()) {
                CalledFromWrongThreadException e = new CalledFromWrongThreadException("Only the "
                        + "original thread that created a view hierarchy can touch its views.");
                // TODO: Throw the exception
                Log.e(TAG, "Accessibility content change on non-UI thread. Future Android "
                        + "versions will throw an exception.", e);
                // Attempt to recover. This code does not eliminate the thread safety issue, but
                // it should force any issues to happen near the above log.
                mHandler.removeCallbacks(this);
                if (mSource != null) {
                    // Dispatch whatever was pending. It's still possible that the runnable started
                    // just before we removed the callbacks, and bad things will happen, but at
                    // least they should happen very close to the logged error.
                    run();
                }
            }
            if (mSource != null) {
                // If there is no common predecessor, then mSource points to
                // a removed view, hence in this case always prefer the source.
                View predecessor = getCommonPredecessor(mSource, source);
                if (predecessor != null) {
                    predecessor = predecessor.getSelfOrParentImportantForA11y();
                }
                mSource = (predecessor != null) ? predecessor : source;
                mChangeTypes |= changeType;
                return;
            }
            mSource = source;
            mChangeTypes = changeType;
            if (AccessibilityEvent.DEBUG_ORIGIN) {
                mOrigin = Thread.currentThread().getStackTrace();
            }
            final long timeSinceLastMillis = SystemClock.uptimeMillis() - mLastEventTimeMillis;
            final long minEventIntevalMillis =
                    ViewConfiguration.getSendRecurringAccessibilityEventsInterval();
            if (timeSinceLastMillis >= minEventIntevalMillis) {
                removeCallbacksAndRun();
            } else {
                mHandler.postDelayed(this, minEventIntevalMillis - timeSinceLastMillis);
            }
        }

        public void removeCallbacksAndRun() {
            mHandler.removeCallbacks(this);
            run();
        }
    }

    private static class UnhandledKeyManager {
        // This is used to ensure that unhandled events are only dispatched once. We attempt
        // to dispatch more than once in order to achieve a certain order. Specifically, if we
        // are in an Activity or Dialog (and have a Window.Callback), the unhandled events should
        // be dispatched after the view hierarchy, but before the Callback. However, if we aren't
        // in an activity, we still want unhandled keys to be dispatched.
        private boolean mDispatched = true;

        // Keeps track of which Views have unhandled key focus for which keys. This doesn't
        // include modifiers.
        private final SparseArray<WeakReference<View>> mCapturedKeys = new SparseArray<>();

        // The current receiver. This value is transient and used between the pre-dispatch and
        // pre-view phase to ensure that other input-stages don't interfere with tracking.
        private WeakReference<View> mCurrentReceiver = null;

        boolean dispatch(View root, KeyEvent event) {
            if (mDispatched) {
                return false;
            }
            View consumer;
            try {
                Trace.traceBegin(Trace.TRACE_TAG_VIEW, "UnhandledKeyEvent dispatch");
                mDispatched = true;

                consumer = root.dispatchUnhandledKeyEvent(event);

                // If an unhandled listener handles one, then keep track of it so that the
                // consuming view is first to receive its repeats and release as well.
                if (event.getAction() == KeyEvent.ACTION_DOWN) {
                    int keycode = event.getKeyCode();
                    if (consumer != null && !KeyEvent.isModifierKey(keycode)) {
                        mCapturedKeys.put(keycode, new WeakReference<>(consumer));
                    }
                }
            } finally {
                Trace.traceEnd(Trace.TRACE_TAG_VIEW);
            }
            return consumer != null;
        }

        
Called before the event gets dispatched to anything
/**
         * Called before the event gets dispatched to anything
         */
        void preDispatch(KeyEvent event) {
            // Always clean-up 'up' events since it's possible for earlier dispatch stages to
            // consume them without consuming the corresponding 'down' event.
            mCurrentReceiver = null;
            if (event.getAction() == KeyEvent.ACTION_UP) {
                int idx = mCapturedKeys.indexOfKey(event.getKeyCode());
                if (idx >= 0) {
                    mCurrentReceiver = mCapturedKeys.valueAt(idx);
                    mCapturedKeys.removeAt(idx);
                }
            }
        }

        
Called before the event gets dispatched to the view hierarchy
Returns:
true if an unhandled handler has focus and consumed the event/**
         * Called before the event gets dispatched to the view hierarchy
         * @return {@code true} if an unhandled handler has focus and consumed the event
         */
        boolean preViewDispatch(KeyEvent event) {
            mDispatched = false;
            if (mCurrentReceiver == null) {
                mCurrentReceiver = mCapturedKeys.get(event.getKeyCode());
            }
            if (mCurrentReceiver != null) {
                View target = mCurrentReceiver.get();
                if (event.getAction() == KeyEvent.ACTION_UP) {
                    mCurrentReceiver = null;
                }
                if (target != null && target.isAttachedToWindow()) {
                    target.onUnhandledKeyEvent(event);
                }
                // consume anyways so that we don't feed uncaptured key events to other views
                return true;
            }
            return false;
        }
    }
}