/*
 * Copyright (C) 2012 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.widget;

import android.R;
import android.animation.ValueAnimator;
import android.annotation.IntDef;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.app.PendingIntent;
import android.app.PendingIntent.CanceledException;
import android.app.RemoteAction;
import android.content.ClipData;
import android.content.ClipData.Item;
import android.content.Context;
import android.content.Intent;
import android.content.UndoManager;
import android.content.UndoOperation;
import android.content.UndoOwner;
import android.content.pm.PackageManager;
import android.content.pm.ResolveInfo;
import android.content.res.TypedArray;
import android.graphics.Canvas;
import android.graphics.Color;
import android.graphics.Matrix;
import android.graphics.Paint;
import android.graphics.Path;
import android.graphics.Point;
import android.graphics.PointF;
import android.graphics.Rect;
import android.graphics.RectF;
import android.graphics.drawable.ColorDrawable;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.os.LocaleList;
import android.os.Parcel;
import android.os.Parcelable;
import android.os.ParcelableParcel;
import android.os.SystemClock;
import android.provider.Settings;
import android.text.DynamicLayout;
import android.text.Editable;
import android.text.InputFilter;
import android.text.InputType;
import android.text.Layout;
import android.text.ParcelableSpan;
import android.text.Selection;
import android.text.SpanWatcher;
import android.text.Spannable;
import android.text.SpannableStringBuilder;
import android.text.Spanned;
import android.text.StaticLayout;
import android.text.TextUtils;
import android.text.method.KeyListener;
import android.text.method.MetaKeyKeyListener;
import android.text.method.MovementMethod;
import android.text.method.WordIterator;
import android.text.style.EasyEditSpan;
import android.text.style.SuggestionRangeSpan;
import android.text.style.SuggestionSpan;
import android.text.style.TextAppearanceSpan;
import android.text.style.URLSpan;
import android.util.ArraySet;
import android.util.DisplayMetrics;
import android.util.Log;
import android.util.SparseArray;
import android.view.ActionMode;
import android.view.ActionMode.Callback;
import android.view.ContextMenu;
import android.view.ContextThemeWrapper;
import android.view.DisplayListCanvas;
import android.view.DragAndDropPermissions;
import android.view.DragEvent;
import android.view.Gravity;
import android.view.HapticFeedbackConstants;
import android.view.InputDevice;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.MotionEvent;
import android.view.RenderNode;
import android.view.SubMenu;
import android.view.View;
import android.view.View.DragShadowBuilder;
import android.view.View.OnClickListener;
import android.view.ViewConfiguration;
import android.view.ViewGroup;
import android.view.ViewGroup.LayoutParams;
import android.view.ViewTreeObserver;
import android.view.WindowManager;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.animation.LinearInterpolator;
import android.view.inputmethod.CorrectionInfo;
import android.view.inputmethod.CursorAnchorInfo;
import android.view.inputmethod.EditorInfo;
import android.view.inputmethod.ExtractedText;
import android.view.inputmethod.ExtractedTextRequest;
import android.view.inputmethod.InputConnection;
import android.view.inputmethod.InputMethodManager;
import android.view.textclassifier.TextClassification;
import android.view.textclassifier.TextClassificationManager;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.TextView.Drawables;
import android.widget.TextView.OnEditorActionListener;

import com.android.internal.annotations.VisibleForTesting;
import com.android.internal.logging.MetricsLogger;
import com.android.internal.logging.nano.MetricsProto.MetricsEvent;
import com.android.internal.util.ArrayUtils;
import com.android.internal.util.GrowingArrayUtils;
import com.android.internal.util.Preconditions;
import com.android.internal.view.FloatingActionMode;
import com.android.internal.widget.EditableInputConnection;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.text.BreakIterator;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Comparator;
import java.util.HashMap;
import java.util.List;
import java.util.Map;

Helper class used by TextView to handle editable text views.
@hide
/**
 * Helper class used by TextView to handle editable text views.
 *
 * @hide
 */
public class Editor {
    private static final String TAG = "Editor";
    private static final boolean DEBUG_UNDO = false;
    // Specifies whether to use or not the magnifier when pressing the insertion or selection
    // handles.
    private static final boolean FLAG_USE_MAGNIFIER = true;

    static final int BLINK = 500;
    private static final int DRAG_SHADOW_MAX_TEXT_LENGTH = 20;
    private static final float LINE_SLOP_MULTIPLIER_FOR_HANDLEVIEWS = 0.5f;
    private static final int UNSET_X_VALUE = -1;
    private static final int UNSET_LINE = -1;
    // Tag used when the Editor maintains its own separate UndoManager.
    private static final String UNDO_OWNER_TAG = "Editor";

    // Ordering constants used to place the Action Mode or context menu items in their menu.
    private static final int MENU_ITEM_ORDER_ASSIST = 0;
    private static final int MENU_ITEM_ORDER_UNDO = 2;
    private static final int MENU_ITEM_ORDER_REDO = 3;
    private static final int MENU_ITEM_ORDER_CUT = 4;
    private static final int MENU_ITEM_ORDER_COPY = 5;
    private static final int MENU_ITEM_ORDER_PASTE = 6;
    private static final int MENU_ITEM_ORDER_SHARE = 7;
    private static final int MENU_ITEM_ORDER_SELECT_ALL = 8;
    private static final int MENU_ITEM_ORDER_REPLACE = 9;
    private static final int MENU_ITEM_ORDER_AUTOFILL = 10;
    private static final int MENU_ITEM_ORDER_PASTE_AS_PLAIN_TEXT = 11;
    private static final int MENU_ITEM_ORDER_SECONDARY_ASSIST_ACTIONS_START = 50;
    private static final int MENU_ITEM_ORDER_PROCESS_TEXT_INTENT_ACTIONS_START = 100;

    @IntDef({MagnifierHandleTrigger.SELECTION_START,
            MagnifierHandleTrigger.SELECTION_END,
            MagnifierHandleTrigger.INSERTION})
    @Retention(RetentionPolicy.SOURCE)
    private @interface MagnifierHandleTrigger {
        int INSERTION = 0;
        int SELECTION_START = 1;
        int SELECTION_END = 2;
    }

    @IntDef({TextActionMode.SELECTION, TextActionMode.INSERTION, TextActionMode.TEXT_LINK})
    @interface TextActionMode {
        int SELECTION = 0;
        int INSERTION = 1;
        int TEXT_LINK = 2;
    }

    // Each Editor manages its own undo stack.
    private final UndoManager mUndoManager = new UndoManager();
    private UndoOwner mUndoOwner = mUndoManager.getOwner(UNDO_OWNER_TAG, this);
    final UndoInputFilter mUndoInputFilter = new UndoInputFilter(this);
    boolean mAllowUndo = true;

    private final MetricsLogger mMetricsLogger = new MetricsLogger();

    // Cursor Controllers.
    private InsertionPointCursorController mInsertionPointCursorController;
    SelectionModifierCursorController mSelectionModifierCursorController;
    // Action mode used when text is selected or when actions on an insertion cursor are triggered.
    private ActionMode mTextActionMode;
    private boolean mInsertionControllerEnabled;
    private boolean mSelectionControllerEnabled;

    private final boolean mHapticTextHandleEnabled;

    private final MagnifierMotionAnimator mMagnifierAnimator;
    private final Runnable mUpdateMagnifierRunnable = new Runnable() {
        @Override
        public void run() {
            mMagnifierAnimator.update();
        }
    };
    // Update the magnifier contents whenever anything in the view hierarchy is updated.
    // Note: this only captures UI thread-visible changes, so it's a known issue that an animating
    // VectorDrawable or Ripple animation will not trigger capture, since they're owned by
    // RenderThread.
    private final ViewTreeObserver.OnDrawListener mMagnifierOnDrawListener =
            new ViewTreeObserver.OnDrawListener() {
        @Override
        public void onDraw() {
            if (mMagnifierAnimator != null) {
                // Posting the method will ensure that updating the magnifier contents will
                // happen right after the rendering of the current frame.
                mTextView.post(mUpdateMagnifierRunnable);
            }
        }
    };

    // Used to highlight a word when it is corrected by the IME
    private CorrectionHighlighter mCorrectionHighlighter;

    InputContentType mInputContentType;
    InputMethodState mInputMethodState;

    private static class TextRenderNode {
        // Render node has 3 recording states:
        // 1. Recorded operations are valid.
        // #needsRecord() returns false, but needsToBeShifted is false.
        // 2. Recorded operations are not valid, but just the position needed to be updated.
        // #needsRecord() returns false, but needsToBeShifted is true.
        // 3. Recorded operations are not valid. Need to record operations. #needsRecord() returns
        // true.
        RenderNode renderNode;
        boolean isDirty;
        // Becomes true when recorded operations can be reused, but the position has to be updated.
        boolean needsToBeShifted;
        public TextRenderNode(String name) {
            renderNode = RenderNode.create(name, null);
            isDirty = true;
            needsToBeShifted = true;
        }
        boolean needsRecord() {
            return isDirty || !renderNode.isValid();
        }
    }
    private TextRenderNode[] mTextRenderNodes;

    boolean mFrozenWithFocus;
    boolean mSelectionMoved;
    boolean mTouchFocusSelected;

    KeyListener mKeyListener;
    int mInputType = EditorInfo.TYPE_NULL;

    boolean mDiscardNextActionUp;
    boolean mIgnoreActionUpEvent;

    private long mShowCursor;
    private boolean mRenderCursorRegardlessTiming;
    private Blink mBlink;

    boolean mCursorVisible = true;
    boolean mSelectAllOnFocus;
    boolean mTextIsSelectable;

    CharSequence mError;
    boolean mErrorWasChanged;
    private ErrorPopup mErrorPopup;

    
This flag is set if the TextView tries to display an error before it
is attached to the window (so its position is still unknown).
It causes the error to be shown later, when onAttachedToWindow()
is called.
/**
     * This flag is set if the TextView tries to display an error before it
     * is attached to the window (so its position is still unknown).
     * It causes the error to be shown later, when onAttachedToWindow()
     * is called.
     */
    private boolean mShowErrorAfterAttach;

    boolean mInBatchEditControllers;
    boolean mShowSoftInputOnFocus = true;
    private boolean mPreserveSelection;
    private boolean mRestartActionModeOnNextRefresh;
    private boolean mRequestingLinkActionMode;

    private SelectionActionModeHelper mSelectionActionModeHelper;

    boolean mIsBeingLongClicked;

    private SuggestionsPopupWindow mSuggestionsPopupWindow;
    SuggestionRangeSpan mSuggestionRangeSpan;
    private Runnable mShowSuggestionRunnable;

    Drawable mDrawableForCursor = null;

    private Drawable mSelectHandleLeft;
    private Drawable mSelectHandleRight;
    private Drawable mSelectHandleCenter;

    // Global listener that detects changes in the global position of the TextView
    private PositionListener mPositionListener;

    private float mLastDownPositionX, mLastDownPositionY;
    private float mLastUpPositionX, mLastUpPositionY;
    private float mContextMenuAnchorX, mContextMenuAnchorY;
    Callback mCustomSelectionActionModeCallback;
    Callback mCustomInsertionActionModeCallback;

    // Set when this TextView gained focus with some text selected. Will start selection mode.
    boolean mCreatedWithASelection;

    // Indicates the current tap state (first tap, double tap, or triple click).
    private int mTapState = TAP_STATE_INITIAL;
    private long mLastTouchUpTime = 0;
    private static final int TAP_STATE_INITIAL = 0;
    private static final int TAP_STATE_FIRST_TAP = 1;
    private static final int TAP_STATE_DOUBLE_TAP = 2;
    // Only for mouse input.
    private static final int TAP_STATE_TRIPLE_CLICK = 3;

    // The button state as of the last time #onTouchEvent is called.
    private int mLastButtonState;

    private Runnable mInsertionActionModeRunnable;

    // The span controller helps monitoring the changes to which the Editor needs to react:
    // - EasyEditSpans, for which we have some UI to display on attach and on hide
    // - SelectionSpans, for which we need to call updateSelection if an IME is attached
    private SpanController mSpanController;

    private WordIterator mWordIterator;
    SpellChecker mSpellChecker;

    // This word iterator is set with text and used to determine word boundaries
    // when a user is selecting text.
    private WordIterator mWordIteratorWithText;
    // Indicate that the text in the word iterator needs to be updated.
    private boolean mUpdateWordIteratorText;

    private Rect mTempRect;

    private final TextView mTextView;

    final ProcessTextIntentActionsHandler mProcessTextIntentActionsHandler;

    private final CursorAnchorInfoNotifier mCursorAnchorInfoNotifier =
            new CursorAnchorInfoNotifier();

    private final Runnable mShowFloatingToolbar = new Runnable() {
        @Override
        public void run() {
            if (mTextActionMode != null) {
                mTextActionMode.hide(0);  // hide off.
            }
        }
    };

    boolean mIsInsertionActionModeStartPending = false;

    private final SuggestionHelper mSuggestionHelper = new SuggestionHelper();

    Editor(TextView textView) {
        mTextView = textView;
        // Synchronize the filter list, which places the undo input filter at the end.
        mTextView.setFilters(mTextView.getFilters());
        mProcessTextIntentActionsHandler = new ProcessTextIntentActionsHandler(this);
        mHapticTextHandleEnabled = mTextView.getContext().getResources().getBoolean(
                com.android.internal.R.bool.config_enableHapticTextHandle);

        if (FLAG_USE_MAGNIFIER) {
            mMagnifierAnimator = new MagnifierMotionAnimator(new Magnifier(mTextView));
        }
    }

    ParcelableParcel saveInstanceState() {
        ParcelableParcel state = new ParcelableParcel(getClass().getClassLoader());
        Parcel parcel = state.getParcel();
        mUndoManager.saveInstanceState(parcel);
        mUndoInputFilter.saveInstanceState(parcel);
        return state;
    }

    void restoreInstanceState(ParcelableParcel state) {
        Parcel parcel = state.getParcel();
        mUndoManager.restoreInstanceState(parcel, state.getClassLoader());
        mUndoInputFilter.restoreInstanceState(parcel);
        // Re-associate this object as the owner of undo state.
        mUndoOwner = mUndoManager.getOwner(UNDO_OWNER_TAG, this);
    }

    
Forgets all undo and redo operations for this Editor.
/**
     * Forgets all undo and redo operations for this Editor.
     */
    void forgetUndoRedo() {
        UndoOwner[] owners = { mUndoOwner };
        mUndoManager.forgetUndos(owners, -1 /* all */);
        mUndoManager.forgetRedos(owners, -1 /* all */);
    }

    boolean canUndo() {
        UndoOwner[] owners = { mUndoOwner };
        return mAllowUndo && mUndoManager.countUndos(owners) > 0;
    }

    boolean canRedo() {
        UndoOwner[] owners = { mUndoOwner };
        return mAllowUndo && mUndoManager.countRedos(owners) > 0;
    }

    void undo() {
        if (!mAllowUndo) {
            return;
        }
        UndoOwner[] owners = { mUndoOwner };
        mUndoManager.undo(owners, 1);  // Undo 1 action.
    }

    void redo() {
        if (!mAllowUndo) {
            return;
        }
        UndoOwner[] owners = { mUndoOwner };
        mUndoManager.redo(owners, 1);  // Redo 1 action.
    }

    void replace() {
        if (mSuggestionsPopupWindow == null) {
            mSuggestionsPopupWindow = new SuggestionsPopupWindow();
        }
        hideCursorAndSpanControllers();
        mSuggestionsPopupWindow.show();

        int middle = (mTextView.getSelectionStart() + mTextView.getSelectionEnd()) / 2;
        Selection.setSelection((Spannable) mTextView.getText(), middle);
    }

    void onAttachedToWindow() {
        if (mShowErrorAfterAttach) {
            showError();
            mShowErrorAfterAttach = false;
        }

        final ViewTreeObserver observer = mTextView.getViewTreeObserver();
        if (observer.isAlive()) {
            // No need to create the controller.
            // The get method will add the listener on controller creation.
            if (mInsertionPointCursorController != null) {
                observer.addOnTouchModeChangeListener(mInsertionPointCursorController);
            }
            if (mSelectionModifierCursorController != null) {
                mSelectionModifierCursorController.resetTouchOffsets();
                observer.addOnTouchModeChangeListener(mSelectionModifierCursorController);
            }
            if (FLAG_USE_MAGNIFIER) {
                observer.addOnDrawListener(mMagnifierOnDrawListener);
            }
        }

        updateSpellCheckSpans(0, mTextView.getText().length(),
                true /* create the spell checker if needed */);

        if (mTextView.hasSelection()) {
            refreshTextActionMode();
        }

        getPositionListener().addSubscriber(mCursorAnchorInfoNotifier, true);
        resumeBlink();
    }

    void onDetachedFromWindow() {
        getPositionListener().removeSubscriber(mCursorAnchorInfoNotifier);

        if (mError != null) {
            hideError();
        }

        suspendBlink();

        if (mInsertionPointCursorController != null) {
            mInsertionPointCursorController.onDetached();
        }

        if (mSelectionModifierCursorController != null) {
            mSelectionModifierCursorController.onDetached();
        }

        if (mShowSuggestionRunnable != null) {
            mTextView.removeCallbacks(mShowSuggestionRunnable);
        }

        // Cancel the single tap delayed runnable.
        if (mInsertionActionModeRunnable != null) {
            mTextView.removeCallbacks(mInsertionActionModeRunnable);
        }

        mTextView.removeCallbacks(mShowFloatingToolbar);

        discardTextDisplayLists();

        if (mSpellChecker != null) {
            mSpellChecker.closeSession();
            // Forces the creation of a new SpellChecker next time this window is created.
            // Will handle the cases where the settings has been changed in the meantime.
            mSpellChecker = null;
        }

        if (FLAG_USE_MAGNIFIER) {
            final ViewTreeObserver observer = mTextView.getViewTreeObserver();
            if (observer.isAlive()) {
                observer.removeOnDrawListener(mMagnifierOnDrawListener);
            }
        }

        hideCursorAndSpanControllers();
        stopTextActionModeWithPreservingSelection();
    }

    private void discardTextDisplayLists() {
        if (mTextRenderNodes != null) {
            for (int i = 0; i < mTextRenderNodes.length; i++) {
                RenderNode displayList = mTextRenderNodes[i] != null
                        ? mTextRenderNodes[i].renderNode : null;
                if (displayList != null && displayList.isValid()) {
                    displayList.discardDisplayList();
                }
            }
        }
    }

    private void showError() {
        if (mTextView.getWindowToken() == null) {
            mShowErrorAfterAttach = true;
            return;
        }

        if (mErrorPopup == null) {
            LayoutInflater inflater = LayoutInflater.from(mTextView.getContext());
            final TextView err = (TextView) inflater.inflate(
                    com.android.internal.R.layout.textview_hint, null);

            final float scale = mTextView.getResources().getDisplayMetrics().density;
            mErrorPopup =
                    new ErrorPopup(err, (int) (200 * scale + 0.5f), (int) (50 * scale + 0.5f));
            mErrorPopup.setFocusable(false);
            // The user is entering text, so the input method is needed.  We
            // don't want the popup to be displayed on top of it.
            mErrorPopup.setInputMethodMode(PopupWindow.INPUT_METHOD_NEEDED);
        }

        TextView tv = (TextView) mErrorPopup.getContentView();
        chooseSize(mErrorPopup, mError, tv);
        tv.setText(mError);

        mErrorPopup.showAsDropDown(mTextView, getErrorX(), getErrorY(),
                Gravity.TOP | Gravity.LEFT);
        mErrorPopup.fixDirection(mErrorPopup.isAboveAnchor());
    }

    public void setError(CharSequence error, Drawable icon) {
        mError = TextUtils.stringOrSpannedString(error);
        mErrorWasChanged = true;

        if (mError == null) {
            setErrorIcon(null);
            if (mErrorPopup != null) {
                if (mErrorPopup.isShowing()) {
                    mErrorPopup.dismiss();
                }

                mErrorPopup = null;
            }
            mShowErrorAfterAttach = false;
        } else {
            setErrorIcon(icon);
            if (mTextView.isFocused()) {
                showError();
            }
        }
    }

    private void setErrorIcon(Drawable icon) {
        Drawables dr = mTextView.mDrawables;
        if (dr == null) {
            mTextView.mDrawables = dr = new Drawables(mTextView.getContext());
        }
        dr.setErrorDrawable(icon, mTextView);

        mTextView.resetResolvedDrawables();
        mTextView.invalidate();
        mTextView.requestLayout();
    }

    private void hideError() {
        if (mErrorPopup != null) {
            if (mErrorPopup.isShowing()) {
                mErrorPopup.dismiss();
            }
        }

        mShowErrorAfterAttach = false;
    }

    
Returns the X offset to make the pointy top of the error point
at the middle of the error icon.
/**
     * Returns the X offset to make the pointy top of the error point
     * at the middle of the error icon.
     */
    private int getErrorX() {
        /*
         * The "25" is the distance between the point and the right edge
         * of the background
         */
        final float scale = mTextView.getResources().getDisplayMetrics().density;

        final Drawables dr = mTextView.mDrawables;

        final int layoutDirection = mTextView.getLayoutDirection();
        int errorX;
        int offset;
        switch (layoutDirection) {
            default:
            case View.LAYOUT_DIRECTION_LTR:
                offset = -(dr != null ? dr.mDrawableSizeRight : 0) / 2 + (int) (25 * scale + 0.5f);
                errorX = mTextView.getWidth() - mErrorPopup.getWidth()
                        - mTextView.getPaddingRight() + offset;
                break;
            case View.LAYOUT_DIRECTION_RTL:
                offset = (dr != null ? dr.mDrawableSizeLeft : 0) / 2 - (int) (25 * scale + 0.5f);
                errorX = mTextView.getPaddingLeft() + offset;
                break;
        }
        return errorX;
    }

    
Returns the Y offset to make the pointy top of the error point
at the bottom of the error icon.
/**
     * Returns the Y offset to make the pointy top of the error point
     * at the bottom of the error icon.
     */
    private int getErrorY() {
        /*
         * Compound, not extended, because the icon is not clipped
         * if the text height is smaller.
         */
        final int compoundPaddingTop = mTextView.getCompoundPaddingTop();
        int vspace = mTextView.getBottom() - mTextView.getTop()
                - mTextView.getCompoundPaddingBottom() - compoundPaddingTop;

        final Drawables dr = mTextView.mDrawables;

        final int layoutDirection = mTextView.getLayoutDirection();
        int height;
        switch (layoutDirection) {
            default:
            case View.LAYOUT_DIRECTION_LTR:
                height = (dr != null ? dr.mDrawableHeightRight : 0);
                break;
            case View.LAYOUT_DIRECTION_RTL:
                height = (dr != null ? dr.mDrawableHeightLeft : 0);
                break;
        }

        int icontop = compoundPaddingTop + (vspace - height) / 2;

        /*
         * The "2" is the distance between the point and the top edge
         * of the background.
         */
        final float scale = mTextView.getResources().getDisplayMetrics().density;
        return icontop + height - mTextView.getHeight() - (int) (2 * scale + 0.5f);
    }

    void createInputContentTypeIfNeeded() {
        if (mInputContentType == null) {
            mInputContentType = new InputContentType();
        }
    }

    void createInputMethodStateIfNeeded() {
        if (mInputMethodState == null) {
            mInputMethodState = new InputMethodState();
        }
    }

    private boolean isCursorVisible() {
        // The default value is true, even when there is no associated Editor
        return mCursorVisible && mTextView.isTextEditable();
    }

    boolean shouldRenderCursor() {
        if (!isCursorVisible()) {
            return false;
        }
        if (mRenderCursorRegardlessTiming) {
            return true;
        }
        final long showCursorDelta = SystemClock.uptimeMillis() - mShowCursor;
        return showCursorDelta % (2 * BLINK) < BLINK;
    }

    void prepareCursorControllers() {
        boolean windowSupportsHandles = false;

        ViewGroup.LayoutParams params = mTextView.getRootView().getLayoutParams();
        if (params instanceof WindowManager.LayoutParams) {
            WindowManager.LayoutParams windowParams = (WindowManager.LayoutParams) params;
            windowSupportsHandles = windowParams.type < WindowManager.LayoutParams.FIRST_SUB_WINDOW
                    || windowParams.type > WindowManager.LayoutParams.LAST_SUB_WINDOW;
        }

        boolean enabled = windowSupportsHandles && mTextView.getLayout() != null;
        mInsertionControllerEnabled = enabled && isCursorVisible();
        mSelectionControllerEnabled = enabled && mTextView.textCanBeSelected();

        if (!mInsertionControllerEnabled) {
            hideInsertionPointCursorController();
            if (mInsertionPointCursorController != null) {
                mInsertionPointCursorController.onDetached();
                mInsertionPointCursorController = null;
            }
        }

        if (!mSelectionControllerEnabled) {
            stopTextActionMode();
            if (mSelectionModifierCursorController != null) {
                mSelectionModifierCursorController.onDetached();
                mSelectionModifierCursorController = null;
            }
        }
    }

    void hideInsertionPointCursorController() {
        if (mInsertionPointCursorController != null) {
            mInsertionPointCursorController.hide();
        }
    }

    
Hides the insertion and span controllers.
/**
     * Hides the insertion and span controllers.
     */
    void hideCursorAndSpanControllers() {
        hideCursorControllers();
        hideSpanControllers();
    }

    private void hideSpanControllers() {
        if (mSpanController != null) {
            mSpanController.hide();
        }
    }

    private void hideCursorControllers() {
        // When mTextView is not ExtractEditText, we need to distinguish two kinds of focus-lost.
        // One is the true focus lost where suggestions pop-up (if any) should be dismissed, and the
        // other is an side effect of showing the suggestions pop-up itself. We use isShowingUp()
        // to distinguish one from the other.
        if (mSuggestionsPopupWindow != null && ((mTextView.isInExtractedMode())
                || !mSuggestionsPopupWindow.isShowingUp())) {
            // Should be done before hide insertion point controller since it triggers a show of it
            mSuggestionsPopupWindow.hide();
        }
        hideInsertionPointCursorController();
    }

    
Create new SpellCheckSpans on the modified region.
/**
     * Create new SpellCheckSpans on the modified region.
     */
    private void updateSpellCheckSpans(int start, int end, boolean createSpellChecker) {
        // Remove spans whose adjacent characters are text not punctuation
        mTextView.removeAdjacentSuggestionSpans(start);
        mTextView.removeAdjacentSuggestionSpans(end);

        if (mTextView.isTextEditable() && mTextView.isSuggestionsEnabled()
                && !(mTextView.isInExtractedMode())) {
            if (mSpellChecker == null && createSpellChecker) {
                mSpellChecker = new SpellChecker(mTextView);
            }
            if (mSpellChecker != null) {
                mSpellChecker.spellCheck(start, end);
            }
        }
    }

    void onScreenStateChanged(int screenState) {
        switch (screenState) {
            case View.SCREEN_STATE_ON:
                resumeBlink();
                break;
            case View.SCREEN_STATE_OFF:
                suspendBlink();
                break;
        }
    }

    private void suspendBlink() {
        if (mBlink != null) {
            mBlink.cancel();
        }
    }

    private void resumeBlink() {
        if (mBlink != null) {
            mBlink.uncancel();
            makeBlink();
        }
    }

    void adjustInputType(boolean password, boolean passwordInputType,
            boolean webPasswordInputType, boolean numberPasswordInputType) {
        // mInputType has been set from inputType, possibly modified by mInputMethod.
        // Specialize mInputType to [web]password if we have a text class and the original input
        // type was a password.
        if ((mInputType & EditorInfo.TYPE_MASK_CLASS) == EditorInfo.TYPE_CLASS_TEXT) {
            if (password || passwordInputType) {
                mInputType = (mInputType & ~(EditorInfo.TYPE_MASK_VARIATION))
                        | EditorInfo.TYPE_TEXT_VARIATION_PASSWORD;
            }
            if (webPasswordInputType) {
                mInputType = (mInputType & ~(EditorInfo.TYPE_MASK_VARIATION))
                        | EditorInfo.TYPE_TEXT_VARIATION_WEB_PASSWORD;
            }
        } else if ((mInputType & EditorInfo.TYPE_MASK_CLASS) == EditorInfo.TYPE_CLASS_NUMBER) {
            if (numberPasswordInputType) {
                mInputType = (mInputType & ~(EditorInfo.TYPE_MASK_VARIATION))
                        | EditorInfo.TYPE_NUMBER_VARIATION_PASSWORD;
            }
        }
    }

    private void chooseSize(@NonNull PopupWindow pop, @NonNull CharSequence text,
            @NonNull TextView tv) {
        final int wid = tv.getPaddingLeft() + tv.getPaddingRight();
        final int ht = tv.getPaddingTop() + tv.getPaddingBottom();

        final int defaultWidthInPixels = mTextView.getResources().getDimensionPixelSize(
                com.android.internal.R.dimen.textview_error_popup_default_width);
        final StaticLayout l = StaticLayout.Builder.obtain(text, 0, text.length(), tv.getPaint(),
                defaultWidthInPixels)
                .setUseLineSpacingFromFallbacks(tv.mUseFallbackLineSpacing)
                .build();

        float max = 0;
        for (int i = 0; i < l.getLineCount(); i++) {
            max = Math.max(max, l.getLineWidth(i));
        }

        /*
         * Now set the popup size to be big enough for the text plus the border capped
         * to DEFAULT_MAX_POPUP_WIDTH
         */
        pop.setWidth(wid + (int) Math.ceil(max));
        pop.setHeight(ht + l.getHeight());
    }

    void setFrame() {
        if (mErrorPopup != null) {
            TextView tv = (TextView) mErrorPopup.getContentView();
            chooseSize(mErrorPopup, mError, tv);
            mErrorPopup.update(mTextView, getErrorX(), getErrorY(),
                    mErrorPopup.getWidth(), mErrorPopup.getHeight());
        }
    }

    private int getWordStart(int offset) {
        // FIXME - For this and similar methods we're not doing anything to check if there's
        // a LocaleSpan in the text, this may be something we should try handling or checking for.
        int retOffset = getWordIteratorWithText().prevBoundary(offset);
        if (getWordIteratorWithText().isOnPunctuation(retOffset)) {
            // On punctuation boundary or within group of punctuation, find punctuation start.
            retOffset = getWordIteratorWithText().getPunctuationBeginning(offset);
        } else {
            // Not on a punctuation boundary, find the word start.
            retOffset = getWordIteratorWithText().getPrevWordBeginningOnTwoWordsBoundary(offset);
        }
        if (retOffset == BreakIterator.DONE) {
            return offset;
        }
        return retOffset;
    }

    private int getWordEnd(int offset) {
        int retOffset = getWordIteratorWithText().nextBoundary(offset);
        if (getWordIteratorWithText().isAfterPunctuation(retOffset)) {
            // On punctuation boundary or within group of punctuation, find punctuation end.
            retOffset = getWordIteratorWithText().getPunctuationEnd(offset);
        } else {
            // Not on a punctuation boundary, find the word end.
            retOffset = getWordIteratorWithText().getNextWordEndOnTwoWordBoundary(offset);
        }
        if (retOffset == BreakIterator.DONE) {
            return offset;
        }
        return retOffset;
    }

    private boolean needsToSelectAllToSelectWordOrParagraph() {
        if (mTextView.hasPasswordTransformationMethod()) {
            // Always select all on a password field.
            // Cut/copy menu entries are not available for passwords, but being able to select all
            // is however useful to delete or paste to replace the entire content.
            return true;
        }

        int inputType = mTextView.getInputType();
        int klass = inputType & InputType.TYPE_MASK_CLASS;
        int variation = inputType & InputType.TYPE_MASK_VARIATION;

        // Specific text field types: select the entire text for these
        if (klass == InputType.TYPE_CLASS_NUMBER
                || klass == InputType.TYPE_CLASS_PHONE
                || klass == InputType.TYPE_CLASS_DATETIME
                || variation == InputType.TYPE_TEXT_VARIATION_URI
                || variation == InputType.TYPE_TEXT_VARIATION_EMAIL_ADDRESS
                || variation == InputType.TYPE_TEXT_VARIATION_WEB_EMAIL_ADDRESS
                || variation == InputType.TYPE_TEXT_VARIATION_FILTER) {
            return true;
        }
        return false;
    }

    
Adjusts selection to the word under last touch offset. Return true if the operation was
successfully performed.
/**
     * Adjusts selection to the word under last touch offset. Return true if the operation was
     * successfully performed.
     */
    boolean selectCurrentWord() {
        if (!mTextView.canSelectText()) {
            return false;
        }

        if (needsToSelectAllToSelectWordOrParagraph()) {
            return mTextView.selectAllText();
        }

        long lastTouchOffsets = getLastTouchOffsets();
        final int minOffset = TextUtils.unpackRangeStartFromLong(lastTouchOffsets);
        final int maxOffset = TextUtils.unpackRangeEndFromLong(lastTouchOffsets);

        // Safety check in case standard touch event handling has been bypassed
        if (minOffset < 0 || minOffset > mTextView.getText().length()) return false;
        if (maxOffset < 0 || maxOffset > mTextView.getText().length()) return false;

        int selectionStart, selectionEnd;

        // If a URLSpan (web address, email, phone...) is found at that position, select it.
        URLSpan[] urlSpans =
                ((Spanned) mTextView.getText()).getSpans(minOffset, maxOffset, URLSpan.class);
        if (urlSpans.length >= 1) {
            URLSpan urlSpan = urlSpans[0];
            selectionStart = ((Spanned) mTextView.getText()).getSpanStart(urlSpan);
            selectionEnd = ((Spanned) mTextView.getText()).getSpanEnd(urlSpan);
        } else {
            // FIXME - We should check if there's a LocaleSpan in the text, this may be
            // something we should try handling or checking for.
            final WordIterator wordIterator = getWordIterator();
            wordIterator.setCharSequence(mTextView.getText(), minOffset, maxOffset);

            selectionStart = wordIterator.getBeginning(minOffset);
            selectionEnd = wordIterator.getEnd(maxOffset);

            if (selectionStart == BreakIterator.DONE || selectionEnd == BreakIterator.DONE
                    || selectionStart == selectionEnd) {
                // Possible when the word iterator does not properly handle the text's language
                long range = getCharClusterRange(minOffset);
                selectionStart = TextUtils.unpackRangeStartFromLong(range);
                selectionEnd = TextUtils.unpackRangeEndFromLong(range);
            }
        }

        Selection.setSelection((Spannable) mTextView.getText(), selectionStart, selectionEnd);
        return selectionEnd > selectionStart;
    }

    
Adjusts selection to the paragraph under last touch offset. Return true if the operation was
successfully performed.
/**
     * Adjusts selection to the paragraph under last touch offset. Return true if the operation was
     * successfully performed.
     */
    private boolean selectCurrentParagraph() {
        if (!mTextView.canSelectText()) {
            return false;
        }

        if (needsToSelectAllToSelectWordOrParagraph()) {
            return mTextView.selectAllText();
        }

        long lastTouchOffsets = getLastTouchOffsets();
        final int minLastTouchOffset = TextUtils.unpackRangeStartFromLong(lastTouchOffsets);
        final int maxLastTouchOffset = TextUtils.unpackRangeEndFromLong(lastTouchOffsets);

        final long paragraphsRange = getParagraphsRange(minLastTouchOffset, maxLastTouchOffset);
        final int start = TextUtils.unpackRangeStartFromLong(paragraphsRange);
        final int end = TextUtils.unpackRangeEndFromLong(paragraphsRange);
        if (start < end) {
            Selection.setSelection((Spannable) mTextView.getText(), start, end);
            return true;
        }
        return false;
    }

    
Get the minimum range of paragraphs that contains startOffset and endOffset.
/**
     * Get the minimum range of paragraphs that contains startOffset and endOffset.
     */
    private long getParagraphsRange(int startOffset, int endOffset) {
        final Layout layout = mTextView.getLayout();
        if (layout == null) {
            return TextUtils.packRangeInLong(-1, -1);
        }
        final CharSequence text = mTextView.getText();
        int minLine = layout.getLineForOffset(startOffset);
        // Search paragraph start.
        while (minLine > 0) {
            final int prevLineEndOffset = layout.getLineEnd(minLine - 1);
            if (text.charAt(prevLineEndOffset - 1) == '\n') {
                break;
            }
            minLine--;
        }
        int maxLine = layout.getLineForOffset(endOffset);
        // Search paragraph end.
        while (maxLine < layout.getLineCount() - 1) {
            final int lineEndOffset = layout.getLineEnd(maxLine);
            if (text.charAt(lineEndOffset - 1) == '\n') {
                break;
            }
            maxLine++;
        }
        return TextUtils.packRangeInLong(layout.getLineStart(minLine), layout.getLineEnd(maxLine));
    }

    void onLocaleChanged() {
        // Will be re-created on demand in getWordIterator and getWordIteratorWithText with the
        // proper new locale
        mWordIterator = null;
        mWordIteratorWithText = null;
    }

    public WordIterator getWordIterator() {
        if (mWordIterator == null) {
            mWordIterator = new WordIterator(mTextView.getTextServicesLocale());
        }
        return mWordIterator;
    }

    private WordIterator getWordIteratorWithText() {
        if (mWordIteratorWithText == null) {
            mWordIteratorWithText = new WordIterator(mTextView.getTextServicesLocale());
            mUpdateWordIteratorText = true;
        }
        if (mUpdateWordIteratorText) {
            // FIXME - Shouldn't copy all of the text as only the area of the text relevant
            // to the user's selection is needed. A possible solution would be to
            // copy some number N of characters near the selection and then when the
            // user approaches N then we'd do another copy of the next N characters.
            CharSequence text = mTextView.getText();
            mWordIteratorWithText.setCharSequence(text, 0, text.length());
            mUpdateWordIteratorText = false;
        }
        return mWordIteratorWithText;
    }

    private int getNextCursorOffset(int offset, boolean findAfterGivenOffset) {
        final Layout layout = mTextView.getLayout();
        if (layout == null) return offset;
        return findAfterGivenOffset == layout.isRtlCharAt(offset)
                ? layout.getOffsetToLeftOf(offset) : layout.getOffsetToRightOf(offset);
    }

    private long getCharClusterRange(int offset) {
        final int textLength = mTextView.getText().length();
        if (offset < textLength) {
            final int clusterEndOffset = getNextCursorOffset(offset, true);
            return TextUtils.packRangeInLong(
                    getNextCursorOffset(clusterEndOffset, false), clusterEndOffset);
        }
        if (offset - 1 >= 0) {
            final int clusterStartOffset = getNextCursorOffset(offset, false);
            return TextUtils.packRangeInLong(clusterStartOffset,
                    getNextCursorOffset(clusterStartOffset, true));
        }
        return TextUtils.packRangeInLong(offset, offset);
    }

    private boolean touchPositionIsInSelection() {
        int selectionStart = mTextView.getSelectionStart();
        int selectionEnd = mTextView.getSelectionEnd();

        if (selectionStart == selectionEnd) {
            return false;
        }

        if (selectionStart > selectionEnd) {
            int tmp = selectionStart;
            selectionStart = selectionEnd;
            selectionEnd = tmp;
            Selection.setSelection((Spannable) mTextView.getText(), selectionStart, selectionEnd);
        }

        SelectionModifierCursorController selectionController = getSelectionController();
        int minOffset = selectionController.getMinTouchOffset();
        int maxOffset = selectionController.getMaxTouchOffset();

        return ((minOffset >= selectionStart) && (maxOffset < selectionEnd));
    }

    private PositionListener getPositionListener() {
        if (mPositionListener == null) {
            mPositionListener = new PositionListener();
        }
        return mPositionListener;
    }

    private interface TextViewPositionListener {
        public void updatePosition(int parentPositionX, int parentPositionY,
                boolean parentPositionChanged, boolean parentScrolled);
    }

    private boolean isOffsetVisible(int offset) {
        Layout layout = mTextView.getLayout();
        if (layout == null) return false;

        final int line = layout.getLineForOffset(offset);
        final int lineBottom = layout.getLineBottom(line);
        final int primaryHorizontal = (int) layout.getPrimaryHorizontal(offset);
        return mTextView.isPositionVisible(
                primaryHorizontal + mTextView.viewportToContentHorizontalOffset(),
                lineBottom + mTextView.viewportToContentVerticalOffset());
    }

    
Returns true if the screen coordinates position (x,y) corresponds to a character displayed
in the view. Returns false when the position is in the empty space of left/right of text.
/** Returns true if the screen coordinates position (x,y) corresponds to a character displayed
     * in the view. Returns false when the position is in the empty space of left/right of text.
     */
    private boolean isPositionOnText(float x, float y) {
        Layout layout = mTextView.getLayout();
        if (layout == null) return false;

        final int line = mTextView.getLineAtCoordinate(y);
        x = mTextView.convertToLocalHorizontalCoordinate(x);

        if (x < layout.getLineLeft(line)) return false;
        if (x > layout.getLineRight(line)) return false;
        return true;
    }

    private void startDragAndDrop() {
        getSelectionActionModeHelper().onSelectionDrag();

        // TODO: Fix drag and drop in full screen extracted mode.
        if (mTextView.isInExtractedMode()) {
            return;
        }
        final int start = mTextView.getSelectionStart();
        final int end = mTextView.getSelectionEnd();
        CharSequence selectedText = mTextView.getTransformedText(start, end);
        ClipData data = ClipData.newPlainText(null, selectedText);
        DragLocalState localState = new DragLocalState(mTextView, start, end);
        mTextView.startDragAndDrop(data, getTextThumbnailBuilder(start, end), localState,
                View.DRAG_FLAG_GLOBAL);
        stopTextActionMode();
        if (hasSelectionController()) {
            getSelectionController().resetTouchOffsets();
        }
    }

    public boolean performLongClick(boolean handled) {
        // Long press in empty space moves cursor and starts the insertion action mode.
        if (!handled && !isPositionOnText(mLastDownPositionX, mLastDownPositionY)
                && mInsertionControllerEnabled) {
            final int offset = mTextView.getOffsetForPosition(mLastDownPositionX,
                    mLastDownPositionY);
            Selection.setSelection((Spannable) mTextView.getText(), offset);
            getInsertionController().show();
            mIsInsertionActionModeStartPending = true;
            handled = true;
            MetricsLogger.action(
                    mTextView.getContext(),
                    MetricsEvent.TEXT_LONGPRESS,
                    TextViewMetrics.SUBTYPE_LONG_PRESS_OTHER);
        }

        if (!handled && mTextActionMode != null) {
            if (touchPositionIsInSelection()) {
                startDragAndDrop();
                MetricsLogger.action(
                        mTextView.getContext(),
                        MetricsEvent.TEXT_LONGPRESS,
                        TextViewMetrics.SUBTYPE_LONG_PRESS_DRAG_AND_DROP);
            } else {
                stopTextActionMode();
                selectCurrentWordAndStartDrag();
                MetricsLogger.action(
                        mTextView.getContext(),
                        MetricsEvent.TEXT_LONGPRESS,
                        TextViewMetrics.SUBTYPE_LONG_PRESS_SELECTION);
            }
            handled = true;
        }

        // Start a new selection
        if (!handled) {
            handled = selectCurrentWordAndStartDrag();
            if (handled) {
                MetricsLogger.action(
                        mTextView.getContext(),
                        MetricsEvent.TEXT_LONGPRESS,
                        TextViewMetrics.SUBTYPE_LONG_PRESS_SELECTION);
            }
        }

        return handled;
    }

    float getLastUpPositionX() {
        return mLastUpPositionX;
    }

    float getLastUpPositionY() {
        return mLastUpPositionY;
    }

    private long getLastTouchOffsets() {
        SelectionModifierCursorController selectionController = getSelectionController();
        final int minOffset = selectionController.getMinTouchOffset();
        final int maxOffset = selectionController.getMaxTouchOffset();
        return TextUtils.packRangeInLong(minOffset, maxOffset);
    }

    void onFocusChanged(boolean focused, int direction) {
        mShowCursor = SystemClock.uptimeMillis();
        ensureEndedBatchEdit();

        if (focused) {
            int selStart = mTextView.getSelectionStart();
            int selEnd = mTextView.getSelectionEnd();

            // SelectAllOnFocus fields are highlighted and not selected. Do not start text selection
            // mode for these, unless there was a specific selection already started.
            final boolean isFocusHighlighted = mSelectAllOnFocus && selStart == 0
                    && selEnd == mTextView.getText().length();

            mCreatedWithASelection = mFrozenWithFocus && mTextView.hasSelection()
                    && !isFocusHighlighted;

            if (!mFrozenWithFocus || (selStart < 0 || selEnd < 0)) {
                // If a tap was used to give focus to that view, move cursor at tap position.
                // Has to be done before onTakeFocus, which can be overloaded.
                final int lastTapPosition = getLastTapPosition();
                if (lastTapPosition >= 0) {
                    Selection.setSelection((Spannable) mTextView.getText(), lastTapPosition);
                }

                // Note this may have to be moved out of the Editor class
                MovementMethod mMovement = mTextView.getMovementMethod();
                if (mMovement != null) {
                    mMovement.onTakeFocus(mTextView, (Spannable) mTextView.getText(), direction);
                }

                // The DecorView does not have focus when the 'Done' ExtractEditText button is
                // pressed. Since it is the ViewAncestor's mView, it requests focus before
                // ExtractEditText clears focus, which gives focus to the ExtractEditText.
                // This special case ensure that we keep current selection in that case.
                // It would be better to know why the DecorView does not have focus at that time.
                if (((mTextView.isInExtractedMode()) || mSelectionMoved)
                        && selStart >= 0 && selEnd >= 0) {
                    /*
                     * Someone intentionally set the selection, so let them
                     * do whatever it is that they wanted to do instead of
                     * the default on-focus behavior.  We reset the selection
                     * here instead of just skipping the onTakeFocus() call
                     * because some movement methods do something other than
                     * just setting the selection in theirs and we still
                     * need to go through that path.
                     */
                    Selection.setSelection((Spannable) mTextView.getText(), selStart, selEnd);
                }

                if (mSelectAllOnFocus) {
                    mTextView.selectAllText();
                }

                mTouchFocusSelected = true;
            }

            mFrozenWithFocus = false;
            mSelectionMoved = false;

            if (mError != null) {
                showError();
            }

            makeBlink();
        } else {
            if (mError != null) {
                hideError();
            }
            // Don't leave us in the middle of a batch edit.
            mTextView.onEndBatchEdit();

            if (mTextView.isInExtractedMode()) {
                hideCursorAndSpanControllers();
                stopTextActionModeWithPreservingSelection();
            } else {
                hideCursorAndSpanControllers();
                if (mTextView.isTemporarilyDetached()) {
                    stopTextActionModeWithPreservingSelection();
                } else {
                    stopTextActionMode();
                }
                downgradeEasyCorrectionSpans();
            }
            // No need to create the controller
            if (mSelectionModifierCursorController != null) {
                mSelectionModifierCursorController.resetTouchOffsets();
            }

            ensureNoSelectionIfNonSelectable();
        }
    }

    private void ensureNoSelectionIfNonSelectable() {
        // This could be the case if a TextLink has been tapped.
        if (!mTextView.textCanBeSelected() && mTextView.hasSelection()) {
            Selection.setSelection((Spannable) mTextView.getText(),
                    mTextView.length(), mTextView.length());
        }
    }

    
Downgrades to simple suggestions all the easy correction spans that are not a spell check
span.
/**
     * Downgrades to simple suggestions all the easy correction spans that are not a spell check
     * span.
     */
    private void downgradeEasyCorrectionSpans() {
        CharSequence text = mTextView.getText();
        if (text instanceof Spannable) {
            Spannable spannable = (Spannable) text;
            SuggestionSpan[] suggestionSpans = spannable.getSpans(0,
                    spannable.length(), SuggestionSpan.class);
            for (int i = 0; i < suggestionSpans.length; i++) {
                int flags = suggestionSpans[i].getFlags();
                if ((flags & SuggestionSpan.FLAG_EASY_CORRECT) != 0
                        && (flags & SuggestionSpan.FLAG_MISSPELLED) == 0) {
                    flags &= ~SuggestionSpan.FLAG_EASY_CORRECT;
                    suggestionSpans[i].setFlags(flags);
                }
            }
        }
    }

    void sendOnTextChanged(int start, int before, int after) {
        getSelectionActionModeHelper().onTextChanged(start, start + before);
        updateSpellCheckSpans(start, start + after, false);

        // Flip flag to indicate the word iterator needs to have the text reset.
        mUpdateWordIteratorText = true;

        // Hide the controllers as soon as text is modified (typing, procedural...)
        // We do not hide the span controllers, since they can be added when a new text is
        // inserted into the text view (voice IME).
        hideCursorControllers();
        // Reset drag accelerator.
        if (mSelectionModifierCursorController != null) {
            mSelectionModifierCursorController.resetTouchOffsets();
        }
        stopTextActionMode();
    }

    private int getLastTapPosition() {
        // No need to create the controller at that point, no last tap position saved
        if (mSelectionModifierCursorController != null) {
            int lastTapPosition = mSelectionModifierCursorController.getMinTouchOffset();
            if (lastTapPosition >= 0) {
                // Safety check, should not be possible.
                if (lastTapPosition > mTextView.getText().length()) {
                    lastTapPosition = mTextView.getText().length();
                }
                return lastTapPosition;
            }
        }

        return -1;
    }

    void onWindowFocusChanged(boolean hasWindowFocus) {
        if (hasWindowFocus) {
            if (mBlink != null) {
                mBlink.uncancel();
                makeBlink();
            }
            if (mTextView.hasSelection() && !extractedTextModeWillBeStarted()) {
                refreshTextActionMode();
            }
        } else {
            if (mBlink != null) {
                mBlink.cancel();
            }
            if (mInputContentType != null) {
                mInputContentType.enterDown = false;
            }
            // Order matters! Must be done before onParentLostFocus to rely on isShowingUp
            hideCursorAndSpanControllers();
            stopTextActionModeWithPreservingSelection();
            if (mSuggestionsPopupWindow != null) {
                mSuggestionsPopupWindow.onParentLostFocus();
            }

            // Don't leave us in the middle of a batch edit. Same as in onFocusChanged
            ensureEndedBatchEdit();

            ensureNoSelectionIfNonSelectable();
        }
    }

    private void updateTapState(MotionEvent event) {
        final int action = event.getActionMasked();
        if (action == MotionEvent.ACTION_DOWN) {
            final boolean isMouse = event.isFromSource(InputDevice.SOURCE_MOUSE);
            // Detect double tap and triple click.
            if (((mTapState == TAP_STATE_FIRST_TAP)
                    || ((mTapState == TAP_STATE_DOUBLE_TAP) && isMouse))
                            && (SystemClock.uptimeMillis() - mLastTouchUpTime)
                                    <= ViewConfiguration.getDoubleTapTimeout()) {
                if (mTapState == TAP_STATE_FIRST_TAP) {
                    mTapState = TAP_STATE_DOUBLE_TAP;
                } else {
                    mTapState = TAP_STATE_TRIPLE_CLICK;
                }
            } else {
                mTapState = TAP_STATE_FIRST_TAP;
            }
        }
        if (action == MotionEvent.ACTION_UP) {
            mLastTouchUpTime = SystemClock.uptimeMillis();
        }
    }

    private boolean shouldFilterOutTouchEvent(MotionEvent event) {
        if (!event.isFromSource(InputDevice.SOURCE_MOUSE)) {
            return false;
        }
        final boolean primaryButtonStateChanged =
                ((mLastButtonState ^ event.getButtonState()) & MotionEvent.BUTTON_PRIMARY) != 0;
        final int action = event.getActionMasked();
        if ((action == MotionEvent.ACTION_DOWN || action == MotionEvent.ACTION_UP)
                && !primaryButtonStateChanged) {
            return true;
        }
        if (action == MotionEvent.ACTION_MOVE
                && !event.isButtonPressed(MotionEvent.BUTTON_PRIMARY)) {
            return true;
        }
        return false;
    }

    void onTouchEvent(MotionEvent event) {
        final boolean filterOutEvent = shouldFilterOutTouchEvent(event);
        mLastButtonState = event.getButtonState();
        if (filterOutEvent) {
            if (event.getActionMasked() == MotionEvent.ACTION_UP) {
                mDiscardNextActionUp = true;
            }
            return;
        }
        updateTapState(event);
        updateFloatingToolbarVisibility(event);

        if (hasSelectionController()) {
            getSelectionController().onTouchEvent(event);
        }

        if (mShowSuggestionRunnable != null) {
            mTextView.removeCallbacks(mShowSuggestionRunnable);
            mShowSuggestionRunnable = null;
        }

        if (event.getActionMasked() == MotionEvent.ACTION_UP) {
            mLastUpPositionX = event.getX();
            mLastUpPositionY = event.getY();
        }

        if (event.getActionMasked() == MotionEvent.ACTION_DOWN) {
            mLastDownPositionX = event.getX();
            mLastDownPositionY = event.getY();

            // Reset this state; it will be re-set if super.onTouchEvent
            // causes focus to move to the view.
            mTouchFocusSelected = false;
            mIgnoreActionUpEvent = false;
        }
    }

    private void updateFloatingToolbarVisibility(MotionEvent event) {
        if (mTextActionMode != null) {
            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_MOVE:
                    hideFloatingToolbar(ActionMode.DEFAULT_HIDE_DURATION);
                    break;
                case MotionEvent.ACTION_UP:  // fall through
                case MotionEvent.ACTION_CANCEL:
                    showFloatingToolbar();
            }
        }
    }

    void hideFloatingToolbar(int duration) {
        if (mTextActionMode != null) {
            mTextView.removeCallbacks(mShowFloatingToolbar);
            mTextActionMode.hide(duration);
        }
    }

    private void showFloatingToolbar() {
        if (mTextActionMode != null) {
            // Delay "show" so it doesn't interfere with click confirmations
            // or double-clicks that could "dismiss" the floating toolbar.
            int delay = ViewConfiguration.getDoubleTapTimeout();
            mTextView.postDelayed(mShowFloatingToolbar, delay);

            // This classifies the text and most likely returns before the toolbar is actually
            // shown. If not, it will update the toolbar with the result when classification
            // returns. We would rather not wait for a long running classification process.
            invalidateActionModeAsync();
        }
    }

    public void beginBatchEdit() {
        mInBatchEditControllers = true;
        final InputMethodState ims = mInputMethodState;
        if (ims != null) {
            int nesting = ++ims.mBatchEditNesting;
            if (nesting == 1) {
                ims.mCursorChanged = false;
                ims.mChangedDelta = 0;
                if (ims.mContentChanged) {
                    // We already have a pending change from somewhere else,
                    // so turn this into a full update.
                    ims.mChangedStart = 0;
                    ims.mChangedEnd = mTextView.getText().length();
                } else {
                    ims.mChangedStart = EXTRACT_UNKNOWN;
                    ims.mChangedEnd = EXTRACT_UNKNOWN;
                    ims.mContentChanged = false;
                }
                mUndoInputFilter.beginBatchEdit();
                mTextView.onBeginBatchEdit();
            }
        }
    }

    public void endBatchEdit() {
        mInBatchEditControllers = false;
        final InputMethodState ims = mInputMethodState;
        if (ims != null) {
            int nesting = --ims.mBatchEditNesting;
            if (nesting == 0) {
                finishBatchEdit(ims);
            }
        }
    }

    void ensureEndedBatchEdit() {
        final InputMethodState ims = mInputMethodState;
        if (ims != null && ims.mBatchEditNesting != 0) {
            ims.mBatchEditNesting = 0;
            finishBatchEdit(ims);
        }
    }

    void finishBatchEdit(final InputMethodState ims) {
        mTextView.onEndBatchEdit();
        mUndoInputFilter.endBatchEdit();

        if (ims.mContentChanged || ims.mSelectionModeChanged) {
            mTextView.updateAfterEdit();
            reportExtractedText();
        } else if (ims.mCursorChanged) {
            // Cheesy way to get us to report the current cursor location.
            mTextView.invalidateCursor();
        }
        // sendUpdateSelection knows to avoid sending if the selection did
        // not actually change.
        sendUpdateSelection();

        // Show drag handles if they were blocked by batch edit mode.
        if (mTextActionMode != null) {
            final CursorController cursorController = mTextView.hasSelection()
                    ? getSelectionController() : getInsertionController();
            if (cursorController != null && !cursorController.isActive()
                    && !cursorController.isCursorBeingModified()) {
                cursorController.show();
            }
        }
    }

    static final int EXTRACT_NOTHING = -2;
    static final int EXTRACT_UNKNOWN = -1;

    boolean extractText(ExtractedTextRequest request, ExtractedText outText) {
        return extractTextInternal(request, EXTRACT_UNKNOWN, EXTRACT_UNKNOWN,
                EXTRACT_UNKNOWN, outText);
    }

    private boolean extractTextInternal(@Nullable ExtractedTextRequest request,
            int partialStartOffset, int partialEndOffset, int delta,
            @Nullable ExtractedText outText) {
        if (request == null || outText == null) {
            return false;
        }

        final CharSequence content = mTextView.getText();
        if (content == null) {
            return false;
        }

        if (partialStartOffset != EXTRACT_NOTHING) {
            final int N = content.length();
            if (partialStartOffset < 0) {
                outText.partialStartOffset = outText.partialEndOffset = -1;
                partialStartOffset = 0;
                partialEndOffset = N;
            } else {
                // Now use the delta to determine the actual amount of text
                // we need.
                partialEndOffset += delta;
                // Adjust offsets to ensure we contain full spans.
                if (content instanceof Spanned) {
                    Spanned spanned = (Spanned) content;
                    Object[] spans = spanned.getSpans(partialStartOffset,
                            partialEndOffset, ParcelableSpan.class);
                    int i = spans.length;
                    while (i > 0) {
                        i--;
                        int j = spanned.getSpanStart(spans[i]);
                        if (j < partialStartOffset) partialStartOffset = j;
                        j = spanned.getSpanEnd(spans[i]);
                        if (j > partialEndOffset) partialEndOffset = j;
                    }
                }
                outText.partialStartOffset = partialStartOffset;
                outText.partialEndOffset = partialEndOffset - delta;

                if (partialStartOffset > N) {
                    partialStartOffset = N;
                } else if (partialStartOffset < 0) {
                    partialStartOffset = 0;
                }
                if (partialEndOffset > N) {
                    partialEndOffset = N;
                } else if (partialEndOffset < 0) {
                    partialEndOffset = 0;
                }
            }
            if ((request.flags & InputConnection.GET_TEXT_WITH_STYLES) != 0) {
                outText.text = content.subSequence(partialStartOffset,
                        partialEndOffset);
            } else {
                outText.text = TextUtils.substring(content, partialStartOffset,
                        partialEndOffset);
            }
        } else {
            outText.partialStartOffset = 0;
            outText.partialEndOffset = 0;
            outText.text = "";
        }
        outText.flags = 0;
        if (MetaKeyKeyListener.getMetaState(content, MetaKeyKeyListener.META_SELECTING) != 0) {
            outText.flags |= ExtractedText.FLAG_SELECTING;
        }
        if (mTextView.isSingleLine()) {
            outText.flags |= ExtractedText.FLAG_SINGLE_LINE;
        }
        outText.startOffset = 0;
        outText.selectionStart = mTextView.getSelectionStart();
        outText.selectionEnd = mTextView.getSelectionEnd();
        outText.hint = mTextView.getHint();
        return true;
    }

    boolean reportExtractedText() {
        final Editor.InputMethodState ims = mInputMethodState;
        if (ims == null) {
            return false;
        }
        final boolean wasContentChanged = ims.mContentChanged;
        if (!wasContentChanged && !ims.mSelectionModeChanged) {
            return false;
        }
        ims.mContentChanged = false;
        ims.mSelectionModeChanged = false;
        final ExtractedTextRequest req = ims.mExtractedTextRequest;
        if (req == null) {
            return false;
        }
        final InputMethodManager imm = InputMethodManager.peekInstance();
        if (imm == null) {
            return false;
        }
        if (TextView.DEBUG_EXTRACT) {
            Log.v(TextView.LOG_TAG, "Retrieving extracted start="
                    + ims.mChangedStart
                    + " end=" + ims.mChangedEnd
                    + " delta=" + ims.mChangedDelta);
        }
        if (ims.mChangedStart < 0 && !wasContentChanged) {
            ims.mChangedStart = EXTRACT_NOTHING;
        }
        if (extractTextInternal(req, ims.mChangedStart, ims.mChangedEnd,
                ims.mChangedDelta, ims.mExtractedText)) {
            if (TextView.DEBUG_EXTRACT) {
                Log.v(TextView.LOG_TAG,
                        "Reporting extracted start="
                                + ims.mExtractedText.partialStartOffset
                                + " end=" + ims.mExtractedText.partialEndOffset
                                + ": " + ims.mExtractedText.text);
            }

            imm.updateExtractedText(mTextView, req.token, ims.mExtractedText);
            ims.mChangedStart = EXTRACT_UNKNOWN;
            ims.mChangedEnd = EXTRACT_UNKNOWN;
            ims.mChangedDelta = 0;
            ims.mContentChanged = false;
            return true;
        }
        return false;
    }

    private void sendUpdateSelection() {
        if (null != mInputMethodState && mInputMethodState.mBatchEditNesting <= 0) {
            final InputMethodManager imm = InputMethodManager.peekInstance();
            if (null != imm) {
                final int selectionStart = mTextView.getSelectionStart();
                final int selectionEnd = mTextView.getSelectionEnd();
                int candStart = -1;
                int candEnd = -1;
                if (mTextView.getText() instanceof Spannable) {
                    final Spannable sp = (Spannable) mTextView.getText();
                    candStart = EditableInputConnection.getComposingSpanStart(sp);
                    candEnd = EditableInputConnection.getComposingSpanEnd(sp);
                }
                // InputMethodManager#updateSelection skips sending the message if
                // none of the parameters have changed since the last time we called it.
                imm.updateSelection(mTextView,
                        selectionStart, selectionEnd, candStart, candEnd);
            }
        }
    }

    void onDraw(Canvas canvas, Layout layout, Path highlight, Paint highlightPaint,
            int cursorOffsetVertical) {
        final int selectionStart = mTextView.getSelectionStart();
        final int selectionEnd = mTextView.getSelectionEnd();

        final InputMethodState ims = mInputMethodState;
        if (ims != null && ims.mBatchEditNesting == 0) {
            InputMethodManager imm = InputMethodManager.peekInstance();
            if (imm != null) {
                if (imm.isActive(mTextView)) {
                    if (ims.mContentChanged || ims.mSelectionModeChanged) {
                        // We are in extract mode and the content has changed
                        // in some way... just report complete new text to the
                        // input method.
                        reportExtractedText();
                    }
                }
            }
        }

        if (mCorrectionHighlighter != null) {
            mCorrectionHighlighter.draw(canvas, cursorOffsetVertical);
        }

        if (highlight != null && selectionStart == selectionEnd && mDrawableForCursor != null) {
            drawCursor(canvas, cursorOffsetVertical);
            // Rely on the drawable entirely, do not draw the cursor line.
            // Has to be done after the IMM related code above which relies on the highlight.
            highlight = null;
        }

        if (mSelectionActionModeHelper != null) {
            mSelectionActionModeHelper.onDraw(canvas);
            if (mSelectionActionModeHelper.isDrawingHighlight()) {
                highlight = null;
            }
        }

        if (mTextView.canHaveDisplayList() && canvas.isHardwareAccelerated()) {
            drawHardwareAccelerated(canvas, layout, highlight, highlightPaint,
                    cursorOffsetVertical);
        } else {
            layout.draw(canvas, highlight, highlightPaint, cursorOffsetVertical);
        }
    }

    private void drawHardwareAccelerated(Canvas canvas, Layout layout, Path highlight,
            Paint highlightPaint, int cursorOffsetVertical) {
        final long lineRange = layout.getLineRangeForDraw(canvas);
        int firstLine = TextUtils.unpackRangeStartFromLong(lineRange);
        int lastLine = TextUtils.unpackRangeEndFromLong(lineRange);
        if (lastLine < 0) return;

        layout.drawBackground(canvas, highlight, highlightPaint, cursorOffsetVertical,
                firstLine, lastLine);

        if (layout instanceof DynamicLayout) {
            if (mTextRenderNodes == null) {
                mTextRenderNodes = ArrayUtils.emptyArray(TextRenderNode.class);
            }

            DynamicLayout dynamicLayout = (DynamicLayout) layout;
            int[] blockEndLines = dynamicLayout.getBlockEndLines();
            int[] blockIndices = dynamicLayout.getBlockIndices();
            final int numberOfBlocks = dynamicLayout.getNumberOfBlocks();
            final int indexFirstChangedBlock = dynamicLayout.getIndexFirstChangedBlock();

            final ArraySet<Integer> blockSet = dynamicLayout.getBlocksAlwaysNeedToBeRedrawn();
            if (blockSet != null) {
                for (int i = 0; i < blockSet.size(); i++) {
                    final int blockIndex = dynamicLayout.getBlockIndex(blockSet.valueAt(i));
                    if (blockIndex != DynamicLayout.INVALID_BLOCK_INDEX
                            && mTextRenderNodes[blockIndex] != null) {
                        mTextRenderNodes[blockIndex].needsToBeShifted = true;
                    }
                }
            }

            int startBlock = Arrays.binarySearch(blockEndLines, 0, numberOfBlocks, firstLine);
            if (startBlock < 0) {
                startBlock = -(startBlock + 1);
            }
            startBlock = Math.min(indexFirstChangedBlock, startBlock);

            int startIndexToFindAvailableRenderNode = 0;
            int lastIndex = numberOfBlocks;

            for (int i = startBlock; i < numberOfBlocks; i++) {
                final int blockIndex = blockIndices[i];
                if (i >= indexFirstChangedBlock
                        && blockIndex != DynamicLayout.INVALID_BLOCK_INDEX
                        && mTextRenderNodes[blockIndex] != null) {
                    mTextRenderNodes[blockIndex].needsToBeShifted = true;
                }
                if (blockEndLines[i] < firstLine) {
                    // Blocks in [indexFirstChangedBlock, firstLine) are not redrawn here. They will
                    // be redrawn after they get scrolled into drawing range.
                    continue;
                }
                startIndexToFindAvailableRenderNode = drawHardwareAcceleratedInner(canvas, layout,
                        highlight, highlightPaint, cursorOffsetVertical, blockEndLines,
                        blockIndices, i, numberOfBlocks, startIndexToFindAvailableRenderNode);
                if (blockEndLines[i] >= lastLine) {
                    lastIndex = Math.max(indexFirstChangedBlock, i + 1);
                    break;
                }
            }
            if (blockSet != null) {
                for (int i = 0; i < blockSet.size(); i++) {
                    final int block = blockSet.valueAt(i);
                    final int blockIndex = dynamicLayout.getBlockIndex(block);
                    if (blockIndex == DynamicLayout.INVALID_BLOCK_INDEX
                            || mTextRenderNodes[blockIndex] == null
                            || mTextRenderNodes[blockIndex].needsToBeShifted) {
                        startIndexToFindAvailableRenderNode = drawHardwareAcceleratedInner(canvas,
                                layout, highlight, highlightPaint, cursorOffsetVertical,
                                blockEndLines, blockIndices, block, numberOfBlocks,
                                startIndexToFindAvailableRenderNode);
                    }
                }
            }

            dynamicLayout.setIndexFirstChangedBlock(lastIndex);
        } else {
            // Boring layout is used for empty and hint text
            layout.drawText(canvas, firstLine, lastLine);
        }
    }

    private int drawHardwareAcceleratedInner(Canvas canvas, Layout layout, Path highlight,
            Paint highlightPaint, int cursorOffsetVertical, int[] blockEndLines,
            int[] blockIndices, int blockInfoIndex, int numberOfBlocks,
            int startIndexToFindAvailableRenderNode) {
        final int blockEndLine = blockEndLines[blockInfoIndex];
        int blockIndex = blockIndices[blockInfoIndex];

        final boolean blockIsInvalid = blockIndex == DynamicLayout.INVALID_BLOCK_INDEX;
        if (blockIsInvalid) {
            blockIndex = getAvailableDisplayListIndex(blockIndices, numberOfBlocks,
                    startIndexToFindAvailableRenderNode);
            // Note how dynamic layout's internal block indices get updated from Editor
            blockIndices[blockInfoIndex] = blockIndex;
            if (mTextRenderNodes[blockIndex] != null) {
                mTextRenderNodes[blockIndex].isDirty = true;
            }
            startIndexToFindAvailableRenderNode = blockIndex + 1;
        }

        if (mTextRenderNodes[blockIndex] == null) {
            mTextRenderNodes[blockIndex] = new TextRenderNode("Text " + blockIndex);
        }

        final boolean blockDisplayListIsInvalid = mTextRenderNodes[blockIndex].needsRecord();
        RenderNode blockDisplayList = mTextRenderNodes[blockIndex].renderNode;
        if (mTextRenderNodes[blockIndex].needsToBeShifted || blockDisplayListIsInvalid) {
            final int blockBeginLine = blockInfoIndex == 0 ?
                    0 : blockEndLines[blockInfoIndex - 1] + 1;
            final int top = layout.getLineTop(blockBeginLine);
            final int bottom = layout.getLineBottom(blockEndLine);
            int left = 0;
            int right = mTextView.getWidth();
            if (mTextView.getHorizontallyScrolling()) {
                float min = Float.MAX_VALUE;
                float max = Float.MIN_VALUE;
                for (int line = blockBeginLine; line <= blockEndLine; line++) {
                    min = Math.min(min, layout.getLineLeft(line));
                    max = Math.max(max, layout.getLineRight(line));
                }
                left = (int) min;
                right = (int) (max + 0.5f);
            }

            // Rebuild display list if it is invalid
            if (blockDisplayListIsInvalid) {
                final DisplayListCanvas displayListCanvas = blockDisplayList.start(
                        right - left, bottom - top);
                try {
                    // drawText is always relative to TextView's origin, this translation
                    // brings this range of text back to the top left corner of the viewport
                    displayListCanvas.translate(-left, -top);
                    layout.drawText(displayListCanvas, blockBeginLine, blockEndLine);
                    mTextRenderNodes[blockIndex].isDirty = false;
                    // No need to untranslate, previous context is popped after
                    // drawDisplayList
                } finally {
                    blockDisplayList.end(displayListCanvas);
                    // Same as drawDisplayList below, handled by our TextView's parent
                    blockDisplayList.setClipToBounds(false);
                }
            }

            // Valid display list only needs to update its drawing location.
            blockDisplayList.setLeftTopRightBottom(left, top, right, bottom);
            mTextRenderNodes[blockIndex].needsToBeShifted = false;
        }
        ((DisplayListCanvas) canvas).drawRenderNode(blockDisplayList);
        return startIndexToFindAvailableRenderNode;
    }

    private int getAvailableDisplayListIndex(int[] blockIndices, int numberOfBlocks,
            int searchStartIndex) {
        int length = mTextRenderNodes.length;
        for (int i = searchStartIndex; i < length; i++) {
            boolean blockIndexFound = false;
            for (int j = 0; j < numberOfBlocks; j++) {
                if (blockIndices[j] == i) {
                    blockIndexFound = true;
                    break;
                }
            }
            if (blockIndexFound) continue;
            return i;
        }

        // No available index found, the pool has to grow
        mTextRenderNodes = GrowingArrayUtils.append(mTextRenderNodes, length, null);
        return length;
    }

    private void drawCursor(Canvas canvas, int cursorOffsetVertical) {
        final boolean translate = cursorOffsetVertical != 0;
        if (translate) canvas.translate(0, cursorOffsetVertical);
        if (mDrawableForCursor != null) {
            mDrawableForCursor.draw(canvas);
        }
        if (translate) canvas.translate(0, -cursorOffsetVertical);
    }

    void invalidateHandlesAndActionMode() {
        if (mSelectionModifierCursorController != null) {
            mSelectionModifierCursorController.invalidateHandles();
        }
        if (mInsertionPointCursorController != null) {
            mInsertionPointCursorController.invalidateHandle();
        }
        if (mTextActionMode != null) {
            invalidateActionMode();
        }
    }

    
Invalidates all the sub-display lists that overlap the specified character range
/**
     * Invalidates all the sub-display lists that overlap the specified character range
     */
    void invalidateTextDisplayList(Layout layout, int start, int end) {
        if (mTextRenderNodes != null && layout instanceof DynamicLayout) {
            final int firstLine = layout.getLineForOffset(start);
            final int lastLine = layout.getLineForOffset(end);

            DynamicLayout dynamicLayout = (DynamicLayout) layout;
            int[] blockEndLines = dynamicLayout.getBlockEndLines();
            int[] blockIndices = dynamicLayout.getBlockIndices();
            final int numberOfBlocks = dynamicLayout.getNumberOfBlocks();

            int i = 0;
            // Skip the blocks before firstLine
            while (i < numberOfBlocks) {
                if (blockEndLines[i] >= firstLine) break;
                i++;
            }

            // Invalidate all subsequent blocks until lastLine is passed
            while (i < numberOfBlocks) {
                final int blockIndex = blockIndices[i];
                if (blockIndex != DynamicLayout.INVALID_BLOCK_INDEX) {
                    mTextRenderNodes[blockIndex].isDirty = true;
                }
                if (blockEndLines[i] >= lastLine) break;
                i++;
            }
        }
    }

    void invalidateTextDisplayList() {
        if (mTextRenderNodes != null) {
            for (int i = 0; i < mTextRenderNodes.length; i++) {
                if (mTextRenderNodes[i] != null) mTextRenderNodes[i].isDirty = true;
            }
        }
    }

    void updateCursorPosition() {
        if (mTextView.mCursorDrawableRes == 0) {
            mDrawableForCursor = null;
            return;
        }

        final Layout layout = mTextView.getLayout();
        final int offset = mTextView.getSelectionStart();
        final int line = layout.getLineForOffset(offset);
        final int top = layout.getLineTop(line);
        final int bottom = layout.getLineBottomWithoutSpacing(line);

        final boolean clamped = layout.shouldClampCursor(line);
        updateCursorPosition(top, bottom, layout.getPrimaryHorizontal(offset, clamped));
    }

    void refreshTextActionMode() {
        if (extractedTextModeWillBeStarted()) {
            mRestartActionModeOnNextRefresh = false;
            return;
        }
        final boolean hasSelection = mTextView.hasSelection();
        final SelectionModifierCursorController selectionController = getSelectionController();
        final InsertionPointCursorController insertionController = getInsertionController();
        if ((selectionController != null && selectionController.isCursorBeingModified())
                || (insertionController != null && insertionController.isCursorBeingModified())) {
            // ActionMode should be managed by the currently active cursor controller.
            mRestartActionModeOnNextRefresh = false;
            return;
        }
        if (hasSelection) {
            hideInsertionPointCursorController();
            if (mTextActionMode == null) {
                if (mRestartActionModeOnNextRefresh) {
                    // To avoid distraction, newly start action mode only when selection action
                    // mode is being restarted.
                    startSelectionActionModeAsync(false);
                }
            } else if (selectionController == null || !selectionController.isActive()) {
                // Insertion action mode is active. Avoid dismissing the selection.
                stopTextActionModeWithPreservingSelection();
                startSelectionActionModeAsync(false);
            } else {
                mTextActionMode.invalidateContentRect();
            }
        } else {
            // Insertion action mode is started only when insertion controller is explicitly
            // activated.
            if (insertionController == null || !insertionController.isActive()) {
                stopTextActionMode();
            } else if (mTextActionMode != null) {
                mTextActionMode.invalidateContentRect();
            }
        }
        mRestartActionModeOnNextRefresh = false;
    }

    
Start an Insertion action mode.
/**
     * Start an Insertion action mode.
     */
    void startInsertionActionMode() {
        if (mInsertionActionModeRunnable != null) {
            mTextView.removeCallbacks(mInsertionActionModeRunnable);
        }
        if (extractedTextModeWillBeStarted()) {
            return;
        }
        stopTextActionMode();

        ActionMode.Callback actionModeCallback =
                new TextActionModeCallback(TextActionMode.INSERTION);
        mTextActionMode = mTextView.startActionMode(
                actionModeCallback, ActionMode.TYPE_FLOATING);
        if (mTextActionMode != null && getInsertionController() != null) {
            getInsertionController().show();
        }
    }

    @NonNull
    TextView getTextView() {
        return mTextView;
    }

    @Nullable
    ActionMode getTextActionMode() {
        return mTextActionMode;
    }

    void setRestartActionModeOnNextRefresh(boolean value) {
        mRestartActionModeOnNextRefresh = value;
    }

    
Asynchronously starts a selection action mode using the TextClassifier.
/**
     * Asynchronously starts a selection action mode using the TextClassifier.
     */
    void startSelectionActionModeAsync(boolean adjustSelection) {
        getSelectionActionModeHelper().startSelectionActionModeAsync(adjustSelection);
    }

    void startLinkActionModeAsync(int start, int end) {
        if (!(mTextView.getText() instanceof Spannable)) {
            return;
        }
        stopTextActionMode();
        mRequestingLinkActionMode = true;
        getSelectionActionModeHelper().startLinkActionModeAsync(start, end);
    }

    
Asynchronously invalidates an action mode using the TextClassifier.
/**
     * Asynchronously invalidates an action mode using the TextClassifier.
     */
    void invalidateActionModeAsync() {
        getSelectionActionModeHelper().invalidateActionModeAsync();
    }

    
Synchronously invalidates an action mode without the TextClassifier.
/**
     * Synchronously invalidates an action mode without the TextClassifier.
     */
    private void invalidateActionMode() {
        if (mTextActionMode != null) {
            mTextActionMode.invalidate();
        }
    }

    private SelectionActionModeHelper getSelectionActionModeHelper() {
        if (mSelectionActionModeHelper == null) {
            mSelectionActionModeHelper = new SelectionActionModeHelper(this);
        }
        return mSelectionActionModeHelper;
    }

    
If the TextView allows text selection, selects the current word when no existing selection
was available and starts a drag.
Returns:
true if the drag was started./**
     * If the TextView allows text selection, selects the current word when no existing selection
     * was available and starts a drag.
     *
     * @return true if the drag was started.
     */
    private boolean selectCurrentWordAndStartDrag() {
        if (mInsertionActionModeRunnable != null) {
            mTextView.removeCallbacks(mInsertionActionModeRunnable);
        }
        if (extractedTextModeWillBeStarted()) {
            return false;
        }
        if (!checkField()) {
            return false;
        }
        if (!mTextView.hasSelection() && !selectCurrentWord()) {
            // No selection and cannot select a word.
            return false;
        }
        stopTextActionModeWithPreservingSelection();
        getSelectionController().enterDrag(
                SelectionModifierCursorController.DRAG_ACCELERATOR_MODE_WORD);
        return true;
    }

    
Checks whether a selection can be performed on the current TextView.
Returns:
true if a selection can be performed/**
     * Checks whether a selection can be performed on the current TextView.
     *
     * @return true if a selection can be performed
     */
    boolean checkField() {
        if (!mTextView.canSelectText() || !mTextView.requestFocus()) {
            Log.w(TextView.LOG_TAG,
                    "TextView does not support text selection. Selection cancelled.");
            return false;
        }
        return true;
    }

    boolean startActionModeInternal(@TextActionMode int actionMode) {
        if (extractedTextModeWillBeStarted()) {
            return false;
        }
        if (mTextActionMode != null) {
            // Text action mode is already started
            invalidateActionMode();
            return false;
        }

        if (actionMode != TextActionMode.TEXT_LINK
                && (!checkField() || !mTextView.hasSelection())) {
            return false;
        }

        ActionMode.Callback actionModeCallback = new TextActionModeCallback(actionMode);
        mTextActionMode = mTextView.startActionMode(actionModeCallback, ActionMode.TYPE_FLOATING);

        final boolean selectableText = mTextView.isTextEditable() || mTextView.isTextSelectable();
        if (actionMode == TextActionMode.TEXT_LINK && !selectableText
                && mTextActionMode instanceof FloatingActionMode) {
            // Make the toolbar outside-touchable so that it can be dismissed when the user clicks
            // outside of it.
            ((FloatingActionMode) mTextActionMode).setOutsideTouchable(true,
                    () -> stopTextActionMode());
        }

        final boolean selectionStarted = mTextActionMode != null;
        if (selectionStarted
                && mTextView.isTextEditable() && !mTextView.isTextSelectable()
                && mShowSoftInputOnFocus) {
            // Show the IME to be able to replace text, except when selecting non editable text.
            final InputMethodManager imm = InputMethodManager.peekInstance();
            if (imm != null) {
                imm.showSoftInput(mTextView, 0, null);
            }
        }
        return selectionStarted;
    }

    private boolean extractedTextModeWillBeStarted() {
        if (!(mTextView.isInExtractedMode())) {
            final InputMethodManager imm = InputMethodManager.peekInstance();
            return  imm != null && imm.isFullscreenMode();
        }
        return false;
    }

    
Returns:
true if it's reasonable to offer to show suggestions depending on the current cursor position or selection range. This method is consistent with the method to show suggestions SuggestionsPopupWindow.updateSuggestions./**
     * @return <code>true</code> if it's reasonable to offer to show suggestions depending on
     * the current cursor position or selection range. This method is consistent with the
     * method to show suggestions {@link SuggestionsPopupWindow#updateSuggestions}.
     */
    private boolean shouldOfferToShowSuggestions() {
        CharSequence text = mTextView.getText();
        if (!(text instanceof Spannable)) return false;

        final Spannable spannable = (Spannable) text;
        final int selectionStart = mTextView.getSelectionStart();
        final int selectionEnd = mTextView.getSelectionEnd();
        final SuggestionSpan[] suggestionSpans = spannable.getSpans(selectionStart, selectionEnd,
                SuggestionSpan.class);
        if (suggestionSpans.length == 0) {
            return false;
        }
        if (selectionStart == selectionEnd) {
            // Spans overlap the cursor.
            for (int i = 0; i < suggestionSpans.length; i++) {
                if (suggestionSpans[i].getSuggestions().length > 0) {
                    return true;
                }
            }
            return false;
        }
        int minSpanStart = mTextView.getText().length();
        int maxSpanEnd = 0;
        int unionOfSpansCoveringSelectionStartStart = mTextView.getText().length();
        int unionOfSpansCoveringSelectionStartEnd = 0;
        boolean hasValidSuggestions = false;
        for (int i = 0; i < suggestionSpans.length; i++) {
            final int spanStart = spannable.getSpanStart(suggestionSpans[i]);
            final int spanEnd = spannable.getSpanEnd(suggestionSpans[i]);
            minSpanStart = Math.min(minSpanStart, spanStart);
            maxSpanEnd = Math.max(maxSpanEnd, spanEnd);
            if (selectionStart < spanStart || selectionStart > spanEnd) {
                // The span doesn't cover the current selection start point.
                continue;
            }
            hasValidSuggestions =
                    hasValidSuggestions || suggestionSpans[i].getSuggestions().length > 0;
            unionOfSpansCoveringSelectionStartStart =
                    Math.min(unionOfSpansCoveringSelectionStartStart, spanStart);
            unionOfSpansCoveringSelectionStartEnd =
                    Math.max(unionOfSpansCoveringSelectionStartEnd, spanEnd);
        }
        if (!hasValidSuggestions) {
            return false;
        }
        if (unionOfSpansCoveringSelectionStartStart >= unionOfSpansCoveringSelectionStartEnd) {
            // No spans cover the selection start point.
            return false;
        }
        if (minSpanStart < unionOfSpansCoveringSelectionStartStart
                || maxSpanEnd > unionOfSpansCoveringSelectionStartEnd) {
            // There is a span that is not covered by the union. In this case, we soouldn't offer
            // to show suggestions as it's confusing.
            return false;
        }
        return true;
    }

    
Returns:
true if the cursor is inside an SuggestionSpan with SuggestionSpan.FLAG_EASY_CORRECT set./**
     * @return <code>true</code> if the cursor is inside an {@link SuggestionSpan} with
     * {@link SuggestionSpan#FLAG_EASY_CORRECT} set.
     */
    private boolean isCursorInsideEasyCorrectionSpan() {
        Spannable spannable = (Spannable) mTextView.getText();
        SuggestionSpan[] suggestionSpans = spannable.getSpans(mTextView.getSelectionStart(),
                mTextView.getSelectionEnd(), SuggestionSpan.class);
        for (int i = 0; i < suggestionSpans.length; i++) {
            if ((suggestionSpans[i].getFlags() & SuggestionSpan.FLAG_EASY_CORRECT) != 0) {
                return true;
            }
        }
        return false;
    }

    void onTouchUpEvent(MotionEvent event) {
        if (getSelectionActionModeHelper().resetSelection(
                getTextView().getOffsetForPosition(event.getX(), event.getY()))) {
            return;
        }

        boolean selectAllGotFocus = mSelectAllOnFocus && mTextView.didTouchFocusSelect();
        hideCursorAndSpanControllers();
        stopTextActionMode();
        CharSequence text = mTextView.getText();
        if (!selectAllGotFocus && text.length() > 0) {
            // Move cursor
            final int offset = mTextView.getOffsetForPosition(event.getX(), event.getY());

            final boolean shouldInsertCursor = !mRequestingLinkActionMode;
            if (shouldInsertCursor) {
                Selection.setSelection((Spannable) text, offset);
                if (mSpellChecker != null) {
                    // When the cursor moves, the word that was typed may need spell check
                    mSpellChecker.onSelectionChanged();
                }
            }

            if (!extractedTextModeWillBeStarted()) {
                if (isCursorInsideEasyCorrectionSpan()) {
                    // Cancel the single tap delayed runnable.
                    if (mInsertionActionModeRunnable != null) {
                        mTextView.removeCallbacks(mInsertionActionModeRunnable);
                    }

                    mShowSuggestionRunnable = this::replace;

                    // removeCallbacks is performed on every touch
                    mTextView.postDelayed(mShowSuggestionRunnable,
                            ViewConfiguration.getDoubleTapTimeout());
                } else if (hasInsertionController()) {
                    if (shouldInsertCursor) {
                        getInsertionController().show();
                    } else {
                        getInsertionController().hide();
                    }
                }
            }
        }
    }

    protected void stopTextActionMode() {
        if (mTextActionMode != null) {
            // This will hide the mSelectionModifierCursorController
            mTextActionMode.finish();
        }
    }

    private void stopTextActionModeWithPreservingSelection() {
        if (mTextActionMode != null) {
            mRestartActionModeOnNextRefresh = true;
        }
        mPreserveSelection = true;
        stopTextActionMode();
        mPreserveSelection = false;
    }

    
Returns:
True if this view supports insertion handles./**
     * @return True if this view supports insertion handles.
     */
    boolean hasInsertionController() {
        return mInsertionControllerEnabled;
    }

    
Returns:
True if this view supports selection handles./**
     * @return True if this view supports selection handles.
     */
    boolean hasSelectionController() {
        return mSelectionControllerEnabled;
    }

    private InsertionPointCursorController getInsertionController() {
        if (!mInsertionControllerEnabled) {
            return null;
        }

        if (mInsertionPointCursorController == null) {
            mInsertionPointCursorController = new InsertionPointCursorController();

            final ViewTreeObserver observer = mTextView.getViewTreeObserver();
            observer.addOnTouchModeChangeListener(mInsertionPointCursorController);
        }

        return mInsertionPointCursorController;
    }

    @Nullable
    SelectionModifierCursorController getSelectionController() {
        if (!mSelectionControllerEnabled) {
            return null;
        }

        if (mSelectionModifierCursorController == null) {
            mSelectionModifierCursorController = new SelectionModifierCursorController();

            final ViewTreeObserver observer = mTextView.getViewTreeObserver();
            observer.addOnTouchModeChangeListener(mSelectionModifierCursorController);
        }

        return mSelectionModifierCursorController;
    }

    @VisibleForTesting
    @Nullable
    public Drawable getCursorDrawable() {
        return mDrawableForCursor;
    }

    private void updateCursorPosition(int top, int bottom, float horizontal) {
        if (mDrawableForCursor == null) {
            mDrawableForCursor = mTextView.getContext().getDrawable(
                    mTextView.mCursorDrawableRes);
        }
        final int left = clampHorizontalPosition(mDrawableForCursor, horizontal);
        final int width = mDrawableForCursor.getIntrinsicWidth();
        mDrawableForCursor.setBounds(left, top - mTempRect.top, left + width,
                bottom + mTempRect.bottom);
    }

    
Return clamped position for the drawable. If the drawable is within the boundaries of the
view, then it is offset with the left padding of the cursor drawable. If the drawable is at
the beginning or the end of the text then its drawable edge is aligned with left or right of
the view boundary. If the drawable is null, horizontal parameter is aligned to left or right
of the view.
Params:
drawable – Drawable. Can be null.
horizontal – Horizontal position for the drawable.
Returns:
The clamped horizontal position for the drawable./**
     * Return clamped position for the drawable. If the drawable is within the boundaries of the
     * view, then it is offset with the left padding of the cursor drawable. If the drawable is at
     * the beginning or the end of the text then its drawable edge is aligned with left or right of
     * the view boundary. If the drawable is null, horizontal parameter is aligned to left or right
     * of the view.
     *
     * @param drawable Drawable. Can be null.
     * @param horizontal Horizontal position for the drawable.
     * @return The clamped horizontal position for the drawable.
     */
    private int clampHorizontalPosition(@Nullable final Drawable drawable, float horizontal) {
        horizontal = Math.max(0.5f, horizontal - 0.5f);
        if (mTempRect == null) mTempRect = new Rect();

        int drawableWidth = 0;
        if (drawable != null) {
            drawable.getPadding(mTempRect);
            drawableWidth = drawable.getIntrinsicWidth();
        } else {
            mTempRect.setEmpty();
        }

        int scrollX = mTextView.getScrollX();
        float horizontalDiff = horizontal - scrollX;
        int viewClippedWidth = mTextView.getWidth() - mTextView.getCompoundPaddingLeft()
                - mTextView.getCompoundPaddingRight();

        final int left;
        if (horizontalDiff >= (viewClippedWidth - 1f)) {
            // at the rightmost position
            left = viewClippedWidth + scrollX - (drawableWidth - mTempRect.right);
        } else if (Math.abs(horizontalDiff) <= 1f
                || (TextUtils.isEmpty(mTextView.getText())
                        && (TextView.VERY_WIDE - scrollX) <= (viewClippedWidth + 1f)
                        && horizontal <= 1f)) {
            // at the leftmost position
            left = scrollX - mTempRect.left;
        } else {
            left = (int) horizontal - mTempRect.left;
        }
        return left;
    }

    
Called by the framework in response to a text auto-correction (such as fixing a typo using a a dictionary) from the current input method, provided by it calling InputConnection.commitCorrection InputConnection.commitCorrection()}. The default implementation flashes the background of the corrected word to provide feedback to the user. 
Params:
info – The auto correct info about the text that was corrected./**
     * Called by the framework in response to a text auto-correction (such as fixing a typo using a
     * a dictionary) from the current input method, provided by it calling
     * {@link InputConnection#commitCorrection} InputConnection.commitCorrection()}. The default
     * implementation flashes the background of the corrected word to provide feedback to the user.
     *
     * @param info The auto correct info about the text that was corrected.
     */
    public void onCommitCorrection(CorrectionInfo info) {
        if (mCorrectionHighlighter == null) {
            mCorrectionHighlighter = new CorrectionHighlighter();
        } else {
            mCorrectionHighlighter.invalidate(false);
        }

        mCorrectionHighlighter.highlight(info);
        mUndoInputFilter.freezeLastEdit();
    }

    void onScrollChanged() {
        if (mPositionListener != null) {
            mPositionListener.onScrollChanged();
        }
        if (mTextActionMode != null) {
            mTextActionMode.invalidateContentRect();
        }
    }

    
Returns:
True when the TextView isFocused and has a valid zero-length selection (cursor)./**
     * @return True when the TextView isFocused and has a valid zero-length selection (cursor).
     */
    private boolean shouldBlink() {
        if (!isCursorVisible() || !mTextView.isFocused()) return false;

        final int start = mTextView.getSelectionStart();
        if (start < 0) return false;

        final int end = mTextView.getSelectionEnd();
        if (end < 0) return false;

        return start == end;
    }

    void makeBlink() {
        if (shouldBlink()) {
            mShowCursor = SystemClock.uptimeMillis();
            if (mBlink == null) mBlink = new Blink();
            mTextView.removeCallbacks(mBlink);
            mTextView.postDelayed(mBlink, BLINK);
        } else {
            if (mBlink != null) mTextView.removeCallbacks(mBlink);
        }
    }

    private class Blink implements Runnable {
        private boolean mCancelled;

        public void run() {
            if (mCancelled) {
                return;
            }

            mTextView.removeCallbacks(this);

            if (shouldBlink()) {
                if (mTextView.getLayout() != null) {
                    mTextView.invalidateCursorPath();
                }

                mTextView.postDelayed(this, BLINK);
            }
        }

        void cancel() {
            if (!mCancelled) {
                mTextView.removeCallbacks(this);
                mCancelled = true;
            }
        }

        void uncancel() {
            mCancelled = false;
        }
    }

    private DragShadowBuilder getTextThumbnailBuilder(int start, int end) {
        TextView shadowView = (TextView) View.inflate(mTextView.getContext(),
                com.android.internal.R.layout.text_drag_thumbnail, null);

        if (shadowView == null) {
            throw new IllegalArgumentException("Unable to inflate text drag thumbnail");
        }

        if (end - start > DRAG_SHADOW_MAX_TEXT_LENGTH) {
            final long range = getCharClusterRange(start + DRAG_SHADOW_MAX_TEXT_LENGTH);
            end = TextUtils.unpackRangeEndFromLong(range);
        }
        final CharSequence text = mTextView.getTransformedText(start, end);
        shadowView.setText(text);
        shadowView.setTextColor(mTextView.getTextColors());

        shadowView.setTextAppearance(R.styleable.Theme_textAppearanceLarge);
        shadowView.setGravity(Gravity.CENTER);

        shadowView.setLayoutParams(new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                ViewGroup.LayoutParams.WRAP_CONTENT));

        final int size = View.MeasureSpec.makeMeasureSpec(0, View.MeasureSpec.UNSPECIFIED);
        shadowView.measure(size, size);

        shadowView.layout(0, 0, shadowView.getMeasuredWidth(), shadowView.getMeasuredHeight());
        shadowView.invalidate();
        return new DragShadowBuilder(shadowView);
    }

    private static class DragLocalState {
        public TextView sourceTextView;
        public int start, end;

        public DragLocalState(TextView sourceTextView, int start, int end) {
            this.sourceTextView = sourceTextView;
            this.start = start;
            this.end = end;
        }
    }

    void onDrop(DragEvent event) {
        SpannableStringBuilder content = new SpannableStringBuilder();

        final DragAndDropPermissions permissions = DragAndDropPermissions.obtain(event);
        if (permissions != null) {
            permissions.takeTransient();
        }

        try {
            ClipData clipData = event.getClipData();
            final int itemCount = clipData.getItemCount();
            for (int i = 0; i < itemCount; i++) {
                Item item = clipData.getItemAt(i);
                content.append(item.coerceToStyledText(mTextView.getContext()));
            }
        } finally {
            if (permissions != null) {
                permissions.release();
            }
        }

        mTextView.beginBatchEdit();
        mUndoInputFilter.freezeLastEdit();
        try {
            final int offset = mTextView.getOffsetForPosition(event.getX(), event.getY());
            Object localState = event.getLocalState();
            DragLocalState dragLocalState = null;
            if (localState instanceof DragLocalState) {
                dragLocalState = (DragLocalState) localState;
            }
            boolean dragDropIntoItself = dragLocalState != null
                    && dragLocalState.sourceTextView == mTextView;

            if (dragDropIntoItself) {
                if (offset >= dragLocalState.start && offset < dragLocalState.end) {
                    // A drop inside the original selection discards the drop.
                    return;
                }
            }

            final int originalLength = mTextView.getText().length();
            int min = offset;
            int max = offset;

            Selection.setSelection((Spannable) mTextView.getText(), max);
            mTextView.replaceText_internal(min, max, content);

            if (dragDropIntoItself) {
                int dragSourceStart = dragLocalState.start;
                int dragSourceEnd = dragLocalState.end;
                if (max <= dragSourceStart) {
                    // Inserting text before selection has shifted positions
                    final int shift = mTextView.getText().length() - originalLength;
                    dragSourceStart += shift;
                    dragSourceEnd += shift;
                }

                // Delete original selection
                mTextView.deleteText_internal(dragSourceStart, dragSourceEnd);

                // Make sure we do not leave two adjacent spaces.
                final int prevCharIdx = Math.max(0,  dragSourceStart - 1);
                final int nextCharIdx = Math.min(mTextView.getText().length(), dragSourceStart + 1);
                if (nextCharIdx > prevCharIdx + 1) {
                    CharSequence t = mTextView.getTransformedText(prevCharIdx, nextCharIdx);
                    if (Character.isSpaceChar(t.charAt(0)) && Character.isSpaceChar(t.charAt(1))) {
                        mTextView.deleteText_internal(prevCharIdx, prevCharIdx + 1);
                    }
                }
            }
        } finally {
            mTextView.endBatchEdit();
            mUndoInputFilter.freezeLastEdit();
        }
    }

    public void addSpanWatchers(Spannable text) {
        final int textLength = text.length();

        if (mKeyListener != null) {
            text.setSpan(mKeyListener, 0, textLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
        }

        if (mSpanController == null) {
            mSpanController = new SpanController();
        }
        text.setSpan(mSpanController, 0, textLength, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
    }

    void setContextMenuAnchor(float x, float y) {
        mContextMenuAnchorX = x;
        mContextMenuAnchorY = y;
    }

    void onCreateContextMenu(ContextMenu menu) {
        if (mIsBeingLongClicked || Float.isNaN(mContextMenuAnchorX)
                || Float.isNaN(mContextMenuAnchorY)) {
            return;
        }
        final int offset = mTextView.getOffsetForPosition(mContextMenuAnchorX, mContextMenuAnchorY);
        if (offset == -1) {
            return;
        }

        stopTextActionModeWithPreservingSelection();
        if (mTextView.canSelectText()) {
            final boolean isOnSelection = mTextView.hasSelection()
                    && offset >= mTextView.getSelectionStart()
                    && offset <= mTextView.getSelectionEnd();
            if (!isOnSelection) {
                // Right clicked position is not on the selection. Remove the selection and move the
                // cursor to the right clicked position.
                Selection.setSelection((Spannable) mTextView.getText(), offset);
                stopTextActionMode();
            }
        }

        if (shouldOfferToShowSuggestions()) {
            final SuggestionInfo[] suggestionInfoArray =
                    new SuggestionInfo[SuggestionSpan.SUGGESTIONS_MAX_SIZE];
            for (int i = 0; i < suggestionInfoArray.length; i++) {
                suggestionInfoArray[i] = new SuggestionInfo();
            }
            final SubMenu subMenu = menu.addSubMenu(Menu.NONE, Menu.NONE, MENU_ITEM_ORDER_REPLACE,
                    com.android.internal.R.string.replace);
            final int numItems = mSuggestionHelper.getSuggestionInfo(suggestionInfoArray, null);
            for (int i = 0; i < numItems; i++) {
                final SuggestionInfo info = suggestionInfoArray[i];
                subMenu.add(Menu.NONE, Menu.NONE, i, info.mText)
                        .setOnMenuItemClickListener(new MenuItem.OnMenuItemClickListener() {
                            @Override
                            public boolean onMenuItemClick(MenuItem item) {
                                replaceWithSuggestion(info);
                                return true;
                            }
                        });
            }
        }

        menu.add(Menu.NONE, TextView.ID_UNDO, MENU_ITEM_ORDER_UNDO,
                com.android.internal.R.string.undo)
                .setAlphabeticShortcut('z')
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener)
                .setEnabled(mTextView.canUndo());
        menu.add(Menu.NONE, TextView.ID_REDO, MENU_ITEM_ORDER_REDO,
                com.android.internal.R.string.redo)
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener)
                .setEnabled(mTextView.canRedo());

        menu.add(Menu.NONE, TextView.ID_CUT, MENU_ITEM_ORDER_CUT,
                com.android.internal.R.string.cut)
                .setAlphabeticShortcut('x')
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener)
                .setEnabled(mTextView.canCut());
        menu.add(Menu.NONE, TextView.ID_COPY, MENU_ITEM_ORDER_COPY,
                com.android.internal.R.string.copy)
                .setAlphabeticShortcut('c')
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener)
                .setEnabled(mTextView.canCopy());
        menu.add(Menu.NONE, TextView.ID_PASTE, MENU_ITEM_ORDER_PASTE,
                com.android.internal.R.string.paste)
                .setAlphabeticShortcut('v')
                .setEnabled(mTextView.canPaste())
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener);
        menu.add(Menu.NONE, TextView.ID_PASTE_AS_PLAIN_TEXT, MENU_ITEM_ORDER_PASTE_AS_PLAIN_TEXT,
                com.android.internal.R.string.paste_as_plain_text)
                .setEnabled(mTextView.canPasteAsPlainText())
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener);
        menu.add(Menu.NONE, TextView.ID_SHARE, MENU_ITEM_ORDER_SHARE,
                com.android.internal.R.string.share)
                .setEnabled(mTextView.canShare())
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener);
        menu.add(Menu.NONE, TextView.ID_SELECT_ALL, MENU_ITEM_ORDER_SELECT_ALL,
                com.android.internal.R.string.selectAll)
                .setAlphabeticShortcut('a')
                .setEnabled(mTextView.canSelectAllText())
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener);
        menu.add(Menu.NONE, TextView.ID_AUTOFILL, MENU_ITEM_ORDER_AUTOFILL,
                android.R.string.autofill)
                .setEnabled(mTextView.canRequestAutofill())
                .setOnMenuItemClickListener(mOnContextMenuItemClickListener);

        mPreserveSelection = true;
    }

    @Nullable
    private SuggestionSpan findEquivalentSuggestionSpan(
            @NonNull SuggestionSpanInfo suggestionSpanInfo) {
        final Editable editable = (Editable) mTextView.getText();
        if (editable.getSpanStart(suggestionSpanInfo.mSuggestionSpan) >= 0) {
            // Exactly same span is found.
            return suggestionSpanInfo.mSuggestionSpan;
        }
        // Suggestion span couldn't be found. Try to find a suggestion span that has the same
        // contents.
        final SuggestionSpan[] suggestionSpans = editable.getSpans(suggestionSpanInfo.mSpanStart,
                suggestionSpanInfo.mSpanEnd, SuggestionSpan.class);
        for (final SuggestionSpan suggestionSpan : suggestionSpans) {
            final int start = editable.getSpanStart(suggestionSpan);
            if (start != suggestionSpanInfo.mSpanStart) {
                continue;
            }
            final int end = editable.getSpanEnd(suggestionSpan);
            if (end != suggestionSpanInfo.mSpanEnd) {
                continue;
            }
            if (suggestionSpan.equals(suggestionSpanInfo.mSuggestionSpan)) {
                return suggestionSpan;
            }
        }
        return null;
    }

    private void replaceWithSuggestion(@NonNull final SuggestionInfo suggestionInfo) {
        final SuggestionSpan targetSuggestionSpan = findEquivalentSuggestionSpan(
                suggestionInfo.mSuggestionSpanInfo);
        if (targetSuggestionSpan == null) {
            // Span has been removed
            return;
        }
        final Editable editable = (Editable) mTextView.getText();
        final int spanStart = editable.getSpanStart(targetSuggestionSpan);
        final int spanEnd = editable.getSpanEnd(targetSuggestionSpan);
        if (spanStart < 0 || spanEnd <= spanStart) {
            // Span has been removed
            return;
        }

        final String originalText = TextUtils.substring(editable, spanStart, spanEnd);
        // SuggestionSpans are removed by replace: save them before
        SuggestionSpan[] suggestionSpans = editable.getSpans(spanStart, spanEnd,
                SuggestionSpan.class);
        final int length = suggestionSpans.length;
        int[] suggestionSpansStarts = new int[length];
        int[] suggestionSpansEnds = new int[length];
        int[] suggestionSpansFlags = new int[length];
        for (int i = 0; i < length; i++) {
            final SuggestionSpan suggestionSpan = suggestionSpans[i];
            suggestionSpansStarts[i] = editable.getSpanStart(suggestionSpan);
            suggestionSpansEnds[i] = editable.getSpanEnd(suggestionSpan);
            suggestionSpansFlags[i] = editable.getSpanFlags(suggestionSpan);

            // Remove potential misspelled flags
            int suggestionSpanFlags = suggestionSpan.getFlags();
            if ((suggestionSpanFlags & SuggestionSpan.FLAG_MISSPELLED) != 0) {
                suggestionSpanFlags &= ~SuggestionSpan.FLAG_MISSPELLED;
                suggestionSpanFlags &= ~SuggestionSpan.FLAG_EASY_CORRECT;
                suggestionSpan.setFlags(suggestionSpanFlags);
            }
        }

        // Notify source IME of the suggestion pick. Do this before swapping texts.
        targetSuggestionSpan.notifySelection(
                mTextView.getContext(), originalText, suggestionInfo.mSuggestionIndex);

        // Swap text content between actual text and Suggestion span
        final int suggestionStart = suggestionInfo.mSuggestionStart;
        final int suggestionEnd = suggestionInfo.mSuggestionEnd;
        final String suggestion = suggestionInfo.mText.subSequence(
                suggestionStart, suggestionEnd).toString();
        mTextView.replaceText_internal(spanStart, spanEnd, suggestion);

        String[] suggestions = targetSuggestionSpan.getSuggestions();
        suggestions[suggestionInfo.mSuggestionIndex] = originalText;

        // Restore previous SuggestionSpans
        final int lengthDelta = suggestion.length() - (spanEnd - spanStart);
        for (int i = 0; i < length; i++) {
            // Only spans that include the modified region make sense after replacement
            // Spans partially included in the replaced region are removed, there is no
            // way to assign them a valid range after replacement
            if (suggestionSpansStarts[i] <= spanStart && suggestionSpansEnds[i] >= spanEnd) {
                mTextView.setSpan_internal(suggestionSpans[i], suggestionSpansStarts[i],
                        suggestionSpansEnds[i] + lengthDelta, suggestionSpansFlags[i]);
            }
        }
        // Move cursor at the end of the replaced word
        final int newCursorPosition = spanEnd + lengthDelta;
        mTextView.setCursorPosition_internal(newCursorPosition, newCursorPosition);
    }

    private final MenuItem.OnMenuItemClickListener mOnContextMenuItemClickListener =
            new MenuItem.OnMenuItemClickListener() {
        @Override
        public boolean onMenuItemClick(MenuItem item) {
            if (mProcessTextIntentActionsHandler.performMenuItemAction(item)) {
                return true;
            }
            return mTextView.onTextContextMenuItem(item.getItemId());
        }
    };

    
Controls the EasyEditSpan monitoring when it is added, and when the related pop-up should be displayed. Also monitors Selection to call back to the attached input method. /**
     * Controls the {@link EasyEditSpan} monitoring when it is added, and when the related
     * pop-up should be displayed.
     * Also monitors {@link Selection} to call back to the attached input method.
     */
    private class SpanController implements SpanWatcher {

        private static final int DISPLAY_TIMEOUT_MS = 3000; // 3 secs

        private EasyEditPopupWindow mPopupWindow;

        private Runnable mHidePopup;

        // This function is pure but inner classes can't have static functions
        private boolean isNonIntermediateSelectionSpan(final Spannable text,
                final Object span) {
            return (Selection.SELECTION_START == span || Selection.SELECTION_END == span)
                    && (text.getSpanFlags(span) & Spanned.SPAN_INTERMEDIATE) == 0;
        }

        @Override
        public void onSpanAdded(Spannable text, Object span, int start, int end) {
            if (isNonIntermediateSelectionSpan(text, span)) {
                sendUpdateSelection();
            } else if (span instanceof EasyEditSpan) {
                if (mPopupWindow == null) {
                    mPopupWindow = new EasyEditPopupWindow();
                    mHidePopup = new Runnable() {
                        @Override
                        public void run() {
                            hide();
                        }
                    };
                }

                // Make sure there is only at most one EasyEditSpan in the text
                if (mPopupWindow.mEasyEditSpan != null) {
                    mPopupWindow.mEasyEditSpan.setDeleteEnabled(false);
                }

                mPopupWindow.setEasyEditSpan((EasyEditSpan) span);
                mPopupWindow.setOnDeleteListener(new EasyEditDeleteListener() {
                    @Override
                    public void onDeleteClick(EasyEditSpan span) {
                        Editable editable = (Editable) mTextView.getText();
                        int start = editable.getSpanStart(span);
                        int end = editable.getSpanEnd(span);
                        if (start >= 0 && end >= 0) {
                            sendEasySpanNotification(EasyEditSpan.TEXT_DELETED, span);
                            mTextView.deleteText_internal(start, end);
                        }
                        editable.removeSpan(span);
                    }
                });

                if (mTextView.getWindowVisibility() != View.VISIBLE) {
                    // The window is not visible yet, ignore the text change.
                    return;
                }

                if (mTextView.getLayout() == null) {
                    // The view has not been laid out yet, ignore the text change
                    return;
                }

                if (extractedTextModeWillBeStarted()) {
                    // The input is in extract mode. Do not handle the easy edit in
                    // the original TextView, as the ExtractEditText will do
                    return;
                }

                mPopupWindow.show();
                mTextView.removeCallbacks(mHidePopup);
                mTextView.postDelayed(mHidePopup, DISPLAY_TIMEOUT_MS);
            }
        }

        @Override
        public void onSpanRemoved(Spannable text, Object span, int start, int end) {
            if (isNonIntermediateSelectionSpan(text, span)) {
                sendUpdateSelection();
            } else if (mPopupWindow != null && span == mPopupWindow.mEasyEditSpan) {
                hide();
            }
        }

        @Override
        public void onSpanChanged(Spannable text, Object span, int previousStart, int previousEnd,
                int newStart, int newEnd) {
            if (isNonIntermediateSelectionSpan(text, span)) {
                sendUpdateSelection();
            } else if (mPopupWindow != null && span instanceof EasyEditSpan) {
                EasyEditSpan easyEditSpan = (EasyEditSpan) span;
                sendEasySpanNotification(EasyEditSpan.TEXT_MODIFIED, easyEditSpan);
                text.removeSpan(easyEditSpan);
            }
        }

        public void hide() {
            if (mPopupWindow != null) {
                mPopupWindow.hide();
                mTextView.removeCallbacks(mHidePopup);
            }
        }

        private void sendEasySpanNotification(int textChangedType, EasyEditSpan span) {
            try {
                PendingIntent pendingIntent = span.getPendingIntent();
                if (pendingIntent != null) {
                    Intent intent = new Intent();
                    intent.putExtra(EasyEditSpan.EXTRA_TEXT_CHANGED_TYPE, textChangedType);
                    pendingIntent.send(mTextView.getContext(), 0, intent);
                }
            } catch (CanceledException e) {
                // This should not happen, as we should try to send the intent only once.
                Log.w(TAG, "PendingIntent for notification cannot be sent", e);
            }
        }
    }

    
Listens for the delete event triggered by EasyEditPopupWindow. /**
     * Listens for the delete event triggered by {@link EasyEditPopupWindow}.
     */
    private interface EasyEditDeleteListener {

        
Clicks the delete pop-up.
/**
         * Clicks the delete pop-up.
         */
        void onDeleteClick(EasyEditSpan span);
    }

    
Displays the actions associated to an EasyEditSpan. The pop-up is controlled by SpanController. /**
     * Displays the actions associated to an {@link EasyEditSpan}. The pop-up is controlled
     * by {@link SpanController}.
     */
    private class EasyEditPopupWindow extends PinnedPopupWindow
            implements OnClickListener {
        private static final int POPUP_TEXT_LAYOUT =
                com.android.internal.R.layout.text_edit_action_popup_text;
        private TextView mDeleteTextView;
        private EasyEditSpan mEasyEditSpan;
        private EasyEditDeleteListener mOnDeleteListener;

        @Override
        protected void createPopupWindow() {
            mPopupWindow = new PopupWindow(mTextView.getContext(), null,
                    com.android.internal.R.attr.textSelectHandleWindowStyle);
            mPopupWindow.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
            mPopupWindow.setClippingEnabled(true);
        }

        @Override
        protected void initContentView() {
            LinearLayout linearLayout = new LinearLayout(mTextView.getContext());
            linearLayout.setOrientation(LinearLayout.HORIZONTAL);
            mContentView = linearLayout;
            mContentView.setBackgroundResource(
                    com.android.internal.R.drawable.text_edit_side_paste_window);

            LayoutInflater inflater = (LayoutInflater) mTextView.getContext()
                    .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

            LayoutParams wrapContent = new LayoutParams(
                    ViewGroup.LayoutParams.WRAP_CONTENT, ViewGroup.LayoutParams.WRAP_CONTENT);

            mDeleteTextView = (TextView) inflater.inflate(POPUP_TEXT_LAYOUT, null);
            mDeleteTextView.setLayoutParams(wrapContent);
            mDeleteTextView.setText(com.android.internal.R.string.delete);
            mDeleteTextView.setOnClickListener(this);
            mContentView.addView(mDeleteTextView);
        }

        public void setEasyEditSpan(EasyEditSpan easyEditSpan) {
            mEasyEditSpan = easyEditSpan;
        }

        private void setOnDeleteListener(EasyEditDeleteListener listener) {
            mOnDeleteListener = listener;
        }

        @Override
        public void onClick(View view) {
            if (view == mDeleteTextView
                    && mEasyEditSpan != null && mEasyEditSpan.isDeleteEnabled()
                    && mOnDeleteListener != null) {
                mOnDeleteListener.onDeleteClick(mEasyEditSpan);
            }
        }

        @Override
        public void hide() {
            if (mEasyEditSpan != null) {
                mEasyEditSpan.setDeleteEnabled(false);
            }
            mOnDeleteListener = null;
            super.hide();
        }

        @Override
        protected int getTextOffset() {
            // Place the pop-up at the end of the span
            Editable editable = (Editable) mTextView.getText();
            return editable.getSpanEnd(mEasyEditSpan);
        }

        @Override
        protected int getVerticalLocalPosition(int line) {
            final Layout layout = mTextView.getLayout();
            return layout.getLineBottomWithoutSpacing(line);
        }

        @Override
        protected int clipVertically(int positionY) {
            // As we display the pop-up below the span, no vertical clipping is required.
            return positionY;
        }
    }

    private class PositionListener implements ViewTreeObserver.OnPreDrawListener {
        // 3 handles
        // 3 ActionPopup [replace, suggestion, easyedit] (suggestionsPopup first hides the others)
        // 1 CursorAnchorInfoNotifier
        private static final int MAXIMUM_NUMBER_OF_LISTENERS = 7;
        private TextViewPositionListener[] mPositionListeners =
                new TextViewPositionListener[MAXIMUM_NUMBER_OF_LISTENERS];
        private boolean[] mCanMove = new boolean[MAXIMUM_NUMBER_OF_LISTENERS];
        private boolean mPositionHasChanged = true;
        // Absolute position of the TextView with respect to its parent window
        private int mPositionX, mPositionY;
        private int mPositionXOnScreen, mPositionYOnScreen;
        private int mNumberOfListeners;
        private boolean mScrollHasChanged;
        final int[] mTempCoords = new int[2];

        public void addSubscriber(TextViewPositionListener positionListener, boolean canMove) {
            if (mNumberOfListeners == 0) {
                updatePosition();
                ViewTreeObserver vto = mTextView.getViewTreeObserver();
                vto.addOnPreDrawListener(this);
            }

            int emptySlotIndex = -1;
            for (int i = 0; i < MAXIMUM_NUMBER_OF_LISTENERS; i++) {
                TextViewPositionListener listener = mPositionListeners[i];
                if (listener == positionListener) {
                    return;
                } else if (emptySlotIndex < 0 && listener == null) {
                    emptySlotIndex = i;
                }
            }

            mPositionListeners[emptySlotIndex] = positionListener;
            mCanMove[emptySlotIndex] = canMove;
            mNumberOfListeners++;
        }

        public void removeSubscriber(TextViewPositionListener positionListener) {
            for (int i = 0; i < MAXIMUM_NUMBER_OF_LISTENERS; i++) {
                if (mPositionListeners[i] == positionListener) {
                    mPositionListeners[i] = null;
                    mNumberOfListeners--;
                    break;
                }
            }

            if (mNumberOfListeners == 0) {
                ViewTreeObserver vto = mTextView.getViewTreeObserver();
                vto.removeOnPreDrawListener(this);
            }
        }

        public int getPositionX() {
            return mPositionX;
        }

        public int getPositionY() {
            return mPositionY;
        }

        public int getPositionXOnScreen() {
            return mPositionXOnScreen;
        }

        public int getPositionYOnScreen() {
            return mPositionYOnScreen;
        }

        @Override
        public boolean onPreDraw() {
            updatePosition();

            for (int i = 0; i < MAXIMUM_NUMBER_OF_LISTENERS; i++) {
                if (mPositionHasChanged || mScrollHasChanged || mCanMove[i]) {
                    TextViewPositionListener positionListener = mPositionListeners[i];
                    if (positionListener != null) {
                        positionListener.updatePosition(mPositionX, mPositionY,
                                mPositionHasChanged, mScrollHasChanged);
                    }
                }
            }

            mScrollHasChanged = false;
            return true;
        }

        private void updatePosition() {
            mTextView.getLocationInWindow(mTempCoords);

            mPositionHasChanged = mTempCoords[0] != mPositionX || mTempCoords[1] != mPositionY;

            mPositionX = mTempCoords[0];
            mPositionY = mTempCoords[1];

            mTextView.getLocationOnScreen(mTempCoords);

            mPositionXOnScreen = mTempCoords[0];
            mPositionYOnScreen = mTempCoords[1];
        }

        public void onScrollChanged() {
            mScrollHasChanged = true;
        }
    }

    private abstract class PinnedPopupWindow implements TextViewPositionListener {
        protected PopupWindow mPopupWindow;
        protected ViewGroup mContentView;
        int mPositionX, mPositionY;
        int mClippingLimitLeft, mClippingLimitRight;

        protected abstract void createPopupWindow();
        protected abstract void initContentView();
        protected abstract int getTextOffset();
        protected abstract int getVerticalLocalPosition(int line);
        protected abstract int clipVertically(int positionY);
        protected void setUp() {
        }

        public PinnedPopupWindow() {
            // Due to calling subclass methods in base constructor, subclass constructor is not
            // called before subclass methods, e.g. createPopupWindow or initContentView. To give
            // a chance to initialize subclasses, call setUp() method here.
            // TODO: It is good to extract non trivial initialization code from constructor.
            setUp();

            createPopupWindow();

            mPopupWindow.setWindowLayoutType(
                    WindowManager.LayoutParams.TYPE_APPLICATION_ABOVE_SUB_PANEL);
            mPopupWindow.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
            mPopupWindow.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);

            initContentView();

            LayoutParams wrapContent = new LayoutParams(ViewGroup.LayoutParams.WRAP_CONTENT,
                    ViewGroup.LayoutParams.WRAP_CONTENT);
            mContentView.setLayoutParams(wrapContent);

            mPopupWindow.setContentView(mContentView);
        }

        public void show() {
            getPositionListener().addSubscriber(this, false /* offset is fixed */);

            computeLocalPosition();

            final PositionListener positionListener = getPositionListener();
            updatePosition(positionListener.getPositionX(), positionListener.getPositionY());
        }

        protected void measureContent() {
            final DisplayMetrics displayMetrics = mTextView.getResources().getDisplayMetrics();
            mContentView.measure(
                    View.MeasureSpec.makeMeasureSpec(displayMetrics.widthPixels,
                            View.MeasureSpec.AT_MOST),
                    View.MeasureSpec.makeMeasureSpec(displayMetrics.heightPixels,
                            View.MeasureSpec.AT_MOST));
        }

        /* The popup window will be horizontally centered on the getTextOffset() and vertically
         * positioned according to viewportToContentHorizontalOffset.
         *
         * This method assumes that mContentView has properly been measured from its content. */
        private void computeLocalPosition() {
            measureContent();
            final int width = mContentView.getMeasuredWidth();
            final int offset = getTextOffset();
            mPositionX = (int) (mTextView.getLayout().getPrimaryHorizontal(offset) - width / 2.0f);
            mPositionX += mTextView.viewportToContentHorizontalOffset();

            final int line = mTextView.getLayout().getLineForOffset(offset);
            mPositionY = getVerticalLocalPosition(line);
            mPositionY += mTextView.viewportToContentVerticalOffset();
        }

        private void updatePosition(int parentPositionX, int parentPositionY) {
            int positionX = parentPositionX + mPositionX;
            int positionY = parentPositionY + mPositionY;

            positionY = clipVertically(positionY);

            // Horizontal clipping
            final DisplayMetrics displayMetrics = mTextView.getResources().getDisplayMetrics();
            final int width = mContentView.getMeasuredWidth();
            positionX = Math.min(
                    displayMetrics.widthPixels - width + mClippingLimitRight, positionX);
            positionX = Math.max(-mClippingLimitLeft, positionX);

            if (isShowing()) {
                mPopupWindow.update(positionX, positionY, -1, -1);
            } else {
                mPopupWindow.showAtLocation(mTextView, Gravity.NO_GRAVITY,
                        positionX, positionY);
            }
        }

        public void hide() {
            if (!isShowing()) {
                return;
            }
            mPopupWindow.dismiss();
            getPositionListener().removeSubscriber(this);
        }

        @Override
        public void updatePosition(int parentPositionX, int parentPositionY,
                boolean parentPositionChanged, boolean parentScrolled) {
            // Either parentPositionChanged or parentScrolled is true, check if still visible
            if (isShowing() && isOffsetVisible(getTextOffset())) {
                if (parentScrolled) computeLocalPosition();
                updatePosition(parentPositionX, parentPositionY);
            } else {
                hide();
            }
        }

        public boolean isShowing() {
            return mPopupWindow.isShowing();
        }
    }

    private static final class SuggestionInfo {
        // Range of actual suggestion within mText
        int mSuggestionStart, mSuggestionEnd;

        // The SuggestionSpan that this TextView represents
        final SuggestionSpanInfo mSuggestionSpanInfo = new SuggestionSpanInfo();

        // The index of this suggestion inside suggestionSpan
        int mSuggestionIndex;

        final SpannableStringBuilder mText = new SpannableStringBuilder();

        void clear() {
            mSuggestionSpanInfo.clear();
            mText.clear();
        }

        // Utility method to set attributes about a SuggestionSpan.
        void setSpanInfo(SuggestionSpan span, int spanStart, int spanEnd) {
            mSuggestionSpanInfo.mSuggestionSpan = span;
            mSuggestionSpanInfo.mSpanStart = spanStart;
            mSuggestionSpanInfo.mSpanEnd = spanEnd;
        }
    }

    private static final class SuggestionSpanInfo {
        // The SuggestionSpan;
        @Nullable
        SuggestionSpan mSuggestionSpan;

        // The SuggestionSpan start position
        int mSpanStart;

        // The SuggestionSpan end position
        int mSpanEnd;

        void clear() {
            mSuggestionSpan = null;
        }
    }

    private class SuggestionHelper {
        private final Comparator<SuggestionSpan> mSuggestionSpanComparator =
                new SuggestionSpanComparator();
        private final HashMap<SuggestionSpan, Integer> mSpansLengths =
                new HashMap<SuggestionSpan, Integer>();

        private class SuggestionSpanComparator implements Comparator<SuggestionSpan> {
            public int compare(SuggestionSpan span1, SuggestionSpan span2) {
                final int flag1 = span1.getFlags();
                final int flag2 = span2.getFlags();
                if (flag1 != flag2) {
                    // The order here should match what is used in updateDrawState
                    final boolean easy1 = (flag1 & SuggestionSpan.FLAG_EASY_CORRECT) != 0;
                    final boolean easy2 = (flag2 & SuggestionSpan.FLAG_EASY_CORRECT) != 0;
                    final boolean misspelled1 = (flag1 & SuggestionSpan.FLAG_MISSPELLED) != 0;
                    final boolean misspelled2 = (flag2 & SuggestionSpan.FLAG_MISSPELLED) != 0;
                    if (easy1 && !misspelled1) return -1;
                    if (easy2 && !misspelled2) return 1;
                    if (misspelled1) return -1;
                    if (misspelled2) return 1;
                }

                return mSpansLengths.get(span1).intValue() - mSpansLengths.get(span2).intValue();
            }
        }

        
Returns the suggestion spans that cover the current cursor position. The suggestion
spans are sorted according to the length of text that they are attached to.
/**
         * Returns the suggestion spans that cover the current cursor position. The suggestion
         * spans are sorted according to the length of text that they are attached to.
         */
        private SuggestionSpan[] getSortedSuggestionSpans() {
            int pos = mTextView.getSelectionStart();
            Spannable spannable = (Spannable) mTextView.getText();
            SuggestionSpan[] suggestionSpans = spannable.getSpans(pos, pos, SuggestionSpan.class);

            mSpansLengths.clear();
            for (SuggestionSpan suggestionSpan : suggestionSpans) {
                int start = spannable.getSpanStart(suggestionSpan);
                int end = spannable.getSpanEnd(suggestionSpan);
                mSpansLengths.put(suggestionSpan, Integer.valueOf(end - start));
            }

            // The suggestions are sorted according to their types (easy correction first, then
            // misspelled) and to the length of the text that they cover (shorter first).
            Arrays.sort(suggestionSpans, mSuggestionSpanComparator);
            mSpansLengths.clear();

            return suggestionSpans;
        }

        
Gets the SuggestionInfo list that contains suggestion information at the current cursor
position.
Params:
suggestionInfos – SuggestionInfo array the results will be set.
misspelledSpanInfo – a struct the misspelled SuggestionSpan info will be set.
Returns:
the number of suggestions actually fetched./**
         * Gets the SuggestionInfo list that contains suggestion information at the current cursor
         * position.
         *
         * @param suggestionInfos SuggestionInfo array the results will be set.
         * @param misspelledSpanInfo a struct the misspelled SuggestionSpan info will be set.
         * @return the number of suggestions actually fetched.
         */
        public int getSuggestionInfo(SuggestionInfo[] suggestionInfos,
                @Nullable SuggestionSpanInfo misspelledSpanInfo) {
            final Spannable spannable = (Spannable) mTextView.getText();
            final SuggestionSpan[] suggestionSpans = getSortedSuggestionSpans();
            final int nbSpans = suggestionSpans.length;
            if (nbSpans == 0) return 0;

            int numberOfSuggestions = 0;
            for (final SuggestionSpan suggestionSpan : suggestionSpans) {
                final int spanStart = spannable.getSpanStart(suggestionSpan);
                final int spanEnd = spannable.getSpanEnd(suggestionSpan);

                if (misspelledSpanInfo != null
                        && (suggestionSpan.getFlags() & SuggestionSpan.FLAG_MISSPELLED) != 0) {
                    misspelledSpanInfo.mSuggestionSpan = suggestionSpan;
                    misspelledSpanInfo.mSpanStart = spanStart;
                    misspelledSpanInfo.mSpanEnd = spanEnd;
                }

                final String[] suggestions = suggestionSpan.getSuggestions();
                final int nbSuggestions = suggestions.length;
                suggestionLoop:
                for (int suggestionIndex = 0; suggestionIndex < nbSuggestions; suggestionIndex++) {
                    final String suggestion = suggestions[suggestionIndex];
                    for (int i = 0; i < numberOfSuggestions; i++) {
                        final SuggestionInfo otherSuggestionInfo = suggestionInfos[i];
                        if (otherSuggestionInfo.mText.toString().equals(suggestion)) {
                            final int otherSpanStart =
                                    otherSuggestionInfo.mSuggestionSpanInfo.mSpanStart;
                            final int otherSpanEnd =
                                    otherSuggestionInfo.mSuggestionSpanInfo.mSpanEnd;
                            if (spanStart == otherSpanStart && spanEnd == otherSpanEnd) {
                                continue suggestionLoop;
                            }
                        }
                    }

                    SuggestionInfo suggestionInfo = suggestionInfos[numberOfSuggestions];
                    suggestionInfo.setSpanInfo(suggestionSpan, spanStart, spanEnd);
                    suggestionInfo.mSuggestionIndex = suggestionIndex;
                    suggestionInfo.mSuggestionStart = 0;
                    suggestionInfo.mSuggestionEnd = suggestion.length();
                    suggestionInfo.mText.replace(0, suggestionInfo.mText.length(), suggestion);
                    numberOfSuggestions++;
                    if (numberOfSuggestions >= suggestionInfos.length) {
                        return numberOfSuggestions;
                    }
                }
            }
            return numberOfSuggestions;
        }
    }

    @VisibleForTesting
    public class SuggestionsPopupWindow extends PinnedPopupWindow implements OnItemClickListener {
        private static final int MAX_NUMBER_SUGGESTIONS = SuggestionSpan.SUGGESTIONS_MAX_SIZE;

        // Key of intent extras for inserting new word into user dictionary.
        private static final String USER_DICTIONARY_EXTRA_WORD = "word";
        private static final String USER_DICTIONARY_EXTRA_LOCALE = "locale";

        private SuggestionInfo[] mSuggestionInfos;
        private int mNumberOfSuggestions;
        private boolean mCursorWasVisibleBeforeSuggestions;
        private boolean mIsShowingUp = false;
        private SuggestionAdapter mSuggestionsAdapter;
        private TextAppearanceSpan mHighlightSpan;  // TODO: Make mHighlightSpan final.
        private TextView mAddToDictionaryButton;
        private TextView mDeleteButton;
        private ListView mSuggestionListView;
        private final SuggestionSpanInfo mMisspelledSpanInfo = new SuggestionSpanInfo();
        private int mContainerMarginWidth;
        private int mContainerMarginTop;
        private LinearLayout mContainerView;
        private Context mContext;  // TODO: Make mContext final.

        private class CustomPopupWindow extends PopupWindow {

            @Override
            public void dismiss() {
                if (!isShowing()) {
                    return;
                }
                super.dismiss();
                getPositionListener().removeSubscriber(SuggestionsPopupWindow.this);

                // Safe cast since show() checks that mTextView.getText() is an Editable
                ((Spannable) mTextView.getText()).removeSpan(mSuggestionRangeSpan);

                mTextView.setCursorVisible(mCursorWasVisibleBeforeSuggestions);
                if (hasInsertionController() && !extractedTextModeWillBeStarted()) {
                    getInsertionController().show();
                }
            }
        }

        public SuggestionsPopupWindow() {
            mCursorWasVisibleBeforeSuggestions = mCursorVisible;
        }

        @Override
        protected void setUp() {
            mContext = applyDefaultTheme(mTextView.getContext());
            mHighlightSpan = new TextAppearanceSpan(mContext,
                    mTextView.mTextEditSuggestionHighlightStyle);
        }

        private Context applyDefaultTheme(Context originalContext) {
            TypedArray a = originalContext.obtainStyledAttributes(
                    new int[]{com.android.internal.R.attr.isLightTheme});
            boolean isLightTheme = a.getBoolean(0, true);
            int themeId = isLightTheme ? R.style.ThemeOverlay_Material_Light
                    : R.style.ThemeOverlay_Material_Dark;
            a.recycle();
            return new ContextThemeWrapper(originalContext, themeId);
        }

        @Override
        protected void createPopupWindow() {
            mPopupWindow = new CustomPopupWindow();
            mPopupWindow.setInputMethodMode(PopupWindow.INPUT_METHOD_NOT_NEEDED);
            mPopupWindow.setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
            mPopupWindow.setFocusable(true);
            mPopupWindow.setClippingEnabled(false);
        }

        @Override
        protected void initContentView() {
            final LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(
                    Context.LAYOUT_INFLATER_SERVICE);
            mContentView = (ViewGroup) inflater.inflate(
                    mTextView.mTextEditSuggestionContainerLayout, null);

            mContainerView = (LinearLayout) mContentView.findViewById(
                    com.android.internal.R.id.suggestionWindowContainer);
            ViewGroup.MarginLayoutParams lp =
                    (ViewGroup.MarginLayoutParams) mContainerView.getLayoutParams();
            mContainerMarginWidth = lp.leftMargin + lp.rightMargin;
            mContainerMarginTop = lp.topMargin;
            mClippingLimitLeft = lp.leftMargin;
            mClippingLimitRight = lp.rightMargin;

            mSuggestionListView = (ListView) mContentView.findViewById(
                    com.android.internal.R.id.suggestionContainer);

            mSuggestionsAdapter = new SuggestionAdapter();
            mSuggestionListView.setAdapter(mSuggestionsAdapter);
            mSuggestionListView.setOnItemClickListener(this);

            // Inflate the suggestion items once and for all.
            mSuggestionInfos = new SuggestionInfo[MAX_NUMBER_SUGGESTIONS];
            for (int i = 0; i < mSuggestionInfos.length; i++) {
                mSuggestionInfos[i] = new SuggestionInfo();
            }

            mAddToDictionaryButton = (TextView) mContentView.findViewById(
                    com.android.internal.R.id.addToDictionaryButton);
            mAddToDictionaryButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    final SuggestionSpan misspelledSpan =
                            findEquivalentSuggestionSpan(mMisspelledSpanInfo);
                    if (misspelledSpan == null) {
                        // Span has been removed.
                        return;
                    }
                    final Editable editable = (Editable) mTextView.getText();
                    final int spanStart = editable.getSpanStart(misspelledSpan);
                    final int spanEnd = editable.getSpanEnd(misspelledSpan);
                    if (spanStart < 0 || spanEnd <= spanStart) {
                        return;
                    }
                    final String originalText = TextUtils.substring(editable, spanStart, spanEnd);

                    final Intent intent = new Intent(Settings.ACTION_USER_DICTIONARY_INSERT);
                    intent.putExtra(USER_DICTIONARY_EXTRA_WORD, originalText);
                    intent.putExtra(USER_DICTIONARY_EXTRA_LOCALE,
                            mTextView.getTextServicesLocale().toString());
                    intent.setFlags(intent.getFlags() | Intent.FLAG_ACTIVITY_NEW_TASK);
                    mTextView.getContext().startActivity(intent);
                    // There is no way to know if the word was indeed added. Re-check.
                    // TODO The ExtractEditText should remove the span in the original text instead
                    editable.removeSpan(mMisspelledSpanInfo.mSuggestionSpan);
                    Selection.setSelection(editable, spanEnd);
                    updateSpellCheckSpans(spanStart, spanEnd, false);
                    hideWithCleanUp();
                }
            });

            mDeleteButton = (TextView) mContentView.findViewById(
                    com.android.internal.R.id.deleteButton);
            mDeleteButton.setOnClickListener(new View.OnClickListener() {
                public void onClick(View v) {
                    final Editable editable = (Editable) mTextView.getText();

                    final int spanUnionStart = editable.getSpanStart(mSuggestionRangeSpan);
                    int spanUnionEnd = editable.getSpanEnd(mSuggestionRangeSpan);
                    if (spanUnionStart >= 0 && spanUnionEnd > spanUnionStart) {
                        // Do not leave two adjacent spaces after deletion, or one at beginning of
                        // text
                        if (spanUnionEnd < editable.length()
                                && Character.isSpaceChar(editable.charAt(spanUnionEnd))
                                && (spanUnionStart == 0
                                        || Character.isSpaceChar(
                                                editable.charAt(spanUnionStart - 1)))) {
                            spanUnionEnd = spanUnionEnd + 1;
                        }
                        mTextView.deleteText_internal(spanUnionStart, spanUnionEnd);
                    }
                    hideWithCleanUp();
                }
            });

        }

        public boolean isShowingUp() {
            return mIsShowingUp;
        }

        public void onParentLostFocus() {
            mIsShowingUp = false;
        }

        private class SuggestionAdapter extends BaseAdapter {
            private LayoutInflater mInflater = (LayoutInflater) mContext.getSystemService(
                    Context.LAYOUT_INFLATER_SERVICE);

            @Override
            public int getCount() {
                return mNumberOfSuggestions;
            }

            @Override
            public Object getItem(int position) {
                return mSuggestionInfos[position];
            }

            @Override
            public long getItemId(int position) {
                return position;
            }

            @Override
            public View getView(int position, View convertView, ViewGroup parent) {
                TextView textView = (TextView) convertView;

                if (textView == null) {
                    textView = (TextView) mInflater.inflate(mTextView.mTextEditSuggestionItemLayout,
                            parent, false);
                }

                final SuggestionInfo suggestionInfo = mSuggestionInfos[position];
                textView.setText(suggestionInfo.mText);
                return textView;
            }
        }

        @VisibleForTesting
        public ViewGroup getContentViewForTesting() {
            return mContentView;
        }

        @Override
        public void show() {
            if (!(mTextView.getText() instanceof Editable)) return;
            if (extractedTextModeWillBeStarted()) {
                return;
            }

            if (updateSuggestions()) {
                mCursorWasVisibleBeforeSuggestions = mCursorVisible;
                mTextView.setCursorVisible(false);
                mIsShowingUp = true;
                super.show();
            }

            mSuggestionListView.setVisibility(mNumberOfSuggestions == 0 ? View.GONE : View.VISIBLE);
        }

        @Override
        protected void measureContent() {
            final DisplayMetrics displayMetrics = mTextView.getResources().getDisplayMetrics();
            final int horizontalMeasure = View.MeasureSpec.makeMeasureSpec(
                    displayMetrics.widthPixels, View.MeasureSpec.AT_MOST);
            final int verticalMeasure = View.MeasureSpec.makeMeasureSpec(
                    displayMetrics.heightPixels, View.MeasureSpec.AT_MOST);

            int width = 0;
            View view = null;
            for (int i = 0; i < mNumberOfSuggestions; i++) {
                view = mSuggestionsAdapter.getView(i, view, mContentView);
                view.getLayoutParams().width = LayoutParams.WRAP_CONTENT;
                view.measure(horizontalMeasure, verticalMeasure);
                width = Math.max(width, view.getMeasuredWidth());
            }

            if (mAddToDictionaryButton.getVisibility() != View.GONE) {
                mAddToDictionaryButton.measure(horizontalMeasure, verticalMeasure);
                width = Math.max(width, mAddToDictionaryButton.getMeasuredWidth());
            }

            mDeleteButton.measure(horizontalMeasure, verticalMeasure);
            width = Math.max(width, mDeleteButton.getMeasuredWidth());

            width += mContainerView.getPaddingLeft() + mContainerView.getPaddingRight()
                    + mContainerMarginWidth;

            // Enforce the width based on actual text widths
            mContentView.measure(
                    View.MeasureSpec.makeMeasureSpec(width, View.MeasureSpec.EXACTLY),
                    verticalMeasure);

            Drawable popupBackground = mPopupWindow.getBackground();
            if (popupBackground != null) {
                if (mTempRect == null) mTempRect = new Rect();
                popupBackground.getPadding(mTempRect);
                width += mTempRect.left + mTempRect.right;
            }
            mPopupWindow.setWidth(width);
        }

        @Override
        protected int getTextOffset() {
            return (mTextView.getSelectionStart() + mTextView.getSelectionStart()) / 2;
        }

        @Override
        protected int getVerticalLocalPosition(int line) {
            final Layout layout = mTextView.getLayout();
            return layout.getLineBottomWithoutSpacing(line) - mContainerMarginTop;
        }

        @Override
        protected int clipVertically(int positionY) {
            final int height = mContentView.getMeasuredHeight();
            final DisplayMetrics displayMetrics = mTextView.getResources().getDisplayMetrics();
            return Math.min(positionY, displayMetrics.heightPixels - height);
        }

        private void hideWithCleanUp() {
            for (final SuggestionInfo info : mSuggestionInfos) {
                info.clear();
            }
            mMisspelledSpanInfo.clear();
            hide();
        }

        private boolean updateSuggestions() {
            Spannable spannable = (Spannable) mTextView.getText();
            mNumberOfSuggestions =
                    mSuggestionHelper.getSuggestionInfo(mSuggestionInfos, mMisspelledSpanInfo);
            if (mNumberOfSuggestions == 0 && mMisspelledSpanInfo.mSuggestionSpan == null) {
                return false;
            }

            int spanUnionStart = mTextView.getText().length();
            int spanUnionEnd = 0;

            for (int i = 0; i < mNumberOfSuggestions; i++) {
                final SuggestionSpanInfo spanInfo = mSuggestionInfos[i].mSuggestionSpanInfo;
                spanUnionStart = Math.min(spanUnionStart, spanInfo.mSpanStart);
                spanUnionEnd = Math.max(spanUnionEnd, spanInfo.mSpanEnd);
            }
            if (mMisspelledSpanInfo.mSuggestionSpan != null) {
                spanUnionStart = Math.min(spanUnionStart, mMisspelledSpanInfo.mSpanStart);
                spanUnionEnd = Math.max(spanUnionEnd, mMisspelledSpanInfo.mSpanEnd);
            }

            for (int i = 0; i < mNumberOfSuggestions; i++) {
                highlightTextDifferences(mSuggestionInfos[i], spanUnionStart, spanUnionEnd);
            }

            // Make "Add to dictionary" item visible if there is a span with the misspelled flag
            int addToDictionaryButtonVisibility = View.GONE;
            if (mMisspelledSpanInfo.mSuggestionSpan != null) {
                if (mMisspelledSpanInfo.mSpanStart >= 0
                        && mMisspelledSpanInfo.mSpanEnd > mMisspelledSpanInfo.mSpanStart) {
                    addToDictionaryButtonVisibility = View.VISIBLE;
                }
            }
            mAddToDictionaryButton.setVisibility(addToDictionaryButtonVisibility);

            if (mSuggestionRangeSpan == null) mSuggestionRangeSpan = new SuggestionRangeSpan();
            final int underlineColor;
            if (mNumberOfSuggestions != 0) {
                underlineColor =
                        mSuggestionInfos[0].mSuggestionSpanInfo.mSuggestionSpan.getUnderlineColor();
            } else {
                underlineColor = mMisspelledSpanInfo.mSuggestionSpan.getUnderlineColor();
            }

            if (underlineColor == 0) {
                // Fallback on the default highlight color when the first span does not provide one
                mSuggestionRangeSpan.setBackgroundColor(mTextView.mHighlightColor);
            } else {
                final float BACKGROUND_TRANSPARENCY = 0.4f;
                final int newAlpha = (int) (Color.alpha(underlineColor) * BACKGROUND_TRANSPARENCY);
                mSuggestionRangeSpan.setBackgroundColor(
                        (underlineColor & 0x00FFFFFF) + (newAlpha << 24));
            }
            spannable.setSpan(mSuggestionRangeSpan, spanUnionStart, spanUnionEnd,
                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

            mSuggestionsAdapter.notifyDataSetChanged();
            return true;
        }

        private void highlightTextDifferences(SuggestionInfo suggestionInfo, int unionStart,
                int unionEnd) {
            final Spannable text = (Spannable) mTextView.getText();
            final int spanStart = suggestionInfo.mSuggestionSpanInfo.mSpanStart;
            final int spanEnd = suggestionInfo.mSuggestionSpanInfo.mSpanEnd;

            // Adjust the start/end of the suggestion span
            suggestionInfo.mSuggestionStart = spanStart - unionStart;
            suggestionInfo.mSuggestionEnd = suggestionInfo.mSuggestionStart
                    + suggestionInfo.mText.length();

            suggestionInfo.mText.setSpan(mHighlightSpan, 0, suggestionInfo.mText.length(),
                    Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);

            // Add the text before and after the span.
            final String textAsString = text.toString();
            suggestionInfo.mText.insert(0, textAsString.substring(unionStart, spanStart));
            suggestionInfo.mText.append(textAsString.substring(spanEnd, unionEnd));
        }

        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            SuggestionInfo suggestionInfo = mSuggestionInfos[position];
            replaceWithSuggestion(suggestionInfo);
            hideWithCleanUp();
        }
    }

    
An ActionMode Callback class that is used to provide actions while in text insertion or
selection mode.
The default callback provides a subset of Select All, Cut, Copy, Paste, Share and Replace
actions, depending on which of these this TextView supports and the current selection.
/**
     * An ActionMode Callback class that is used to provide actions while in text insertion or
     * selection mode.
     *
     * The default callback provides a subset of Select All, Cut, Copy, Paste, Share and Replace
     * actions, depending on which of these this TextView supports and the current selection.
     */
    private class TextActionModeCallback extends ActionMode.Callback2 {
        private final Path mSelectionPath = new Path();
        private final RectF mSelectionBounds = new RectF();
        private final boolean mHasSelection;
        private final int mHandleHeight;
        private final Map<MenuItem, OnClickListener> mAssistClickHandlers = new HashMap<>();

        TextActionModeCallback(@TextActionMode int mode) {
            mHasSelection = mode == TextActionMode.SELECTION
                    || (mTextIsSelectable && mode == TextActionMode.TEXT_LINK);
            if (mHasSelection) {
                SelectionModifierCursorController selectionController = getSelectionController();
                if (selectionController.mStartHandle == null) {
                    // As these are for initializing selectionController, hide() must be called.
                    selectionController.initDrawables();
                    selectionController.initHandles();
                    selectionController.hide();
                }
                mHandleHeight = Math.max(
                        mSelectHandleLeft.getMinimumHeight(),
                        mSelectHandleRight.getMinimumHeight());
            } else {
                InsertionPointCursorController insertionController = getInsertionController();
                if (insertionController != null) {
                    insertionController.getHandle();
                    mHandleHeight = mSelectHandleCenter.getMinimumHeight();
                } else {
                    mHandleHeight = 0;
                }
            }
        }

        @Override
        public boolean onCreateActionMode(ActionMode mode, Menu menu) {
            mAssistClickHandlers.clear();

            mode.setTitle(null);
            mode.setSubtitle(null);
            mode.setTitleOptionalHint(true);
            populateMenuWithItems(menu);

            Callback customCallback = getCustomCallback();
            if (customCallback != null) {
                if (!customCallback.onCreateActionMode(mode, menu)) {
                    // The custom mode can choose to cancel the action mode, dismiss selection.
                    Selection.setSelection((Spannable) mTextView.getText(),
                            mTextView.getSelectionEnd());
                    return false;
                }
            }

            if (mTextView.canProcessText()) {
                mProcessTextIntentActionsHandler.onInitializeMenu(menu);
            }

            if (mHasSelection && !mTextView.hasTransientState()) {
                mTextView.setHasTransientState(true);
            }
            return true;
        }

        private Callback getCustomCallback() {
            return mHasSelection
                    ? mCustomSelectionActionModeCallback
                    : mCustomInsertionActionModeCallback;
        }

        private void populateMenuWithItems(Menu menu) {
            if (mTextView.canCut()) {
                menu.add(Menu.NONE, TextView.ID_CUT, MENU_ITEM_ORDER_CUT,
                        com.android.internal.R.string.cut)
                                .setAlphabeticShortcut('x')
                                .setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
            }

            if (mTextView.canCopy()) {
                menu.add(Menu.NONE, TextView.ID_COPY, MENU_ITEM_ORDER_COPY,
                        com.android.internal.R.string.copy)
                                .setAlphabeticShortcut('c')
                                .setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
            }

            if (mTextView.canPaste()) {
                menu.add(Menu.NONE, TextView.ID_PASTE, MENU_ITEM_ORDER_PASTE,
                        com.android.internal.R.string.paste)
                                .setAlphabeticShortcut('v')
                                .setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
            }

            if (mTextView.canShare()) {
                menu.add(Menu.NONE, TextView.ID_SHARE, MENU_ITEM_ORDER_SHARE,
                        com.android.internal.R.string.share)
                        .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            }

            if (mTextView.canRequestAutofill()) {
                final String selected = mTextView.getSelectedText();
                if (selected == null || selected.isEmpty()) {
                    menu.add(Menu.NONE, TextView.ID_AUTOFILL, MENU_ITEM_ORDER_AUTOFILL,
                            com.android.internal.R.string.autofill)
                            .setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
                }
            }

            if (mTextView.canPasteAsPlainText()) {
                menu.add(
                        Menu.NONE,
                        TextView.ID_PASTE_AS_PLAIN_TEXT,
                        MENU_ITEM_ORDER_PASTE_AS_PLAIN_TEXT,
                        com.android.internal.R.string.paste_as_plain_text)
                        .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            }

            updateSelectAllItem(menu);
            updateReplaceItem(menu);
            updateAssistMenuItems(menu);
        }

        @Override
        public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
            updateSelectAllItem(menu);
            updateReplaceItem(menu);
            updateAssistMenuItems(menu);

            Callback customCallback = getCustomCallback();
            if (customCallback != null) {
                return customCallback.onPrepareActionMode(mode, menu);
            }
            return true;
        }

        private void updateSelectAllItem(Menu menu) {
            boolean canSelectAll = mTextView.canSelectAllText();
            boolean selectAllItemExists = menu.findItem(TextView.ID_SELECT_ALL) != null;
            if (canSelectAll && !selectAllItemExists) {
                menu.add(Menu.NONE, TextView.ID_SELECT_ALL, MENU_ITEM_ORDER_SELECT_ALL,
                        com.android.internal.R.string.selectAll)
                    .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            } else if (!canSelectAll && selectAllItemExists) {
                menu.removeItem(TextView.ID_SELECT_ALL);
            }
        }

        private void updateReplaceItem(Menu menu) {
            boolean canReplace = mTextView.isSuggestionsEnabled() && shouldOfferToShowSuggestions();
            boolean replaceItemExists = menu.findItem(TextView.ID_REPLACE) != null;
            if (canReplace && !replaceItemExists) {
                menu.add(Menu.NONE, TextView.ID_REPLACE, MENU_ITEM_ORDER_REPLACE,
                        com.android.internal.R.string.replace)
                    .setShowAsAction(MenuItem.SHOW_AS_ACTION_IF_ROOM);
            } else if (!canReplace && replaceItemExists) {
                menu.removeItem(TextView.ID_REPLACE);
            }
        }

        private void updateAssistMenuItems(Menu menu) {
            clearAssistMenuItems(menu);
            if (!shouldEnableAssistMenuItems()) {
                return;
            }
            final TextClassification textClassification =
                    getSelectionActionModeHelper().getTextClassification();
            if (textClassification == null) {
                return;
            }
            if (!textClassification.getActions().isEmpty()) {
                // Primary assist action (Always shown).
                final MenuItem item = addAssistMenuItem(menu,
                        textClassification.getActions().get(0), TextView.ID_ASSIST,
                        MENU_ITEM_ORDER_ASSIST, MenuItem.SHOW_AS_ACTION_ALWAYS);
                item.setIntent(textClassification.getIntent());
            } else if (hasLegacyAssistItem(textClassification)) {
                // Legacy primary assist action (Always shown).
                final MenuItem item = menu.add(
                        TextView.ID_ASSIST, TextView.ID_ASSIST, MENU_ITEM_ORDER_ASSIST,
                        textClassification.getLabel())
                        .setIcon(textClassification.getIcon())
                        .setIntent(textClassification.getIntent());
                item.setShowAsAction(MenuItem.SHOW_AS_ACTION_ALWAYS);
                mAssistClickHandlers.put(item, TextClassification.createIntentOnClickListener(
                        TextClassification.createPendingIntent(mTextView.getContext(),
                                textClassification.getIntent(),
                                createAssistMenuItemPendingIntentRequestCode())));
            }
            final int count = textClassification.getActions().size();
            for (int i = 1; i < count; i++) {
                // Secondary assist action (Never shown).
                addAssistMenuItem(menu, textClassification.getActions().get(i), Menu.NONE,
                        MENU_ITEM_ORDER_SECONDARY_ASSIST_ACTIONS_START + i - 1,
                        MenuItem.SHOW_AS_ACTION_NEVER);
            }
        }

        private MenuItem addAssistMenuItem(Menu menu, RemoteAction action, int intemId, int order,
                int showAsAction) {
            final MenuItem item = menu.add(TextView.ID_ASSIST, intemId, order, action.getTitle())
                    .setContentDescription(action.getContentDescription());
            if (action.shouldShowIcon()) {
                item.setIcon(action.getIcon().loadDrawable(mTextView.getContext()));
            }
            item.setShowAsAction(showAsAction);
            mAssistClickHandlers.put(item,
                    TextClassification.createIntentOnClickListener(action.getActionIntent()));
            return item;
        }

        private void clearAssistMenuItems(Menu menu) {
            int i = 0;
            while (i < menu.size()) {
                final MenuItem menuItem = menu.getItem(i);
                if (menuItem.getGroupId() == TextView.ID_ASSIST) {
                    menu.removeItem(menuItem.getItemId());
                    continue;
                }
                i++;
            }
        }

        private boolean hasLegacyAssistItem(TextClassification classification) {
            // Check whether we have the UI data and and action.
            return (classification.getIcon() != null || !TextUtils.isEmpty(
                    classification.getLabel())) && (classification.getIntent() != null
                    || classification.getOnClickListener() != null);
        }

        private boolean onAssistMenuItemClicked(MenuItem assistMenuItem) {
            Preconditions.checkArgument(assistMenuItem.getGroupId() == TextView.ID_ASSIST);

            final TextClassification textClassification =
                    getSelectionActionModeHelper().getTextClassification();
            if (!shouldEnableAssistMenuItems() || textClassification == null) {
                // No textClassification result to handle the click. Eat the click.
                return true;
            }

            OnClickListener onClickListener = mAssistClickHandlers.get(assistMenuItem);
            if (onClickListener == null) {
                final Intent intent = assistMenuItem.getIntent();
                if (intent != null) {
                    onClickListener = TextClassification.createIntentOnClickListener(
                            TextClassification.createPendingIntent(
                                    mTextView.getContext(), intent,
                                    createAssistMenuItemPendingIntentRequestCode()));
                }
            }
            if (onClickListener != null) {
                onClickListener.onClick(mTextView);
                stopTextActionMode();
            }
            // We tried our best.
            return true;
        }

        private int createAssistMenuItemPendingIntentRequestCode() {
            return mTextView.hasSelection()
                    ? mTextView.getText().subSequence(
                            mTextView.getSelectionStart(), mTextView.getSelectionEnd())
                            .hashCode()
                    : 0;
        }

        private boolean shouldEnableAssistMenuItems() {
            return mTextView.isDeviceProvisioned()
                && TextClassificationManager.getSettings(mTextView.getContext())
                        .isSmartTextShareEnabled();
        }

        @Override
        public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
            getSelectionActionModeHelper().onSelectionAction(item.getItemId());

            if (mProcessTextIntentActionsHandler.performMenuItemAction(item)) {
                return true;
            }
            Callback customCallback = getCustomCallback();
            if (customCallback != null && customCallback.onActionItemClicked(mode, item)) {
                return true;
            }
            if (item.getGroupId() == TextView.ID_ASSIST && onAssistMenuItemClicked(item)) {
                return true;
            }
            return mTextView.onTextContextMenuItem(item.getItemId());
        }

        @Override
        public void onDestroyActionMode(ActionMode mode) {
            // Clear mTextActionMode not to recursively destroy action mode by clearing selection.
            getSelectionActionModeHelper().onDestroyActionMode();
            mTextActionMode = null;
            Callback customCallback = getCustomCallback();
            if (customCallback != null) {
                customCallback.onDestroyActionMode(mode);
            }

            if (!mPreserveSelection) {
                /*
                 * Leave current selection when we tentatively destroy action mode for the
                 * selection. If we're detaching from a window, we'll bring back the selection
                 * mode when (if) we get reattached.
                 */
                Selection.setSelection((Spannable) mTextView.getText(),
                        mTextView.getSelectionEnd());
            }

            if (mSelectionModifierCursorController != null) {
                mSelectionModifierCursorController.hide();
            }

            mAssistClickHandlers.clear();
            mRequestingLinkActionMode = false;
        }

        @Override
        public void onGetContentRect(ActionMode mode, View view, Rect outRect) {
            if (!view.equals(mTextView) || mTextView.getLayout() == null) {
                super.onGetContentRect(mode, view, outRect);
                return;
            }
            if (mTextView.getSelectionStart() != mTextView.getSelectionEnd()) {
                // We have a selection.
                mSelectionPath.reset();
                mTextView.getLayout().getSelectionPath(
                        mTextView.getSelectionStart(), mTextView.getSelectionEnd(), mSelectionPath);
                mSelectionPath.computeBounds(mSelectionBounds, true);
                mSelectionBounds.bottom += mHandleHeight;
            } else {
                // We have a cursor.
                Layout layout = mTextView.getLayout();
                int line = layout.getLineForOffset(mTextView.getSelectionStart());
                float primaryHorizontal = clampHorizontalPosition(null,
                        layout.getPrimaryHorizontal(mTextView.getSelectionStart()));
                mSelectionBounds.set(
                        primaryHorizontal,
                        layout.getLineTop(line),
                        primaryHorizontal,
                        layout.getLineBottom(line) + mHandleHeight);
            }
            // Take TextView's padding and scroll into account.
            int textHorizontalOffset = mTextView.viewportToContentHorizontalOffset();
            int textVerticalOffset = mTextView.viewportToContentVerticalOffset();
            outRect.set(
                    (int) Math.floor(mSelectionBounds.left + textHorizontalOffset),
                    (int) Math.floor(mSelectionBounds.top + textVerticalOffset),
                    (int) Math.ceil(mSelectionBounds.right + textHorizontalOffset),
                    (int) Math.ceil(mSelectionBounds.bottom + textVerticalOffset));
        }
    }

    
A listener to call InputMethodManager.updateCursorAnchorInfo(View, CursorAnchorInfo) while the input method is requesting the cursor/anchor position. Does nothing as long as InputMethodManager.isWatchingCursor(View) returns false. /**
     * A listener to call {@link InputMethodManager#updateCursorAnchorInfo(View, CursorAnchorInfo)}
     * while the input method is requesting the cursor/anchor position. Does nothing as long as
     * {@link InputMethodManager#isWatchingCursor(View)} returns false.
     */
    private final class CursorAnchorInfoNotifier implements TextViewPositionListener {
        final CursorAnchorInfo.Builder mSelectionInfoBuilder = new CursorAnchorInfo.Builder();
        final int[] mTmpIntOffset = new int[2];
        final Matrix mViewToScreenMatrix = new Matrix();

        @Override
        public void updatePosition(int parentPositionX, int parentPositionY,
                boolean parentPositionChanged, boolean parentScrolled) {
            final InputMethodState ims = mInputMethodState;
            if (ims == null || ims.mBatchEditNesting > 0) {
                return;
            }
            final InputMethodManager imm = InputMethodManager.peekInstance();
            if (null == imm) {
                return;
            }
            if (!imm.isActive(mTextView)) {
                return;
            }
            // Skip if the IME has not requested the cursor/anchor position.
            if (!imm.isCursorAnchorInfoEnabled()) {
                return;
            }
            Layout layout = mTextView.getLayout();
            if (layout == null) {
                return;
            }

            final CursorAnchorInfo.Builder builder = mSelectionInfoBuilder;
            builder.reset();

            final int selectionStart = mTextView.getSelectionStart();
            builder.setSelectionRange(selectionStart, mTextView.getSelectionEnd());

            // Construct transformation matrix from view local coordinates to screen coordinates.
            mViewToScreenMatrix.set(mTextView.getMatrix());
            mTextView.getLocationOnScreen(mTmpIntOffset);
            mViewToScreenMatrix.postTranslate(mTmpIntOffset[0], mTmpIntOffset[1]);
            builder.setMatrix(mViewToScreenMatrix);

            final float viewportToContentHorizontalOffset =
                    mTextView.viewportToContentHorizontalOffset();
            final float viewportToContentVerticalOffset =
                    mTextView.viewportToContentVerticalOffset();

            final CharSequence text = mTextView.getText();
            if (text instanceof Spannable) {
                final Spannable sp = (Spannable) text;
                int composingTextStart = EditableInputConnection.getComposingSpanStart(sp);
                int composingTextEnd = EditableInputConnection.getComposingSpanEnd(sp);
                if (composingTextEnd < composingTextStart) {
                    final int temp = composingTextEnd;
                    composingTextEnd = composingTextStart;
                    composingTextStart = temp;
                }
                final boolean hasComposingText =
                        (0 <= composingTextStart) && (composingTextStart < composingTextEnd);
                if (hasComposingText) {
                    final CharSequence composingText = text.subSequence(composingTextStart,
                            composingTextEnd);
                    builder.setComposingText(composingTextStart, composingText);
                    mTextView.populateCharacterBounds(builder, composingTextStart,
                            composingTextEnd, viewportToContentHorizontalOffset,
                            viewportToContentVerticalOffset);
                }
            }

            // Treat selectionStart as the insertion point.
            if (0 <= selectionStart) {
                final int offset = selectionStart;
                final int line = layout.getLineForOffset(offset);
                final float insertionMarkerX = layout.getPrimaryHorizontal(offset)
                        + viewportToContentHorizontalOffset;
                final float insertionMarkerTop = layout.getLineTop(line)
                        + viewportToContentVerticalOffset;
                final float insertionMarkerBaseline = layout.getLineBaseline(line)
                        + viewportToContentVerticalOffset;
                final float insertionMarkerBottom = layout.getLineBottomWithoutSpacing(line)
                        + viewportToContentVerticalOffset;
                final boolean isTopVisible = mTextView
                        .isPositionVisible(insertionMarkerX, insertionMarkerTop);
                final boolean isBottomVisible = mTextView
                        .isPositionVisible(insertionMarkerX, insertionMarkerBottom);
                int insertionMarkerFlags = 0;
                if (isTopVisible || isBottomVisible) {
                    insertionMarkerFlags |= CursorAnchorInfo.FLAG_HAS_VISIBLE_REGION;
                }
                if (!isTopVisible || !isBottomVisible) {
                    insertionMarkerFlags |= CursorAnchorInfo.FLAG_HAS_INVISIBLE_REGION;
                }
                if (layout.isRtlCharAt(offset)) {
                    insertionMarkerFlags |= CursorAnchorInfo.FLAG_IS_RTL;
                }
                builder.setInsertionMarkerLocation(insertionMarkerX, insertionMarkerTop,
                        insertionMarkerBaseline, insertionMarkerBottom, insertionMarkerFlags);
            }

            imm.updateCursorAnchorInfo(mTextView, builder.build());
        }
    }

    private static class MagnifierMotionAnimator {
        private static final long DURATION = 100 /* miliseconds */;

        // The magnifier being animated.
        private final Magnifier mMagnifier;
        // A value animator used to animate the magnifier.
        private final ValueAnimator mAnimator;

        // Whether the magnifier is currently visible.
        private boolean mMagnifierIsShowing;
        // The coordinates of the magnifier when the currently running animation started.
        private float mAnimationStartX;
        private float mAnimationStartY;
        // The coordinates of the magnifier in the latest animation frame.
        private float mAnimationCurrentX;
        private float mAnimationCurrentY;
        // The latest coordinates the motion animator was asked to #show() the magnifier at.
        private float mLastX;
        private float mLastY;

        private MagnifierMotionAnimator(final Magnifier magnifier) {
            mMagnifier = magnifier;
            // Prepare the animator used to run the motion animation.
            mAnimator = ValueAnimator.ofFloat(0, 1);
            mAnimator.setDuration(DURATION);
            mAnimator.setInterpolator(new LinearInterpolator());
            mAnimator.addUpdateListener((animation) -> {
                // Interpolate to find the current position of the magnifier.
                mAnimationCurrentX = mAnimationStartX
                        + (mLastX - mAnimationStartX) * animation.getAnimatedFraction();
                mAnimationCurrentY = mAnimationStartY
                        + (mLastY - mAnimationStartY) * animation.getAnimatedFraction();
                mMagnifier.show(mAnimationCurrentX, mAnimationCurrentY);
            });
        }

        
Shows the magnifier at a new position.
If the y coordinate is different from the previous y coordinate
(probably corresponding to a line jump in the text), a short
animation is added to the jump.
/**
         * Shows the magnifier at a new position.
         * If the y coordinate is different from the previous y coordinate
         * (probably corresponding to a line jump in the text), a short
         * animation is added to the jump.
         */
        private void show(final float x, final float y) {
            final boolean startNewAnimation = mMagnifierIsShowing && y != mLastY;

            if (startNewAnimation) {
                if (mAnimator.isRunning()) {
                    mAnimator.cancel();
                    mAnimationStartX = mAnimationCurrentX;
                    mAnimationStartY = mAnimationCurrentY;
                } else {
                    mAnimationStartX = mLastX;
                    mAnimationStartY = mLastY;
                }
                mAnimator.start();
            } else {
                if (!mAnimator.isRunning()) {
                    mMagnifier.show(x, y);
                }
            }
            mLastX = x;
            mLastY = y;
            mMagnifierIsShowing = true;
        }

        
Updates the content of the magnifier.
/**
         * Updates the content of the magnifier.
         */
        private void update() {
            mMagnifier.update();
        }

        
Dismisses the magnifier, or does nothing if it is already dismissed.
/**
         * Dismisses the magnifier, or does nothing if it is already dismissed.
         */
        private void dismiss() {
            mMagnifier.dismiss();
            mAnimator.cancel();
            mMagnifierIsShowing = false;
        }
    }

    @VisibleForTesting
    public abstract class HandleView extends View implements TextViewPositionListener {
        protected Drawable mDrawable;
        protected Drawable mDrawableLtr;
        protected Drawable mDrawableRtl;
        private final PopupWindow mContainer;
        // Position with respect to the parent TextView
        private int mPositionX, mPositionY;
        private boolean mIsDragging;
        // Offset from touch position to mPosition
        private float mTouchToWindowOffsetX, mTouchToWindowOffsetY;
        protected int mHotspotX;
        protected int mHorizontalGravity;
        // Offsets the hotspot point up, so that cursor is not hidden by the finger when moving up
        private float mTouchOffsetY;
        // Where the touch position should be on the handle to ensure a maximum cursor visibility
        private float mIdealVerticalOffset;
        // Parent's (TextView) previous position in window
        private int mLastParentX, mLastParentY;
        // Parent's (TextView) previous position on screen
        private int mLastParentXOnScreen, mLastParentYOnScreen;
        // Previous text character offset
        protected int mPreviousOffset = -1;
        // Previous text character offset
        private boolean mPositionHasChanged = true;
        // Minimum touch target size for handles
        private int mMinSize;
        // Indicates the line of text that the handle is on.
        protected int mPrevLine = UNSET_LINE;
        // Indicates the line of text that the user was touching. This can differ from mPrevLine
        // when selecting text when the handles jump to the end / start of words which may be on
        // a different line.
        protected int mPreviousLineTouched = UNSET_LINE;

        private HandleView(Drawable drawableLtr, Drawable drawableRtl, final int id) {
            super(mTextView.getContext());
            setId(id);
            mContainer = new PopupWindow(mTextView.getContext(), null,
                    com.android.internal.R.attr.textSelectHandleWindowStyle);
            mContainer.setSplitTouchEnabled(true);
            mContainer.setClippingEnabled(false);
            mContainer.setWindowLayoutType(WindowManager.LayoutParams.TYPE_APPLICATION_SUB_PANEL);
            mContainer.setWidth(ViewGroup.LayoutParams.WRAP_CONTENT);
            mContainer.setHeight(ViewGroup.LayoutParams.WRAP_CONTENT);
            mContainer.setContentView(this);

            mDrawableLtr = drawableLtr;
            mDrawableRtl = drawableRtl;
            mMinSize = mTextView.getContext().getResources().getDimensionPixelSize(
                    com.android.internal.R.dimen.text_handle_min_size);

            updateDrawable();

            final int handleHeight = getPreferredHeight();
            mTouchOffsetY = -0.3f * handleHeight;
            mIdealVerticalOffset = 0.7f * handleHeight;
        }

        public float getIdealVerticalOffset() {
            return mIdealVerticalOffset;
        }

        protected void updateDrawable() {
            if (mIsDragging) {
                // Don't update drawable during dragging.
                return;
            }
            final Layout layout = mTextView.getLayout();
            if (layout == null) {
                return;
            }
            final int offset = getCurrentCursorOffset();
            final boolean isRtlCharAtOffset = isAtRtlRun(layout, offset);
            final Drawable oldDrawable = mDrawable;
            mDrawable = isRtlCharAtOffset ? mDrawableRtl : mDrawableLtr;
            mHotspotX = getHotspotX(mDrawable, isRtlCharAtOffset);
            mHorizontalGravity = getHorizontalGravity(isRtlCharAtOffset);
            if (oldDrawable != mDrawable && isShowing()) {
                // Update popup window position.
                mPositionX = getCursorHorizontalPosition(layout, offset) - mHotspotX
                        - getHorizontalOffset() + getCursorOffset();
                mPositionX += mTextView.viewportToContentHorizontalOffset();
                mPositionHasChanged = true;
                updatePosition(mLastParentX, mLastParentY, false, false);
                postInvalidate();
            }
        }

        protected abstract int getHotspotX(Drawable drawable, boolean isRtlRun);
        protected abstract int getHorizontalGravity(boolean isRtlRun);

        // Touch-up filter: number of previous positions remembered
        private static final int HISTORY_SIZE = 5;
        private static final int TOUCH_UP_FILTER_DELAY_AFTER = 150;
        private static final int TOUCH_UP_FILTER_DELAY_BEFORE = 350;
        private final long[] mPreviousOffsetsTimes = new long[HISTORY_SIZE];
        private final int[] mPreviousOffsets = new int[HISTORY_SIZE];
        private int mPreviousOffsetIndex = 0;
        private int mNumberPreviousOffsets = 0;

        private void startTouchUpFilter(int offset) {
            mNumberPreviousOffsets = 0;
            addPositionToTouchUpFilter(offset);
        }

        private void addPositionToTouchUpFilter(int offset) {
            mPreviousOffsetIndex = (mPreviousOffsetIndex + 1) % HISTORY_SIZE;
            mPreviousOffsets[mPreviousOffsetIndex] = offset;
            mPreviousOffsetsTimes[mPreviousOffsetIndex] = SystemClock.uptimeMillis();
            mNumberPreviousOffsets++;
        }

        private void filterOnTouchUp(boolean fromTouchScreen) {
            final long now = SystemClock.uptimeMillis();
            int i = 0;
            int index = mPreviousOffsetIndex;
            final int iMax = Math.min(mNumberPreviousOffsets, HISTORY_SIZE);
            while (i < iMax && (now - mPreviousOffsetsTimes[index]) < TOUCH_UP_FILTER_DELAY_AFTER) {
                i++;
                index = (mPreviousOffsetIndex - i + HISTORY_SIZE) % HISTORY_SIZE;
            }

            if (i > 0 && i < iMax
                    && (now - mPreviousOffsetsTimes[index]) > TOUCH_UP_FILTER_DELAY_BEFORE) {
                positionAtCursorOffset(mPreviousOffsets[index], false, fromTouchScreen);
            }
        }

        public boolean offsetHasBeenChanged() {
            return mNumberPreviousOffsets > 1;
        }

        @Override
        protected void onMeasure(int widthMeasureSpec, int heightMeasureSpec) {
            setMeasuredDimension(getPreferredWidth(), getPreferredHeight());
        }

        @Override
        public void invalidate() {
            super.invalidate();
            if (isShowing()) {
                positionAtCursorOffset(getCurrentCursorOffset(), true, false);
            }
        };

        private int getPreferredWidth() {
            return Math.max(mDrawable.getIntrinsicWidth(), mMinSize);
        }

        private int getPreferredHeight() {
            return Math.max(mDrawable.getIntrinsicHeight(), mMinSize);
        }

        public void show() {
            if (isShowing()) return;

            getPositionListener().addSubscriber(this, true /* local position may change */);

            // Make sure the offset is always considered new, even when focusing at same position
            mPreviousOffset = -1;
            positionAtCursorOffset(getCurrentCursorOffset(), false, false);
        }

        protected void dismiss() {
            mIsDragging = false;
            mContainer.dismiss();
            onDetached();
        }

        public void hide() {
            dismiss();

            getPositionListener().removeSubscriber(this);
        }

        public boolean isShowing() {
            return mContainer.isShowing();
        }

        private boolean shouldShow() {
            // A dragging handle should always be shown.
            if (mIsDragging) {
                return true;
            }

            if (mTextView.isInBatchEditMode()) {
                return false;
            }

            return mTextView.isPositionVisible(
                    mPositionX + mHotspotX + getHorizontalOffset(), mPositionY);
        }

        private void setVisible(final boolean visible) {
            mContainer.getContentView().setVisibility(visible ? VISIBLE : INVISIBLE);
        }

        public abstract int getCurrentCursorOffset();

        protected abstract void updateSelection(int offset);

        protected abstract void updatePosition(float x, float y, boolean fromTouchScreen);

        @MagnifierHandleTrigger
        protected abstract int getMagnifierHandleTrigger();

        protected boolean isAtRtlRun(@NonNull Layout layout, int offset) {
            return layout.isRtlCharAt(offset);
        }

        @VisibleForTesting
        public float getHorizontal(@NonNull Layout layout, int offset) {
            return layout.getPrimaryHorizontal(offset);
        }

        protected int getOffsetAtCoordinate(@NonNull Layout layout, int line, float x) {
            return mTextView.getOffsetAtCoordinate(line, x);
        }

        
Params:
offset – Cursor offset. Must be in [-1, length].
forceUpdatePosition – whether to force update the position.  This should be true
when If the parent has been scrolled, for example.
fromTouchScreen – true if the cursor is moved with motion events from the touch screen./**
         * @param offset Cursor offset. Must be in [-1, length].
         * @param forceUpdatePosition whether to force update the position.  This should be true
         * when If the parent has been scrolled, for example.
         * @param fromTouchScreen {@code true} if the cursor is moved with motion events from the
         * touch screen.
         */
        protected void positionAtCursorOffset(int offset, boolean forceUpdatePosition,
                boolean fromTouchScreen) {
            // A HandleView relies on the layout, which may be nulled by external methods
            Layout layout = mTextView.getLayout();
            if (layout == null) {
                // Will update controllers' state, hiding them and stopping selection mode if needed
                prepareCursorControllers();
                return;
            }
            layout = mTextView.getLayout();

            boolean offsetChanged = offset != mPreviousOffset;
            if (offsetChanged || forceUpdatePosition) {
                if (offsetChanged) {
                    updateSelection(offset);
                    if (fromTouchScreen && mHapticTextHandleEnabled) {
                        mTextView.performHapticFeedback(HapticFeedbackConstants.TEXT_HANDLE_MOVE);
                    }
                    addPositionToTouchUpFilter(offset);
                }
                final int line = layout.getLineForOffset(offset);
                mPrevLine = line;

                mPositionX = getCursorHorizontalPosition(layout, offset) - mHotspotX
                        - getHorizontalOffset() + getCursorOffset();
                mPositionY = layout.getLineBottomWithoutSpacing(line);

                // Take TextView's padding and scroll into account.
                mPositionX += mTextView.viewportToContentHorizontalOffset();
                mPositionY += mTextView.viewportToContentVerticalOffset();

                mPreviousOffset = offset;
                mPositionHasChanged = true;
            }
        }

        
Return the clamped horizontal position for the cursor.
Params:
layout – Text layout.
offset – Character offset for the cursor.
Returns:
The clamped horizontal position for the cursor./**
         * Return the clamped horizontal position for the cursor.
         *
         * @param layout Text layout.
         * @param offset Character offset for the cursor.
         * @return The clamped horizontal position for the cursor.
         */
        int getCursorHorizontalPosition(Layout layout, int offset) {
            return (int) (getHorizontal(layout, offset) - 0.5f);
        }

        @Override
        public void updatePosition(int parentPositionX, int parentPositionY,
                boolean parentPositionChanged, boolean parentScrolled) {
            positionAtCursorOffset(getCurrentCursorOffset(), parentScrolled, false);
            if (parentPositionChanged || mPositionHasChanged) {
                if (mIsDragging) {
                    // Update touchToWindow offset in case of parent scrolling while dragging
                    if (parentPositionX != mLastParentX || parentPositionY != mLastParentY) {
                        mTouchToWindowOffsetX += parentPositionX - mLastParentX;
                        mTouchToWindowOffsetY += parentPositionY - mLastParentY;
                        mLastParentX = parentPositionX;
                        mLastParentY = parentPositionY;
                    }

                    onHandleMoved();
                }

                if (shouldShow()) {
                    // Transform to the window coordinates to follow the view tranformation.
                    final int[] pts = { mPositionX + mHotspotX + getHorizontalOffset(), mPositionY};
                    mTextView.transformFromViewToWindowSpace(pts);
                    pts[0] -= mHotspotX + getHorizontalOffset();

                    if (isShowing()) {
                        mContainer.update(pts[0], pts[1], -1, -1);
                    } else {
                        mContainer.showAtLocation(mTextView, Gravity.NO_GRAVITY, pts[0], pts[1]);
                    }
                } else {
                    if (isShowing()) {
                        dismiss();
                    }
                }

                mPositionHasChanged = false;
            }
        }

        @Override
        protected void onDraw(Canvas c) {
            final int drawWidth = mDrawable.getIntrinsicWidth();
            final int left = getHorizontalOffset();

            mDrawable.setBounds(left, 0, left + drawWidth, mDrawable.getIntrinsicHeight());
            mDrawable.draw(c);
        }

        private int getHorizontalOffset() {
            final int width = getPreferredWidth();
            final int drawWidth = mDrawable.getIntrinsicWidth();
            final int left;
            switch (mHorizontalGravity) {
                case Gravity.LEFT:
                    left = 0;
                    break;
                default:
                case Gravity.CENTER:
                    left = (width - drawWidth) / 2;
                    break;
                case Gravity.RIGHT:
                    left = width - drawWidth;
                    break;
            }
            return left;
        }

        protected int getCursorOffset() {
            return 0;
        }

        private boolean tooLargeTextForMagnifier() {
            final float magnifierContentHeight = Math.round(
                    mMagnifierAnimator.mMagnifier.getHeight()
                            / mMagnifierAnimator.mMagnifier.getZoom());
            final Paint.FontMetrics fontMetrics = mTextView.getPaint().getFontMetrics();
            final float glyphHeight = fontMetrics.descent - fontMetrics.ascent;
            return glyphHeight > magnifierContentHeight;
        }

        
Computes the position where the magnifier should be shown, relative to mTextView, and writes them to showPosInView. Also decides whether the magnifier should be shown or dismissed after this touch event. 
Returns:
Whether the magnifier should be shown at the computed coordinates or dismissed./**
         * Computes the position where the magnifier should be shown, relative to
         * {@code mTextView}, and writes them to {@code showPosInView}. Also decides
         * whether the magnifier should be shown or dismissed after this touch event.
         * @return Whether the magnifier should be shown at the computed coordinates or dismissed.
         */
        private boolean obtainMagnifierShowCoordinates(@NonNull final MotionEvent event,
                final PointF showPosInView) {

            final int trigger = getMagnifierHandleTrigger();
            final int offset;
            final int otherHandleOffset;
            switch (trigger) {
                case MagnifierHandleTrigger.INSERTION:
                    offset = mTextView.getSelectionStart();
                    otherHandleOffset = -1;
                    break;
                case MagnifierHandleTrigger.SELECTION_START:
                    offset = mTextView.getSelectionStart();
                    otherHandleOffset = mTextView.getSelectionEnd();
                    break;
                case MagnifierHandleTrigger.SELECTION_END:
                    offset = mTextView.getSelectionEnd();
                    otherHandleOffset = mTextView.getSelectionStart();
                    break;
                default:
                    offset = -1;
                    otherHandleOffset = -1;
                    break;
            }

            if (offset == -1) {
                return false;
            }

            final Layout layout = mTextView.getLayout();
            final int lineNumber = layout.getLineForOffset(offset);
            // Compute whether the selection handles are currently on the same line, and,
            // in this particular case, whether the selected text is right to left.
            final boolean sameLineSelection = otherHandleOffset != -1
                    && lineNumber == layout.getLineForOffset(otherHandleOffset);
            final boolean rtl = sameLineSelection
                    && (offset < otherHandleOffset)
                        != (getHorizontal(mTextView.getLayout(), offset)
                            < getHorizontal(mTextView.getLayout(), otherHandleOffset));

            // Horizontally move the magnifier smoothly, clamp inside the current line / selection.
            final int[] textViewLocationOnScreen = new int[2];
            mTextView.getLocationOnScreen(textViewLocationOnScreen);
            final float touchXInView = event.getRawX() - textViewLocationOnScreen[0];
            float leftBound = mTextView.getTotalPaddingLeft() - mTextView.getScrollX();
            float rightBound = mTextView.getTotalPaddingLeft() - mTextView.getScrollX();
            if (sameLineSelection && ((trigger == MagnifierHandleTrigger.SELECTION_END) ^ rtl)) {
                leftBound += getHorizontal(mTextView.getLayout(), otherHandleOffset);
            } else {
                leftBound += mTextView.getLayout().getLineLeft(lineNumber);
            }
            if (sameLineSelection && ((trigger == MagnifierHandleTrigger.SELECTION_START) ^ rtl)) {
                rightBound += getHorizontal(mTextView.getLayout(), otherHandleOffset);
            } else {
                rightBound += mTextView.getLayout().getLineRight(lineNumber);
            }
            final float contentWidth = Math.round(mMagnifierAnimator.mMagnifier.getWidth()
                    / mMagnifierAnimator.mMagnifier.getZoom());
            if (touchXInView < leftBound - contentWidth / 2
                    || touchXInView > rightBound + contentWidth / 2) {
                // The touch is too far from the current line / selection, so hide the magnifier.
                return false;
            }
            showPosInView.x = Math.max(leftBound, Math.min(rightBound, touchXInView));

            // Vertically snap to middle of current line.
            showPosInView.y = (mTextView.getLayout().getLineTop(lineNumber)
                    + mTextView.getLayout().getLineBottom(lineNumber)) / 2.0f
                    + mTextView.getTotalPaddingTop() - mTextView.getScrollY();

            return true;
        }

        private boolean handleOverlapsMagnifier(@NonNull final HandleView handle,
                @NonNull final Rect magnifierRect) {
            final PopupWindow window = handle.mContainer;
            if (!window.hasDecorView()) {
                return false;
            }
            final Rect handleRect = new Rect(
                    window.getDecorViewLayoutParams().x,
                    window.getDecorViewLayoutParams().y,
                    window.getDecorViewLayoutParams().x + window.getContentView().getWidth(),
                    window.getDecorViewLayoutParams().y + window.getContentView().getHeight());
            return Rect.intersects(handleRect, magnifierRect);
        }

        private @Nullable HandleView getOtherSelectionHandle() {
            final SelectionModifierCursorController controller = getSelectionController();
            if (controller == null || !controller.isActive()) {
                return null;
            }
            return controller.mStartHandle != this
                    ? controller.mStartHandle
                    : controller.mEndHandle;
        }

        private final Magnifier.Callback mHandlesVisibilityCallback = new Magnifier.Callback() {
            @Override
            public void onOperationComplete() {
                final Point magnifierTopLeft = mMagnifierAnimator.mMagnifier.getWindowCoords();
                if (magnifierTopLeft == null) {
                    return;
                }
                final Rect magnifierRect = new Rect(magnifierTopLeft.x, magnifierTopLeft.y,
                        magnifierTopLeft.x + mMagnifierAnimator.mMagnifier.getWidth(),
                        magnifierTopLeft.y + mMagnifierAnimator.mMagnifier.getHeight());
                setVisible(!handleOverlapsMagnifier(HandleView.this, magnifierRect));
                final HandleView otherHandle = getOtherSelectionHandle();
                if (otherHandle != null) {
                    otherHandle.setVisible(!handleOverlapsMagnifier(otherHandle, magnifierRect));
                }
            }
        };

        protected final void updateMagnifier(@NonNull final MotionEvent event) {
            if (mMagnifierAnimator == null) {
                return;
            }

            final PointF showPosInView = new PointF();
            final boolean shouldShow = !tooLargeTextForMagnifier()
                    && obtainMagnifierShowCoordinates(event, showPosInView);
            if (shouldShow) {
                // Make the cursor visible and stop blinking.
                mRenderCursorRegardlessTiming = true;
                mTextView.invalidateCursorPath();
                suspendBlink();
                mMagnifierAnimator.mMagnifier
                        .setOnOperationCompleteCallback(mHandlesVisibilityCallback);

                mMagnifierAnimator.show(showPosInView.x, showPosInView.y);
            } else {
                dismissMagnifier();
            }
        }

        protected final void dismissMagnifier() {
            if (mMagnifierAnimator != null) {
                mMagnifierAnimator.dismiss();
                mRenderCursorRegardlessTiming = false;
                resumeBlink();
                setVisible(true);
                final HandleView otherHandle = getOtherSelectionHandle();
                if (otherHandle != null) {
                    otherHandle.setVisible(true);
                }
            }
        }

        @Override
        public boolean onTouchEvent(MotionEvent ev) {
            updateFloatingToolbarVisibility(ev);

            switch (ev.getActionMasked()) {
                case MotionEvent.ACTION_DOWN: {
                    startTouchUpFilter(getCurrentCursorOffset());

                    final PositionListener positionListener = getPositionListener();
                    mLastParentX = positionListener.getPositionX();
                    mLastParentY = positionListener.getPositionY();
                    mLastParentXOnScreen = positionListener.getPositionXOnScreen();
                    mLastParentYOnScreen = positionListener.getPositionYOnScreen();

                    final float xInWindow = ev.getRawX() - mLastParentXOnScreen + mLastParentX;
                    final float yInWindow = ev.getRawY() - mLastParentYOnScreen + mLastParentY;
                    mTouchToWindowOffsetX = xInWindow - mPositionX;
                    mTouchToWindowOffsetY = yInWindow - mPositionY;

                    mIsDragging = true;
                    mPreviousLineTouched = UNSET_LINE;
                    break;
                }

                case MotionEvent.ACTION_MOVE: {
                    final float xInWindow = ev.getRawX() - mLastParentXOnScreen + mLastParentX;
                    final float yInWindow = ev.getRawY() - mLastParentYOnScreen + mLastParentY;

                    // Vertical hysteresis: vertical down movement tends to snap to ideal offset
                    final float previousVerticalOffset = mTouchToWindowOffsetY - mLastParentY;
                    final float currentVerticalOffset = yInWindow - mPositionY - mLastParentY;
                    float newVerticalOffset;
                    if (previousVerticalOffset < mIdealVerticalOffset) {
                        newVerticalOffset = Math.min(currentVerticalOffset, mIdealVerticalOffset);
                        newVerticalOffset = Math.max(newVerticalOffset, previousVerticalOffset);
                    } else {
                        newVerticalOffset = Math.max(currentVerticalOffset, mIdealVerticalOffset);
                        newVerticalOffset = Math.min(newVerticalOffset, previousVerticalOffset);
                    }
                    mTouchToWindowOffsetY = newVerticalOffset + mLastParentY;

                    final float newPosX =
                            xInWindow - mTouchToWindowOffsetX + mHotspotX + getHorizontalOffset();
                    final float newPosY = yInWindow - mTouchToWindowOffsetY + mTouchOffsetY;

                    updatePosition(newPosX, newPosY,
                            ev.isFromSource(InputDevice.SOURCE_TOUCHSCREEN));
                    break;
                }

                case MotionEvent.ACTION_UP:
                    filterOnTouchUp(ev.isFromSource(InputDevice.SOURCE_TOUCHSCREEN));
                    // Fall through.
                case MotionEvent.ACTION_CANCEL:
                    mIsDragging = false;
                    updateDrawable();
                    break;
            }
            return true;
        }

        public boolean isDragging() {
            return mIsDragging;
        }

        void onHandleMoved() {}

        public void onDetached() {}
    }

    private class InsertionHandleView extends HandleView {
        private static final int DELAY_BEFORE_HANDLE_FADES_OUT = 4000;
        private static final int RECENT_CUT_COPY_DURATION = 15 * 1000; // seconds

        // Used to detect taps on the insertion handle, which will affect the insertion action mode
        private float mDownPositionX, mDownPositionY;
        private Runnable mHider;

        public InsertionHandleView(Drawable drawable) {
            super(drawable, drawable, com.android.internal.R.id.insertion_handle);
        }

        @Override
        public void show() {
            super.show();

            final long durationSinceCutOrCopy =
                    SystemClock.uptimeMillis() - TextView.sLastCutCopyOrTextChangedTime;

            // Cancel the single tap delayed runnable.
            if (mInsertionActionModeRunnable != null
                    && ((mTapState == TAP_STATE_DOUBLE_TAP)
                            || (mTapState == TAP_STATE_TRIPLE_CLICK)
                            || isCursorInsideEasyCorrectionSpan())) {
                mTextView.removeCallbacks(mInsertionActionModeRunnable);
            }

            // Prepare and schedule the single tap runnable to run exactly after the double tap
            // timeout has passed.
            if ((mTapState != TAP_STATE_DOUBLE_TAP) && (mTapState != TAP_STATE_TRIPLE_CLICK)
                    && !isCursorInsideEasyCorrectionSpan()
                    && (durationSinceCutOrCopy < RECENT_CUT_COPY_DURATION)) {
                if (mTextActionMode == null) {
                    if (mInsertionActionModeRunnable == null) {
                        mInsertionActionModeRunnable = new Runnable() {
                            @Override
                            public void run() {
                                startInsertionActionMode();
                            }
                        };
                    }
                    mTextView.postDelayed(
                            mInsertionActionModeRunnable,
                            ViewConfiguration.getDoubleTapTimeout() + 1);
                }

            }

            hideAfterDelay();
        }

        private void hideAfterDelay() {
            if (mHider == null) {
                mHider = new Runnable() {
                    public void run() {
                        hide();
                    }
                };
            } else {
                removeHiderCallback();
            }
            mTextView.postDelayed(mHider, DELAY_BEFORE_HANDLE_FADES_OUT);
        }

        private void removeHiderCallback() {
            if (mHider != null) {
                mTextView.removeCallbacks(mHider);
            }
        }

        @Override
        protected int getHotspotX(Drawable drawable, boolean isRtlRun) {
            return drawable.getIntrinsicWidth() / 2;
        }

        @Override
        protected int getHorizontalGravity(boolean isRtlRun) {
            return Gravity.CENTER_HORIZONTAL;
        }

        @Override
        protected int getCursorOffset() {
            int offset = super.getCursorOffset();
            if (mDrawableForCursor != null) {
                mDrawableForCursor.getPadding(mTempRect);
                offset += (mDrawableForCursor.getIntrinsicWidth()
                           - mTempRect.left - mTempRect.right) / 2;
            }
            return offset;
        }

        @Override
        int getCursorHorizontalPosition(Layout layout, int offset) {
            if (mDrawableForCursor != null) {
                final float horizontal = getHorizontal(layout, offset);
                return clampHorizontalPosition(mDrawableForCursor, horizontal) + mTempRect.left;
            }
            return super.getCursorHorizontalPosition(layout, offset);
        }

        @Override
        public boolean onTouchEvent(MotionEvent ev) {
            final boolean result = super.onTouchEvent(ev);

            switch (ev.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    mDownPositionX = ev.getRawX();
                    mDownPositionY = ev.getRawY();
                    updateMagnifier(ev);
                    break;

                case MotionEvent.ACTION_MOVE:
                    updateMagnifier(ev);
                    break;

                case MotionEvent.ACTION_UP:
                    if (!offsetHasBeenChanged()) {
                        final float deltaX = mDownPositionX - ev.getRawX();
                        final float deltaY = mDownPositionY - ev.getRawY();
                        final float distanceSquared = deltaX * deltaX + deltaY * deltaY;

                        final ViewConfiguration viewConfiguration = ViewConfiguration.get(
                                mTextView.getContext());
                        final int touchSlop = viewConfiguration.getScaledTouchSlop();

                        if (distanceSquared < touchSlop * touchSlop) {
                            // Tapping on the handle toggles the insertion action mode.
                            if (mTextActionMode != null) {
                                stopTextActionMode();
                            } else {
                                startInsertionActionMode();
                            }
                        }
                    } else {
                        if (mTextActionMode != null) {
                            mTextActionMode.invalidateContentRect();
                        }
                    }
                    // Fall through.
                case MotionEvent.ACTION_CANCEL:
                    hideAfterDelay();
                    dismissMagnifier();
                    break;

                default:
                    break;
            }

            return result;
        }

        @Override
        public int getCurrentCursorOffset() {
            return mTextView.getSelectionStart();
        }

        @Override
        public void updateSelection(int offset) {
            Selection.setSelection((Spannable) mTextView.getText(), offset);
        }

        @Override
        protected void updatePosition(float x, float y, boolean fromTouchScreen) {
            Layout layout = mTextView.getLayout();
            int offset;
            if (layout != null) {
                if (mPreviousLineTouched == UNSET_LINE) {
                    mPreviousLineTouched = mTextView.getLineAtCoordinate(y);
                }
                int currLine = getCurrentLineAdjustedForSlop(layout, mPreviousLineTouched, y);
                offset = getOffsetAtCoordinate(layout, currLine, x);
                mPreviousLineTouched = currLine;
            } else {
                offset = -1;
            }
            positionAtCursorOffset(offset, false, fromTouchScreen);
            if (mTextActionMode != null) {
                invalidateActionMode();
            }
        }

        @Override
        void onHandleMoved() {
            super.onHandleMoved();
            removeHiderCallback();
        }

        @Override
        public void onDetached() {
            super.onDetached();
            removeHiderCallback();
        }

        @Override
        @MagnifierHandleTrigger
        protected int getMagnifierHandleTrigger() {
            return MagnifierHandleTrigger.INSERTION;
        }
    }

    @Retention(RetentionPolicy.SOURCE)
    @IntDef(prefix = { "HANDLE_TYPE_" }, value = {
            HANDLE_TYPE_SELECTION_START,
            HANDLE_TYPE_SELECTION_END
    })
    public @interface HandleType {}
    public static final int HANDLE_TYPE_SELECTION_START = 0;
    public static final int HANDLE_TYPE_SELECTION_END = 1;

    
For selection handles /** For selection handles */
    @VisibleForTesting
    public final class SelectionHandleView extends HandleView {
        // Indicates the handle type, selection start (HANDLE_TYPE_SELECTION_START) or selection
        // end (HANDLE_TYPE_SELECTION_END).
        @HandleType
        private final int mHandleType;
        // Indicates whether the cursor is making adjustments within a word.
        private boolean mInWord = false;
        // Difference between touch position and word boundary position.
        private float mTouchWordDelta;
        // X value of the previous updatePosition call.
        private float mPrevX;
        // Indicates if the handle has moved a boundary between LTR and RTL text.
        private boolean mLanguageDirectionChanged = false;
        // Distance from edge of horizontally scrolling text view
        // to use to switch to character mode.
        private final float mTextViewEdgeSlop;
        // Used to save text view location.
        private final int[] mTextViewLocation = new int[2];

        public SelectionHandleView(Drawable drawableLtr, Drawable drawableRtl, int id,
                @HandleType int handleType) {
            super(drawableLtr, drawableRtl, id);
            mHandleType = handleType;
            ViewConfiguration viewConfiguration = ViewConfiguration.get(mTextView.getContext());
            mTextViewEdgeSlop = viewConfiguration.getScaledTouchSlop() * 4;
        }

        private boolean isStartHandle() {
            return mHandleType == HANDLE_TYPE_SELECTION_START;
        }

        @Override
        protected int getHotspotX(Drawable drawable, boolean isRtlRun) {
            if (isRtlRun == isStartHandle()) {
                return drawable.getIntrinsicWidth() / 4;
            } else {
                return (drawable.getIntrinsicWidth() * 3) / 4;
            }
        }

        @Override
        protected int getHorizontalGravity(boolean isRtlRun) {
            return (isRtlRun == isStartHandle()) ? Gravity.LEFT : Gravity.RIGHT;
        }

        @Override
        public int getCurrentCursorOffset() {
            return isStartHandle() ? mTextView.getSelectionStart() : mTextView.getSelectionEnd();
        }

        @Override
        protected void updateSelection(int offset) {
            if (isStartHandle()) {
                Selection.setSelection((Spannable) mTextView.getText(), offset,
                        mTextView.getSelectionEnd());
            } else {
                Selection.setSelection((Spannable) mTextView.getText(),
                        mTextView.getSelectionStart(), offset);
            }
            updateDrawable();
            if (mTextActionMode != null) {
                invalidateActionMode();
            }
        }

        @Override
        protected void updatePosition(float x, float y, boolean fromTouchScreen) {
            final Layout layout = mTextView.getLayout();
            if (layout == null) {
                // HandleView will deal appropriately in positionAtCursorOffset when
                // layout is null.
                positionAndAdjustForCrossingHandles(mTextView.getOffsetForPosition(x, y),
                        fromTouchScreen);
                return;
            }

            if (mPreviousLineTouched == UNSET_LINE) {
                mPreviousLineTouched = mTextView.getLineAtCoordinate(y);
            }

            boolean positionCursor = false;
            final int anotherHandleOffset =
                    isStartHandle() ? mTextView.getSelectionEnd() : mTextView.getSelectionStart();
            int currLine = getCurrentLineAdjustedForSlop(layout, mPreviousLineTouched, y);
            int initialOffset = getOffsetAtCoordinate(layout, currLine, x);

            if (isStartHandle() && initialOffset >= anotherHandleOffset
                    || !isStartHandle() && initialOffset <= anotherHandleOffset) {
                // Handles have crossed, bound it to the first selected line and
                // adjust by word / char as normal.
                currLine = layout.getLineForOffset(anotherHandleOffset);
                initialOffset = getOffsetAtCoordinate(layout, currLine, x);
            }

            int offset = initialOffset;
            final int wordEnd = getWordEnd(offset);
            final int wordStart = getWordStart(offset);

            if (mPrevX == UNSET_X_VALUE) {
                mPrevX = x;
            }

            final int currentOffset = getCurrentCursorOffset();
            final boolean rtlAtCurrentOffset = isAtRtlRun(layout, currentOffset);
            final boolean atRtl = isAtRtlRun(layout, offset);
            final boolean isLvlBoundary = layout.isLevelBoundary(offset);

            // We can't determine if the user is expanding or shrinking the selection if they're
            // on a bi-di boundary, so until they've moved past the boundary we'll just place
            // the cursor at the current position.
            if (isLvlBoundary || (rtlAtCurrentOffset && !atRtl) || (!rtlAtCurrentOffset && atRtl)) {
                // We're on a boundary or this is the first direction change -- just update
                // to the current position.
                mLanguageDirectionChanged = true;
                mTouchWordDelta = 0.0f;
                positionAndAdjustForCrossingHandles(offset, fromTouchScreen);
                return;
            } else if (mLanguageDirectionChanged && !isLvlBoundary) {
                // We've just moved past the boundary so update the position. After this we can
                // figure out if the user is expanding or shrinking to go by word or character.
                positionAndAdjustForCrossingHandles(offset, fromTouchScreen);
                mTouchWordDelta = 0.0f;
                mLanguageDirectionChanged = false;
                return;
            }

            boolean isExpanding;
            final float xDiff = x - mPrevX;
            if (isStartHandle()) {
                isExpanding = currLine < mPreviousLineTouched;
            } else {
                isExpanding = currLine > mPreviousLineTouched;
            }
            if (atRtl == isStartHandle()) {
                isExpanding |= xDiff > 0;
            } else {
                isExpanding |= xDiff < 0;
            }

            if (mTextView.getHorizontallyScrolling()) {
                if (positionNearEdgeOfScrollingView(x, atRtl)
                        && ((isStartHandle() && mTextView.getScrollX() != 0)
                                || (!isStartHandle()
                                        && mTextView.canScrollHorizontally(atRtl ? -1 : 1)))
                        && ((isExpanding && ((isStartHandle() && offset < currentOffset)
                                || (!isStartHandle() && offset > currentOffset)))
                                        || !isExpanding)) {
                    // If we're expanding ensure that the offset is actually expanding compared to
                    // the current offset, if the handle snapped to the word, the finger position
                    // may be out of sync and we don't want the selection to jump back.
                    mTouchWordDelta = 0.0f;
                    final int nextOffset = (atRtl == isStartHandle())
                            ? layout.getOffsetToRightOf(mPreviousOffset)
                            : layout.getOffsetToLeftOf(mPreviousOffset);
                    positionAndAdjustForCrossingHandles(nextOffset, fromTouchScreen);
                    return;
                }
            }

            if (isExpanding) {
                // User is increasing the selection.
                int wordBoundary = isStartHandle() ? wordStart : wordEnd;
                final boolean snapToWord = (!mInWord
                        || (isStartHandle() ? currLine < mPrevLine : currLine > mPrevLine))
                                && atRtl == isAtRtlRun(layout, wordBoundary);
                if (snapToWord) {
                    // Sometimes words can be broken across lines (Chinese, hyphenation).
                    // We still snap to the word boundary but we only use the letters on the
                    // current line to determine if the user is far enough into the word to snap.
                    if (layout.getLineForOffset(wordBoundary) != currLine) {
                        wordBoundary = isStartHandle()
                                ? layout.getLineStart(currLine) : layout.getLineEnd(currLine);
                    }
                    final int offsetThresholdToSnap = isStartHandle()
                            ? wordEnd - ((wordEnd - wordBoundary) / 2)
                            : wordStart + ((wordBoundary - wordStart) / 2);
                    if (isStartHandle()
                            && (offset <= offsetThresholdToSnap || currLine < mPrevLine)) {
                        // User is far enough into the word or on a different line so we expand by
                        // word.
                        offset = wordStart;
                    } else if (!isStartHandle()
                            && (offset >= offsetThresholdToSnap || currLine > mPrevLine)) {
                        // User is far enough into the word or on a different line so we expand by
                        // word.
                        offset = wordEnd;
                    } else {
                        offset = mPreviousOffset;
                    }
                }
                if ((isStartHandle() && offset < initialOffset)
                        || (!isStartHandle() && offset > initialOffset)) {
                    final float adjustedX = getHorizontal(layout, offset);
                    mTouchWordDelta =
                            mTextView.convertToLocalHorizontalCoordinate(x) - adjustedX;
                } else {
                    mTouchWordDelta = 0.0f;
                }
                positionCursor = true;
            } else {
                final int adjustedOffset =
                        getOffsetAtCoordinate(layout, currLine, x - mTouchWordDelta);
                final boolean shrinking = isStartHandle()
                        ? adjustedOffset > mPreviousOffset || currLine > mPrevLine
                        : adjustedOffset < mPreviousOffset || currLine < mPrevLine;
                if (shrinking) {
                    // User is shrinking the selection.
                    if (currLine != mPrevLine) {
                        // We're on a different line, so we'll snap to word boundaries.
                        offset = isStartHandle() ? wordStart : wordEnd;
                        if ((isStartHandle() && offset < initialOffset)
                                || (!isStartHandle() && offset > initialOffset)) {
                            final float adjustedX = getHorizontal(layout, offset);
                            mTouchWordDelta =
                                    mTextView.convertToLocalHorizontalCoordinate(x) - adjustedX;
                        } else {
                            mTouchWordDelta = 0.0f;
                        }
                    } else {
                        offset = adjustedOffset;
                    }
                    positionCursor = true;
                } else if ((isStartHandle() && adjustedOffset < mPreviousOffset)
                        || (!isStartHandle() && adjustedOffset > mPreviousOffset)) {
                    // Handle has jumped to the word boundary, and the user is moving
                    // their finger towards the handle, the delta should be updated.
                    mTouchWordDelta = mTextView.convertToLocalHorizontalCoordinate(x)
                            - getHorizontal(layout, mPreviousOffset);
                }
            }

            if (positionCursor) {
                mPreviousLineTouched = currLine;
                positionAndAdjustForCrossingHandles(offset, fromTouchScreen);
            }
            mPrevX = x;
        }

        @Override
        protected void positionAtCursorOffset(int offset, boolean forceUpdatePosition,
                boolean fromTouchScreen) {
            super.positionAtCursorOffset(offset, forceUpdatePosition, fromTouchScreen);
            mInWord = (offset != -1) && !getWordIteratorWithText().isBoundary(offset);
        }

        @Override
        public boolean onTouchEvent(MotionEvent event) {
            boolean superResult = super.onTouchEvent(event);

            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    // Reset the touch word offset and x value when the user
                    // re-engages the handle.
                    mTouchWordDelta = 0.0f;
                    mPrevX = UNSET_X_VALUE;
                    updateMagnifier(event);
                    break;

                case MotionEvent.ACTION_MOVE:
                    updateMagnifier(event);
                    break;

                case MotionEvent.ACTION_UP:
                case MotionEvent.ACTION_CANCEL:
                    dismissMagnifier();
                    break;
            }

            return superResult;
        }

        private void positionAndAdjustForCrossingHandles(int offset, boolean fromTouchScreen) {
            final int anotherHandleOffset =
                    isStartHandle() ? mTextView.getSelectionEnd() : mTextView.getSelectionStart();
            if ((isStartHandle() && offset >= anotherHandleOffset)
                    || (!isStartHandle() && offset <= anotherHandleOffset)) {
                mTouchWordDelta = 0.0f;
                final Layout layout = mTextView.getLayout();
                if (layout != null && offset != anotherHandleOffset) {
                    final float horiz = getHorizontal(layout, offset);
                    final float anotherHandleHoriz = getHorizontal(layout, anotherHandleOffset,
                            !isStartHandle());
                    final float currentHoriz = getHorizontal(layout, mPreviousOffset);
                    if (currentHoriz < anotherHandleHoriz && horiz < anotherHandleHoriz
                            || currentHoriz > anotherHandleHoriz && horiz > anotherHandleHoriz) {
                        // This handle passes another one as it crossed a direction boundary.
                        // Don't minimize the selection, but keep the handle at the run boundary.
                        final int currentOffset = getCurrentCursorOffset();
                        final int offsetToGetRunRange = isStartHandle()
                                ? currentOffset : Math.max(currentOffset - 1, 0);
                        final long range = layout.getRunRange(offsetToGetRunRange);
                        if (isStartHandle()) {
                            offset = TextUtils.unpackRangeStartFromLong(range);
                        } else {
                            offset = TextUtils.unpackRangeEndFromLong(range);
                        }
                        positionAtCursorOffset(offset, false, fromTouchScreen);
                        return;
                    }
                }
                // Handles can not cross and selection is at least one character.
                offset = getNextCursorOffset(anotherHandleOffset, !isStartHandle());
            }
            positionAtCursorOffset(offset, false, fromTouchScreen);
        }

        private boolean positionNearEdgeOfScrollingView(float x, boolean atRtl) {
            mTextView.getLocationOnScreen(mTextViewLocation);
            boolean nearEdge;
            if (atRtl == isStartHandle()) {
                int rightEdge = mTextViewLocation[0] + mTextView.getWidth()
                        - mTextView.getPaddingRight();
                nearEdge = x > rightEdge - mTextViewEdgeSlop;
            } else {
                int leftEdge = mTextViewLocation[0] + mTextView.getPaddingLeft();
                nearEdge = x < leftEdge + mTextViewEdgeSlop;
            }
            return nearEdge;
        }

        @Override
        protected boolean isAtRtlRun(@NonNull Layout layout, int offset) {
            final int offsetToCheck = isStartHandle() ? offset : Math.max(offset - 1, 0);
            return layout.isRtlCharAt(offsetToCheck);
        }

        @Override
        public float getHorizontal(@NonNull Layout layout, int offset) {
            return getHorizontal(layout, offset, isStartHandle());
        }

        private float getHorizontal(@NonNull Layout layout, int offset, boolean startHandle) {
            final int line = layout.getLineForOffset(offset);
            final int offsetToCheck = startHandle ? offset : Math.max(offset - 1, 0);
            final boolean isRtlChar = layout.isRtlCharAt(offsetToCheck);
            final boolean isRtlParagraph = layout.getParagraphDirection(line) == -1;
            return (isRtlChar == isRtlParagraph)
                    ? layout.getPrimaryHorizontal(offset) : layout.getSecondaryHorizontal(offset);
        }

        @Override
        protected int getOffsetAtCoordinate(@NonNull Layout layout, int line, float x) {
            final float localX = mTextView.convertToLocalHorizontalCoordinate(x);
            final int primaryOffset = layout.getOffsetForHorizontal(line, localX, true);
            if (!layout.isLevelBoundary(primaryOffset)) {
                return primaryOffset;
            }
            final int secondaryOffset = layout.getOffsetForHorizontal(line, localX, false);
            final int currentOffset = getCurrentCursorOffset();
            final int primaryDiff = Math.abs(primaryOffset - currentOffset);
            final int secondaryDiff = Math.abs(secondaryOffset - currentOffset);
            if (primaryDiff < secondaryDiff) {
                return primaryOffset;
            } else if (primaryDiff > secondaryDiff) {
                return secondaryOffset;
            } else {
                final int offsetToCheck = isStartHandle()
                        ? currentOffset : Math.max(currentOffset - 1, 0);
                final boolean isRtlChar = layout.isRtlCharAt(offsetToCheck);
                final boolean isRtlParagraph = layout.getParagraphDirection(line) == -1;
                return isRtlChar == isRtlParagraph ? primaryOffset : secondaryOffset;
            }
        }

        @MagnifierHandleTrigger
        protected int getMagnifierHandleTrigger() {
            return isStartHandle()
                    ? MagnifierHandleTrigger.SELECTION_START
                    : MagnifierHandleTrigger.SELECTION_END;
        }
    }

    private int getCurrentLineAdjustedForSlop(Layout layout, int prevLine, float y) {
        final int trueLine = mTextView.getLineAtCoordinate(y);
        if (layout == null || prevLine > layout.getLineCount()
                || layout.getLineCount() <= 0 || prevLine < 0) {
            // Invalid parameters, just return whatever line is at y.
            return trueLine;
        }

        if (Math.abs(trueLine - prevLine) >= 2) {
            // Only stick to lines if we're within a line of the previous selection.
            return trueLine;
        }

        final float verticalOffset = mTextView.viewportToContentVerticalOffset();
        final int lineCount = layout.getLineCount();
        final float slop = mTextView.getLineHeight() * LINE_SLOP_MULTIPLIER_FOR_HANDLEVIEWS;

        final float firstLineTop = layout.getLineTop(0) + verticalOffset;
        final float prevLineTop = layout.getLineTop(prevLine) + verticalOffset;
        final float yTopBound = Math.max(prevLineTop - slop, firstLineTop + slop);

        final float lastLineBottom = layout.getLineBottom(lineCount - 1) + verticalOffset;
        final float prevLineBottom = layout.getLineBottom(prevLine) + verticalOffset;
        final float yBottomBound = Math.min(prevLineBottom + slop, lastLineBottom - slop);

        // Determine if we've moved lines based on y position and previous line.
        int currLine;
        if (y <= yTopBound) {
            currLine = Math.max(prevLine - 1, 0);
        } else if (y >= yBottomBound) {
            currLine = Math.min(prevLine + 1, lineCount - 1);
        } else {
            currLine = prevLine;
        }
        return currLine;
    }

    
A CursorController instance can be used to control a cursor in the text.
/**
     * A CursorController instance can be used to control a cursor in the text.
     */
    private interface CursorController extends ViewTreeObserver.OnTouchModeChangeListener {
        
Makes the cursor controller visible on screen. See also hide(). /**
         * Makes the cursor controller visible on screen.
         * See also {@link #hide()}.
         */
        public void show();

        
Hide the cursor controller from screen. See also show(). /**
         * Hide the cursor controller from screen.
         * See also {@link #show()}.
         */
        public void hide();

        
Called when the view is detached from window. Perform house keeping task, such as
stopping Runnable thread that would otherwise keep a reference on the context, thus
preventing the activity from being recycled.
/**
         * Called when the view is detached from window. Perform house keeping task, such as
         * stopping Runnable thread that would otherwise keep a reference on the context, thus
         * preventing the activity from being recycled.
         */
        public void onDetached();

        public boolean isCursorBeingModified();

        public boolean isActive();
    }

    private class InsertionPointCursorController implements CursorController {
        private InsertionHandleView mHandle;

        public void show() {
            getHandle().show();

            if (mSelectionModifierCursorController != null) {
                mSelectionModifierCursorController.hide();
            }
        }

        public void hide() {
            if (mHandle != null) {
                mHandle.hide();
            }
        }

        public void onTouchModeChanged(boolean isInTouchMode) {
            if (!isInTouchMode) {
                hide();
            }
        }

        private InsertionHandleView getHandle() {
            if (mSelectHandleCenter == null) {
                mSelectHandleCenter = mTextView.getContext().getDrawable(
                        mTextView.mTextSelectHandleRes);
            }
            if (mHandle == null) {
                mHandle = new InsertionHandleView(mSelectHandleCenter);
            }
            return mHandle;
        }

        @Override
        public void onDetached() {
            final ViewTreeObserver observer = mTextView.getViewTreeObserver();
            observer.removeOnTouchModeChangeListener(this);

            if (mHandle != null) mHandle.onDetached();
        }

        @Override
        public boolean isCursorBeingModified() {
            return mHandle != null && mHandle.isDragging();
        }

        @Override
        public boolean isActive() {
            return mHandle != null && mHandle.isShowing();
        }

        public void invalidateHandle() {
            if (mHandle != null) {
                mHandle.invalidate();
            }
        }
    }

    class SelectionModifierCursorController implements CursorController {
        // The cursor controller handles, lazily created when shown.
        private SelectionHandleView mStartHandle;
        private SelectionHandleView mEndHandle;
        // The offsets of that last touch down event. Remembered to start selection there.
        private int mMinTouchOffset, mMaxTouchOffset;

        private float mDownPositionX, mDownPositionY;
        private boolean mGestureStayedInTapRegion;

        // Where the user first starts the drag motion.
        private int mStartOffset = -1;

        private boolean mHaventMovedEnoughToStartDrag;
        // The line that a selection happened most recently with the drag accelerator.
        private int mLineSelectionIsOn = -1;
        // Whether the drag accelerator has selected past the initial line.
        private boolean mSwitchedLines = false;

        // Indicates the drag accelerator mode that the user is currently using.
        private int mDragAcceleratorMode = DRAG_ACCELERATOR_MODE_INACTIVE;
        // Drag accelerator is inactive.
        private static final int DRAG_ACCELERATOR_MODE_INACTIVE = 0;
        // Character based selection by dragging. Only for mouse.
        private static final int DRAG_ACCELERATOR_MODE_CHARACTER = 1;
        // Word based selection by dragging. Enabled after long pressing or double tapping.
        private static final int DRAG_ACCELERATOR_MODE_WORD = 2;
        // Paragraph based selection by dragging. Enabled after mouse triple click.
        private static final int DRAG_ACCELERATOR_MODE_PARAGRAPH = 3;

        SelectionModifierCursorController() {
            resetTouchOffsets();
        }

        public void show() {
            if (mTextView.isInBatchEditMode()) {
                return;
            }
            initDrawables();
            initHandles();
        }

        private void initDrawables() {
            if (mSelectHandleLeft == null) {
                mSelectHandleLeft = mTextView.getContext().getDrawable(
                        mTextView.mTextSelectHandleLeftRes);
            }
            if (mSelectHandleRight == null) {
                mSelectHandleRight = mTextView.getContext().getDrawable(
                        mTextView.mTextSelectHandleRightRes);
            }
        }

        private void initHandles() {
            // Lazy object creation has to be done before updatePosition() is called.
            if (mStartHandle == null) {
                mStartHandle = new SelectionHandleView(mSelectHandleLeft, mSelectHandleRight,
                        com.android.internal.R.id.selection_start_handle,
                        HANDLE_TYPE_SELECTION_START);
            }
            if (mEndHandle == null) {
                mEndHandle = new SelectionHandleView(mSelectHandleRight, mSelectHandleLeft,
                        com.android.internal.R.id.selection_end_handle,
                        HANDLE_TYPE_SELECTION_END);
            }

            mStartHandle.show();
            mEndHandle.show();

            hideInsertionPointCursorController();
        }

        public void hide() {
            if (mStartHandle != null) mStartHandle.hide();
            if (mEndHandle != null) mEndHandle.hide();
        }

        public void enterDrag(int dragAcceleratorMode) {
            // Just need to init the handles / hide insertion cursor.
            show();
            mDragAcceleratorMode = dragAcceleratorMode;
            // Start location of selection.
            mStartOffset = mTextView.getOffsetForPosition(mLastDownPositionX,
                    mLastDownPositionY);
            mLineSelectionIsOn = mTextView.getLineAtCoordinate(mLastDownPositionY);
            // Don't show the handles until user has lifted finger.
            hide();

            // This stops scrolling parents from intercepting the touch event, allowing
            // the user to continue dragging across the screen to select text; TextView will
            // scroll as necessary.
            mTextView.getParent().requestDisallowInterceptTouchEvent(true);
            mTextView.cancelLongPress();
        }

        public void onTouchEvent(MotionEvent event) {
            // This is done even when the View does not have focus, so that long presses can start
            // selection and tap can move cursor from this tap position.
            final float eventX = event.getX();
            final float eventY = event.getY();
            final boolean isMouse = event.isFromSource(InputDevice.SOURCE_MOUSE);
            switch (event.getActionMasked()) {
                case MotionEvent.ACTION_DOWN:
                    if (extractedTextModeWillBeStarted()) {
                        // Prevent duplicating the selection handles until the mode starts.
                        hide();
                    } else {
                        // Remember finger down position, to be able to start selection from there.
                        mMinTouchOffset = mMaxTouchOffset = mTextView.getOffsetForPosition(
                                eventX, eventY);

                        // Double tap detection
                        if (mGestureStayedInTapRegion) {
                            if (mTapState == TAP_STATE_DOUBLE_TAP
                                    || mTapState == TAP_STATE_TRIPLE_CLICK) {
                                final float deltaX = eventX - mDownPositionX;
                                final float deltaY = eventY - mDownPositionY;
                                final float distanceSquared = deltaX * deltaX + deltaY * deltaY;

                                ViewConfiguration viewConfiguration = ViewConfiguration.get(
                                        mTextView.getContext());
                                int doubleTapSlop = viewConfiguration.getScaledDoubleTapSlop();
                                boolean stayedInArea =
                                        distanceSquared < doubleTapSlop * doubleTapSlop;

                                if (stayedInArea && (isMouse || isPositionOnText(eventX, eventY))) {
                                    if (mTapState == TAP_STATE_DOUBLE_TAP) {
                                        selectCurrentWordAndStartDrag();
                                    } else if (mTapState == TAP_STATE_TRIPLE_CLICK) {
                                        selectCurrentParagraphAndStartDrag();
                                    }
                                    mDiscardNextActionUp = true;
                                }
                            }
                        }

                        mDownPositionX = eventX;
                        mDownPositionY = eventY;
                        mGestureStayedInTapRegion = true;
                        mHaventMovedEnoughToStartDrag = true;
                    }
                    break;

                case MotionEvent.ACTION_POINTER_DOWN:
                case MotionEvent.ACTION_POINTER_UP:
                    // Handle multi-point gestures. Keep min and max offset positions.
                    // Only activated for devices that correctly handle multi-touch.
                    if (mTextView.getContext().getPackageManager().hasSystemFeature(
                            PackageManager.FEATURE_TOUCHSCREEN_MULTITOUCH_DISTINCT)) {
                        updateMinAndMaxOffsets(event);
                    }
                    break;

                case MotionEvent.ACTION_MOVE:
                    final ViewConfiguration viewConfig = ViewConfiguration.get(
                            mTextView.getContext());
                    final int touchSlop = viewConfig.getScaledTouchSlop();

                    if (mGestureStayedInTapRegion || mHaventMovedEnoughToStartDrag) {
                        final float deltaX = eventX - mDownPositionX;
                        final float deltaY = eventY - mDownPositionY;
                        final float distanceSquared = deltaX * deltaX + deltaY * deltaY;

                        if (mGestureStayedInTapRegion) {
                            int doubleTapTouchSlop = viewConfig.getScaledDoubleTapTouchSlop();
                            mGestureStayedInTapRegion =
                                    distanceSquared <= doubleTapTouchSlop * doubleTapTouchSlop;
                        }
                        if (mHaventMovedEnoughToStartDrag) {
                            // We don't start dragging until the user has moved enough.
                            mHaventMovedEnoughToStartDrag =
                                    distanceSquared <= touchSlop * touchSlop;
                        }
                    }

                    if (isMouse && !isDragAcceleratorActive()) {
                        final int offset = mTextView.getOffsetForPosition(eventX, eventY);
                        if (mTextView.hasSelection()
                                && (!mHaventMovedEnoughToStartDrag || mStartOffset != offset)
                                && offset >= mTextView.getSelectionStart()
                                && offset <= mTextView.getSelectionEnd()) {
                            startDragAndDrop();
                            break;
                        }

                        if (mStartOffset != offset) {
                            // Start character based drag accelerator.
                            stopTextActionMode();
                            enterDrag(DRAG_ACCELERATOR_MODE_CHARACTER);
                            mDiscardNextActionUp = true;
                            mHaventMovedEnoughToStartDrag = false;
                        }
                    }

                    if (mStartHandle != null && mStartHandle.isShowing()) {
                        // Don't do the drag if the handles are showing already.
                        break;
                    }

                    updateSelection(event);
                    break;

                case MotionEvent.ACTION_UP:
                    if (!isDragAcceleratorActive()) {
                        break;
                    }
                    updateSelection(event);

                    // No longer dragging to select text, let the parent intercept events.
                    mTextView.getParent().requestDisallowInterceptTouchEvent(false);

                    // No longer the first dragging motion, reset.
                    resetDragAcceleratorState();

                    if (mTextView.hasSelection()) {
                        // Drag selection should not be adjusted by the text classifier.
                        startSelectionActionModeAsync(mHaventMovedEnoughToStartDrag);
                    }
                    break;
            }
        }

        private void updateSelection(MotionEvent event) {
            if (mTextView.getLayout() != null) {
                switch (mDragAcceleratorMode) {
                    case DRAG_ACCELERATOR_MODE_CHARACTER:
                        updateCharacterBasedSelection(event);
                        break;
                    case DRAG_ACCELERATOR_MODE_WORD:
                        updateWordBasedSelection(event);
                        break;
                    case DRAG_ACCELERATOR_MODE_PARAGRAPH:
                        updateParagraphBasedSelection(event);
                        break;
                }
            }
        }

        
If the TextView allows text selection, selects the current paragraph and starts a drag.
Returns:
true if the drag was started./**
         * If the TextView allows text selection, selects the current paragraph and starts a drag.
         *
         * @return true if the drag was started.
         */
        private boolean selectCurrentParagraphAndStartDrag() {
            if (mInsertionActionModeRunnable != null) {
                mTextView.removeCallbacks(mInsertionActionModeRunnable);
            }
            stopTextActionMode();
            if (!selectCurrentParagraph()) {
                return false;
            }
            enterDrag(SelectionModifierCursorController.DRAG_ACCELERATOR_MODE_PARAGRAPH);
            return true;
        }

        private void updateCharacterBasedSelection(MotionEvent event) {
            final int offset = mTextView.getOffsetForPosition(event.getX(), event.getY());
            updateSelectionInternal(mStartOffset, offset,
                    event.isFromSource(InputDevice.SOURCE_TOUCHSCREEN));
        }

        private void updateWordBasedSelection(MotionEvent event) {
            if (mHaventMovedEnoughToStartDrag) {
                return;
            }
            final boolean isMouse = event.isFromSource(InputDevice.SOURCE_MOUSE);
            final ViewConfiguration viewConfig = ViewConfiguration.get(
                    mTextView.getContext());
            final float eventX = event.getX();
            final float eventY = event.getY();
            final int currLine;
            if (isMouse) {
                // No need to offset the y coordinate for mouse input.
                currLine = mTextView.getLineAtCoordinate(eventY);
            } else {
                float y = eventY;
                if (mSwitchedLines) {
                    // Offset the finger by the same vertical offset as the handles.
                    // This improves visibility of the content being selected by
                    // shifting the finger below the content, this is applied once
                    // the user has switched lines.
                    final int touchSlop = viewConfig.getScaledTouchSlop();
                    final float fingerOffset = (mStartHandle != null)
                            ? mStartHandle.getIdealVerticalOffset()
                            : touchSlop;
                    y = eventY - fingerOffset;
                }

                currLine = getCurrentLineAdjustedForSlop(mTextView.getLayout(), mLineSelectionIsOn,
                        y);
                if (!mSwitchedLines && currLine != mLineSelectionIsOn) {
                    // Break early here, we want to offset the finger position from
                    // the selection highlight, once the user moved their finger
                    // to a different line we should apply the offset and *not* switch
                    // lines until recomputing the position with the finger offset.
                    mSwitchedLines = true;
                    return;
                }
            }

            int startOffset;
            int offset = mTextView.getOffsetAtCoordinate(currLine, eventX);
            // Snap to word boundaries.
            if (mStartOffset < offset) {
                // Expanding with end handle.
                offset = getWordEnd(offset);
                startOffset = getWordStart(mStartOffset);
            } else {
                // Expanding with start handle.
                offset = getWordStart(offset);
                startOffset = getWordEnd(mStartOffset);
                if (startOffset == offset) {
                    offset = getNextCursorOffset(offset, false);
                }
            }
            mLineSelectionIsOn = currLine;
            updateSelectionInternal(startOffset, offset,
                    event.isFromSource(InputDevice.SOURCE_TOUCHSCREEN));
        }

        private void updateParagraphBasedSelection(MotionEvent event) {
            final int offset = mTextView.getOffsetForPosition(event.getX(), event.getY());

            final int start = Math.min(offset, mStartOffset);
            final int end = Math.max(offset, mStartOffset);
            final long paragraphsRange = getParagraphsRange(start, end);
            final int selectionStart = TextUtils.unpackRangeStartFromLong(paragraphsRange);
            final int selectionEnd = TextUtils.unpackRangeEndFromLong(paragraphsRange);
            updateSelectionInternal(selectionStart, selectionEnd,
                    event.isFromSource(InputDevice.SOURCE_TOUCHSCREEN));
        }

        private void updateSelectionInternal(int selectionStart, int selectionEnd,
                boolean fromTouchScreen) {
            final boolean performHapticFeedback = fromTouchScreen && mHapticTextHandleEnabled
                    && ((mTextView.getSelectionStart() != selectionStart)
                            || (mTextView.getSelectionEnd() != selectionEnd));
            Selection.setSelection((Spannable) mTextView.getText(), selectionStart, selectionEnd);
            if (performHapticFeedback) {
                mTextView.performHapticFeedback(HapticFeedbackConstants.TEXT_HANDLE_MOVE);
            }
        }

        
Params:
event – /**
         * @param event
         */
        private void updateMinAndMaxOffsets(MotionEvent event) {
            int pointerCount = event.getPointerCount();
            for (int index = 0; index < pointerCount; index++) {
                int offset = mTextView.getOffsetForPosition(event.getX(index), event.getY(index));
                if (offset < mMinTouchOffset) mMinTouchOffset = offset;
                if (offset > mMaxTouchOffset) mMaxTouchOffset = offset;
            }
        }

        public int getMinTouchOffset() {
            return mMinTouchOffset;
        }

        public int getMaxTouchOffset() {
            return mMaxTouchOffset;
        }

        public void resetTouchOffsets() {
            mMinTouchOffset = mMaxTouchOffset = -1;
            resetDragAcceleratorState();
        }

        private void resetDragAcceleratorState() {
            mStartOffset = -1;
            mDragAcceleratorMode = DRAG_ACCELERATOR_MODE_INACTIVE;
            mSwitchedLines = false;
            final int selectionStart = mTextView.getSelectionStart();
            final int selectionEnd = mTextView.getSelectionEnd();
            if (selectionStart < 0 || selectionEnd < 0) {
                Selection.removeSelection((Spannable) mTextView.getText());
            } else if (selectionStart > selectionEnd) {
                Selection.setSelection((Spannable) mTextView.getText(),
                        selectionEnd, selectionStart);
            }
        }

        
Returns:
true iff this controller is currently used to move the selection start./**
         * @return true iff this controller is currently used to move the selection start.
         */
        public boolean isSelectionStartDragged() {
            return mStartHandle != null && mStartHandle.isDragging();
        }

        @Override
        public boolean isCursorBeingModified() {
            return isDragAcceleratorActive() || isSelectionStartDragged()
                    || (mEndHandle != null && mEndHandle.isDragging());
        }

        
Returns:
true if the user is selecting text using the drag accelerator./**
         * @return true if the user is selecting text using the drag accelerator.
         */
        public boolean isDragAcceleratorActive() {
            return mDragAcceleratorMode != DRAG_ACCELERATOR_MODE_INACTIVE;
        }

        public void onTouchModeChanged(boolean isInTouchMode) {
            if (!isInTouchMode) {
                hide();
            }
        }

        @Override
        public void onDetached() {
            final ViewTreeObserver observer = mTextView.getViewTreeObserver();
            observer.removeOnTouchModeChangeListener(this);

            if (mStartHandle != null) mStartHandle.onDetached();
            if (mEndHandle != null) mEndHandle.onDetached();
        }

        @Override
        public boolean isActive() {
            return mStartHandle != null && mStartHandle.isShowing();
        }

        public void invalidateHandles() {
            if (mStartHandle != null) {
                mStartHandle.invalidate();
            }
            if (mEndHandle != null) {
                mEndHandle.invalidate();
            }
        }
    }

    private class CorrectionHighlighter {
        private final Path mPath = new Path();
        private final Paint mPaint = new Paint(Paint.ANTI_ALIAS_FLAG);
        private int mStart, mEnd;
        private long mFadingStartTime;
        private RectF mTempRectF;
        private static final int FADE_OUT_DURATION = 400;

        public CorrectionHighlighter() {
            mPaint.setCompatibilityScaling(
                    mTextView.getResources().getCompatibilityInfo().applicationScale);
            mPaint.setStyle(Paint.Style.FILL);
        }

        public void highlight(CorrectionInfo info) {
            mStart = info.getOffset();
            mEnd = mStart + info.getNewText().length();
            mFadingStartTime = SystemClock.uptimeMillis();

            if (mStart < 0 || mEnd < 0) {
                stopAnimation();
            }
        }

        public void draw(Canvas canvas, int cursorOffsetVertical) {
            if (updatePath() && updatePaint()) {
                if (cursorOffsetVertical != 0) {
                    canvas.translate(0, cursorOffsetVertical);
                }

                canvas.drawPath(mPath, mPaint);

                if (cursorOffsetVertical != 0) {
                    canvas.translate(0, -cursorOffsetVertical);
                }
                invalidate(true); // TODO invalidate cursor region only
            } else {
                stopAnimation();
                invalidate(false); // TODO invalidate cursor region only
            }
        }

        private boolean updatePaint() {
            final long duration = SystemClock.uptimeMillis() - mFadingStartTime;
            if (duration > FADE_OUT_DURATION) return false;

            final float coef = 1.0f - (float) duration / FADE_OUT_DURATION;
            final int highlightColorAlpha = Color.alpha(mTextView.mHighlightColor);
            final int color = (mTextView.mHighlightColor & 0x00FFFFFF)
                    + ((int) (highlightColorAlpha * coef) << 24);
            mPaint.setColor(color);
            return true;
        }

        private boolean updatePath() {
            final Layout layout = mTextView.getLayout();
            if (layout == null) return false;

            // Update in case text is edited while the animation is run
            final int length = mTextView.getText().length();
            int start = Math.min(length, mStart);
            int end = Math.min(length, mEnd);

            mPath.reset();
            layout.getSelectionPath(start, end, mPath);
            return true;
        }

        private void invalidate(boolean delayed) {
            if (mTextView.getLayout() == null) return;

            if (mTempRectF == null) mTempRectF = new RectF();
            mPath.computeBounds(mTempRectF, false);

            int left = mTextView.getCompoundPaddingLeft();
            int top = mTextView.getExtendedPaddingTop() + mTextView.getVerticalOffset(true);

            if (delayed) {
                mTextView.postInvalidateOnAnimation(
                        left + (int) mTempRectF.left, top + (int) mTempRectF.top,
                        left + (int) mTempRectF.right, top + (int) mTempRectF.bottom);
            } else {
                mTextView.postInvalidate((int) mTempRectF.left, (int) mTempRectF.top,
                        (int) mTempRectF.right, (int) mTempRectF.bottom);
            }
        }

        private void stopAnimation() {
            Editor.this.mCorrectionHighlighter = null;
        }
    }

    private static class ErrorPopup extends PopupWindow {
        private boolean mAbove = false;
        private final TextView mView;
        private int mPopupInlineErrorBackgroundId = 0;
        private int mPopupInlineErrorAboveBackgroundId = 0;

        ErrorPopup(TextView v, int width, int height) {
            super(v, width, height);
            mView = v;
            // Make sure the TextView has a background set as it will be used the first time it is
            // shown and positioned. Initialized with below background, which should have
            // dimensions identical to the above version for this to work (and is more likely).
            mPopupInlineErrorBackgroundId = getResourceId(mPopupInlineErrorBackgroundId,
                    com.android.internal.R.styleable.Theme_errorMessageBackground);
            mView.setBackgroundResource(mPopupInlineErrorBackgroundId);
        }

        void fixDirection(boolean above) {
            mAbove = above;

            if (above) {
                mPopupInlineErrorAboveBackgroundId =
                    getResourceId(mPopupInlineErrorAboveBackgroundId,
                            com.android.internal.R.styleable.Theme_errorMessageAboveBackground);
            } else {
                mPopupInlineErrorBackgroundId = getResourceId(mPopupInlineErrorBackgroundId,
                        com.android.internal.R.styleable.Theme_errorMessageBackground);
            }

            mView.setBackgroundResource(
                    above ? mPopupInlineErrorAboveBackgroundId : mPopupInlineErrorBackgroundId);
        }

        private int getResourceId(int currentId, int index) {
            if (currentId == 0) {
                TypedArray styledAttributes = mView.getContext().obtainStyledAttributes(
                        R.styleable.Theme);
                currentId = styledAttributes.getResourceId(index, 0);
                styledAttributes.recycle();
            }
            return currentId;
        }

        @Override
        public void update(int x, int y, int w, int h, boolean force) {
            super.update(x, y, w, h, force);

            boolean above = isAboveAnchor();
            if (above != mAbove) {
                fixDirection(above);
            }
        }
    }

    static class InputContentType {
        int imeOptions = EditorInfo.IME_NULL;
        String privateImeOptions;
        CharSequence imeActionLabel;
        int imeActionId;
        Bundle extras;
        OnEditorActionListener onEditorActionListener;
        boolean enterDown;
        LocaleList imeHintLocales;
    }

    static class InputMethodState {
        ExtractedTextRequest mExtractedTextRequest;
        final ExtractedText mExtractedText = new ExtractedText();
        int mBatchEditNesting;
        boolean mCursorChanged;
        boolean mSelectionModeChanged;
        boolean mContentChanged;
        int mChangedStart, mChangedEnd, mChangedDelta;
    }

    
Returns:
True iff (start, end) is a valid range within the text./**
     * @return True iff (start, end) is a valid range within the text.
     */
    private static boolean isValidRange(CharSequence text, int start, int end) {
        return 0 <= start && start <= end && end <= text.length();
    }

    @VisibleForTesting
    public SuggestionsPopupWindow getSuggestionsPopupWindowForTesting() {
        return mSuggestionsPopupWindow;
    }

    
An InputFilter that monitors text input to maintain undo history. It does not modify the
text being typed (and hence always returns null from the filter() method).
TODO: Make this span aware.
/**
     * An InputFilter that monitors text input to maintain undo history. It does not modify the
     * text being typed (and hence always returns null from the filter() method).
     *
     * TODO: Make this span aware.
     */
    public static class UndoInputFilter implements InputFilter {
        private final Editor mEditor;

        // Whether the current filter pass is directly caused by an end-user text edit.
        private boolean mIsUserEdit;

        // Whether the text field is handling an IME composition. Must be parceled in case the user
        // rotates the screen during composition.
        private boolean mHasComposition;

        // Whether the user is expanding or shortening the text
        private boolean mExpanding;

        // Whether the previous edit operation was in the current batch edit.
        private boolean mPreviousOperationWasInSameBatchEdit;

        public UndoInputFilter(Editor editor) {
            mEditor = editor;
        }

        public void saveInstanceState(Parcel parcel) {
            parcel.writeInt(mIsUserEdit ? 1 : 0);
            parcel.writeInt(mHasComposition ? 1 : 0);
            parcel.writeInt(mExpanding ? 1 : 0);
            parcel.writeInt(mPreviousOperationWasInSameBatchEdit ? 1 : 0);
        }

        public void restoreInstanceState(Parcel parcel) {
            mIsUserEdit = parcel.readInt() != 0;
            mHasComposition = parcel.readInt() != 0;
            mExpanding = parcel.readInt() != 0;
            mPreviousOperationWasInSameBatchEdit = parcel.readInt() != 0;
        }

        
Signals that a user-triggered edit is starting.
/**
         * Signals that a user-triggered edit is starting.
         */
        public void beginBatchEdit() {
            if (DEBUG_UNDO) Log.d(TAG, "beginBatchEdit");
            mIsUserEdit = true;
        }

        public void endBatchEdit() {
            if (DEBUG_UNDO) Log.d(TAG, "endBatchEdit");
            mIsUserEdit = false;
            mPreviousOperationWasInSameBatchEdit = false;
        }

        @Override
        public CharSequence filter(CharSequence source, int start, int end,
                Spanned dest, int dstart, int dend) {
            if (DEBUG_UNDO) {
                Log.d(TAG, "filter: source=" + source + " (" + start + "-" + end + ") "
                        + "dest=" + dest + " (" + dstart + "-" + dend + ")");
            }

            // Check to see if this edit should be tracked for undo.
            if (!canUndoEdit(source, start, end, dest, dstart, dend)) {
                return null;
            }

            final boolean hadComposition = mHasComposition;
            mHasComposition = isComposition(source);
            final boolean wasExpanding = mExpanding;
            boolean shouldCreateSeparateState = false;
            if ((end - start) != (dend - dstart)) {
                mExpanding = (end - start) > (dend - dstart);
                if (hadComposition && mExpanding != wasExpanding) {
                    shouldCreateSeparateState = true;
                }
            }

            // Handle edit.
            handleEdit(source, start, end, dest, dstart, dend, shouldCreateSeparateState);
            return null;
        }

        void freezeLastEdit() {
            mEditor.mUndoManager.beginUpdate("Edit text");
            EditOperation lastEdit = getLastEdit();
            if (lastEdit != null) {
                lastEdit.mFrozen = true;
            }
            mEditor.mUndoManager.endUpdate();
        }

        @Retention(RetentionPolicy.SOURCE)
        @IntDef(prefix = { "MERGE_EDIT_MODE_" }, value = {
                MERGE_EDIT_MODE_FORCE_MERGE,
                MERGE_EDIT_MODE_NEVER_MERGE,
                MERGE_EDIT_MODE_NORMAL
        })
        private @interface MergeMode {}
        private static final int MERGE_EDIT_MODE_FORCE_MERGE = 0;
        private static final int MERGE_EDIT_MODE_NEVER_MERGE = 1;
        
Use EditOperation.mergeWith to merge /** Use {@link EditOperation#mergeWith} to merge */
        private static final int MERGE_EDIT_MODE_NORMAL = 2;

        private void handleEdit(CharSequence source, int start, int end,
                Spanned dest, int dstart, int dend, boolean shouldCreateSeparateState) {
            // An application may install a TextWatcher to provide additional modifications after
            // the initial input filters run (e.g. a credit card formatter that adds spaces to a
            // string). This results in multiple filter() calls for what the user considers to be
            // a single operation. Always undo the whole set of changes in one step.
            @MergeMode
            final int mergeMode;
            if (isInTextWatcher() || mPreviousOperationWasInSameBatchEdit) {
                mergeMode = MERGE_EDIT_MODE_FORCE_MERGE;
            } else if (shouldCreateSeparateState) {
                mergeMode = MERGE_EDIT_MODE_NEVER_MERGE;
            } else {
                mergeMode = MERGE_EDIT_MODE_NORMAL;
            }
            // Build a new operation with all the information from this edit.
            String newText = TextUtils.substring(source, start, end);
            String oldText = TextUtils.substring(dest, dstart, dend);
            EditOperation edit = new EditOperation(mEditor, oldText, dstart, newText,
                    mHasComposition);
            if (mHasComposition && TextUtils.equals(edit.mNewText, edit.mOldText)) {
                return;
            }
            recordEdit(edit, mergeMode);
        }

        private EditOperation getLastEdit() {
            final UndoManager um = mEditor.mUndoManager;
            return um.getLastOperation(
                  EditOperation.class, mEditor.mUndoOwner, UndoManager.MERGE_MODE_UNIQUE);
        }
        
Fetches the last undo operation and checks to see if a new edit should be merged into it.
If forceMerge is true then the new edit is always merged.
/**
         * Fetches the last undo operation and checks to see if a new edit should be merged into it.
         * If forceMerge is true then the new edit is always merged.
         */
        private void recordEdit(EditOperation edit, @MergeMode int mergeMode) {
            // Fetch the last edit operation and attempt to merge in the new edit.
            final UndoManager um = mEditor.mUndoManager;
            um.beginUpdate("Edit text");
            EditOperation lastEdit = getLastEdit();
            if (lastEdit == null) {
                // Add this as the first edit.
                if (DEBUG_UNDO) Log.d(TAG, "filter: adding first op " + edit);
                um.addOperation(edit, UndoManager.MERGE_MODE_NONE);
            } else if (mergeMode == MERGE_EDIT_MODE_FORCE_MERGE) {
                // Forced merges take priority because they could be the result of a non-user-edit
                // change and this case should not create a new undo operation.
                if (DEBUG_UNDO) Log.d(TAG, "filter: force merge " + edit);
                lastEdit.forceMergeWith(edit);
            } else if (!mIsUserEdit) {
                // An application directly modified the Editable outside of a text edit. Treat this
                // as a new change and don't attempt to merge.
                if (DEBUG_UNDO) Log.d(TAG, "non-user edit, new op " + edit);
                um.commitState(mEditor.mUndoOwner);
                um.addOperation(edit, UndoManager.MERGE_MODE_NONE);
            } else if (mergeMode == MERGE_EDIT_MODE_NORMAL && lastEdit.mergeWith(edit)) {
                // Merge succeeded, nothing else to do.
                if (DEBUG_UNDO) Log.d(TAG, "filter: merge succeeded, created " + lastEdit);
            } else {
                // Could not merge with the last edit, so commit the last edit and add this edit.
                if (DEBUG_UNDO) Log.d(TAG, "filter: merge failed, adding " + edit);
                um.commitState(mEditor.mUndoOwner);
                um.addOperation(edit, UndoManager.MERGE_MODE_NONE);
            }
            mPreviousOperationWasInSameBatchEdit = mIsUserEdit;
            um.endUpdate();
        }

        private boolean canUndoEdit(CharSequence source, int start, int end,
                Spanned dest, int dstart, int dend) {
            if (!mEditor.mAllowUndo) {
                if (DEBUG_UNDO) Log.d(TAG, "filter: undo is disabled");
                return false;
            }

            if (mEditor.mUndoManager.isInUndo()) {
                if (DEBUG_UNDO) Log.d(TAG, "filter: skipping, currently performing undo/redo");
                return false;
            }

            // Text filters run before input operations are applied. However, some input operations
            // are invalid and will throw exceptions when applied. This is common in tests. Don't
            // attempt to undo invalid operations.
            if (!isValidRange(source, start, end) || !isValidRange(dest, dstart, dend)) {
                if (DEBUG_UNDO) Log.d(TAG, "filter: invalid op");
                return false;
            }

            // Earlier filters can rewrite input to be a no-op, for example due to a length limit
            // on an input field. Skip no-op changes.
            if (start == end && dstart == dend) {
                if (DEBUG_UNDO) Log.d(TAG, "filter: skipping no-op");
                return false;
            }

            return true;
        }

        private static boolean isComposition(CharSequence source) {
            if (!(source instanceof Spannable)) {
                return false;
            }
            // This is a composition edit if the source has a non-zero-length composing span.
            Spannable text = (Spannable) source;
            int composeBegin = EditableInputConnection.getComposingSpanStart(text);
            int composeEnd = EditableInputConnection.getComposingSpanEnd(text);
            return composeBegin < composeEnd;
        }

        private boolean isInTextWatcher() {
            CharSequence text = mEditor.mTextView.getText();
            return (text instanceof SpannableStringBuilder)
                    && ((SpannableStringBuilder) text).getTextWatcherDepth() > 0;
        }
    }

    
An operation to undo a single "edit" to a text view.
/**
     * An operation to undo a single "edit" to a text view.
     */
    public static class EditOperation extends UndoOperation<Editor> {
        private static final int TYPE_INSERT = 0;
        private static final int TYPE_DELETE = 1;
        private static final int TYPE_REPLACE = 2;

        private int mType;
        private String mOldText;
        private String mNewText;
        private int mStart;

        private int mOldCursorPos;
        private int mNewCursorPos;
        private boolean mFrozen;
        private boolean mIsComposition;

        
Constructs an edit operation from a text input operation on editor that replaces the
oldText starting at dstart with newText.
/**
         * Constructs an edit operation from a text input operation on editor that replaces the
         * oldText starting at dstart with newText.
         */
        public EditOperation(Editor editor, String oldText, int dstart, String newText,
                boolean isComposition) {
            super(editor.mUndoOwner);
            mOldText = oldText;
            mNewText = newText;

            // Determine the type of the edit.
            if (mNewText.length() > 0 && mOldText.length() == 0) {
                mType = TYPE_INSERT;
            } else if (mNewText.length() == 0 && mOldText.length() > 0) {
                mType = TYPE_DELETE;
            } else {
                mType = TYPE_REPLACE;
            }

            mStart = dstart;
            // Store cursor data.
            mOldCursorPos = editor.mTextView.getSelectionStart();
            mNewCursorPos = dstart + mNewText.length();
            mIsComposition = isComposition;
        }

        public EditOperation(Parcel src, ClassLoader loader) {
            super(src, loader);
            mType = src.readInt();
            mOldText = src.readString();
            mNewText = src.readString();
            mStart = src.readInt();
            mOldCursorPos = src.readInt();
            mNewCursorPos = src.readInt();
            mFrozen = src.readInt() == 1;
            mIsComposition = src.readInt() == 1;
        }

        @Override
        public void writeToParcel(Parcel dest, int flags) {
            dest.writeInt(mType);
            dest.writeString(mOldText);
            dest.writeString(mNewText);
            dest.writeInt(mStart);
            dest.writeInt(mOldCursorPos);
            dest.writeInt(mNewCursorPos);
            dest.writeInt(mFrozen ? 1 : 0);
            dest.writeInt(mIsComposition ? 1 : 0);
        }

        private int getNewTextEnd() {
            return mStart + mNewText.length();
        }

        private int getOldTextEnd() {
            return mStart + mOldText.length();
        }

        @Override
        public void commit() {
        }

        @Override
        public void undo() {
            if (DEBUG_UNDO) Log.d(TAG, "undo");
            // Remove the new text and insert the old.
            Editor editor = getOwnerData();
            Editable text = (Editable) editor.mTextView.getText();
            modifyText(text, mStart, getNewTextEnd(), mOldText, mStart, mOldCursorPos);
        }

        @Override
        public void redo() {
            if (DEBUG_UNDO) Log.d(TAG, "redo");
            // Remove the old text and insert the new.
            Editor editor = getOwnerData();
            Editable text = (Editable) editor.mTextView.getText();
            modifyText(text, mStart, getOldTextEnd(), mNewText, mStart, mNewCursorPos);
        }

        
Attempts to merge this existing operation with a new edit.
Params:
edit – The new edit operation.
Returns:
If the merge succeeded, returns true. Otherwise returns false and leaves this
object unchanged./**
         * Attempts to merge this existing operation with a new edit.
         * @param edit The new edit operation.
         * @return If the merge succeeded, returns true. Otherwise returns false and leaves this
         * object unchanged.
         */
        private boolean mergeWith(EditOperation edit) {
            if (DEBUG_UNDO) {
                Log.d(TAG, "mergeWith old " + this);
                Log.d(TAG, "mergeWith new " + edit);
            }

            if (mFrozen) {
                return false;
            }

            switch (mType) {
                case TYPE_INSERT:
                    return mergeInsertWith(edit);
                case TYPE_DELETE:
                    return mergeDeleteWith(edit);
                case TYPE_REPLACE:
                    return mergeReplaceWith(edit);
                default:
                    return false;
            }
        }

        private boolean mergeInsertWith(EditOperation edit) {
            if (edit.mType == TYPE_INSERT) {
                // Merge insertions that are contiguous even when it's frozen.
                if (getNewTextEnd() != edit.mStart) {
                    return false;
                }
                mNewText += edit.mNewText;
                mNewCursorPos = edit.mNewCursorPos;
                mFrozen = edit.mFrozen;
                mIsComposition = edit.mIsComposition;
                return true;
            }
            if (mIsComposition && edit.mType == TYPE_REPLACE
                    && mStart <= edit.mStart && getNewTextEnd() >= edit.getOldTextEnd()) {
                // Merge insertion with replace as they can be single insertion.
                mNewText = mNewText.substring(0, edit.mStart - mStart) + edit.mNewText
                        + mNewText.substring(edit.getOldTextEnd() - mStart, mNewText.length());
                mNewCursorPos = edit.mNewCursorPos;
                mIsComposition = edit.mIsComposition;
                return true;
            }
            return false;
        }

        // TODO: Support forward delete.
        private boolean mergeDeleteWith(EditOperation edit) {
            // Only merge continuous deletes.
            if (edit.mType != TYPE_DELETE) {
                return false;
            }
            // Only merge deletions that are contiguous.
            if (mStart != edit.getOldTextEnd()) {
                return false;
            }
            mStart = edit.mStart;
            mOldText = edit.mOldText + mOldText;
            mNewCursorPos = edit.mNewCursorPos;
            mIsComposition = edit.mIsComposition;
            return true;
        }

        private boolean mergeReplaceWith(EditOperation edit) {
            if (edit.mType == TYPE_INSERT && getNewTextEnd() == edit.mStart) {
                // Merge with adjacent insert.
                mNewText += edit.mNewText;
                mNewCursorPos = edit.mNewCursorPos;
                return true;
            }
            if (!mIsComposition) {
                return false;
            }
            if (edit.mType == TYPE_DELETE && mStart <= edit.mStart
                    && getNewTextEnd() >= edit.getOldTextEnd()) {
                // Merge with delete as they can be single operation.
                mNewText = mNewText.substring(0, edit.mStart - mStart)
                        + mNewText.substring(edit.getOldTextEnd() - mStart, mNewText.length());
                if (mNewText.isEmpty()) {
                    mType = TYPE_DELETE;
                }
                mNewCursorPos = edit.mNewCursorPos;
                mIsComposition = edit.mIsComposition;
                return true;
            }
            if (edit.mType == TYPE_REPLACE && mStart == edit.mStart
                    && TextUtils.equals(mNewText, edit.mOldText)) {
                // Merge with the replace that replaces the same region.
                mNewText = edit.mNewText;
                mNewCursorPos = edit.mNewCursorPos;
                mIsComposition = edit.mIsComposition;
                return true;
            }
            return false;
        }

        
Forcibly creates a single merged edit operation by simulating the entire text
contents being replaced.
/**
         * Forcibly creates a single merged edit operation by simulating the entire text
         * contents being replaced.
         */
        public void forceMergeWith(EditOperation edit) {
            if (DEBUG_UNDO) Log.d(TAG, "forceMerge");
            if (mergeWith(edit)) {
                return;
            }
            Editor editor = getOwnerData();

            // Copy the text of the current field.
            // NOTE: Using StringBuilder instead of SpannableStringBuilder would be somewhat faster,
            // but would require two parallel implementations of modifyText() because Editable and
            // StringBuilder do not share an interface for replace/delete/insert.
            Editable editable = (Editable) editor.mTextView.getText();
            Editable originalText = new SpannableStringBuilder(editable.toString());

            // Roll back the last operation.
            modifyText(originalText, mStart, getNewTextEnd(), mOldText, mStart, mOldCursorPos);

            // Clone the text again and apply the new operation.
            Editable finalText = new SpannableStringBuilder(editable.toString());
            modifyText(finalText, edit.mStart, edit.getOldTextEnd(),
                    edit.mNewText, edit.mStart, edit.mNewCursorPos);

            // Convert this operation into a replace operation.
            mType = TYPE_REPLACE;
            mNewText = finalText.toString();
            mOldText = originalText.toString();
            mStart = 0;
            mNewCursorPos = edit.mNewCursorPos;
            mIsComposition = edit.mIsComposition;
            // mOldCursorPos is unchanged.
        }

        private static void modifyText(Editable text, int deleteFrom, int deleteTo,
                CharSequence newText, int newTextInsertAt, int newCursorPos) {
            // Apply the edit if it is still valid.
            if (isValidRange(text, deleteFrom, deleteTo)
                    && newTextInsertAt <= text.length() - (deleteTo - deleteFrom)) {
                if (deleteFrom != deleteTo) {
                    text.delete(deleteFrom, deleteTo);
                }
                if (newText.length() != 0) {
                    text.insert(newTextInsertAt, newText);
                }
            }
            // Restore the cursor position. If there wasn't an old cursor (newCursorPos == -1) then
            // don't explicitly set it and rely on SpannableStringBuilder to position it.
            // TODO: Select all the text that was undone.
            if (0 <= newCursorPos && newCursorPos <= text.length()) {
                Selection.setSelection(text, newCursorPos);
            }
        }

        private String getTypeString() {
            switch (mType) {
                case TYPE_INSERT:
                    return "insert";
                case TYPE_DELETE:
                    return "delete";
                case TYPE_REPLACE:
                    return "replace";
                default:
                    return "";
            }
        }

        @Override
        public String toString() {
            return "[mType=" + getTypeString() + ", "
                    + "mOldText=" + mOldText + ", "
                    + "mNewText=" + mNewText + ", "
                    + "mStart=" + mStart + ", "
                    + "mOldCursorPos=" + mOldCursorPos + ", "
                    + "mNewCursorPos=" + mNewCursorPos + ", "
                    + "mFrozen=" + mFrozen + ", "
                    + "mIsComposition=" + mIsComposition + "]";
        }

        public static final Parcelable.ClassLoaderCreator<EditOperation> CREATOR =
                new Parcelable.ClassLoaderCreator<EditOperation>() {
            @Override
            public EditOperation createFromParcel(Parcel in) {
                return new EditOperation(in, null);
            }

            @Override
            public EditOperation createFromParcel(Parcel in, ClassLoader loader) {
                return new EditOperation(in, loader);
            }

            @Override
            public EditOperation[] newArray(int size) {
                return new EditOperation[size];
            }
        };
    }

    
A helper for enabling and handling "PROCESS_TEXT" menu actions.
These allow external applications to plug into currently selected text.
/**
     * A helper for enabling and handling "PROCESS_TEXT" menu actions.
     * These allow external applications to plug into currently selected text.
     */
    static final class ProcessTextIntentActionsHandler {

        private final Editor mEditor;
        private final TextView mTextView;
        private final Context mContext;
        private final PackageManager mPackageManager;
        private final String mPackageName;
        private final SparseArray<Intent> mAccessibilityIntents = new SparseArray<>();
        private final SparseArray<AccessibilityNodeInfo.AccessibilityAction> mAccessibilityActions =
                new SparseArray<>();
        private final List<ResolveInfo> mSupportedActivities = new ArrayList<>();

        private ProcessTextIntentActionsHandler(Editor editor) {
            mEditor = Preconditions.checkNotNull(editor);
            mTextView = Preconditions.checkNotNull(mEditor.mTextView);
            mContext = Preconditions.checkNotNull(mTextView.getContext());
            mPackageManager = Preconditions.checkNotNull(mContext.getPackageManager());
            mPackageName = Preconditions.checkNotNull(mContext.getPackageName());
        }

        
Adds "PROCESS_TEXT" menu items to the specified menu.
/**
         * Adds "PROCESS_TEXT" menu items to the specified menu.
         */
        public void onInitializeMenu(Menu menu) {
            loadSupportedActivities();
            final int size = mSupportedActivities.size();
            for (int i = 0; i < size; i++) {
                final ResolveInfo resolveInfo = mSupportedActivities.get(i);
                menu.add(Menu.NONE, Menu.NONE,
                        Editor.MENU_ITEM_ORDER_PROCESS_TEXT_INTENT_ACTIONS_START + i,
                        getLabel(resolveInfo))
                        .setIntent(createProcessTextIntentForResolveInfo(resolveInfo))
                        .setShowAsAction(MenuItem.SHOW_AS_ACTION_NEVER);
            }
        }

        
Performs a "PROCESS_TEXT" action if there is one associated with the specified
menu item.
Returns:
True if the action was performed, false otherwise./**
         * Performs a "PROCESS_TEXT" action if there is one associated with the specified
         * menu item.
         *
         * @return True if the action was performed, false otherwise.
         */
        public boolean performMenuItemAction(MenuItem item) {
            return fireIntent(item.getIntent());
        }

        
Initializes and caches "PROCESS_TEXT" accessibility actions.
/**
         * Initializes and caches "PROCESS_TEXT" accessibility actions.
         */
        public void initializeAccessibilityActions() {
            mAccessibilityIntents.clear();
            mAccessibilityActions.clear();
            int i = 0;
            loadSupportedActivities();
            for (ResolveInfo resolveInfo : mSupportedActivities) {
                int actionId = TextView.ACCESSIBILITY_ACTION_PROCESS_TEXT_START_ID + i++;
                mAccessibilityActions.put(
                        actionId,
                        new AccessibilityNodeInfo.AccessibilityAction(
                                actionId, getLabel(resolveInfo)));
                mAccessibilityIntents.put(
                        actionId, createProcessTextIntentForResolveInfo(resolveInfo));
            }
        }

        
Adds "PROCESS_TEXT" accessibility actions to the specified accessibility node info. NOTE: This needs a prior call to initializeAccessibilityActions() to make the latest accessibility actions available for this call. /**
         * Adds "PROCESS_TEXT" accessibility actions to the specified accessibility node info.
         * NOTE: This needs a prior call to {@link #initializeAccessibilityActions()} to make the
         * latest accessibility actions available for this call.
         */
        public void onInitializeAccessibilityNodeInfo(AccessibilityNodeInfo nodeInfo) {
            for (int i = 0; i < mAccessibilityActions.size(); i++) {
                nodeInfo.addAction(mAccessibilityActions.valueAt(i));
            }
        }

        
Performs a "PROCESS_TEXT" action if there is one associated with the specified
accessibility action id.
Returns:
True if the action was performed, false otherwise./**
         * Performs a "PROCESS_TEXT" action if there is one associated with the specified
         * accessibility action id.
         *
         * @return True if the action was performed, false otherwise.
         */
        public boolean performAccessibilityAction(int actionId) {
            return fireIntent(mAccessibilityIntents.get(actionId));
        }

        private boolean fireIntent(Intent intent) {
            if (intent != null && Intent.ACTION_PROCESS_TEXT.equals(intent.getAction())) {
                String selectedText = mTextView.getSelectedText();
                selectedText = TextUtils.trimToParcelableSize(selectedText);
                intent.putExtra(Intent.EXTRA_PROCESS_TEXT, selectedText);
                mEditor.mPreserveSelection = true;
                mTextView.startActivityForResult(intent, TextView.PROCESS_TEXT_REQUEST_CODE);
                return true;
            }
            return false;
        }

        private void loadSupportedActivities() {
            mSupportedActivities.clear();
            if (!mContext.canStartActivityForResult()) {
                return;
            }
            PackageManager packageManager = mTextView.getContext().getPackageManager();
            List<ResolveInfo> unfiltered =
                    packageManager.queryIntentActivities(createProcessTextIntent(), 0);
            for (ResolveInfo info : unfiltered) {
                if (isSupportedActivity(info)) {
                    mSupportedActivities.add(info);
                }
            }
        }

        private boolean isSupportedActivity(ResolveInfo info) {
            return mPackageName.equals(info.activityInfo.packageName)
                    || info.activityInfo.exported
                            && (info.activityInfo.permission == null
                                    || mContext.checkSelfPermission(info.activityInfo.permission)
                                            == PackageManager.PERMISSION_GRANTED);
        }

        private Intent createProcessTextIntentForResolveInfo(ResolveInfo info) {
            return createProcessTextIntent()
                    .putExtra(Intent.EXTRA_PROCESS_TEXT_READONLY, !mTextView.isTextEditable())
                    .setClassName(info.activityInfo.packageName, info.activityInfo.name);
        }

        private Intent createProcessTextIntent() {
            return new Intent()
                    .setAction(Intent.ACTION_PROCESS_TEXT)
                    .setType("text/plain");
        }

        private CharSequence getLabel(ResolveInfo resolveInfo) {
            return resolveInfo.loadLabel(mPackageManager);
        }
    }
}