https://source.android.com/ 
/*
 * Copyright (C) 2009 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.accessibilityservice;

import android.accessibilityservice.GestureDescription.MotionEventGenerator;
import android.annotation.IntDef;
import android.annotation.NonNull;
import android.annotation.Nullable;
import android.annotation.RequiresPermission;
import android.app.Service;
import android.content.Context;
import android.content.Intent;
import android.content.pm.ParceledListSlice;
import android.graphics.Region;
import android.os.Handler;
import android.os.IBinder;
import android.os.Looper;
import android.os.Message;
import android.os.RemoteException;
import android.provider.Settings;
import android.util.ArrayMap;
import android.util.Log;
import android.util.Slog;
import android.util.SparseArray;
import android.view.KeyEvent;
import android.view.WindowManager;
import android.view.WindowManagerImpl;
import android.view.accessibility.AccessibilityEvent;
import android.view.accessibility.AccessibilityInteractionClient;
import android.view.accessibility.AccessibilityNodeInfo;
import android.view.accessibility.AccessibilityWindowInfo;

import com.android.internal.os.HandlerCaller;
import com.android.internal.os.SomeArgs;

import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.util.List;


Accessibility services should only be used to assist users with disabilities in using Android devices and apps. They run in the background and receive callbacks by the system when AccessibilityEvents are fired. Such events denote some state transition in the user interface, for example, the focus has changed, a button has been clicked, etc. Such a service can optionally request the capability for querying the content of the active window. Development of an accessibility service requires extending this class and implementing its abstract methods. 


Developer Guides


For more information about creating AccessibilityServices, read the
Accessibility
developer guide.




Lifecycle


 The lifecycle of an accessibility service is managed exclusively by the system and follows the established service life cycle. Starting an accessibility service is triggered exclusively by the user explicitly turning the service on in device settings. After the system binds to a service, it calls onServiceConnected(). This method can be overridden by clients that want to perform post binding setup. 


 An accessibility service stops either when the user turns it off in device settings or when it calls disableSelf(). 


Declaration



An accessibility is declared as any other service in an AndroidManifest.xml, but it
must do two things:

    
    
       Specify that it handles the "android.accessibilityservice.AccessibilityService" Intent. 
    
    
       Request the BIND_ACCESSIBILITY_SERVICE.BIND_ACCESSIBILITY_SERVICE permission to ensure that only the system can bind to it. 
    


If either of these items is missing, the system will ignore the accessibility service.
Following is an example declaration:



 <service android:name=".MyAccessibilityService"
        android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE">
    <intent-filter>
        <action android:name="android.accessibilityservice.AccessibilityService" />
    </intent-filter>
    . . .
</service>


Configuration



An accessibility service can be configured to receive specific types of accessibility events,
listen only to specific packages, get events from each type only once in a given time frame,
retrieve window content, specify a settings activity, etc.




There are two approaches for configuring an accessibility service:




Retrieving window content


 A service can specify in its declaration that it can retrieve window content which is represented as a tree of AccessibilityWindowInfo and AccessibilityNodeInfo objects. Note that declaring this capability requires that the service declares its configuration via an XML resource referenced by SERVICE_META_DATA. 


 Window content may be retrieved with AccessibilityEvent.getSource(), findFocus(int), getWindows(), or getRootInActiveWindow(). 



Note An accessibility service may have requested to be notified for
a subset of the event types, and thus be unaware when the node hierarchy has changed. It is also
possible for a node to contain outdated information because the window content may change at any
time.



Notification strategy



All accessibility services are notified of all events they have requested, regardless of their
feedback type.




Note: The event notification timeout is useful to avoid propagating
events to the client too frequently since this is accomplished via an expensive
interprocess call. One can think of the timeout as a criteria to determine when
event generation has settled down.


Event types



Feedback types



See Also:
/**
 * Accessibility services should only be used to assist users with disabilities in using
 * Android devices and apps. They run in the background and receive callbacks by the system
 * when {@link AccessibilityEvent}s are fired. Such events denote some state transition
 * in the user interface, for example, the focus has changed, a button has been clicked,
 * etc. Such a service can optionally request the capability for querying the content
 * of the active window. Development of an accessibility service requires extending this
 * class and implementing its abstract methods.
 *
 * <div class="special reference">
 * <h3>Developer Guides</h3>
 * <p>For more information about creating AccessibilityServices, read the
 * <a href="{@docRoot}guide/topics/ui/accessibility/index.html">Accessibility</a>
 * developer guide.</p>
 * </div>
 *
 * <h3>Lifecycle</h3>
 * <p>
 * The lifecycle of an accessibility service is managed exclusively by the system and
 * follows the established service life cycle. Starting an accessibility service is triggered
 * exclusively by the user explicitly turning the service on in device settings. After the system
 * binds to a service, it calls {@link AccessibilityService#onServiceConnected()}. This method can
 * be overridden by clients that want to perform post binding setup.
 * </p>
 * <p>
 * An accessibility service stops either when the user turns it off in device settings or when
 * it calls {@link AccessibilityService#disableSelf()}.
 * </p>
 * <h3>Declaration</h3>
 * <p>
 * An accessibility is declared as any other service in an AndroidManifest.xml, but it
 * must do two things:
 * <ul>
 *     <ol>
 *         Specify that it handles the "android.accessibilityservice.AccessibilityService"
 *         {@link android.content.Intent}.
 *     </ol>
 *     <ol>
 *         Request the {@link android.Manifest.permission#BIND_ACCESSIBILITY_SERVICE} permission to
 *         ensure that only the system can bind to it.
 *     </ol>
 * </ul>
 * If either of these items is missing, the system will ignore the accessibility service.
 * Following is an example declaration:
 * </p>
 * <pre> &lt;service android:name=".MyAccessibilityService"
 *         android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE"&gt;
 *     &lt;intent-filter&gt;
 *         &lt;action android:name="android.accessibilityservice.AccessibilityService" /&gt;
 *     &lt;/intent-filter&gt;
 *     . . .
 * &lt;/service&gt;</pre>
 * <h3>Configuration</h3>
 * <p>
 * An accessibility service can be configured to receive specific types of accessibility events,
 * listen only to specific packages, get events from each type only once in a given time frame,
 * retrieve window content, specify a settings activity, etc.
 * </p>
 * <p>
 * There are two approaches for configuring an accessibility service:
 * </p>
 * <ul>
 * <li>
 * Providing a {@link #SERVICE_META_DATA meta-data} entry in the manifest when declaring
 * the service. A service declaration with a meta-data tag is presented below:
 * <pre> &lt;service android:name=".MyAccessibilityService"&gt;
 *     &lt;intent-filter&gt;
 *         &lt;action android:name="android.accessibilityservice.AccessibilityService" /&gt;
 *     &lt;/intent-filter&gt;
 *     &lt;meta-data android:name="android.accessibilityservice" android:resource="@xml/accessibilityservice" /&gt;
 * &lt;/service&gt;</pre>
 * <p class="note">
 * <strong>Note:</strong> This approach enables setting all properties.
 * </p>
 * <p>
 * For more details refer to {@link #SERVICE_META_DATA} and
 * <code>&lt;{@link android.R.styleable#AccessibilityService accessibility-service}&gt;</code>.
 * </p>
 * </li>
 * <li>
 * Calling {@link AccessibilityService#setServiceInfo(AccessibilityServiceInfo)}. Note
 * that this method can be called any time to dynamically change the service configuration.
 * <p class="note">
 * <strong>Note:</strong> This approach enables setting only dynamically configurable properties:
 * {@link AccessibilityServiceInfo#eventTypes},
 * {@link AccessibilityServiceInfo#feedbackType},
 * {@link AccessibilityServiceInfo#flags},
 * {@link AccessibilityServiceInfo#notificationTimeout},
 * {@link AccessibilityServiceInfo#packageNames}
 * </p>
 * <p>
 * For more details refer to {@link AccessibilityServiceInfo}.
 * </p>
 * </li>
 * </ul>
 * <h3>Retrieving window content</h3>
 * <p>
 * A service can specify in its declaration that it can retrieve window
 * content which is represented as a tree of {@link AccessibilityWindowInfo} and
 * {@link AccessibilityNodeInfo} objects. Note that
 * declaring this capability requires that the service declares its configuration via
 * an XML resource referenced by {@link #SERVICE_META_DATA}.
 * </p>
 * <p>
 * Window content may be retrieved with
 * {@link AccessibilityEvent#getSource() AccessibilityEvent.getSource()},
 * {@link AccessibilityService#findFocus(int)},
 * {@link AccessibilityService#getWindows()}, or
 * {@link AccessibilityService#getRootInActiveWindow()}.
 * </p>
 * <p class="note">
 * <strong>Note</strong> An accessibility service may have requested to be notified for
 * a subset of the event types, and thus be unaware when the node hierarchy has changed. It is also
 * possible for a node to contain outdated information because the window content may change at any
 * time.
 * </p>
 * <h3>Notification strategy</h3>
 * <p>
 * All accessibility services are notified of all events they have requested, regardless of their
 * feedback type.
 * </p>
 * <p class="note">
 * <strong>Note:</strong> The event notification timeout is useful to avoid propagating
 * events to the client too frequently since this is accomplished via an expensive
 * interprocess call. One can think of the timeout as a criteria to determine when
 * event generation has settled down.</p>
 * <h3>Event types</h3>
 * <ul>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_CLICKED}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_LONG_CLICKED}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_FOCUSED}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_SELECTED}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_TEXT_CHANGED}</li>
 * <li>{@link AccessibilityEvent#TYPE_WINDOW_STATE_CHANGED}</li>
 * <li>{@link AccessibilityEvent#TYPE_NOTIFICATION_STATE_CHANGED}</li>
 * <li>{@link AccessibilityEvent#TYPE_TOUCH_EXPLORATION_GESTURE_START}</li>
 * <li>{@link AccessibilityEvent#TYPE_TOUCH_EXPLORATION_GESTURE_END}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_HOVER_ENTER}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_HOVER_EXIT}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_SCROLLED}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_TEXT_SELECTION_CHANGED}</li>
 * <li>{@link AccessibilityEvent#TYPE_WINDOW_CONTENT_CHANGED}</li>
 * <li>{@link AccessibilityEvent#TYPE_ANNOUNCEMENT}</li>
 * <li>{@link AccessibilityEvent#TYPE_GESTURE_DETECTION_START}</li>
 * <li>{@link AccessibilityEvent#TYPE_GESTURE_DETECTION_END}</li>
 * <li>{@link AccessibilityEvent#TYPE_TOUCH_INTERACTION_START}</li>
 * <li>{@link AccessibilityEvent#TYPE_TOUCH_INTERACTION_END}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_ACCESSIBILITY_FOCUSED}</li>
 * <li>{@link AccessibilityEvent#TYPE_WINDOWS_CHANGED}</li>
 * <li>{@link AccessibilityEvent#TYPE_VIEW_ACCESSIBILITY_FOCUS_CLEARED}</li>
 * </ul>
 * <h3>Feedback types</h3>
 * <ul>
 * <li>{@link AccessibilityServiceInfo#FEEDBACK_AUDIBLE}</li>
 * <li>{@link AccessibilityServiceInfo#FEEDBACK_HAPTIC}</li>
 * <li>{@link AccessibilityServiceInfo#FEEDBACK_AUDIBLE}</li>
 * <li>{@link AccessibilityServiceInfo#FEEDBACK_VISUAL}</li>
 * <li>{@link AccessibilityServiceInfo#FEEDBACK_GENERIC}</li>
 * <li>{@link AccessibilityServiceInfo#FEEDBACK_BRAILLE}</li>
 * </ul>
 * @see AccessibilityEvent
 * @see AccessibilityServiceInfo
 * @see android.view.accessibility.AccessibilityManager
 */
public abstract class AccessibilityService extends Service {

    
The user has performed a swipe up gesture on the touch screen.

/**
     * The user has performed a swipe up gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_UP = 1;

    
The user has performed a swipe down gesture on the touch screen.

/**
     * The user has performed a swipe down gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_DOWN = 2;

    
The user has performed a swipe left gesture on the touch screen.

/**
     * The user has performed a swipe left gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_LEFT = 3;

    
The user has performed a swipe right gesture on the touch screen.

/**
     * The user has performed a swipe right gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_RIGHT = 4;

    
The user has performed a swipe left and right gesture on the touch screen.

/**
     * The user has performed a swipe left and right gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_LEFT_AND_RIGHT = 5;

    
The user has performed a swipe right and left gesture on the touch screen.

/**
     * The user has performed a swipe right and left gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_RIGHT_AND_LEFT = 6;

    
The user has performed a swipe up and down gesture on the touch screen.

/**
     * The user has performed a swipe up and down gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_UP_AND_DOWN = 7;

    
The user has performed a swipe down and up gesture on the touch screen.

/**
     * The user has performed a swipe down and up gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_DOWN_AND_UP = 8;

    
The user has performed a left and up gesture on the touch screen.

/**
     * The user has performed a left and up gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_LEFT_AND_UP = 9;

    
The user has performed a left and down gesture on the touch screen.

/**
     * The user has performed a left and down gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_LEFT_AND_DOWN = 10;

    
The user has performed a right and up gesture on the touch screen.

/**
     * The user has performed a right and up gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_RIGHT_AND_UP = 11;

    
The user has performed a right and down gesture on the touch screen.

/**
     * The user has performed a right and down gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_RIGHT_AND_DOWN = 12;

    
The user has performed an up and left gesture on the touch screen.

/**
     * The user has performed an up and left gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_UP_AND_LEFT = 13;

    
The user has performed an up and right gesture on the touch screen.

/**
     * The user has performed an up and right gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_UP_AND_RIGHT = 14;

    
The user has performed an down and left gesture on the touch screen.

/**
     * The user has performed an down and left gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_DOWN_AND_LEFT = 15;

    
The user has performed an down and right gesture on the touch screen.

/**
     * The user has performed an down and right gesture on the touch screen.
     */
    public static final int GESTURE_SWIPE_DOWN_AND_RIGHT = 16;

    
The Intent that must be declared as handled by the service. 
/**
     * The {@link Intent} that must be declared as handled by the service.
     */
    public static final String SERVICE_INTERFACE =
        "android.accessibilityservice.AccessibilityService";

    
Name under which an AccessibilityService component publishes information
about itself. This meta-data must reference an XML resource containing an
<accessibility-service>
tag. This is a a sample XML file configuring an accessibility service:

 <accessibility-service
    android:accessibilityEventTypes="typeViewClicked|typeViewFocused"
    android:packageNames="foo.bar, foo.baz"
    android:accessibilityFeedbackType="feedbackSpoken"
    android:notificationTimeout="100"
    android:accessibilityFlags="flagDefault"
    android:settingsActivity="foo.bar.TestBackActivity"
    android:canRetrieveWindowContent="true"
    android:canRequestTouchExplorationMode="true"
    . . .
/>


/**
     * Name under which an AccessibilityService component publishes information
     * about itself. This meta-data must reference an XML resource containing an
     * <code>&lt;{@link android.R.styleable#AccessibilityService accessibility-service}&gt;</code>
     * tag. This is a a sample XML file configuring an accessibility service:
     * <pre> &lt;accessibility-service
     *     android:accessibilityEventTypes="typeViewClicked|typeViewFocused"
     *     android:packageNames="foo.bar, foo.baz"
     *     android:accessibilityFeedbackType="feedbackSpoken"
     *     android:notificationTimeout="100"
     *     android:accessibilityFlags="flagDefault"
     *     android:settingsActivity="foo.bar.TestBackActivity"
     *     android:canRetrieveWindowContent="true"
     *     android:canRequestTouchExplorationMode="true"
     *     . . .
     * /&gt;</pre>
     */
    public static final String SERVICE_META_DATA = "android.accessibilityservice";

    
Action to go back.

/**
     * Action to go back.
     */
    public static final int GLOBAL_ACTION_BACK = 1;

    
Action to go home.

/**
     * Action to go home.
     */
    public static final int GLOBAL_ACTION_HOME = 2;

    
Action to toggle showing the overview of recent apps. Will fail on platforms that don't
show recent apps.

/**
     * Action to toggle showing the overview of recent apps. Will fail on platforms that don't
     * show recent apps.
     */
    public static final int GLOBAL_ACTION_RECENTS = 3;

    
Action to open the notifications.

/**
     * Action to open the notifications.
     */
    public static final int GLOBAL_ACTION_NOTIFICATIONS = 4;

    
Action to open the quick settings.

/**
     * Action to open the quick settings.
     */
    public static final int GLOBAL_ACTION_QUICK_SETTINGS = 5;

    
Action to open the power long-press dialog.

/**
     * Action to open the power long-press dialog.
     */
    public static final int GLOBAL_ACTION_POWER_DIALOG = 6;

    
Action to toggle docking the current app's window

/**
     * Action to toggle docking the current app's window
     */
    public static final int GLOBAL_ACTION_TOGGLE_SPLIT_SCREEN = 7;

    
Action to lock the screen

/**
     * Action to lock the screen
     */
    public static final int GLOBAL_ACTION_LOCK_SCREEN = 8;

    
Action to take a screenshot

/**
     * Action to take a screenshot
     */
    public static final int GLOBAL_ACTION_TAKE_SCREENSHOT = 9;

    private static final String LOG_TAG = "AccessibilityService";

    
Interface used by IAccessibilityServiceWrapper to call the service from its main thread.

@hide
/**
     * Interface used by IAccessibilityServiceWrapper to call the service from its main thread.
     * @hide
     */
    public interface Callbacks {
        void onAccessibilityEvent(AccessibilityEvent event);
        void onInterrupt();
        void onServiceConnected();
        void init(int connectionId, IBinder windowToken);
        boolean onGesture(int gestureId);
        boolean onKeyEvent(KeyEvent event);
        void onMagnificationChanged(@NonNull Region region,
                float scale, float centerX, float centerY);
        void onSoftKeyboardShowModeChanged(int showMode);
        void onPerformGestureResult(int sequence, boolean completedSuccessfully);
        void onFingerprintCapturingGesturesChanged(boolean active);
        void onFingerprintGesture(int gesture);
        void onAccessibilityButtonClicked();
        void onAccessibilityButtonAvailabilityChanged(boolean available);
    }

    
Annotations for Soft Keyboard show modes so tools can catch invalid show modes.

@hide
/**
     * Annotations for Soft Keyboard show modes so tools can catch invalid show modes.
     * @hide
     */
    @Retention(RetentionPolicy.SOURCE)
    @IntDef(prefix = { "SHOW_MODE_" }, value = {
            SHOW_MODE_AUTO,
            SHOW_MODE_HIDDEN
    })
    public @interface SoftKeyboardShowMode {}

    public static final int SHOW_MODE_AUTO = 0;
    public static final int SHOW_MODE_HIDDEN = 1;

    private int mConnectionId = AccessibilityInteractionClient.NO_ID;

    private AccessibilityServiceInfo mInfo;

    private IBinder mWindowToken;

    private WindowManager mWindowManager;

    private MagnificationController mMagnificationController;
    private SoftKeyboardController mSoftKeyboardController;
    private AccessibilityButtonController mAccessibilityButtonController;

    private int mGestureStatusCallbackSequence;

    private SparseArray<GestureResultCallbackInfo> mGestureStatusCallbackInfos;

    private final Object mLock = new Object();

    private FingerprintGestureController mFingerprintGestureController;

    
Callback for AccessibilityEvents. 
Params:
  • event – The new event. This event is owned by the caller and cannot be used after
this method returns. Services wishing to use the event after this method returns should
make a copy.
/**
     * Callback for {@link android.view.accessibility.AccessibilityEvent}s.
     *
     * @param event The new event. This event is owned by the caller and cannot be used after
     * this method returns. Services wishing to use the event after this method returns should
     * make a copy.
     */
    public abstract void onAccessibilityEvent(AccessibilityEvent event);

    
Callback for interrupting the accessibility feedback.

/**
     * Callback for interrupting the accessibility feedback.
     */
    public abstract void onInterrupt();

    
Dispatches service connection to internal components first, then the
client code.

/**
     * Dispatches service connection to internal components first, then the
     * client code.
     */
    private void dispatchServiceConnected() {
        if (mMagnificationController != null) {
            mMagnificationController.onServiceConnected();
        }
        if (mSoftKeyboardController != null) {
            mSoftKeyboardController.onServiceConnected();
        }

        // The client gets to handle service connection last, after we've set
        // up any state upon which their code may rely.
        onServiceConnected();
    }

    
This method is a part of the AccessibilityService lifecycle and is called after the system has successfully bound to the service. If is convenient to use this method for setting the AccessibilityServiceInfo. 
See Also:
/**
     * This method is a part of the {@link AccessibilityService} lifecycle and is
     * called after the system has successfully bound to the service. If is
     * convenient to use this method for setting the {@link AccessibilityServiceInfo}.
     *
     * @see AccessibilityServiceInfo
     * @see #setServiceInfo(AccessibilityServiceInfo)
     */
    protected void onServiceConnected() {

    }

    
Called by the system when the user performs a specific gesture on the
touch screen.
Note: To receive gestures an accessibility service must request that the device is in touch exploration mode by setting the AccessibilityServiceInfo.FLAG_REQUEST_TOUCH_EXPLORATION_MODE flag. 
Params:
  • gestureId – The unique id of the performed gesture.
See Also:
Returns:Whether the gesture was handled.
/**
     * Called by the system when the user performs a specific gesture on the
     * touch screen.
     *
     * <strong>Note:</strong> To receive gestures an accessibility service must
     * request that the device is in touch exploration mode by setting the
     * {@link android.accessibilityservice.AccessibilityServiceInfo#FLAG_REQUEST_TOUCH_EXPLORATION_MODE}
     * flag.
     *
     * @param gestureId The unique id of the performed gesture.
     *
     * @return Whether the gesture was handled.
     *
     * @see #GESTURE_SWIPE_UP
     * @see #GESTURE_SWIPE_UP_AND_LEFT
     * @see #GESTURE_SWIPE_UP_AND_DOWN
     * @see #GESTURE_SWIPE_UP_AND_RIGHT
     * @see #GESTURE_SWIPE_DOWN
     * @see #GESTURE_SWIPE_DOWN_AND_LEFT
     * @see #GESTURE_SWIPE_DOWN_AND_UP
     * @see #GESTURE_SWIPE_DOWN_AND_RIGHT
     * @see #GESTURE_SWIPE_LEFT
     * @see #GESTURE_SWIPE_LEFT_AND_UP
     * @see #GESTURE_SWIPE_LEFT_AND_RIGHT
     * @see #GESTURE_SWIPE_LEFT_AND_DOWN
     * @see #GESTURE_SWIPE_RIGHT
     * @see #GESTURE_SWIPE_RIGHT_AND_UP
     * @see #GESTURE_SWIPE_RIGHT_AND_LEFT
     * @see #GESTURE_SWIPE_RIGHT_AND_DOWN
     */
    protected boolean onGesture(int gestureId) {
        return false;
    }

    
Callback that allows an accessibility service to observe the key events
before they are passed to the rest of the system. This means that the events
are first delivered here before they are passed to the device policy, the
input method, or applications.


Note: It is important that key events are handled in such
a way that the event stream that would be passed to the rest of the system
is well-formed. For example, handling the down event but not the up event
and vice versa would generate an inconsistent event stream.




Note: The key events delivered in this method are copies
and modifying them will have no effect on the events that will be passed
to the system. This method is intended to perform purely filtering
functionality.



Params:
  • event – The event to be processed. This event is owned by the caller and cannot be used
after this method returns. Services wishing to use the event after this method returns should
make a copy.
Returns:If true then the event will be consumed and not delivered to
        applications, otherwise it will be delivered as usual.
/**
     * Callback that allows an accessibility service to observe the key events
     * before they are passed to the rest of the system. This means that the events
     * are first delivered here before they are passed to the device policy, the
     * input method, or applications.
     * <p>
     * <strong>Note:</strong> It is important that key events are handled in such
     * a way that the event stream that would be passed to the rest of the system
     * is well-formed. For example, handling the down event but not the up event
     * and vice versa would generate an inconsistent event stream.
     * </p>
     * <p>
     * <strong>Note:</strong> The key events delivered in this method are copies
     * and modifying them will have no effect on the events that will be passed
     * to the system. This method is intended to perform purely filtering
     * functionality.
     * <p>
     *
     * @param event The event to be processed. This event is owned by the caller and cannot be used
     * after this method returns. Services wishing to use the event after this method returns should
     * make a copy.
     * @return If true then the event will be consumed and not delivered to
     *         applications, otherwise it will be delivered as usual.
     */
    protected boolean onKeyEvent(KeyEvent event) {
        return false;
    }

    
Gets the windows on the screen. This method returns only the windows
that a sighted user can interact with, as opposed to all windows.
For example, if there is a modal dialog shown and the user cannot touch
anything behind it, then only the modal window will be reported
(assuming it is the top one). For convenience the returned windows
are ordered in a descending layer order, which is the windows that
are on top are reported first. Since the user can always
interact with the window that has input focus by typing, the focused
window is always returned (even if covered by a modal window).


Note: In order to access the windows your service has to declare the capability to retrieve window content by setting the AccessibilityService_canRetrieveWindowContent.AccessibilityService_canRetrieveWindowContent property in its meta-data. For details refer to SERVICE_META_DATA. Also the service has to opt-in to retrieve the interactive windows by setting the AccessibilityServiceInfo.FLAG_RETRIEVE_INTERACTIVE_WINDOWS flag. 


Returns:The windows if there are windows and the service is can retrieve
        them, otherwise an empty list.
/**
     * Gets the windows on the screen. This method returns only the windows
     * that a sighted user can interact with, as opposed to all windows.
     * For example, if there is a modal dialog shown and the user cannot touch
     * anything behind it, then only the modal window will be reported
     * (assuming it is the top one). For convenience the returned windows
     * are ordered in a descending layer order, which is the windows that
     * are on top are reported first. Since the user can always
     * interact with the window that has input focus by typing, the focused
     * window is always returned (even if covered by a modal window).
     * <p>
     * <strong>Note:</strong> In order to access the windows your service has
     * to declare the capability to retrieve window content by setting the
     * {@link android.R.styleable#AccessibilityService_canRetrieveWindowContent}
     * property in its meta-data. For details refer to {@link #SERVICE_META_DATA}.
     * Also the service has to opt-in to retrieve the interactive windows by
     * setting the {@link AccessibilityServiceInfo#FLAG_RETRIEVE_INTERACTIVE_WINDOWS}
     * flag.
     * </p>
     *
     * @return The windows if there are windows and the service is can retrieve
     *         them, otherwise an empty list.
     */
    public List<AccessibilityWindowInfo> getWindows() {
        return AccessibilityInteractionClient.getInstance().getWindows(mConnectionId);
    }

    
Gets the root node in the currently active window if this service
can retrieve window content. The active window is the one that the user
is currently touching or the window with input focus, if the user is not
touching any window.

 The currently active window is defined as the window that most recently fired one of the following events: AccessibilityEvent.TYPE_WINDOW_STATE_CHANGED, AccessibilityEvent.TYPE_VIEW_HOVER_ENTER, AccessibilityEvent.TYPE_VIEW_HOVER_EXIT. In other words, the last window shown that also has input focus. 



Note: In order to access the root node your service has to declare the capability to retrieve window content by setting the AccessibilityService_canRetrieveWindowContent.AccessibilityService_canRetrieveWindowContent property in its meta-data. For details refer to SERVICE_META_DATA. 


Returns:The root node if this service can retrieve window content.
/**
     * Gets the root node in the currently active window if this service
     * can retrieve window content. The active window is the one that the user
     * is currently touching or the window with input focus, if the user is not
     * touching any window.
     * <p>
     * The currently active window is defined as the window that most recently fired one
     * of the following events:
     * {@link AccessibilityEvent#TYPE_WINDOW_STATE_CHANGED},
     * {@link AccessibilityEvent#TYPE_VIEW_HOVER_ENTER},
     * {@link AccessibilityEvent#TYPE_VIEW_HOVER_EXIT}.
     * In other words, the last window shown that also has input focus.
     * </p>
     * <p>
     * <strong>Note:</strong> In order to access the root node your service has
     * to declare the capability to retrieve window content by setting the
     * {@link android.R.styleable#AccessibilityService_canRetrieveWindowContent}
     * property in its meta-data. For details refer to {@link #SERVICE_META_DATA}.
     * </p>
     *
     * @return The root node if this service can retrieve window content.
     */
    public AccessibilityNodeInfo getRootInActiveWindow() {
        return AccessibilityInteractionClient.getInstance().getRootInActiveWindow(mConnectionId);
    }

    
Disables the service. After calling this method, the service will be disabled and settings
will show that it is turned off.

/**
     * Disables the service. After calling this method, the service will be disabled and settings
     * will show that it is turned off.
     */
    public final void disableSelf() {
        final IAccessibilityServiceConnection connection =
                AccessibilityInteractionClient.getInstance().getConnection(mConnectionId);
        if (connection != null) {
            try {
                connection.disableSelf();
            } catch (RemoteException re) {
                throw new RuntimeException(re);
            }
        }
    }

    
Returns the magnification controller, which may be used to query and
modify the state of display magnification.


Note: In order to control magnification, your service must declare the capability by setting the AccessibilityService_canControlMagnification.AccessibilityService_canControlMagnification property in its meta-data. For more information, see SERVICE_META_DATA. 
Returns:the magnification controller
/**
     * Returns the magnification controller, which may be used to query and
     * modify the state of display magnification.
     * <p>
     * <strong>Note:</strong> In order to control magnification, your service
     * must declare the capability by setting the
     * {@link android.R.styleable#AccessibilityService_canControlMagnification}
     * property in its meta-data. For more information, see
     * {@link #SERVICE_META_DATA}.
     *
     * @return the magnification controller
     */
    @NonNull
    public final MagnificationController getMagnificationController() {
        synchronized (mLock) {
            if (mMagnificationController == null) {
                mMagnificationController = new MagnificationController(this, mLock);
            }
            return mMagnificationController;
        }
    }

    
Get the controller for fingerprint gestures. This feature requires AccessibilityServiceInfo.CAPABILITY_CAN_REQUEST_FINGERPRINT_GESTURES. Note:  The service must be connected before this method is called.

Returns:The controller for fingerprint gestures, or null if gestures are unavailable.
/**
     * Get the controller for fingerprint gestures. This feature requires {@link
     * AccessibilityServiceInfo#CAPABILITY_CAN_REQUEST_FINGERPRINT_GESTURES}.
     *
     *<strong>Note: </strong> The service must be connected before this method is called.
     *
     * @return The controller for fingerprint gestures, or {@code null} if gestures are unavailable.
     */
    @RequiresPermission(android.Manifest.permission.USE_FINGERPRINT)
    public final @NonNull FingerprintGestureController getFingerprintGestureController() {
        if (mFingerprintGestureController == null) {
            mFingerprintGestureController = new FingerprintGestureController(
                    AccessibilityInteractionClient.getInstance().getConnection(mConnectionId));
        }
        return mFingerprintGestureController;
    }

    
Dispatch a gesture to the touch screen. Any gestures currently in progress, whether from
the user, this service, or another service, will be cancelled.


The gesture will be dispatched as if it were performed directly on the screen by a user, so
the events may be affected by features such as magnification and explore by touch.




Note: In order to dispatch gestures, your service must declare the capability by setting the AccessibilityService_canPerformGestures.AccessibilityService_canPerformGestures property in its meta-data. For more information, see SERVICE_META_DATA. 


Params:
  • gesture – The gesture to dispatch
  • callback – The object to call back when the status of the gesture is known. If null, no status is reported.
  • handler – The handler on which to call back the callback object. If null, the object is called back on the service's main thread.
Returns:true if the gesture is dispatched, false if not.
/**
     * Dispatch a gesture to the touch screen. Any gestures currently in progress, whether from
     * the user, this service, or another service, will be cancelled.
     * <p>
     * The gesture will be dispatched as if it were performed directly on the screen by a user, so
     * the events may be affected by features such as magnification and explore by touch.
     * </p>
     * <p>
     * <strong>Note:</strong> In order to dispatch gestures, your service
     * must declare the capability by setting the
     * {@link android.R.styleable#AccessibilityService_canPerformGestures}
     * property in its meta-data. For more information, see
     * {@link #SERVICE_META_DATA}.
     * </p>
     *
     * @param gesture The gesture to dispatch
     * @param callback The object to call back when the status of the gesture is known. If
     * {@code null}, no status is reported.
     * @param handler The handler on which to call back the {@code callback} object. If
     * {@code null}, the object is called back on the service's main thread.
     *
     * @return {@code true} if the gesture is dispatched, {@code false} if not.
     */
    public final boolean dispatchGesture(@NonNull GestureDescription gesture,
            @Nullable GestureResultCallback callback,
            @Nullable Handler handler) {
        final IAccessibilityServiceConnection connection =
                AccessibilityInteractionClient.getInstance().getConnection(
                        mConnectionId);
        if (connection == null) {
            return false;
        }
        List<GestureDescription.GestureStep> steps =
                MotionEventGenerator.getGestureStepsFromGestureDescription(gesture, 100);
        try {
            synchronized (mLock) {
                mGestureStatusCallbackSequence++;
                if (callback != null) {
                    if (mGestureStatusCallbackInfos == null) {
                        mGestureStatusCallbackInfos = new SparseArray<>();
                    }
                    GestureResultCallbackInfo callbackInfo = new GestureResultCallbackInfo(gesture,
                            callback, handler);
                    mGestureStatusCallbackInfos.put(mGestureStatusCallbackSequence, callbackInfo);
                }
                connection.sendGesture(mGestureStatusCallbackSequence,
                        new ParceledListSlice<>(steps));
            }
        } catch (RemoteException re) {
            throw new RuntimeException(re);
        }
        return true;
    }

    void onPerformGestureResult(int sequence, final boolean completedSuccessfully) {
        if (mGestureStatusCallbackInfos == null) {
            return;
        }
        GestureResultCallbackInfo callbackInfo;
        synchronized (mLock) {
            callbackInfo = mGestureStatusCallbackInfos.get(sequence);
        }
        final GestureResultCallbackInfo finalCallbackInfo = callbackInfo;
        if ((callbackInfo != null) && (callbackInfo.gestureDescription != null)
                && (callbackInfo.callback != null)) {
            if (callbackInfo.handler != null) {
                callbackInfo.handler.post(new Runnable() {
                    @Override
                    public void run() {
                        if (completedSuccessfully) {
                            finalCallbackInfo.callback
                                    .onCompleted(finalCallbackInfo.gestureDescription);
                        } else {
                            finalCallbackInfo.callback
                                    .onCancelled(finalCallbackInfo.gestureDescription);
                        }
                    }
                });
                return;
            }
            if (completedSuccessfully) {
                callbackInfo.callback.onCompleted(callbackInfo.gestureDescription);
            } else {
                callbackInfo.callback.onCancelled(callbackInfo.gestureDescription);
            }
        }
    }

    private void onMagnificationChanged(@NonNull Region region, float scale,
            float centerX, float centerY) {
        if (mMagnificationController != null) {
            mMagnificationController.dispatchMagnificationChanged(
                    region, scale, centerX, centerY);
        }
    }

    
Callback for fingerprint gesture handling

Params:
  • active – If gesture detection is active
/**
     * Callback for fingerprint gesture handling
     * @param active If gesture detection is active
     */
    private void onFingerprintCapturingGesturesChanged(boolean active) {
        getFingerprintGestureController().onGestureDetectionActiveChanged(active);
    }

    
Callback for fingerprint gesture handling

Params:
  • gesture – The identifier for the gesture performed
/**
     * Callback for fingerprint gesture handling
     * @param gesture The identifier for the gesture performed
     */
    private void onFingerprintGesture(int gesture) {
        getFingerprintGestureController().onGesture(gesture);
    }

    
Used to control and query the state of display magnification.

/**
     * Used to control and query the state of display magnification.
     */
    public static final class MagnificationController {
        private final AccessibilityService mService;

        
Map of listeners to their handlers. Lazily created when adding the
first magnification listener.

/**
         * Map of listeners to their handlers. Lazily created when adding the
         * first magnification listener.
         */
        private ArrayMap<OnMagnificationChangedListener, Handler> mListeners;
        private final Object mLock;

        MagnificationController(@NonNull AccessibilityService service, @NonNull Object lock) {
            mService = service;
            mLock = lock;
        }

        
Called when the service is connected.

/**
         * Called when the service is connected.
         */
        void onServiceConnected() {
            synchronized (mLock) {
                if (mListeners != null && !mListeners.isEmpty()) {
                    setMagnificationCallbackEnabled(true);
                }
            }
        }

        
Adds the specified change listener to the list of magnification
change listeners. The callback will occur on the service's main
thread.

Params:
  • listener – the listener to add, must be non-null
/**
         * Adds the specified change listener to the list of magnification
         * change listeners. The callback will occur on the service's main
         * thread.
         *
         * @param listener the listener to add, must be non-{@code null}
         */
        public void addListener(@NonNull OnMagnificationChangedListener listener) {
            addListener(listener, null);
        }

        
Adds the specified change listener to the list of magnification change listeners. The callback will occur on the specified Handler's thread, or on the service's main thread if the handler is null. 
Params:
  • listener – the listener to add, must be non-null
  • handler – the handler on which the callback should execute, or null to execute on the service's main thread
/**
         * Adds the specified change listener to the list of magnification
         * change listeners. The callback will occur on the specified
         * {@link Handler}'s thread, or on the service's main thread if the
         * handler is {@code null}.
         *
         * @param listener the listener to add, must be non-null
         * @param handler the handler on which the callback should execute, or
         *        {@code null} to execute on the service's main thread
         */
        public void addListener(@NonNull OnMagnificationChangedListener listener,
                @Nullable Handler handler) {
            synchronized (mLock) {
                if (mListeners == null) {
                    mListeners = new ArrayMap<>();
                }

                final boolean shouldEnableCallback = mListeners.isEmpty();
                mListeners.put(listener, handler);

                if (shouldEnableCallback) {
                    // This may fail if the service is not connected yet, but if we
                    // still have listeners when it connects then we can try again.
                    setMagnificationCallbackEnabled(true);
                }
            }
        }

        
Removes the specified change listener from the list of magnification change listeners.

Params:
  • listener – the listener to remove, must be non-null
Returns:true if the listener was removed, false otherwise
/**
         * Removes the specified change listener from the list of magnification change listeners.
         *
         * @param listener the listener to remove, must be non-null
         * @return {@code true} if the listener was removed, {@code false} otherwise
         */
        public boolean removeListener(@NonNull OnMagnificationChangedListener listener) {
            if (mListeners == null) {
                return false;
            }

            synchronized (mLock) {
                final int keyIndex = mListeners.indexOfKey(listener);
                final boolean hasKey = keyIndex >= 0;
                if (hasKey) {
                    mListeners.removeAt(keyIndex);
                }

                if (hasKey && mListeners.isEmpty()) {
                    // We just removed the last listener, so we don't need
                    // callbacks from the service anymore.
                    setMagnificationCallbackEnabled(false);
                }

                return hasKey;
            }
        }

        private void setMagnificationCallbackEnabled(boolean enabled) {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    connection.setMagnificationCallbackEnabled(enabled);
                } catch (RemoteException re) {
                    throw new RuntimeException(re);
                }
            }
        }

        
Dispatches magnification changes to any registered listeners. This
should be called on the service's main thread.

/**
         * Dispatches magnification changes to any registered listeners. This
         * should be called on the service's main thread.
         */
        void dispatchMagnificationChanged(final @NonNull Region region, final float scale,
                final float centerX, final float centerY) {
            final ArrayMap<OnMagnificationChangedListener, Handler> entries;
            synchronized (mLock) {
                if (mListeners == null || mListeners.isEmpty()) {
                    Slog.d(LOG_TAG, "Received magnification changed "
                            + "callback with no listeners registered!");
                    setMagnificationCallbackEnabled(false);
                    return;
                }

                // Listeners may remove themselves. Perform a shallow copy to avoid concurrent
                // modification.
                entries = new ArrayMap<>(mListeners);
            }

            for (int i = 0, count = entries.size(); i < count; i++) {
                final OnMagnificationChangedListener listener = entries.keyAt(i);
                final Handler handler = entries.valueAt(i);
                if (handler != null) {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            listener.onMagnificationChanged(MagnificationController.this,
                                    region, scale, centerX, centerY);
                        }
                    });
                } else {
                    // We're already on the main thread, just run the listener.
                    listener.onMagnificationChanged(this, region, scale, centerX, centerY);
                }
            }
        }

        
Returns the current magnification scale.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will return a default value of 1.0f. 
Returns:the current magnification scale
/**
         * Returns the current magnification scale.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will
         * return a default value of {@code 1.0f}.
         *
         * @return the current magnification scale
         */
        public float getScale() {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.getMagnificationScale();
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to obtain scale", re);
                    re.rethrowFromSystemServer();
                }
            }
            return 1.0f;
        }

        
Returns the unscaled screen-relative X coordinate of the focal
center of the magnified region. This is the point around which
zooming occurs and is guaranteed to lie within the magnified
region.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will return a default value of 0.0f. 
Returns:the unscaled screen-relative X coordinate of the center of
        the magnified region
/**
         * Returns the unscaled screen-relative X coordinate of the focal
         * center of the magnified region. This is the point around which
         * zooming occurs and is guaranteed to lie within the magnified
         * region.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will
         * return a default value of {@code 0.0f}.
         *
         * @return the unscaled screen-relative X coordinate of the center of
         *         the magnified region
         */
        public float getCenterX() {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.getMagnificationCenterX();
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to obtain center X", re);
                    re.rethrowFromSystemServer();
                }
            }
            return 0.0f;
        }

        
Returns the unscaled screen-relative Y coordinate of the focal
center of the magnified region. This is the point around which
zooming occurs and is guaranteed to lie within the magnified
region.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will return a default value of 0.0f. 
Returns:the unscaled screen-relative Y coordinate of the center of
        the magnified region
/**
         * Returns the unscaled screen-relative Y coordinate of the focal
         * center of the magnified region. This is the point around which
         * zooming occurs and is guaranteed to lie within the magnified
         * region.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will
         * return a default value of {@code 0.0f}.
         *
         * @return the unscaled screen-relative Y coordinate of the center of
         *         the magnified region
         */
        public float getCenterY() {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.getMagnificationCenterY();
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to obtain center Y", re);
                    re.rethrowFromSystemServer();
                }
            }
            return 0.0f;
        }

        
Returns the region of the screen currently active for magnification. Changes to
magnification scale and center only affect this portion of the screen. The rest of the
screen, for example input methods, cannot be magnified. This region is relative to the
unscaled screen and is independent of the scale and center point.


The returned region will be empty if magnification is not active. Magnification is active
if magnification gestures are enabled or if a service is running that can control
magnification.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will return an empty region. 
Returns:the region of the screen currently active for magnification, or an empty region
if magnification is not active.
/**
         * Returns the region of the screen currently active for magnification. Changes to
         * magnification scale and center only affect this portion of the screen. The rest of the
         * screen, for example input methods, cannot be magnified. This region is relative to the
         * unscaled screen and is independent of the scale and center point.
         * <p>
         * The returned region will be empty if magnification is not active. Magnification is active
         * if magnification gestures are enabled or if a service is running that can control
         * magnification.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will
         * return an empty region.
         *
         * @return the region of the screen currently active for magnification, or an empty region
         * if magnification is not active.
         */
        @NonNull
        public Region getMagnificationRegion() {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.getMagnificationRegion();
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to obtain magnified region", re);
                    re.rethrowFromSystemServer();
                }
            }
            return Region.obtain();
        }

        
Resets magnification scale and center to their default (e.g. no
magnification) values.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will have no effect and return false. 
Params:
  • animate – true to animate from the current scale and center or false to reset the scale and center immediately
Returns:true on success, false on failure
/**
         * Resets magnification scale and center to their default (e.g. no
         * magnification) values.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will have
         * no effect and return {@code false}.
         *
         * @param animate {@code true} to animate from the current scale and
         *                center or {@code false} to reset the scale and center
         *                immediately
         * @return {@code true} on success, {@code false} on failure
         */
        public boolean reset(boolean animate) {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.resetMagnification(animate);
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to reset", re);
                    re.rethrowFromSystemServer();
                }
            }
            return false;
        }

        
Sets the magnification scale.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will have no effect and return false. 
Params:
  • scale – the magnification scale to set, must be >= 1 and <= 5
  • animate – true to animate from the current scale or false to set the scale immediately
Returns:true on success, false on failure
/**
         * Sets the magnification scale.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will have
         * no effect and return {@code false}.
         *
         * @param scale the magnification scale to set, must be >= 1 and <= 5
         * @param animate {@code true} to animate from the current scale or
         *                {@code false} to set the scale immediately
         * @return {@code true} on success, {@code false} on failure
         */
        public boolean setScale(float scale, boolean animate) {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.setMagnificationScaleAndCenter(
                            scale, Float.NaN, Float.NaN, animate);
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to set scale", re);
                    re.rethrowFromSystemServer();
                }
            }
            return false;
        }

        
Sets the center of the magnified viewport.


Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will have no effect and return false. 
Params:
  • centerX – the unscaled screen-relative X coordinate on which to
               center the viewport
  • centerY – the unscaled screen-relative Y coordinate on which to
               center the viewport
  • animate – true to animate from the current viewport center or false to set the center immediately
Returns:true on success, false on failure
/**
         * Sets the center of the magnified viewport.
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been
         * called) or the service has been disconnected, this method will have
         * no effect and return {@code false}.
         *
         * @param centerX the unscaled screen-relative X coordinate on which to
         *                center the viewport
         * @param centerY the unscaled screen-relative Y coordinate on which to
         *                center the viewport
         * @param animate {@code true} to animate from the current viewport
         *                center or {@code false} to set the center immediately
         * @return {@code true} on success, {@code false} on failure
         */
        public boolean setCenter(float centerX, float centerY, boolean animate) {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    return connection.setMagnificationScaleAndCenter(
                            Float.NaN, centerX, centerY, animate);
                } catch (RemoteException re) {
                    Log.w(LOG_TAG, "Failed to set center", re);
                    re.rethrowFromSystemServer();
                }
            }
            return false;
        }

        
Listener for changes in the state of magnification.

/**
         * Listener for changes in the state of magnification.
         */
        public interface OnMagnificationChangedListener {
            
Called when the magnified region, scale, or center changes.

Params:
  • controller – the magnification controller
  • region – the magnification region
  • scale – the new scale
  • centerX – the new X coordinate, in unscaled coordinates, around which
magnification is focused
  • centerY – the new Y coordinate, in unscaled coordinates, around which
magnification is focused
/**
             * Called when the magnified region, scale, or center changes.
             *
             * @param controller the magnification controller
             * @param region the magnification region
             * @param scale the new scale
             * @param centerX the new X coordinate, in unscaled coordinates, around which
             * magnification is focused
             * @param centerY the new Y coordinate, in unscaled coordinates, around which
             * magnification is focused
             */
            void onMagnificationChanged(@NonNull MagnificationController controller,
                    @NonNull Region region, float scale, float centerX, float centerY);
        }
    }

    
Returns the soft keyboard controller, which may be used to query and modify the soft keyboard
show mode.

Returns:the soft keyboard controller
/**
     * Returns the soft keyboard controller, which may be used to query and modify the soft keyboard
     * show mode.
     *
     * @return the soft keyboard controller
     */
    @NonNull
    public final SoftKeyboardController getSoftKeyboardController() {
        synchronized (mLock) {
            if (mSoftKeyboardController == null) {
                mSoftKeyboardController = new SoftKeyboardController(this, mLock);
            }
            return mSoftKeyboardController;
        }
    }

    private void onSoftKeyboardShowModeChanged(int showMode) {
        if (mSoftKeyboardController != null) {
            mSoftKeyboardController.dispatchSoftKeyboardShowModeChanged(showMode);
        }
    }

    
Used to control and query the soft keyboard show mode.

/**
     * Used to control and query the soft keyboard show mode.
     */
    public static final class SoftKeyboardController {
        private final AccessibilityService mService;

        
Map of listeners to their handlers. Lazily created when adding the first
soft keyboard change listener.

/**
         * Map of listeners to their handlers. Lazily created when adding the first
         * soft keyboard change listener.
         */
        private ArrayMap<OnShowModeChangedListener, Handler> mListeners;
        private final Object mLock;

        SoftKeyboardController(@NonNull AccessibilityService service, @NonNull Object lock) {
            mService = service;
            mLock = lock;
        }

        
Called when the service is connected.

/**
         * Called when the service is connected.
         */
        void onServiceConnected() {
            synchronized(mLock) {
                if (mListeners != null && !mListeners.isEmpty()) {
                    setSoftKeyboardCallbackEnabled(true);
                }
            }
        }

        
Adds the specified change listener to the list of show mode change listeners. The
callback will occur on the service's main thread. Listener is not called on registration.

/**
         * Adds the specified change listener to the list of show mode change listeners. The
         * callback will occur on the service's main thread. Listener is not called on registration.
         */
        public void addOnShowModeChangedListener(@NonNull OnShowModeChangedListener listener) {
            addOnShowModeChangedListener(listener, null);
        }

        
Adds the specified change listener to the list of soft keyboard show mode change listeners. The callback will occur on the specified Handler's thread, or on the services's main thread if the handler is null. 
Params:
  • listener – the listener to add, must be non-null
  • handler – the handler on which to callback should execute, or null to execute on the service's main thread
/**
         * Adds the specified change listener to the list of soft keyboard show mode change
         * listeners. The callback will occur on the specified {@link Handler}'s thread, or on the
         * services's main thread if the handler is {@code null}.
         *
         * @param listener the listener to add, must be non-null
         * @param handler the handler on which to callback should execute, or {@code null} to
         *        execute on the service's main thread
         */
        public void addOnShowModeChangedListener(@NonNull OnShowModeChangedListener listener,
                @Nullable Handler handler) {
            synchronized (mLock) {
                if (mListeners == null) {
                    mListeners = new ArrayMap<>();
                }

                final boolean shouldEnableCallback = mListeners.isEmpty();
                mListeners.put(listener, handler);

                if (shouldEnableCallback) {
                    // This may fail if the service is not connected yet, but if we still have
                    // listeners when it connects, we can try again.
                    setSoftKeyboardCallbackEnabled(true);
                }
            }
        }

        
Removes the specified change listener from the list of keyboard show mode change
listeners.

Params:
  • listener – the listener to remove, must be non-null
Returns:true if the listener was removed, false otherwise
/**
         * Removes the specified change listener from the list of keyboard show mode change
         * listeners.
         *
         * @param listener the listener to remove, must be non-null
         * @return {@code true} if the listener was removed, {@code false} otherwise
         */
        public boolean removeOnShowModeChangedListener(@NonNull OnShowModeChangedListener listener) {
            if (mListeners == null) {
                return false;
            }

            synchronized (mLock) {
                final int keyIndex = mListeners.indexOfKey(listener);
                final boolean hasKey = keyIndex >= 0;
                if (hasKey) {
                    mListeners.removeAt(keyIndex);
                }

                if (hasKey && mListeners.isEmpty()) {
                    // We just removed the last listener, so we don't need callbacks from the
                    // service anymore.
                    setSoftKeyboardCallbackEnabled(false);
                }

                return hasKey;
            }
        }

        private void setSoftKeyboardCallbackEnabled(boolean enabled) {
            final IAccessibilityServiceConnection connection =
                    AccessibilityInteractionClient.getInstance().getConnection(
                            mService.mConnectionId);
            if (connection != null) {
                try {
                    connection.setSoftKeyboardCallbackEnabled(enabled);
                } catch (RemoteException re) {
                    throw new RuntimeException(re);
                }
            }
        }

        
Dispatches the soft keyboard show mode change to any registered listeners. This should
be called on the service's main thread.

/**
         * Dispatches the soft keyboard show mode change to any registered listeners. This should
         * be called on the service's main thread.
         */
        void dispatchSoftKeyboardShowModeChanged(final int showMode) {
            final ArrayMap<OnShowModeChangedListener, Handler> entries;
            synchronized (mLock) {
                if (mListeners == null || mListeners.isEmpty()) {
                    Slog.w(LOG_TAG, "Received soft keyboard show mode changed callback"
                            + " with no listeners registered!");
                    setSoftKeyboardCallbackEnabled(false);
                    return;
                }

                // Listeners may remove themselves. Perform a shallow copy to avoid concurrent
                // modification.
                entries = new ArrayMap<>(mListeners);
            }

            for (int i = 0, count = entries.size(); i < count; i++) {
                final OnShowModeChangedListener listener = entries.keyAt(i);
                final Handler handler = entries.valueAt(i);
                if (handler != null) {
                    handler.post(new Runnable() {
                        @Override
                        public void run() {
                            listener.onShowModeChanged(SoftKeyboardController.this, showMode);
                        }
                    });
                } else {
                    // We're already on the main thread, just run the listener.
                    listener.onShowModeChanged(this, showMode);
                }
            }
        }

        
Returns the show mode of the soft keyboard. The default show mode is SHOW_MODE_AUTO, where the soft keyboard is shown when a text input field is focused. An AccessibilityService can also request the show mode SHOW_MODE_HIDDEN, where the soft keyboard is never shown. 
Returns:the current soft keyboard show mode
/**
         * Returns the show mode of the soft keyboard. The default show mode is
         * {@code SHOW_MODE_AUTO}, where the soft keyboard is shown when a text input field is
         * focused. An AccessibilityService can also request the show mode
         * {@code SHOW_MODE_HIDDEN}, where the soft keyboard is never shown.
         *
         * @return the current soft keyboard show mode
         */
        @SoftKeyboardShowMode
        public int getShowMode() {
           try {
               return Settings.Secure.getInt(mService.getContentResolver(),
                       Settings.Secure.ACCESSIBILITY_SOFT_KEYBOARD_MODE);
           } catch (Settings.SettingNotFoundException e) {
               Log.v(LOG_TAG, "Failed to obtain the soft keyboard mode", e);
               // The settings hasn't been changed yet, so it's value is null. Return the default.
               return 0;
           }
        }

        
Sets the soft keyboard show mode. The default show mode is SHOW_MODE_AUTO, where the soft keyboard is shown when a text input field is focused. An AccessibilityService can also request the show mode SHOW_MODE_HIDDEN, where the soft keyboard is never shown. The The lastto this method will be honored, regardless of any previous calls (including those made by other AccessibilityServices). 

Note: If the service is not yet connected (e.g. AccessibilityService.onServiceConnected() has not yet been called) or the service has been disconnected, this method will have no effect and return false. 
Params:
  • showMode – the new show mode for the soft keyboard
Returns:true on success
/**
         * Sets the soft keyboard show mode. The default show mode is
         * {@code SHOW_MODE_AUTO}, where the soft keyboard is shown when a text input field is
         * focused. An AccessibilityService can also request the show mode
         * {@code SHOW_MODE_HIDDEN}, where the soft keyboard is never shown. The
         * The lastto this method will be honored, regardless of any previous calls (including those
         * made by other AccessibilityServices).
         * <p>
         * <strong>Note:</strong> If the service is not yet connected (e.g.
         * {@link AccessibilityService#onServiceConnected()} has not yet been called) or the
         * service has been disconnected, this method will have no effect and return {@code false}.
         *
         * @param showMode the new show mode for the soft keyboard
         * @return {@code true} on success
         */
        public boolean setShowMode(@SoftKeyboardShowMode int showMode) {
           final IAccessibilityServiceConnection connection =
                   AccessibilityInteractionClient.getInstance().getConnection(
                           mService.mConnectionId);
           if (connection != null) {
               try {
                   return connection.setSoftKeyboardShowMode(showMode);
               } catch (RemoteException re) {
                   Log.w(LOG_TAG, "Failed to set soft keyboard behavior", re);
                   re.rethrowFromSystemServer();
               }
           }
           return false;
        }

        
Listener for changes in the soft keyboard show mode.

/**
         * Listener for changes in the soft keyboard show mode.
         */
        public interface OnShowModeChangedListener {
           
Called when the soft keyboard behavior changes. The default show mode is SHOW_MODE_AUTO, where the soft keyboard is shown when a text input field is focused. An AccessibilityService can also request the show mode SHOW_MODE_HIDDEN, where the soft keyboard is never shown. 
Params:
  • controller – the soft keyboard controller
  • showMode – the current soft keyboard show mode
/**
            * Called when the soft keyboard behavior changes. The default show mode is
            * {@code SHOW_MODE_AUTO}, where the soft keyboard is shown when a text input field is
            * focused. An AccessibilityService can also request the show mode
            * {@code SHOW_MODE_HIDDEN}, where the soft keyboard is never shown.
            *
            * @param controller the soft keyboard controller
            * @param showMode the current soft keyboard show mode
            */
            void onShowModeChanged(@NonNull SoftKeyboardController controller,
                    @SoftKeyboardShowMode int showMode);
        }
    }

    
Returns the controller for the accessibility button within the system's navigation area. This instance may be used to query the accessibility button's state and register listeners for interactions with and state changes for the accessibility button when AccessibilityServiceInfo.FLAG_REQUEST_ACCESSIBILITY_BUTTON is set. 

Note: Not all devices are capable of displaying the accessibility button
within a navigation area, and as such, use of this class should be considered only as an
optional feature or shortcut on supported device implementations.



Returns:the accessibility button controller for this AccessibilityService
/**
     * Returns the controller for the accessibility button within the system's navigation area.
     * This instance may be used to query the accessibility button's state and register listeners
     * for interactions with and state changes for the accessibility button when
     * {@link AccessibilityServiceInfo#FLAG_REQUEST_ACCESSIBILITY_BUTTON} is set.
     * <p>
     * <strong>Note:</strong> Not all devices are capable of displaying the accessibility button
     * within a navigation area, and as such, use of this class should be considered only as an
     * optional feature or shortcut on supported device implementations.
     * </p>
     *
     * @return the accessibility button controller for this {@link AccessibilityService}
     */
    @NonNull
    public final AccessibilityButtonController getAccessibilityButtonController() {
        synchronized (mLock) {
            if (mAccessibilityButtonController == null) {
                mAccessibilityButtonController = new AccessibilityButtonController(
                        AccessibilityInteractionClient.getInstance().getConnection(mConnectionId));
            }
            return mAccessibilityButtonController;
        }
    }

    private void onAccessibilityButtonClicked() {
        getAccessibilityButtonController().dispatchAccessibilityButtonClicked();
    }

    private void onAccessibilityButtonAvailabilityChanged(boolean available) {
        getAccessibilityButtonController().dispatchAccessibilityButtonAvailabilityChanged(
                available);
    }

    
Performs a global action. Such an action can be performed
at any moment regardless of the current application or user
location in that application. For example going back, going
home, opening recents, etc.

Params:
  • action – The action to perform.
See Also:
Returns:Whether the action was successfully performed.
/**
     * Performs a global action. Such an action can be performed
     * at any moment regardless of the current application or user
     * location in that application. For example going back, going
     * home, opening recents, etc.
     *
     * @param action The action to perform.
     * @return Whether the action was successfully performed.
     *
     * @see #GLOBAL_ACTION_BACK
     * @see #GLOBAL_ACTION_HOME
     * @see #GLOBAL_ACTION_NOTIFICATIONS
     * @see #GLOBAL_ACTION_RECENTS
     */
    public final boolean performGlobalAction(int action) {
        IAccessibilityServiceConnection connection =
            AccessibilityInteractionClient.getInstance().getConnection(mConnectionId);
        if (connection != null) {
            try {
                return connection.performGlobalAction(action);
            } catch (RemoteException re) {
                Log.w(LOG_TAG, "Error while calling performGlobalAction", re);
                re.rethrowFromSystemServer();
            }
        }
        return false;
    }

    
Find the view that has the specified focus type. The search is performed
across all windows.


Note: In order to access the windows your service has to declare the capability to retrieve window content by setting the AccessibilityService_canRetrieveWindowContent.AccessibilityService_canRetrieveWindowContent property in its meta-data. For details refer to SERVICE_META_DATA. Also the service has to opt-in to retrieve the interactive windows by setting the AccessibilityServiceInfo.FLAG_RETRIEVE_INTERACTIVE_WINDOWS flag. Otherwise, the search will be performed only in the active window. 


Params:
See Also:
Returns:The node info of the focused view or null.
/**
     * Find the view that has the specified focus type. The search is performed
     * across all windows.
     * <p>
     * <strong>Note:</strong> In order to access the windows your service has
     * to declare the capability to retrieve window content by setting the
     * {@link android.R.styleable#AccessibilityService_canRetrieveWindowContent}
     * property in its meta-data. For details refer to {@link #SERVICE_META_DATA}.
     * Also the service has to opt-in to retrieve the interactive windows by
     * setting the {@link AccessibilityServiceInfo#FLAG_RETRIEVE_INTERACTIVE_WINDOWS}
     * flag. Otherwise, the search will be performed only in the active window.
     * </p>
     *
     * @param focus The focus to find. One of {@link AccessibilityNodeInfo#FOCUS_INPUT} or
     *         {@link AccessibilityNodeInfo#FOCUS_ACCESSIBILITY}.
     * @return The node info of the focused view or null.
     *
     * @see AccessibilityNodeInfo#FOCUS_INPUT
     * @see AccessibilityNodeInfo#FOCUS_ACCESSIBILITY
     */
    public AccessibilityNodeInfo findFocus(int focus) {
        return AccessibilityInteractionClient.getInstance().findFocus(mConnectionId,
                AccessibilityWindowInfo.ANY_WINDOW_ID, AccessibilityNodeInfo.ROOT_NODE_ID, focus);
    }

    
Gets the an AccessibilityServiceInfo describing this AccessibilityService. This method is useful if one wants to change some of the dynamically configurable properties at runtime. 
See Also:
Returns:The accessibility service info.
/**
     * Gets the an {@link AccessibilityServiceInfo} describing this
     * {@link AccessibilityService}. This method is useful if one wants
     * to change some of the dynamically configurable properties at
     * runtime.
     *
     * @return The accessibility service info.
     *
     * @see AccessibilityServiceInfo
     */
    public final AccessibilityServiceInfo getServiceInfo() {
        IAccessibilityServiceConnection connection =
            AccessibilityInteractionClient.getInstance().getConnection(mConnectionId);
        if (connection != null) {
            try {
                return connection.getServiceInfo();
            } catch (RemoteException re) {
                Log.w(LOG_TAG, "Error while getting AccessibilityServiceInfo", re);
                re.rethrowFromSystemServer();
            }
        }
        return null;
    }

    
Sets the AccessibilityServiceInfo that describes this service. 

Note: You can call this method any time but the info will be picked up after
      the system has bound to this service and when this method is called thereafter.

Params:
  • info – The info.
/**
     * Sets the {@link AccessibilityServiceInfo} that describes this service.
     * <p>
     * Note: You can call this method any time but the info will be picked up after
     *       the system has bound to this service and when this method is called thereafter.
     *
     * @param info The info.
     */
    public final void setServiceInfo(AccessibilityServiceInfo info) {
        mInfo = info;
        sendServiceInfo();
    }

    
Sets the AccessibilityServiceInfo for this service if the latter is properly set and there is an IAccessibilityServiceConnection to the AccessibilityManagerService. 
/**
     * Sets the {@link AccessibilityServiceInfo} for this service if the latter is
     * properly set and there is an {@link IAccessibilityServiceConnection} to the
     * AccessibilityManagerService.
     */
    private void sendServiceInfo() {
        IAccessibilityServiceConnection connection =
            AccessibilityInteractionClient.getInstance().getConnection(mConnectionId);
        if (mInfo != null && connection != null) {
            try {
                connection.setServiceInfo(mInfo);
                mInfo = null;
                AccessibilityInteractionClient.getInstance().clearCache();
            } catch (RemoteException re) {
                Log.w(LOG_TAG, "Error while setting AccessibilityServiceInfo", re);
                re.rethrowFromSystemServer();
            }
        }
    }

    @Override
    public Object getSystemService(@ServiceName @NonNull String name) {
        if (getBaseContext() == null) {
            throw new IllegalStateException(
                    "System services not available to Activities before onCreate()");
        }

        // Guarantee that we always return the same window manager instance.
        if (WINDOW_SERVICE.equals(name)) {
            if (mWindowManager == null) {
                mWindowManager = (WindowManager) getBaseContext().getSystemService(name);
            }
            return mWindowManager;
        }
        return super.getSystemService(name);
    }

    
Implement to return the implementation of the internal accessibility
service interface.

/**
     * Implement to return the implementation of the internal accessibility
     * service interface.
     */
    @Override
    public final IBinder onBind(Intent intent) {
        return new IAccessibilityServiceClientWrapper(this, getMainLooper(), new Callbacks() {
            @Override
            public void onServiceConnected() {
                AccessibilityService.this.dispatchServiceConnected();
            }

            @Override
            public void onInterrupt() {
                AccessibilityService.this.onInterrupt();
            }

            @Override
            public void onAccessibilityEvent(AccessibilityEvent event) {
                AccessibilityService.this.onAccessibilityEvent(event);
            }

            @Override
            public void init(int connectionId, IBinder windowToken) {
                mConnectionId = connectionId;
                mWindowToken = windowToken;

                // The client may have already obtained the window manager, so
                // update the default token on whatever manager we gave them.
                final WindowManagerImpl wm = (WindowManagerImpl) getSystemService(WINDOW_SERVICE);
                wm.setDefaultToken(windowToken);
            }

            @Override
            public boolean onGesture(int gestureId) {
                return AccessibilityService.this.onGesture(gestureId);
            }

            @Override
            public boolean onKeyEvent(KeyEvent event) {
                return AccessibilityService.this.onKeyEvent(event);
            }

            @Override
            public void onMagnificationChanged(@NonNull Region region,
                    float scale, float centerX, float centerY) {
                AccessibilityService.this.onMagnificationChanged(region, scale, centerX, centerY);
            }

            @Override
            public void onSoftKeyboardShowModeChanged(int showMode) {
                AccessibilityService.this.onSoftKeyboardShowModeChanged(showMode);
            }

            @Override
            public void onPerformGestureResult(int sequence, boolean completedSuccessfully) {
                AccessibilityService.this.onPerformGestureResult(sequence, completedSuccessfully);
            }

            @Override
            public void onFingerprintCapturingGesturesChanged(boolean active) {
                AccessibilityService.this.onFingerprintCapturingGesturesChanged(active);
            }

            @Override
            public void onFingerprintGesture(int gesture) {
                AccessibilityService.this.onFingerprintGesture(gesture);
            }

            @Override
            public void onAccessibilityButtonClicked() {
                AccessibilityService.this.onAccessibilityButtonClicked();
            }

            @Override
            public void onAccessibilityButtonAvailabilityChanged(boolean available) {
                AccessibilityService.this.onAccessibilityButtonAvailabilityChanged(available);
            }
        });
    }

    
Implements the internal IAccessibilityServiceClient interface to convert incoming calls to it back to calls on an AccessibilityService. 
@hide
/**
     * Implements the internal {@link IAccessibilityServiceClient} interface to convert
     * incoming calls to it back to calls on an {@link AccessibilityService}.
     *
     * @hide
     */
    public static class IAccessibilityServiceClientWrapper extends IAccessibilityServiceClient.Stub
            implements HandlerCaller.Callback {
        private static final int DO_INIT = 1;
        private static final int DO_ON_INTERRUPT = 2;
        private static final int DO_ON_ACCESSIBILITY_EVENT = 3;
        private static final int DO_ON_GESTURE = 4;
        private static final int DO_CLEAR_ACCESSIBILITY_CACHE = 5;
        private static final int DO_ON_KEY_EVENT = 6;
        private static final int DO_ON_MAGNIFICATION_CHANGED = 7;
        private static final int DO_ON_SOFT_KEYBOARD_SHOW_MODE_CHANGED = 8;
        private static final int DO_GESTURE_COMPLETE = 9;
        private static final int DO_ON_FINGERPRINT_ACTIVE_CHANGED = 10;
        private static final int DO_ON_FINGERPRINT_GESTURE = 11;
        private static final int DO_ACCESSIBILITY_BUTTON_CLICKED = 12;
        private static final int DO_ACCESSIBILITY_BUTTON_AVAILABILITY_CHANGED = 13;

        private final HandlerCaller mCaller;

        private final Callbacks mCallback;

        private int mConnectionId = AccessibilityInteractionClient.NO_ID;

        public IAccessibilityServiceClientWrapper(Context context, Looper looper,
                Callbacks callback) {
            mCallback = callback;
            mCaller = new HandlerCaller(context, looper, this, true /*asyncHandler*/);
        }

        public void init(IAccessibilityServiceConnection connection, int connectionId,
                IBinder windowToken) {
            Message message = mCaller.obtainMessageIOO(DO_INIT, connectionId,
                    connection, windowToken);
            mCaller.sendMessage(message);
        }

        public void onInterrupt() {
            Message message = mCaller.obtainMessage(DO_ON_INTERRUPT);
            mCaller.sendMessage(message);
        }

        public void onAccessibilityEvent(AccessibilityEvent event, boolean serviceWantsEvent) {
            Message message = mCaller.obtainMessageBO(
                    DO_ON_ACCESSIBILITY_EVENT, serviceWantsEvent, event);
            mCaller.sendMessage(message);
        }

        public void onGesture(int gestureId) {
            Message message = mCaller.obtainMessageI(DO_ON_GESTURE, gestureId);
            mCaller.sendMessage(message);
        }

        public void clearAccessibilityCache() {
            Message message = mCaller.obtainMessage(DO_CLEAR_ACCESSIBILITY_CACHE);
            mCaller.sendMessage(message);
        }

        @Override
        public void onKeyEvent(KeyEvent event, int sequence) {
            Message message = mCaller.obtainMessageIO(DO_ON_KEY_EVENT, sequence, event);
            mCaller.sendMessage(message);
        }

        public void onMagnificationChanged(@NonNull Region region,
                float scale, float centerX, float centerY) {
            final SomeArgs args = SomeArgs.obtain();
            args.arg1 = region;
            args.arg2 = scale;
            args.arg3 = centerX;
            args.arg4 = centerY;

            final Message message = mCaller.obtainMessageO(DO_ON_MAGNIFICATION_CHANGED, args);
            mCaller.sendMessage(message);
        }

        public void onSoftKeyboardShowModeChanged(int showMode) {
          final Message message =
                  mCaller.obtainMessageI(DO_ON_SOFT_KEYBOARD_SHOW_MODE_CHANGED, showMode);
          mCaller.sendMessage(message);
        }

        public void onPerformGestureResult(int sequence, boolean successfully) {
            Message message = mCaller.obtainMessageII(DO_GESTURE_COMPLETE, sequence,
                    successfully ? 1 : 0);
            mCaller.sendMessage(message);
        }

        public void onFingerprintCapturingGesturesChanged(boolean active) {
            mCaller.sendMessage(mCaller.obtainMessageI(
                    DO_ON_FINGERPRINT_ACTIVE_CHANGED, active ? 1 : 0));
        }

        public void onFingerprintGesture(int gesture) {
            mCaller.sendMessage(mCaller.obtainMessageI(DO_ON_FINGERPRINT_GESTURE, gesture));
        }

        public void onAccessibilityButtonClicked() {
            final Message message = mCaller.obtainMessage(DO_ACCESSIBILITY_BUTTON_CLICKED);
            mCaller.sendMessage(message);
        }

        public void onAccessibilityButtonAvailabilityChanged(boolean available) {
            final Message message = mCaller.obtainMessageI(
                    DO_ACCESSIBILITY_BUTTON_AVAILABILITY_CHANGED, (available ? 1 : 0));
            mCaller.sendMessage(message);
        }

        @Override
        public void executeMessage(Message message) {
            switch (message.what) {
                case DO_ON_ACCESSIBILITY_EVENT: {
                    AccessibilityEvent event = (AccessibilityEvent) message.obj;
                    boolean serviceWantsEvent = message.arg1 != 0;
                    if (event != null) {
                        // Send the event to AccessibilityCache via AccessibilityInteractionClient
                        AccessibilityInteractionClient.getInstance().onAccessibilityEvent(event);
                        if (serviceWantsEvent
                                && (mConnectionId != AccessibilityInteractionClient.NO_ID)) {
                            // Send the event to AccessibilityService
                            mCallback.onAccessibilityEvent(event);
                        }
                        // Make sure the event is recycled.
                        try {
                            event.recycle();
                        } catch (IllegalStateException ise) {
                            /* ignore - best effort */
                        }
                    }
                } return;

                case DO_ON_INTERRUPT: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        mCallback.onInterrupt();
                    }
                } return;

                case DO_INIT: {
                    mConnectionId = message.arg1;
                    SomeArgs args = (SomeArgs) message.obj;
                    IAccessibilityServiceConnection connection =
                            (IAccessibilityServiceConnection) args.arg1;
                    IBinder windowToken = (IBinder) args.arg2;
                    args.recycle();
                    if (connection != null) {
                        AccessibilityInteractionClient.getInstance().addConnection(mConnectionId,
                                connection);
                        mCallback.init(mConnectionId, windowToken);
                        mCallback.onServiceConnected();
                    } else {
                        AccessibilityInteractionClient.getInstance().removeConnection(
                                mConnectionId);
                        mConnectionId = AccessibilityInteractionClient.NO_ID;
                        AccessibilityInteractionClient.getInstance().clearCache();
                        mCallback.init(AccessibilityInteractionClient.NO_ID, null);
                    }
                } return;

                case DO_ON_GESTURE: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        final int gestureId = message.arg1;
                        mCallback.onGesture(gestureId);
                    }
                } return;

                case DO_CLEAR_ACCESSIBILITY_CACHE: {
                    AccessibilityInteractionClient.getInstance().clearCache();
                } return;

                case DO_ON_KEY_EVENT: {
                    KeyEvent event = (KeyEvent) message.obj;
                    try {
                        IAccessibilityServiceConnection connection = AccessibilityInteractionClient
                                .getInstance().getConnection(mConnectionId);
                        if (connection != null) {
                            final boolean result = mCallback.onKeyEvent(event);
                            final int sequence = message.arg1;
                            try {
                                connection.setOnKeyEventResult(result, sequence);
                            } catch (RemoteException re) {
                                /* ignore */
                            }
                        }
                    } finally {
                        // Make sure the event is recycled.
                        try {
                            event.recycle();
                        } catch (IllegalStateException ise) {
                            /* ignore - best effort */
                        }
                    }
                } return;

                case DO_ON_MAGNIFICATION_CHANGED: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        final SomeArgs args = (SomeArgs) message.obj;
                        final Region region = (Region) args.arg1;
                        final float scale = (float) args.arg2;
                        final float centerX = (float) args.arg3;
                        final float centerY = (float) args.arg4;
                        mCallback.onMagnificationChanged(region, scale, centerX, centerY);
                    }
                } return;

                case DO_ON_SOFT_KEYBOARD_SHOW_MODE_CHANGED: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        final int showMode = (int) message.arg1;
                        mCallback.onSoftKeyboardShowModeChanged(showMode);
                    }
                } return;

                case DO_GESTURE_COMPLETE: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        final boolean successfully = message.arg2 == 1;
                        mCallback.onPerformGestureResult(message.arg1, successfully);
                    }
                } return;
                case DO_ON_FINGERPRINT_ACTIVE_CHANGED: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        mCallback.onFingerprintCapturingGesturesChanged(message.arg1 == 1);
                    }
                } return;
                case DO_ON_FINGERPRINT_GESTURE: {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        mCallback.onFingerprintGesture(message.arg1);
                    }
                } return;

                case (DO_ACCESSIBILITY_BUTTON_CLICKED): {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        mCallback.onAccessibilityButtonClicked();
                    }
                } return;

                case (DO_ACCESSIBILITY_BUTTON_AVAILABILITY_CHANGED): {
                    if (mConnectionId != AccessibilityInteractionClient.NO_ID) {
                        final boolean available = (message.arg1 != 0);
                        mCallback.onAccessibilityButtonAvailabilityChanged(available);
                    }
                } return;

                default :
                    Log.w(LOG_TAG, "Unknown message type " + message.what);
            }
        }
    }

    
Class used to report status of dispatched gestures

/**
     * Class used to report status of dispatched gestures
     */
    public static abstract class GestureResultCallback {
        
Called when the gesture has completed successfully

Params:
  • gestureDescription – The description of the gesture that completed.
/** Called when the gesture has completed successfully
         *
         * @param gestureDescription The description of the gesture that completed.
         */
        public void onCompleted(GestureDescription gestureDescription) {
        }

        
Called when the gesture was cancelled

Params:
  • gestureDescription – The description of the gesture that was cancelled.
/** Called when the gesture was cancelled
         *
         * @param gestureDescription The description of the gesture that was cancelled.
         */
        public void onCancelled(GestureDescription gestureDescription) {
        }
    }

    /* Object to keep track of gesture result callbacks */
    private static class GestureResultCallbackInfo {
        GestureDescription gestureDescription;
        GestureResultCallback callback;
        Handler handler;

        GestureResultCallbackInfo(GestureDescription gestureDescription,
                GestureResultCallback callback, Handler handler) {
            this.gestureDescription = gestureDescription;
            this.callback = callback;
            this.handler = handler;
        }
    }
}