/* * 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.annotation.NonNull; import android.app.Service; import android.content.Context; import android.content.Intent; import android.os.IBinder; import android.os.Looper; import android.os.Message; import android.os.RemoteException; import android.util.Log; 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.util.List; /** * An accessibility service runs in the background and receives 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. Additionally, starting or stopping an * accessibility service is triggered exclusively by an explicit user action through * enabling or disabling it in the device settings. After the system binds to a service it * calls {@link AccessibilityService#onServiceConnected()}. This method can be * overriden by clients that want to perform post binding setup. * </p> * <h3>Declaration</h3> * <p> * An accessibility is declared as any other service in an AndroidManifest.xml but it * must also specify that it handles the "android.accessibilityservice.AccessibilityService" * {@link android.content.Intent}. Failure to declare this intent will cause the system to * ignore the accessibility service. Additionally an accessibility service must request the * {@link android.Manifest.permission#BIND_ACCESSIBILITY_SERVICE} permission to ensure * that only the system * can bind to it. Failure to declare this intent will cause the system to ignore the * accessibility service. Following is an example declaration: * </p> * <pre> <service android:name=".MyAccessibilityService" * android:permission="android.permission.BIND_ACCESSIBILITY_SERVICE"> * <intent-filter> * <action android:name="android.accessibilityservice.AccessibilityService" /> * </intent-filter> * . . . * </service></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> <service android:name=".MyAccessibilityService"> * <intent-filter> * <action android:name="android.accessibilityservice.AccessibilityService" /> * </intent-filter> * <meta-data android:name="android.accessibilityservice" android:resource="@xml/accessibilityservice" /> * </service></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><{@link android.R.styleable#AccessibilityService accessibility-service}></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 the active window * content which is represented as a tree of {@link AccessibilityNodeInfo}. Note that * declaring this capability requires that the service declares its configuration via * an XML resource referenced by {@link #SERVICE_META_DATA}. * </p> * <p> * For security purposes an accessibility service can retrieve only the content of the * currently active window. The currently active window is defined as the window from * which was fired the last event of the following types: * {@link AccessibilityEvent#TYPE_WINDOW_STATE_CHANGED}, * {@link AccessibilityEvent#TYPE_VIEW_HOVER_ENTER}, * {@link AccessibilityEvent#TYPE_VIEW_HOVER_EXIT}, * In other words, the last window that was shown or the last window that the user has touched * during touch exploration. * </p> * <p> * The entry point for retrieving window content is through calling * {@link AccessibilityEvent#getSource() AccessibilityEvent.getSource()} of the last received * event of the above types or a previous event from the same window * (see {@link AccessibilityEvent#getWindowId() AccessibilityEvent.getWindowId()}). Invoking * this method will return an {@link AccessibilityNodeInfo} that can be used to traverse the * window content which represented as a tree of such objects. * </p> * <p class="note"> * <strong>Note</strong> An accessibility service may have requested to be notified for * a subset of the event types, thus be unaware that the active window has changed. Therefore * accessibility service that would like to retrieve window content should: * <ul> * <li> * Register for all event types with no notification timeout and keep track for the active * window by calling {@link AccessibilityEvent#getWindowId()} of the last received event and * compare this with the {@link AccessibilityNodeInfo#getWindowId()} before calling retrieval * methods on the latter. * </li> * <li> * Prepare that a retrieval method on {@link AccessibilityNodeInfo} may fail since the * active window has changed and the service did not get the accessibility event yet. Note * that it is possible to have a retrieval method failing even adopting the strategy * specified in the previous bullet because the accessibility event dispatch is asynchronous * and crosses process boundaries. * </li> * </ul> * </p> * <h3>Notification strategy</h3> * <p> * For each feedback type only one accessibility service is notified. Services are notified * in the order of registration. Hence, if two services are registered for the same * feedback type in the same package the first one wins. It is possible however, to * register a service as the default one for a given feedback type. In such a case this * service is invoked if no other service was interested in the event. In other words, default * services do not compete with other services and are notified last regardless of the * registration order. This enables "generic" accessibility services that work reasonably * well with most applications to coexist with "polished" ones that are targeted for * specific applications. * </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. */ public static final int GESTURE_SWIPE_UP = 1; /** * 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. */ public static final int GESTURE_SWIPE_LEFT = 3; /** * 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. */ public static final int GESTURE_SWIPE_LEFT_AND_RIGHT = 5; /** * 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. */ public static final int GESTURE_SWIPE_UP_AND_DOWN = 7; /** * 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. */ public static final int GESTURE_SWIPE_LEFT_AND_UP = 9; /** * 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. */ public static final int GESTURE_SWIPE_RIGHT_AND_UP = 11; /** * 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. */ public static final int GESTURE_SWIPE_UP_AND_LEFT = 13; /** * 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. */ public static final int GESTURE_SWIPE_DOWN_AND_LEFT = 15; /** * The user has performed an down and right gesture on the touch screen. */ public static final int GESTURE_SWIPE_DOWN_AND_RIGHT = 16; /** * 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 * <code><{@link android.R.styleable#AccessibilityService accessibility-service}></code> * tag. This is a a sample XML file configuring an accessibility service: * <pre> <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" * android:canRequestEnhancedWebAccessibility="true" * . . . * /></pre> */ public static final String SERVICE_META_DATA = "android.accessibilityservice"; /** * Action to go back. */ public static final int GLOBAL_ACTION_BACK = 1; /** * Action to go home. */ public static final int GLOBAL_ACTION_HOME = 2; /** * Action to open the recent apps. */ public static final int GLOBAL_ACTION_RECENTS = 3; /** * Action to open the notifications. */ public static final int GLOBAL_ACTION_NOTIFICATIONS = 4; /** * Action to open the quick settings. */ public static final int GLOBAL_ACTION_QUICK_SETTINGS = 5; /** * Action to open the power long-press dialog. */ public static final int GLOBAL_ACTION_POWER_DIALOG = 6; private static final String LOG_TAG = "AccessibilityService"; /** * @hide */ public interface Callbacks { public void onAccessibilityEvent(AccessibilityEvent event); public void onInterrupt(); public void onServiceConnected(); public void init(int connectionId, IBinder windowToken); public boolean onGesture(int gestureId); public boolean onKeyEvent(KeyEvent event); } private int mConnectionId; private AccessibilityServiceInfo mInfo; private IBinder mWindowToken; private WindowManager mWindowManager; /** * Callback for {@link android.view.accessibility.AccessibilityEvent}s. * * @param event An event. */ public abstract void onAccessibilityEvent(AccessibilityEvent event); /** * Callback for interrupting the accessibility feedback. */ public abstract void onInterrupt(); /** * 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. * * <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. * <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. * @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 higher in the Z-order 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. * <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); } /** * 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); } } return false; } /** * 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, AccessibilityNodeInfo.ANY_WINDOW_ID, AccessibilityNodeInfo.ROOT_NODE_ID, focus); } /** * 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); } } return null; } /** * 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 {@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); } } } @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. */ @Override public final IBinder onBind(Intent intent) { return new IAccessibilityServiceClientWrapper(this, getMainLooper(), new Callbacks() { @Override public void onServiceConnected() { AccessibilityService.this.onServiceConnected(); } @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); } }); } /** * 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 final HandlerCaller mCaller; private final Callbacks mCallback; private int mConnectionId; 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) { Message message = mCaller.obtainMessageO(DO_ON_ACCESSIBILITY_EVENT, 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); } @Override public void executeMessage(Message message) { switch (message.what) { case DO_ON_ACCESSIBILITY_EVENT: { AccessibilityEvent event = (AccessibilityEvent) message.obj; if (event != null) { AccessibilityInteractionClient.getInstance().onAccessibilityEvent(event); mCallback.onAccessibilityEvent(event); // Make sure the event is recycled. try { event.recycle(); } catch (IllegalStateException ise) { /* ignore - best effort */ } } } return; case DO_ON_INTERRUPT: { 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: { 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; default : Log.w(LOG_TAG, "Unknown message type " + message.what); } } } }