| /* |
| * Copyright (C) 2019 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.app; |
| |
| import static android.hardware.display.DisplayManager.VIRTUAL_DISPLAY_FLAG_DESTROY_CONTENT_ON_REMOVAL; |
| import static android.hardware.display.DisplayManager.VIRTUAL_DISPLAY_FLAG_OWN_CONTENT_ONLY; |
| import static android.hardware.display.DisplayManager.VIRTUAL_DISPLAY_FLAG_PUBLIC; |
| |
| import android.annotation.NonNull; |
| import android.annotation.Nullable; |
| import android.content.ComponentName; |
| import android.content.Context; |
| import android.content.Intent; |
| import android.content.pm.LauncherApps; |
| import android.content.pm.ShortcutInfo; |
| import android.graphics.Insets; |
| import android.graphics.Matrix; |
| import android.graphics.Point; |
| import android.graphics.Rect; |
| import android.graphics.Region; |
| import android.hardware.display.DisplayManager; |
| import android.hardware.display.VirtualDisplay; |
| import android.hardware.input.InputManager; |
| import android.os.RemoteException; |
| import android.os.SystemClock; |
| import android.os.UserHandle; |
| import android.util.DisplayMetrics; |
| import android.util.Log; |
| import android.view.Display; |
| import android.view.IWindow; |
| import android.view.IWindowManager; |
| import android.view.IWindowSession; |
| import android.view.InputDevice; |
| import android.view.KeyCharacterMap; |
| import android.view.KeyEvent; |
| import android.view.SurfaceControl; |
| import android.view.WindowManager; |
| import android.view.WindowManagerGlobal; |
| import android.view.inputmethod.InputMethodManager; |
| |
| import dalvik.system.CloseGuard; |
| |
| import java.util.List; |
| |
| /** |
| * A component which handles embedded display of tasks within another window. The embedded task can |
| * be presented using the SurfaceControl provided from {@link #getSurfaceControl()}. |
| * |
| * @hide |
| */ |
| public class TaskEmbedder { |
| private static final String TAG = "TaskEmbedder"; |
| private static final String DISPLAY_NAME = "TaskVirtualDisplay"; |
| |
| /** |
| * A component which will host the task. |
| */ |
| public interface Host { |
| /** @return the screen area where touches should be dispatched to the embedded Task */ |
| Region getTapExcludeRegion(); |
| |
| /** @return a matrix which transforms from screen-space to the embedded task surface */ |
| Matrix getScreenToTaskMatrix(); |
| |
| /** @return the window containing the parent surface, if attached and available */ |
| @Nullable IWindow getWindow(); |
| |
| /** @return the x/y offset from the origin of the window to the surface */ |
| Point getPositionInWindow(); |
| |
| /** @return whether this surface is able to receive pointer events */ |
| boolean canReceivePointerEvents(); |
| |
| /** @return the width of the container for the embedded task */ |
| int getWidth(); |
| |
| /** @return the height of the container for the embedded task */ |
| int getHeight(); |
| |
| /** |
| * Called to inform the host of the task's background color. This can be used to |
| * fill unpainted areas if necessary. |
| */ |
| void onTaskBackgroundColorChanged(TaskEmbedder ts, int bgColor); |
| } |
| |
| /** |
| * Describes changes to the state of the TaskEmbedder as well the tasks within. |
| */ |
| public interface Listener { |
| /** Called when the container is ready for launching activities. */ |
| default void onInitialized() {} |
| |
| /** Called when the container can no longer launch activities. */ |
| default void onReleased() {} |
| |
| /** Called when a task is created inside the container. */ |
| default void onTaskCreated(int taskId, ComponentName name) {} |
| |
| /** Called when a task is moved to the front of the stack inside the container. */ |
| default void onTaskMovedToFront(int taskId) {} |
| |
| /** Called when a task is about to be removed from the stack inside the container. */ |
| default void onTaskRemovalStarted(int taskId) {} |
| } |
| |
| private IActivityTaskManager mActivityTaskManager = ActivityTaskManager.getService(); |
| |
| private final Context mContext; |
| private TaskEmbedder.Host mHost; |
| private int mDisplayDensityDpi; |
| private final boolean mSingleTaskInstance; |
| private SurfaceControl.Transaction mTransaction; |
| private SurfaceControl mSurfaceControl; |
| private VirtualDisplay mVirtualDisplay; |
| private Insets mForwardedInsets; |
| private TaskStackListener mTaskStackListener; |
| private Listener mListener; |
| private boolean mOpened; // Protected by mGuard. |
| |
| private final CloseGuard mGuard = CloseGuard.get(); |
| |
| |
| /** |
| * Constructs a new TaskEmbedder. |
| * |
| * @param context the context |
| * @param host the host for this embedded task |
| * @param singleTaskInstance whether to apply a single-task constraint to this container |
| */ |
| public TaskEmbedder(Context context, TaskEmbedder.Host host, boolean singleTaskInstance) { |
| mContext = context; |
| mHost = host; |
| mSingleTaskInstance = singleTaskInstance; |
| } |
| |
| /** |
| * Whether this container has been initialized. |
| * |
| * @return true if initialized |
| */ |
| public boolean isInitialized() { |
| return mVirtualDisplay != null; |
| } |
| |
| /** |
| * Initialize this container. |
| * |
| * @param parent the surface control for the parent surface |
| * @return true if initialized successfully |
| */ |
| public boolean initialize(SurfaceControl parent) { |
| if (mVirtualDisplay != null) { |
| throw new IllegalStateException("Trying to initialize for the second time."); |
| } |
| |
| mTransaction = new SurfaceControl.Transaction(); |
| |
| final DisplayManager displayManager = mContext.getSystemService(DisplayManager.class); |
| mDisplayDensityDpi = getBaseDisplayDensity(); |
| |
| mVirtualDisplay = displayManager.createVirtualDisplay( |
| DISPLAY_NAME + "@" + System.identityHashCode(this), mHost.getWidth(), |
| mHost.getHeight(), mDisplayDensityDpi, null, |
| VIRTUAL_DISPLAY_FLAG_PUBLIC | VIRTUAL_DISPLAY_FLAG_OWN_CONTENT_ONLY |
| | VIRTUAL_DISPLAY_FLAG_DESTROY_CONTENT_ON_REMOVAL); |
| |
| if (mVirtualDisplay == null) { |
| Log.e(TAG, "Failed to initialize TaskEmbedder"); |
| return false; |
| } |
| |
| // Create a container surface to which the DisplayContent will be reparented |
| final String name = "TaskEmbedder - " + Integer.toHexString(System.identityHashCode(this)); |
| mSurfaceControl = new SurfaceControl.Builder() |
| .setContainerLayer() |
| .setParent(parent) |
| .setName(name) |
| .build(); |
| |
| final int displayId = getDisplayId(); |
| |
| final IWindowManager wm = WindowManagerGlobal.getWindowManagerService(); |
| try { |
| // TODO: Find a way to consolidate these calls to the server. |
| WindowManagerGlobal.getWindowSession().reparentDisplayContent( |
| mHost.getWindow(), mSurfaceControl, displayId); |
| wm.dontOverrideDisplayInfo(displayId); |
| if (mSingleTaskInstance) { |
| mContext.getSystemService(ActivityTaskManager.class) |
| .setDisplayToSingleTaskInstance(displayId); |
| } |
| setForwardedInsets(mForwardedInsets); |
| if (mHost.getWindow() != null) { |
| updateLocationAndTapExcludeRegion(); |
| } |
| mTaskStackListener = new TaskStackListenerImpl(); |
| try { |
| mActivityTaskManager.registerTaskStackListener(mTaskStackListener); |
| } catch (RemoteException e) { |
| Log.e(TAG, "Failed to register task stack listener", e); |
| } |
| } catch (RemoteException e) { |
| e.rethrowAsRuntimeException(); |
| } |
| if (mListener != null && mVirtualDisplay != null) { |
| mListener.onInitialized(); |
| } |
| mOpened = true; |
| mGuard.open("release"); |
| return true; |
| } |
| |
| /** |
| * Returns the surface control for the task surface. This should be parented to a screen |
| * surface for display/embedding purposes. |
| * |
| * @return the surface control for the task |
| */ |
| public SurfaceControl getSurfaceControl() { |
| return mSurfaceControl; |
| } |
| |
| /** |
| * Set forwarded insets on the virtual display. |
| * |
| * @see IWindowManager#setForwardedInsets |
| */ |
| public void setForwardedInsets(Insets insets) { |
| mForwardedInsets = insets; |
| if (mVirtualDisplay == null) { |
| return; |
| } |
| try { |
| final IWindowManager wm = WindowManagerGlobal.getWindowManagerService(); |
| wm.setForwardedInsets(getDisplayId(), mForwardedInsets); |
| } catch (RemoteException e) { |
| e.rethrowAsRuntimeException(); |
| } |
| } |
| |
| /** An opaque unique identifier for this task surface among others being managed by the app. */ |
| public int getId() { |
| return getDisplayId(); |
| } |
| |
| int getDisplayId() { |
| if (mVirtualDisplay != null) { |
| return mVirtualDisplay.getDisplay().getDisplayId(); |
| } |
| return Display.INVALID_DISPLAY; |
| } |
| |
| /** |
| * Set the callback to be notified about state changes. |
| * <p>This class must finish initializing before {@link #startActivity(Intent)} can be called. |
| * <p>Note: If the instance was ready prior to this call being made, then |
| * {@link Listener#onInitialized()} will be called from within this method call. |
| * |
| * @param listener The listener to report events to. |
| * |
| * @see ActivityView.StateCallback |
| * @see #startActivity(Intent) |
| */ |
| public void setListener(TaskEmbedder.Listener listener) { |
| mListener = listener; |
| if (mListener != null && isInitialized()) { |
| mListener.onInitialized(); |
| } |
| } |
| |
| /** |
| * Launch a new activity into this container. |
| * |
| * @param intent Intent used to launch an activity |
| * |
| * @see #startActivity(PendingIntent) |
| */ |
| public void startActivity(@NonNull Intent intent) { |
| final ActivityOptions options = prepareActivityOptions(); |
| mContext.startActivity(intent, options.toBundle()); |
| } |
| |
| /** |
| * Launch a new activity into this container. |
| * |
| * @param intent Intent used to launch an activity |
| * @param user The UserHandle of the user to start this activity for |
| * |
| * @see #startActivity(PendingIntent) |
| */ |
| public void startActivity(@NonNull Intent intent, UserHandle user) { |
| final ActivityOptions options = prepareActivityOptions(); |
| mContext.startActivityAsUser(intent, options.toBundle(), user); |
| } |
| |
| /** |
| * Launch a new activity into this container. |
| * |
| * @param pendingIntent Intent used to launch an activity |
| * |
| * @see #startActivity(Intent) |
| */ |
| public void startActivity(@NonNull PendingIntent pendingIntent) { |
| final ActivityOptions options = prepareActivityOptions(); |
| try { |
| pendingIntent.send(null /* context */, 0 /* code */, null /* intent */, |
| null /* onFinished */, null /* handler */, null /* requiredPermission */, |
| options.toBundle()); |
| } catch (PendingIntent.CanceledException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| * Launch a new activity into this container. |
| * |
| * @param pendingIntent Intent used to launch an activity |
| * @param fillInIntent Additional Intent data, see {@link Intent#fillIn Intent.fillIn()} |
| * @param options options for the activity |
| * |
| * @see #startActivity(Intent) |
| */ |
| public void startActivity(@NonNull PendingIntent pendingIntent, @Nullable Intent fillInIntent, |
| @NonNull ActivityOptions options) { |
| |
| options.setLaunchDisplayId(mVirtualDisplay.getDisplay().getDisplayId()); |
| try { |
| pendingIntent.send(mContext, 0 /* code */, fillInIntent, |
| null /* onFinished */, null /* handler */, null /* requiredPermission */, |
| options.toBundle()); |
| } catch (PendingIntent.CanceledException e) { |
| throw new RuntimeException(e); |
| } |
| } |
| |
| /** |
| * Launch an activity represented by {@link ShortcutInfo} into this container. |
| * <p>The owner of this container must be allowed to access the shortcut information, |
| * as defined in {@link LauncherApps#hasShortcutHostPermission()} to use this method. |
| * |
| * @param shortcut the shortcut used to launch the activity. |
| * @param options options for the activity. |
| * @param sourceBounds the rect containing the source bounds of the clicked icon to open |
| * this shortcut. |
| * |
| * @see #startActivity(Intent) |
| */ |
| public void startShortcutActivity(@NonNull ShortcutInfo shortcut, |
| @NonNull ActivityOptions options, @Nullable Rect sourceBounds) { |
| LauncherApps service = |
| (LauncherApps) mContext.getSystemService(Context.LAUNCHER_APPS_SERVICE); |
| options.setLaunchDisplayId(mVirtualDisplay.getDisplay().getDisplayId()); |
| service.startShortcut(shortcut, sourceBounds, options.toBundle()); |
| } |
| |
| /** |
| * Check if container is ready to launch and create {@link ActivityOptions} to target the |
| * virtual display. |
| */ |
| private ActivityOptions prepareActivityOptions() { |
| if (mVirtualDisplay == null) { |
| throw new IllegalStateException( |
| "Trying to start activity before ActivityView is ready."); |
| } |
| final ActivityOptions options = ActivityOptions.makeBasic(); |
| options.setLaunchDisplayId(getDisplayId()); |
| return options; |
| } |
| |
| /** |
| * Stops presentation of tasks in this container. |
| */ |
| public void stop() { |
| if (mVirtualDisplay != null) { |
| mVirtualDisplay.setDisplayState(false); |
| clearActivityViewGeometryForIme(); |
| clearTapExcludeRegion(); |
| } |
| } |
| |
| /** |
| * Starts presentation of tasks in this container. |
| */ |
| public void start() { |
| if (mVirtualDisplay != null) { |
| mVirtualDisplay.setDisplayState(true); |
| updateLocationAndTapExcludeRegion(); |
| } |
| } |
| |
| /** |
| * This should be called whenever the position or size of the surface changes |
| * or if touchable areas above the surface are added or removed. |
| */ |
| public void notifyBoundsChanged() { |
| updateLocationAndTapExcludeRegion(); |
| } |
| |
| /** |
| * Updates position and bounds information needed by WM and IME to manage window |
| * focus and touch events properly. |
| * <p> |
| * This should be called whenever the position or size of the surface changes |
| * or if touchable areas above the surface are added or removed. |
| */ |
| private void updateLocationAndTapExcludeRegion() { |
| if (mVirtualDisplay == null || mHost.getWindow() == null) { |
| return; |
| } |
| reportLocation(mHost.getScreenToTaskMatrix(), mHost.getPositionInWindow()); |
| applyTapExcludeRegion(mHost.getWindow(), hashCode(), mHost.getTapExcludeRegion()); |
| } |
| |
| /** |
| * Call to update the position and transform matrix for the embedded surface. |
| * <p> |
| * This should not normally be called directly, but through |
| * {@link #updateLocationAndTapExcludeRegion()}. This method |
| * is provided as an optimization when managing multiple TaskSurfaces within a view. |
| * |
| * @param screenToViewMatrix the matrix/transform from screen space to view space |
| * @param positionInWindow the window-relative position of the surface |
| * |
| * @see InputMethodManager#reportActivityView(int, Matrix) |
| */ |
| private void reportLocation(Matrix screenToViewMatrix, Point positionInWindow) { |
| try { |
| final int displayId = getDisplayId(); |
| mContext.getSystemService(InputMethodManager.class) |
| .reportActivityView(displayId, screenToViewMatrix); |
| IWindowSession session = WindowManagerGlobal.getWindowSession(); |
| session.updateDisplayContentLocation(mHost.getWindow(), positionInWindow.x, |
| positionInWindow.y, displayId); |
| } catch (RemoteException e) { |
| e.rethrowAsRuntimeException(); |
| } |
| } |
| |
| /** |
| * Call to update the tap exclude region for the window. |
| * <p> |
| * This should not normally be called directly, but through |
| * {@link #updateLocationAndTapExcludeRegion()}. This method |
| * is provided as an optimization when managing multiple TaskSurfaces within a view. |
| * |
| * @see IWindowSession#updateTapExcludeRegion(IWindow, int, Region) |
| */ |
| private void applyTapExcludeRegion(IWindow window, int regionId, |
| @Nullable Region tapExcludeRegion) { |
| try { |
| IWindowSession session = WindowManagerGlobal.getWindowSession(); |
| session.updateTapExcludeRegion(window, regionId, tapExcludeRegion); |
| } catch (RemoteException e) { |
| e.rethrowAsRuntimeException(); |
| } |
| } |
| |
| /** |
| * @see InputMethodManager#reportActivityView(int, Matrix) |
| */ |
| private void clearActivityViewGeometryForIme() { |
| final int displayId = getDisplayId(); |
| mContext.getSystemService(InputMethodManager.class).reportActivityView(displayId, null); |
| } |
| |
| /** |
| * Removes the tap exclude region set by {@link #updateLocationAndTapExcludeRegion()}. |
| */ |
| private void clearTapExcludeRegion() { |
| if (mHost.getWindow() == null) { |
| Log.w(TAG, "clearTapExcludeRegion: not attached to window!"); |
| return; |
| } |
| applyTapExcludeRegion(mHost.getWindow(), hashCode(), null); |
| } |
| |
| /** |
| * Called to update the dimensions whenever the host size changes. |
| * |
| * @param width the new width of the surface |
| * @param height the new height of the surface |
| */ |
| public void resizeTask(int width, int height) { |
| mDisplayDensityDpi = getBaseDisplayDensity(); |
| if (mVirtualDisplay != null) { |
| mVirtualDisplay.resize(width, height, mDisplayDensityDpi); |
| } |
| } |
| |
| /** |
| * Injects a pair of down/up key events with keycode {@link KeyEvent#KEYCODE_BACK} to the |
| * virtual display. |
| */ |
| public void performBackPress() { |
| if (mVirtualDisplay == null) { |
| return; |
| } |
| final int displayId = mVirtualDisplay.getDisplay().getDisplayId(); |
| final InputManager im = InputManager.getInstance(); |
| im.injectInputEvent(createKeyEvent(KeyEvent.ACTION_DOWN, KeyEvent.KEYCODE_BACK, displayId), |
| InputManager.INJECT_INPUT_EVENT_MODE_ASYNC); |
| im.injectInputEvent(createKeyEvent(KeyEvent.ACTION_UP, KeyEvent.KEYCODE_BACK, displayId), |
| InputManager.INJECT_INPUT_EVENT_MODE_ASYNC); |
| } |
| |
| private static KeyEvent createKeyEvent(int action, int code, int displayId) { |
| long when = SystemClock.uptimeMillis(); |
| final KeyEvent ev = new KeyEvent(when, when, action, code, 0 /* repeat */, |
| 0 /* metaState */, KeyCharacterMap.VIRTUAL_KEYBOARD, 0 /* scancode */, |
| KeyEvent.FLAG_FROM_SYSTEM | KeyEvent.FLAG_VIRTUAL_HARD_KEY, |
| InputDevice.SOURCE_KEYBOARD); |
| ev.setDisplayId(displayId); |
| return ev; |
| } |
| |
| /** |
| * Releases the resources for this TaskEmbedder. Tasks will no longer be launchable |
| * within this container. |
| * |
| * <p>Note: Calling this method is allowed after {@link Listener#onInitialized()} callback is |
| * triggered and before {@link Listener#onReleased()}. |
| */ |
| public void release() { |
| if (mVirtualDisplay == null) { |
| throw new IllegalStateException( |
| "Trying to release container that is not initialized."); |
| } |
| performRelease(); |
| } |
| |
| private boolean performRelease() { |
| if (!mOpened) { |
| return false; |
| } |
| mTransaction.reparent(mSurfaceControl, null).apply(); |
| mSurfaceControl.release(); |
| |
| // Clear activity view geometry for IME on this display |
| clearActivityViewGeometryForIme(); |
| |
| // Clear tap-exclude region (if any) for this window. |
| clearTapExcludeRegion(); |
| |
| if (mTaskStackListener != null) { |
| try { |
| mActivityTaskManager.unregisterTaskStackListener(mTaskStackListener); |
| } catch (RemoteException e) { |
| Log.e(TAG, "Failed to unregister task stack listener", e); |
| } |
| mTaskStackListener = null; |
| } |
| |
| boolean reportReleased = false; |
| if (mVirtualDisplay != null) { |
| mVirtualDisplay.release(); |
| mVirtualDisplay = null; |
| reportReleased = true; |
| |
| } |
| |
| if (mListener != null && reportReleased) { |
| mListener.onReleased(); |
| } |
| mOpened = false; |
| mGuard.close(); |
| return true; |
| } |
| |
| @Override |
| protected void finalize() throws Throwable { |
| try { |
| if (mGuard != null) { |
| mGuard.warnIfOpen(); |
| performRelease(); |
| } |
| } finally { |
| super.finalize(); |
| } |
| } |
| |
| /** Get density of the hosting display. */ |
| private int getBaseDisplayDensity() { |
| final WindowManager wm = mContext.getSystemService(WindowManager.class); |
| final DisplayMetrics metrics = new DisplayMetrics(); |
| wm.getDefaultDisplay().getMetrics(metrics); |
| return metrics.densityDpi; |
| } |
| |
| /** |
| * A task change listener that detects background color change of the topmost stack on our |
| * virtual display and updates the background of the surface view. This background will be shown |
| * when surface view is resized, but the app hasn't drawn its content in new size yet. |
| * It also calls StateCallback.onTaskMovedToFront to notify interested parties that the stack |
| * associated with the {@link ActivityView} has had a Task moved to the front. This is useful |
| * when needing to also bring the host Activity to the foreground at the same time. |
| */ |
| private class TaskStackListenerImpl extends TaskStackListener { |
| |
| @Override |
| public void onTaskDescriptionChanged(ActivityManager.RunningTaskInfo taskInfo) |
| throws RemoteException { |
| if (!isInitialized() |
| || taskInfo.displayId != getDisplayId()) { |
| return; |
| } |
| |
| ActivityManager.StackInfo stackInfo = getTopMostStackInfo(); |
| if (stackInfo == null) { |
| return; |
| } |
| // Found the topmost stack on target display. Now check if the topmost task's |
| // description changed. |
| if (taskInfo.taskId == stackInfo.taskIds[stackInfo.taskIds.length - 1]) { |
| mHost.onTaskBackgroundColorChanged(TaskEmbedder.this, |
| taskInfo.taskDescription.getBackgroundColor()); |
| } |
| } |
| |
| @Override |
| public void onTaskMovedToFront(ActivityManager.RunningTaskInfo taskInfo) |
| throws RemoteException { |
| if (!isInitialized() || mListener == null |
| || taskInfo.displayId != getDisplayId()) { |
| return; |
| } |
| |
| ActivityManager.StackInfo stackInfo = getTopMostStackInfo(); |
| // if StackInfo was null or unrelated to the "move to front" then there's no use |
| // notifying the callback |
| if (stackInfo != null |
| && taskInfo.taskId == stackInfo.taskIds[stackInfo.taskIds.length - 1]) { |
| mListener.onTaskMovedToFront(taskInfo.taskId); |
| } |
| } |
| |
| @Override |
| public void onTaskCreated(int taskId, ComponentName componentName) throws RemoteException { |
| if (mListener == null || !isInitialized()) { |
| return; |
| } |
| |
| ActivityManager.StackInfo stackInfo = getTopMostStackInfo(); |
| // if StackInfo was null or unrelated to the task creation then there's no use |
| // notifying the callback |
| if (stackInfo != null |
| && taskId == stackInfo.taskIds[stackInfo.taskIds.length - 1]) { |
| mListener.onTaskCreated(taskId, componentName); |
| } |
| } |
| |
| @Override |
| public void onTaskRemovalStarted(ActivityManager.RunningTaskInfo taskInfo) |
| throws RemoteException { |
| if (mListener == null || !isInitialized() |
| || taskInfo.displayId != getDisplayId()) { |
| return; |
| } |
| mListener.onTaskRemovalStarted(taskInfo.taskId); |
| } |
| |
| private ActivityManager.StackInfo getTopMostStackInfo() throws RemoteException { |
| // Find the topmost task on our virtual display - it will define the background |
| // color of the surface view during resizing. |
| final int displayId = getDisplayId(); |
| final List<ActivityManager.StackInfo> stackInfoList = |
| mActivityTaskManager.getAllStackInfosOnDisplay(displayId); |
| if (stackInfoList.isEmpty()) { |
| return null; |
| } |
| return stackInfoList.get(0); |
| } |
| } |
| } |