Android 13屏蔽Activity或包的手势禁止滑动退出

在Android设备中，左/右滑两次会出现一个箭头然后退出Activity页面，有些Activity页面不想出现箭头及退出．
以下是对项目中的别人已实现的代码解析．

在config.xml中配置要禁用的Activity

packages/apps/Launcher3/quickstep/res/values/config.xml
resources中gesture_blocking_activitiesg添加Activity到item中，此例中为GestureSandboxActivity

<resources><string name="overscroll_plugin_factory_class" translatable="false" /><string name="task_overlay_factory_class" translatable="false"/><!-- Activities which block home gesture --><string-array name="gesture_blocking_activities" translatable="false"><item>com.android.launcher3/com.android.quickstep.interaction.GestureSandboxActivity</item></string-array>

后面所有代码都在这个java文件中
frameworks/base/packages/SystemUI/src/com/android/systemui/navigationbar/gestural/EdgeBackGestureHandler.java

config.xml中禁用内容读出来

EdgeBackGestureHandler构造函数中把config.xml中内容读出来，把禁用的Activity读到mGestureBlockingActivities.contains变量中．

    // Activities which should not trigger Back gesture.private final List<ComponentName> mGestureBlockingActivities = new ArrayList<>();ComponentName recentsComponentName = ComponentName.unflattenFromString(context.getString(com.android.internal.R.string.config_recentsComponentName));if (recentsComponentName != null) {String recentsPackageName = recentsComponentName.getPackageName();PackageManager manager = context.getPackageManager();try {Resources resources = manager.getResourcesForApplication(manager.getApplicationInfo(recentsPackageName,PackageManager.MATCH_UNINSTALLED_PACKAGES| PackageManager.MATCH_DISABLED_COMPONENTS| PackageManager.GET_SHARED_LIBRARY_FILES));int resId = resources.getIdentifier("gesture_blocking_activities", "array", recentsPackageName);if (resId == 0) {Log.e(TAG, "No resource found for gesture-blocking activities");} else {String[] gestureBlockingActivities = resources.getStringArray(resId);for (String gestureBlockingActivity : gestureBlockingActivities) {mGestureBlockingActivities.add(ComponentName.unflattenFromString(gestureBlockingActivity));}}} catch (NameNotFoundException e) {Log.e(TAG, "Failed to add gesture blocking activities", e);}}

函数判断是否要对当前Activity进行手势禁用

isGestureBlockingActivityRunning函数用于判断是否要对当前Activity进行手势禁用．

    private boolean isGestureBlockingActivityRunning() {ActivityManager.RunningTaskInfo runningTask =ActivityManagerWrapper.getInstance().getRunningTask();ComponentName topActivity = runningTask == null ? null : runningTask.topActivity;if (topActivity != null) {mPackageName = topActivity.getPackageName();} else {mPackageName = "_UNKNOWN";}return topActivity != null && mGestureBlockingActivities.contains(topActivity);}

监听应用任务变化，判断当前是否要禁用手势

mGestureBlockingActivityRunning为true则要禁用．

    private boolean mGestureBlockingActivityRunning;private TaskStackChangeListener mTaskStackListener = new TaskStackChangeListener() {@Overridepublic void onTaskStackChanged() {mGestureBlockingActivityRunning = isGestureBlockingActivityRunning();}@Overridepublic void onTaskCreated(int taskId, ComponentName componentName) {if (componentName != null) {mPackageName = componentName.getPackageName();} else {mPackageName = "_UNKNOWN";}}@Overridepublic void onActivityPinned(String packageName, int userId, int taskId, int stackId) {mIsInPipMode = true;}@Overridepublic void onActivityUnpinned() {mIsInPipMode = false;}};

禁用

在onMotionEvent函数中，设置mAllowGesture为false就会禁用手势，其中 mGestureBlockingActivityRunning为true时会设置mAllowGesture为false，这个变量赋值后面会提到．

    private void onMotionEvent(MotionEvent ev) {int action = ev.getActionMasked();if (action == MotionEvent.ACTION_DOWN) {if (DEBUG_MISSING_GESTURE) {Log.d(DEBUG_MISSING_GESTURE_TAG, "Start gesture: " + ev);}// Verify if this is in within the touch region and we aren't in immersive mode, and// either the bouncer is showing or the notification panel is hiddenmInputEventReceiver.setBatchingEnabled(false);mIsOnLeftEdge = ev.getX() <= mEdgeWidthLeft + mLeftInset;mMLResults = 0;mLogGesture = false;mInRejectedExclusion = false;boolean isWithinInsets = isWithinInsets((int) ev.getX(), (int) ev.getY());mAllowGesture = !mDisabledForQuickstep && mIsBackGestureAllowed && isWithinInsets&& !mGestureBlockingActivityRunning&& !QuickStepContract.isBackGestureDisabled(mSysUiFlags)&& isWithinTouchRegion((int) ev.getX(), (int) ev.getY());if (mAllowGesture) {mEdgeBackPlugin.setIsLeftPanel(mIsOnLeftEdge);mEdgeBackPlugin.onMotionEvent(ev);}