Check if package matches home package and allow exceptions.

This avoids playing the sound effect if other launcher activities come
to front and the user navigates back to home.
Exceptions are allowed for activity types dream and assistant and system
apps can set the manifest flag FLAG_NO_HOME_SOUND to avoid the home
sound effect from being played when the home app moves to front next.

Test: manual
Test: atest HomeSoundEffectControllerTest
Bug: 167946828
Bug: 157407957
Change-Id: I9a448e7ed769c48cc0d0448fa7b49cb95d2b7470
diff --git a/packages/SystemUI/res/values/config.xml b/packages/SystemUI/res/values/config.xml
index af6df32..fbe7175 100644
--- a/packages/SystemUI/res/values/config.xml
+++ b/packages/SystemUI/res/values/config.xml
@@ -591,4 +591,12 @@
 
     <!-- Determines whether to allow the nav bar handle to be forced to be opaque. -->
     <bool name="allow_force_nav_bar_handle_opaque">true</bool>
+
+    <!-- Whether a transition of ACTIVITY_TYPE_DREAM to the home app should play a home sound
+         effect -->
+    <bool name="config_playHomeSoundAfterDream">false</bool>
+
+    <!-- Whether a transition of ACTIVITY_TYPE_ASSISTANT to the home app should play a home sound
+         effect -->
+    <bool name="config_playHomeSoundAfterAssistant">false</bool>
 </resources>
diff --git a/packages/SystemUI/src/com/android/systemui/media/systemsounds/HomeSoundEffectController.java b/packages/SystemUI/src/com/android/systemui/media/systemsounds/HomeSoundEffectController.java
index dd3d02a..31e4939 100644
--- a/packages/SystemUI/src/com/android/systemui/media/systemsounds/HomeSoundEffectController.java
+++ b/packages/SystemUI/src/com/android/systemui/media/systemsounds/HomeSoundEffectController.java
@@ -16,38 +16,64 @@
 
 package com.android.systemui.media.systemsounds;
 
+import android.Manifest;
 import android.app.ActivityManager;
 import android.app.WindowConfiguration;
 import android.content.Context;
+import android.content.pm.ActivityInfo;
+import android.content.pm.PackageManager;
 import android.media.AudioManager;
+import android.util.Slog;
 
+import com.android.systemui.R;
 import com.android.systemui.SystemUI;
 import com.android.systemui.dagger.SysUISingleton;
+import com.android.systemui.shared.system.ActivityManagerWrapper;
 import com.android.systemui.shared.system.TaskStackChangeListener;
 import com.android.systemui.shared.system.TaskStackChangeListeners;
 
 import javax.inject.Inject;
 
 /**
- * If a sound effect is defined for {@link android.media.AudioManager#FX_HOME}, a sound is played
- * when the home task moves to front and the last task that moved to front was not the home task.
+ * If a sound effect is defined for {@link android.media.AudioManager#FX_HOME}, a
+ * {@link TaskStackChangeListener} is registered to play a home sound effect when conditions
+ * documented at {@link #handleTaskStackChanged} apply.
  */
 @SysUISingleton
 public class HomeSoundEffectController extends SystemUI {
 
+    private static final String TAG = "HomeSoundEffectController";
     private final AudioManager mAudioManager;
     private final TaskStackChangeListeners mTaskStackChangeListeners;
+    private final ActivityManagerWrapper mActivityManagerWrapper;
+    private final PackageManager mPm;
+    private final boolean mPlayHomeSoundAfterAssistant;
+    private final boolean mPlayHomeSoundAfterDream;
     // Initialize true because home sound should not be played when the system boots.
     private boolean mIsLastTaskHome = true;
+    // mLastHomePackageName could go out of sync in rare circumstances if launcher changes,
+    // but it's cheaper than the alternative and potential impact is low
+    private String mLastHomePackageName;
+    private @WindowConfiguration.ActivityType int mLastActivityType;
+    private boolean mLastActivityHasNoHomeSound = false;
+    private int mLastTaskId;
 
     @Inject
     public HomeSoundEffectController(
             Context context,
             AudioManager audioManager,
-            TaskStackChangeListeners taskStackChangeListeners) {
+            TaskStackChangeListeners taskStackChangeListeners,
+            ActivityManagerWrapper activityManagerWrapper,
+            PackageManager packageManager) {
         super(context);
         mAudioManager = audioManager;
         mTaskStackChangeListeners = taskStackChangeListeners;
+        mActivityManagerWrapper = activityManagerWrapper;
+        mPm = packageManager;
+        mPlayHomeSoundAfterAssistant = context.getResources().getBoolean(
+                R.bool.config_playHomeSoundAfterAssistant);
+        mPlayHomeSoundAfterDream = context.getResources().getBoolean(
+                R.bool.config_playHomeSoundAfterDream);
     }
 
     @Override
@@ -56,27 +82,94 @@
             mTaskStackChangeListeners.registerTaskStackListener(
                     new TaskStackChangeListener() {
                         @Override
-                        public void onTaskMovedToFront(ActivityManager.RunningTaskInfo taskInfo) {
-                            handleHomeTaskMovedToFront(taskInfo);
+                        public void onTaskStackChanged() {
+                            ActivityManager.RunningTaskInfo currentTask =
+                                    mActivityManagerWrapper.getRunningTask();
+                            if (currentTask == null || currentTask.topActivityInfo == null) {
+                                return;
+                            }
+                            handleTaskStackChanged(currentTask);
                         }
                     });
         }
     }
 
-    private boolean isHomeTask(ActivityManager.RunningTaskInfo taskInfo) {
-        return taskInfo.getActivityType() == WindowConfiguration.ACTIVITY_TYPE_HOME;
+    private boolean hasFlagNoSound(ActivityInfo activityInfo) {
+        if ((activityInfo.privateFlags & ActivityInfo.PRIVATE_FLAG_HOME_TRANSITION_SOUND) == 0) {
+            // Only allow flag if app has permission
+            if (mPm.checkPermission(Manifest.permission.DISABLE_SYSTEM_SOUND_EFFECTS,
+                    activityInfo.packageName) == PackageManager.PERMISSION_GRANTED) {
+                return true;
+            } else {
+                Slog.w(TAG,
+                        "Activity has flag playHomeTransition set to false but doesn't hold "
+                                + "required permission "
+                                + Manifest.permission.DISABLE_SYSTEM_SOUND_EFFECTS);
+                return false;
+            }
+        }
+        return false;
     }
 
     /**
-     * To enable a home sound, check if the home app moves to front.
+     * The home sound is played if all of the following conditions are met:
+     * <ul>
+     * <li>The last task which moved to front was not home. This avoids playing the sound
+     * e.g. after FallbackHome transitions to home, another activity of the home app like a
+     * notification panel moved to front, or in case the home app crashed.</li>
+     * <li>The current activity which moved to front is home</li>
+     * <li>The topActivity of the last task has {@link android.R.attr#playHomeTransitionSound} set
+     * to <code>true</code>.</li>
+     * <li>The topActivity of the last task is not of type
+     * {@link WindowConfiguration#ACTIVITY_TYPE_ASSISTANT} if config_playHomeSoundAfterAssistant is
+     * set to <code>false</code> (default).</li>
+     * <li>The topActivity of the last task is not of type
+     * {@link WindowConfiguration#ACTIVITY_TYPE_DREAM} if config_playHomeSoundAfterDream is
+     * set to <code>false</code> (default).</li>
+     * </ul>
      */
-    private void handleHomeTaskMovedToFront(ActivityManager.RunningTaskInfo taskInfo) {
-        boolean isCurrentTaskHome = isHomeTask(taskInfo);
-        // If the last task is home we don't want to play the home sound. This avoids playing
-        // the home sound after FallbackHome transitions to Home
-        if (!mIsLastTaskHome && isCurrentTaskHome) {
+    private boolean shouldPlayHomeSoundForCurrentTransition(
+            ActivityManager.RunningTaskInfo currentTask) {
+        boolean isHomeActivity =
+                currentTask.topActivityType == WindowConfiguration.ACTIVITY_TYPE_HOME;
+        if (currentTask.taskId == mLastTaskId) {
+            return false;
+        }
+        if (mIsLastTaskHome || !isHomeActivity) {
+            return false;
+        }
+        if (mLastActivityHasNoHomeSound) {
+            return false;
+        }
+        if (mLastActivityType == WindowConfiguration.ACTIVITY_TYPE_ASSISTANT
+                && !mPlayHomeSoundAfterAssistant) {
+            return false;
+        }
+        if (mLastActivityType == WindowConfiguration.ACTIVITY_TYPE_DREAM
+                && !mPlayHomeSoundAfterDream) {
+            return false;
+        }
+        return true;
+    }
+
+    private void updateLastTaskInfo(ActivityManager.RunningTaskInfo currentTask) {
+        mLastTaskId = currentTask.taskId;
+        mLastActivityType = currentTask.topActivityType;
+        mLastActivityHasNoHomeSound = hasFlagNoSound(currentTask.topActivityInfo);
+        boolean isHomeActivity =
+                currentTask.topActivityType == WindowConfiguration.ACTIVITY_TYPE_HOME;
+        boolean isHomePackage = currentTask.topActivityInfo.packageName.equals(
+                mLastHomePackageName);
+        mIsLastTaskHome = isHomeActivity || isHomePackage;
+        if (isHomeActivity && !isHomePackage) {
+            mLastHomePackageName = currentTask.topActivityInfo.packageName;
+        }
+    }
+
+    private void handleTaskStackChanged(ActivityManager.RunningTaskInfo frontTask) {
+        if (shouldPlayHomeSoundForCurrentTransition(frontTask)) {
             mAudioManager.playSoundEffect(AudioManager.FX_HOME);
         }
-        mIsLastTaskHome = isCurrentTaskHome;
+        updateLastTaskInfo(frontTask);
     }
 }
diff --git a/packages/SystemUI/tests/src/com/android/systemui/media/systemsounds/HomeSoundEffectControllerTest.java b/packages/SystemUI/tests/src/com/android/systemui/media/systemsounds/HomeSoundEffectControllerTest.java
index 3a77f7ee..33a30e0 100644
--- a/packages/SystemUI/tests/src/com/android/systemui/media/systemsounds/HomeSoundEffectControllerTest.java
+++ b/packages/SystemUI/tests/src/com/android/systemui/media/systemsounds/HomeSoundEffectControllerTest.java
@@ -21,16 +21,20 @@
 import static org.mockito.Mockito.never;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
 
+import android.Manifest;
 import android.app.ActivityManager;
 import android.app.WindowConfiguration;
-import android.content.Context;
+import android.content.pm.ActivityInfo;
+import android.content.pm.PackageManager;
 import android.media.AudioManager;
 
 import androidx.test.filters.SmallTest;
 import androidx.test.runner.AndroidJUnit4;
 
 import com.android.systemui.SysuiTestCase;
+import com.android.systemui.shared.system.ActivityManagerWrapper;
 import com.android.systemui.shared.system.TaskStackChangeListener;
 import com.android.systemui.shared.system.TaskStackChangeListeners;
 
@@ -41,30 +45,50 @@
 import org.mockito.Mock;
 import org.mockito.MockitoAnnotations;
 
+
 @SmallTest
 @RunWith(AndroidJUnit4.class)
 public class HomeSoundEffectControllerTest extends SysuiTestCase {
 
-    private @Mock Context mContext;
+    private static final String HOME_PACKAGE_NAME = "com.android.apps.home";
+    private static final String NON_HOME_PACKAGE_NAME = "com.android.apps.not.home";
+    private static final int HOME_TASK_ID = 0;
+    private static final int NON_HOME_TASK_ID = 1;
+
     private @Mock AudioManager mAudioManager;
     private @Mock TaskStackChangeListeners mTaskStackChangeListeners;
-    private @Mock ActivityManager.RunningTaskInfo mStandardActivityTaskInfo;
-    private @Mock ActivityManager.RunningTaskInfo mHomeActivityTaskInfo;
+    private @Mock ActivityManagerWrapper mActivityManagerWrapper;
+    private @Mock PackageManager mPackageManager;
 
+    private ActivityManager.RunningTaskInfo mTaskAStandardActivity;
+    private ActivityManager.RunningTaskInfo mTaskAExceptionActivity;
+    private ActivityManager.RunningTaskInfo mHomeTaskHomeActivity;
+    private ActivityManager.RunningTaskInfo mHomeTaskStandardActivity;
+    private ActivityManager.RunningTaskInfo mEmptyTask;
     private HomeSoundEffectController mController;
     private TaskStackChangeListener mTaskStackChangeListener;
 
     @Before
     public void setUp() throws Exception {
         MockitoAnnotations.initMocks(this);
-
-        doReturn(WindowConfiguration.ACTIVITY_TYPE_STANDARD).when(
-                mStandardActivityTaskInfo).getActivityType();
-        doReturn(WindowConfiguration.ACTIVITY_TYPE_HOME).when(
-                mHomeActivityTaskInfo).getActivityType();
-
+        mTaskAStandardActivity = createRunningTaskInfo(NON_HOME_PACKAGE_NAME,
+                WindowConfiguration.ACTIVITY_TYPE_STANDARD, NON_HOME_TASK_ID,
+                true /* playHomeTransitionSound */);
+        mTaskAExceptionActivity = createRunningTaskInfo(NON_HOME_PACKAGE_NAME,
+                WindowConfiguration.ACTIVITY_TYPE_STANDARD, NON_HOME_TASK_ID,
+                false /* playHomeTransitionSound */);
+        mHomeTaskHomeActivity = createRunningTaskInfo(HOME_PACKAGE_NAME,
+                WindowConfiguration.ACTIVITY_TYPE_HOME, HOME_TASK_ID,
+                true /* playHomeTransitionSound */);
+        mHomeTaskStandardActivity = createRunningTaskInfo(HOME_PACKAGE_NAME,
+                WindowConfiguration.ACTIVITY_TYPE_STANDARD, HOME_TASK_ID,
+                true /* playHomeTransitionSound */);
+        mEmptyTask = new ActivityManager.RunningTaskInfo();
+        mContext.setMockPackageManager(mPackageManager);
+        when(mPackageManager.checkPermission(Manifest.permission.DISABLE_SYSTEM_SOUND_EFFECTS,
+                NON_HOME_PACKAGE_NAME)).thenReturn(PackageManager.PERMISSION_GRANTED);
         mController = new HomeSoundEffectController(mContext, mAudioManager,
-                mTaskStackChangeListeners);
+                mTaskStackChangeListeners, mActivityManagerWrapper, mPackageManager);
     }
 
     @Test
@@ -73,43 +97,60 @@
         startController(true /* isHomeSoundEffectEnabled */);
 
         // And the home task moves to the front,
-        mTaskStackChangeListener.onTaskMovedToFront(mHomeActivityTaskInfo);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(mHomeTaskHomeActivity);
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // Then no home sound effect should be played.
         verify(mAudioManager, never()).playSoundEffect(AudioManager.FX_HOME);
     }
 
+    /**
+     * Task A (playHomeTransitionSound = true) -> HOME
+     * Expectation: Home sound is played
+     */
     @Test
     public void testHomeSoundEffectPlayedWhenEnabled() {
         // When HomeSoundEffectController is started and the home sound effect is enabled,
         startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mHomeTaskHomeActivity);
 
         // And first a task different from the home task moves to front,
-        mTaskStackChangeListener.onTaskMovedToFront(mStandardActivityTaskInfo);
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // And the home task moves to the front,
-        mTaskStackChangeListener.onTaskMovedToFront(mHomeActivityTaskInfo);
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // Then the home sound effect should be played.
         verify(mAudioManager).playSoundEffect(AudioManager.FX_HOME);
     }
 
+    /**
+     * Task A (playHomeTransitionSound = true) -> HOME -> HOME
+     * Expectation: Home sound is played once after HOME moves to front the first time
+     */
     @Test
     public void testHomeSoundEffectNotPlayedTwiceInRow() {
         // When HomeSoundEffectController is started and the home sound effect is enabled,
         startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mHomeTaskHomeActivity,
+                mHomeTaskHomeActivity);
+
 
         // And first a task different from the home task moves to front,
-        mTaskStackChangeListener.onTaskMovedToFront(mStandardActivityTaskInfo);
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // And the home task moves to the front,
-        mTaskStackChangeListener.onTaskMovedToFront(mHomeActivityTaskInfo);
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // Then the home sound effect should be played.
         verify(mAudioManager).playSoundEffect(AudioManager.FX_HOME);
 
         // If the home task moves to front a second time in a row,
-        mTaskStackChangeListener.onTaskMovedToFront(mHomeActivityTaskInfo);
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // Then no home sound effect should be played.
         verify(mAudioManager, times(1)).playSoundEffect(AudioManager.FX_HOME);
@@ -121,7 +162,59 @@
         startController(true /* isHomeSoundEffectEnabled */);
 
         // And a standard, non-home task, moves to the front,
-        mTaskStackChangeListener.onTaskMovedToFront(mStandardActivityTaskInfo);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(mTaskAStandardActivity);
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then no home sound effect should be played.
+        verify(mAudioManager, never()).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * Task A (playHomeTransitionSound = true) -> HOME -> HOME (activity type standard)
+     * Expectation: Home sound is played once after HOME moves to front
+     */
+    @Test
+    public void testHomeSoundEffectNotPlayedWhenOtherHomeActivityMovesToFront() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mHomeTaskHomeActivity,
+                mHomeTaskStandardActivity);
+
+        // And first a task different from the home task moves to front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then the home sound effect should be played.
+        verify(mAudioManager).playSoundEffect(AudioManager.FX_HOME);
+
+        // If the home task moves to front a second time in a row,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then no home sound effect should be played.
+        verify(mAudioManager, times(1)).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * Task A (playHomeTransitionSound = true) -> HOME (activity type standard)
+     * Expectation: Home sound is not played
+     */
+    @Test
+    public void testHomeSoundEffectNotPlayedWhenOtherHomeActivityMovesToFrontOfOtherApp() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+
+        // And first a task different from the home task moves to front,
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mHomeTaskStandardActivity);
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And an activity from the home package but not the home root activity moves to front
+        mTaskStackChangeListener.onTaskStackChanged();
 
         // Then no home sound effect should be played.
         verify(mAudioManager, never()).playSoundEffect(AudioManager.FX_HOME);
@@ -138,6 +231,171 @@
     }
 
     /**
+     * Task A (playHomeTransitionSound = false) -> HOME
+     * Expectation: Home sound is not played
+     */
+    @Test
+    public void testHomeSoundEffectNotPlayedWhenHomeActivityMovesToFrontAfterException() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+
+        // And first a task different from the home task moves to front, which has
+        // {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND} set to <code>false</code>
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAExceptionActivity,
+                mHomeTaskHomeActivity);
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then no home sound effect should be played because the last package is an exception.
+        verify(mAudioManager, never()).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * HOME -> Task A (playHomeTransitionSound = true) -> Task A (playHomeTransitionSound = false)
+     * -> HOME
+     * Expectation: Home sound is not played
+     */
+    @Test
+    public void testHomeSoundEffectNotPlayedWhenHomeActivityMovesToFrontAfterException2() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mTaskAExceptionActivity,
+                mHomeTaskHomeActivity);
+
+        // And first a task different from the home task moves to front
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then a different activity from the same task moves to front, which has
+        // {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND} set to <code>false</code>
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then no home sound effect should be played.
+        verify(mAudioManager, never()).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * HOME -> Task A (playHomeTransitionSound = false) -> Task A (playHomeTransitionSound = true)
+     * -> HOME
+     * Expectation: Home sound is played
+     */
+    @Test
+    public void testHomeSoundEffectPlayedWhenHomeActivityMovesToFrontAfterException() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAExceptionActivity,
+                mTaskAStandardActivity,
+                mHomeTaskHomeActivity);
+
+        // And first a task different from the home task moves to front,
+        // the topActivity of this task has {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND}
+        // set to <code>false</code>
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then a different activity from the same task moves to front, which has
+        // {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND} set to <code>true</code>
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then the home sound effect should be played.
+        verify(mAudioManager).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * HOME -> Task A (playHomeTransitionSound = false) -> Task A (empty task, no top activity)
+     * -> HOME
+     * Expectation: Home sound is not played
+     */
+    @Test
+    public void testHomeSoundEffectNotPlayedWhenEmptyTaskMovesToFrontAfterException() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAExceptionActivity,
+                mEmptyTask,
+                mHomeTaskHomeActivity);
+
+        // And first a task different from the home task moves to front, whose topActivity has
+        // {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND} set to <code>false</code>
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then a task with no topActivity moves to front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then no home sound effect should be played.
+        verify(mAudioManager, never()).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * HOME -> Task A (playHomeTransitionSound = true) -> Task A (empty task, no top activity)
+     * -> HOME
+     * Expectation: Home sound is played
+     */
+    @Test
+    public void testHomeSoundEffectPlayedWhenEmptyTaskMovesToFrontAfterStandardActivity() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mEmptyTask,
+                mHomeTaskHomeActivity);
+
+        // And first a task different from the home task moves to front, whose topActivity has
+        // {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND} set to <code>false</code>
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then a task with no topActivity moves to front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then the home sound effect should be played.
+        verify(mAudioManager).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
+     * HOME -> Task A (playHomeTransitionSound = false, no permission) -> HOME
+     * Expectation: Home sound is played
+     */
+    @Test
+    public void testHomeSoundEffectPlayedWhenFlagSetButPermissionNotGranted() {
+        // When HomeSoundEffectController is started and the home sound effect is enabled,
+        startController(true /* isHomeSoundEffectEnabled */);
+        when(mActivityManagerWrapper.getRunningTask()).thenReturn(
+                mTaskAStandardActivity,
+                mHomeTaskHomeActivity);
+        when(mPackageManager.checkPermission(Manifest.permission.DISABLE_SYSTEM_SOUND_EFFECTS,
+                NON_HOME_PACKAGE_NAME)).thenReturn(PackageManager.PERMISSION_DENIED);
+
+        // And first a task different from the home task moves to front, whose topActivity has
+        // {@link ActivityInfo#PRIVATE_FLAG_HOME_TRANSITION_SOUND} set to <code>true</code>,
+        // but the app doesn't have the right permission granted
+        mTaskStackChangeListener.onTaskStackChanged();
+
+
+        // And the home task moves to the front,
+        mTaskStackChangeListener.onTaskStackChanged();
+
+        // Then the home sound effect should be played.
+        verify(mAudioManager).playSoundEffect(AudioManager.FX_HOME);
+    }
+
+    /**
      * Sets {@link AudioManager#isHomeSoundEffectEnabled()} and starts HomeSoundEffectController.
      * If the home sound effect is enabled, the registered TaskStackChangeListener is extracted.
      */
@@ -155,4 +413,20 @@
             mTaskStackChangeListener = listenerCaptor.getValue();
         }
     }
+
+    private ActivityManager.RunningTaskInfo createRunningTaskInfo(String packageName,
+            int activityType, int taskId, boolean playHomeTransitionSound) {
+        ActivityManager.RunningTaskInfo res = new ActivityManager.RunningTaskInfo();
+        res.topActivityInfo = new ActivityInfo();
+        res.topActivityInfo.packageName = packageName;
+        res.topActivityType = activityType;
+        res.taskId = taskId;
+        if (!playHomeTransitionSound) {
+            // set the flag to 0
+            res.topActivityInfo.privateFlags &=  ~ActivityInfo.PRIVATE_FLAG_HOME_TRANSITION_SOUND;
+        } else {
+            res.topActivityInfo.privateFlags |= ActivityInfo.PRIVATE_FLAG_HOME_TRANSITION_SOUND;
+        }
+        return res;
+    }
 }