Merge "Expose the HomeVisibilityListener API"

5 files changed, 91 insertions, 36 deletions

diff --git a/api/module-lib-current.txt b/api/module-lib-current.txt
index dc92b52dc466..b8b66879dbae 100644
--- a/api/module-lib-current.txt
+++ b/api/module-lib-current.txt
@@ -1,10 +1,20 @@
 // Signature format: 2.0
 package android.app {
 
+  public class ActivityManager {
+    method @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER) public void addHomeVisibilityListener(@NonNull java.util.concurrent.Executor, @NonNull android.app.HomeVisibilityListener);
+    method @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER) public void removeHomeVisibilityListener(@NonNull android.app.HomeVisibilityListener);
+  }
+
   public class AppOpsManager {
     field public static final String OPSTR_NO_ISOLATED_STORAGE = "android:no_isolated_storage";
   }
 
+  public abstract class HomeVisibilityListener {
+    ctor public HomeVisibilityListener();
+    method public abstract void onHomeVisibilityChanged(boolean);
+  }
+
   public class NotificationManager {
     method public boolean hasEnabledNotificationListener(@NonNull String, @NonNull android.os.UserHandle);
     field public static final String ACTION_NOTIFICATION_LISTENER_ENABLED_CHANGED = "android.app.action.NOTIFICATION_LISTENER_ENABLED_CHANGED";
diff --git a/api/test-current.txt b/api/test-current.txt
index 18320cd21078..85be4ec74bae 100644
--- a/api/test-current.txt
+++ b/api/test-current.txt
@@ -79,6 +79,7 @@ package android.app {
   }
 
   public class ActivityManager {
+    method @RequiresPermission("android.permission.SET_ACTIVITY_WATCHER") public void addHomeVisibilityListener(@NonNull java.util.concurrent.Executor, @NonNull android.app.HomeVisibilityListener);
     method @RequiresPermission(android.Manifest.permission.PACKAGE_USAGE_STATS) public void addOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener, int);
     method public void alwaysShowUnsupportedCompileSdkWarning(android.content.ComponentName);
     method @RequiresPermission(android.Manifest.permission.FORCE_STOP_PACKAGES) public void forceStopPackage(String);
@@ -88,6 +89,7 @@ package android.app {
     method @RequiresPermission(android.Manifest.permission.INJECT_EVENTS) public void holdLock(int);
     method public static boolean isHighEndGfx();
     method @RequiresPermission(android.Manifest.permission.FORCE_STOP_PACKAGES) public void killProcessesWhenImperceptible(@NonNull int[], @NonNull String);
+    method @RequiresPermission("android.permission.SET_ACTIVITY_WATCHER") public void removeHomeVisibilityListener(@NonNull android.app.HomeVisibilityListener);
     method @RequiresPermission(android.Manifest.permission.PACKAGE_USAGE_STATS) public void removeOnUidImportanceListener(android.app.ActivityManager.OnUidImportanceListener);
     method @RequiresPermission(android.Manifest.permission.RESET_APP_ERRORS) public void resetAppErrors();
     method public static void resumeAppSwitches() throws android.os.RemoteException;
@@ -458,6 +460,11 @@ package android.app {
     method @RequiresPermission(android.Manifest.permission.WRITE_DREAM_STATE) public void stopDream();
   }
 
+  public abstract class HomeVisibilityListener {
+    ctor public HomeVisibilityListener();
+    method public abstract void onHomeVisibilityChanged(boolean);
+  }
+
   public final class NotificationChannel implements android.os.Parcelable {
     method public int getOriginalImportance();
     method public boolean isBlockable();
diff --git a/core/java/android/app/ActivityManager.java b/core/java/android/app/ActivityManager.java
index e75d2f60bb87..30efb48cc188 100644
--- a/core/java/android/app/ActivityManager.java
+++ b/core/java/android/app/ActivityManager.java
@@ -100,6 +100,7 @@ import java.util.Collection;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
+import java.util.concurrent.Executor;
 
 /**
  * <p>
@@ -4752,31 +4753,43 @@ public class ActivityManager {
     }
 
     /**
-     * Register with {@link HomeVisibilityObserver} with ActivityManager.
-     * TODO: b/144351078 expose as SystemApi
+     * Register to be notified when the visibility of the home screen changes.
+     *
+     * @param executor The executor on which the listener should be called.
+     * @param listener The listener that is called when home visibility changes.
      * @hide
      */
-    public void registerHomeVisibilityObserver(@NonNull HomeVisibilityObserver observer) {
-        Preconditions.checkNotNull(observer);
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @TestApi
+    @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER)
+    public void addHomeVisibilityListener(@NonNull Executor executor,
+            @NonNull HomeVisibilityListener listener) {
+        Preconditions.checkNotNull(listener);
+        Preconditions.checkNotNull(executor);
         try {
-            observer.init(mContext, this);
-            getService().registerProcessObserver(observer.mObserver);
+            listener.init(mContext, executor, this);
+            getService().registerProcessObserver(listener.mObserver);
             // Notify upon first registration.
-            observer.onHomeVisibilityChanged(observer.mIsHomeActivityVisible);
+            executor.execute(() ->
+                    listener.onHomeVisibilityChanged(listener.mIsHomeActivityVisible));
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
     }
 
     /**
-     * Unregister with {@link HomeVisibilityObserver} with ActivityManager.
-     * TODO: b/144351078 expose as SystemApi
+     * Removes a listener that was previously added with {@link #addHomeVisibilityListener}.
+     *
+     * @param listener The listener that was previously added.
      * @hide
      */
-    public void unregisterHomeVisibilityObserver(@NonNull HomeVisibilityObserver observer) {
-        Preconditions.checkNotNull(observer);
+    @SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+    @TestApi
+    @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER)
+    public void removeHomeVisibilityListener(@NonNull HomeVisibilityListener listener) {
+        Preconditions.checkNotNull(listener);
         try {
-            getService().unregisterProcessObserver(observer.mObserver);
+            getService().unregisterProcessObserver(listener.mObserver);
         } catch (RemoteException e) {
             throw e.rethrowFromSystemServer();
         }
diff --git a/core/java/android/app/HomeVisibilityObserver.java b/core/java/android/app/HomeVisibilityListener.java
index 8422c6f6f872..c6e5699c5fe2 100644
--- a/core/java/android/app/HomeVisibilityObserver.java
+++ b/core/java/android/app/HomeVisibilityListener.java
@@ -16,49 +16,56 @@
 
 package android.app;
 
+import android.annotation.SuppressLint;
+import android.annotation.SystemApi;
+import android.annotation.TestApi;
 import android.content.Context;
-import android.content.Intent;
-import android.content.pm.PackageManager;
-import android.content.pm.ResolveInfo;
+import android.os.Binder;
 
+import java.util.ArrayList;
 import java.util.List;
+import java.util.Objects;
+import java.util.concurrent.Executor;
 
 /**
- * An observer / callback to create and register by
- * {@link ActivityManager#registerHomeVisibilityObserver} so that it's triggered when
- * visibility of home page changes.
- * TODO: b/144351078 expose as SystemApi
+ * A listener that will be invoked when the visibility of the home screen changes.
+ * Register this callback via {@link ActivityManager#addHomeVisibilityListener}
  * @hide
  */
-public abstract class HomeVisibilityObserver {
+// This is a single-method listener that needs a bunch of supporting code, so it can't be an
+// interface
+@SuppressLint("ListenerInterface")
+@SystemApi(client = SystemApi.Client.MODULE_LIBRARIES)
+@TestApi
+public abstract class HomeVisibilityListener {
     private Context mContext;
     private ActivityManager mActivityManager;
+    private Executor mExecutor;
     /** @hide */
-    IProcessObserver.Stub mObserver;
+    android.app.IProcessObserver.Stub mObserver;
     /** @hide */
     boolean mIsHomeActivityVisible;
 
     /** @hide */
-    void init(Context context, ActivityManager activityManager) {
+    void init(Context context, Executor executor, ActivityManager activityManager) {
         mContext = context;
         mActivityManager = activityManager;
         mIsHomeActivityVisible = isHomeActivityVisible();
+        mExecutor = executor;
     }
 
     /**
-     * The API that needs implemented and will be triggered when activity on home page changes.
+     * Called when the visibility of the home screen changes.
+     *
+     * @param isHomeActivityVisible Whether the home screen activity is now visible.
      */
     public abstract void onHomeVisibilityChanged(boolean isHomeActivityVisible);
 
-    public HomeVisibilityObserver() {
-        mObserver = new IProcessObserver.Stub() {
+    public HomeVisibilityListener() {
+        mObserver = new android.app.IProcessObserver.Stub() {
             @Override
             public void onForegroundActivitiesChanged(int pid, int uid, boolean fg) {
-                boolean isHomeActivityVisible = isHomeActivityVisible();
-                if (mIsHomeActivityVisible != isHomeActivityVisible) {
-                    mIsHomeActivityVisible = isHomeActivityVisible;
-                    onHomeVisibilityChanged(mIsHomeActivityVisible);
-                }
+                refreshHomeVisibility();
             }
 
             @Override
@@ -67,6 +74,17 @@ public abstract class HomeVisibilityObserver {
 
             @Override
             public void onProcessDied(int pid, int uid) {
+                refreshHomeVisibility();
+            }
+
+            private void refreshHomeVisibility() {
+                boolean isHomeActivityVisible = isHomeActivityVisible();
+                if (mIsHomeActivityVisible != isHomeActivityVisible) {
+                    mIsHomeActivityVisible = isHomeActivityVisible;
+                    Binder.withCleanCallingIdentity(() ->
+                            mExecutor.execute(() ->
+                                    onHomeVisibilityChanged(mIsHomeActivityVisible)));
+                }
             }
         };
     }
@@ -83,12 +101,9 @@ public abstract class HomeVisibilityObserver {
         }
 
         // We can assume that the screen is idle if the home application is in the foreground.
-        final Intent intent = new Intent(Intent.ACTION_MAIN, null);
-        intent.addCategory(Intent.CATEGORY_HOME);
-
-        ResolveInfo info = mContext.getPackageManager().resolveActivity(intent,
-                PackageManager.MATCH_DEFAULT_ONLY);
-        if (info != null && top.equals(info.activityInfo.packageName)) {
+        String defaultHomePackage = mContext.getPackageManager()
+                .getHomeActivities(new ArrayList<>()).getPackageName();
+        if (Objects.equals(top, defaultHomePackage)) {
             return true;
         }
 
diff --git a/non-updatable-api/module-lib-current.txt b/non-updatable-api/module-lib-current.txt
index b19ce4886589..e135a3b734cf 100644
--- a/non-updatable-api/module-lib-current.txt
+++ b/non-updatable-api/module-lib-current.txt
@@ -1,10 +1,20 @@
 // Signature format: 2.0
 package android.app {
 
+  public class ActivityManager {
+    method @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER) public void addHomeVisibilityListener(@NonNull java.util.concurrent.Executor, @NonNull android.app.HomeVisibilityListener);
+    method @RequiresPermission(android.Manifest.permission.SET_ACTIVITY_WATCHER) public void removeHomeVisibilityListener(@NonNull android.app.HomeVisibilityListener);
+  }
+
   public class AppOpsManager {
     field public static final String OPSTR_NO_ISOLATED_STORAGE = "android:no_isolated_storage";
   }
 
+  public abstract class HomeVisibilityListener {
+    ctor public HomeVisibilityListener();
+    method public abstract void onHomeVisibilityChanged(boolean);
+  }
+
   public class NotificationManager {
     method public boolean hasEnabledNotificationListener(@NonNull String, @NonNull android.os.UserHandle);
     field public static final String ACTION_NOTIFICATION_LISTENER_ENABLED_CHANGED = "android.app.action.NOTIFICATION_LISTENER_ENABLED_CHANGED";