Media: Add MSM#getMediaKeyEventSession

Add MediaSessionManager#getMediaKeyEventSession
for system apps to get the current media key event session,
which may be different from the first session in
MediaSessionManager#getActiveSessions().

Bug: 181383356
Test: atest MediaSessionManagerTest
Change-Id: I56ece75e352150693a5658e2660f39b5702d8612

core/api/system-current.txt

@@ -5433,6 +5433,8 @@ package android.media.session {
   public final class MediaSessionManager {
     method @RequiresPermission(android.Manifest.permission.MEDIA_CONTENT_CONTROL) public void addOnMediaKeyEventDispatchedListener(@NonNull java.util.concurrent.Executor, @NonNull android.media.session.MediaSessionManager.OnMediaKeyEventDispatchedListener);
     method @RequiresPermission(android.Manifest.permission.MEDIA_CONTENT_CONTROL) public void addOnMediaKeyEventSessionChangedListener(@NonNull java.util.concurrent.Executor, @NonNull android.media.session.MediaSessionManager.OnMediaKeyEventSessionChangedListener);
+    method @Nullable @RequiresPermission(android.Manifest.permission.MEDIA_CONTENT_CONTROL) public android.media.session.MediaSession.Token getMediaKeyEventSession();
+    method @NonNull @RequiresPermission(android.Manifest.permission.MEDIA_CONTENT_CONTROL) public String getMediaKeyEventSessionPackageName();
     method @RequiresPermission(android.Manifest.permission.MEDIA_CONTENT_CONTROL) public void removeOnMediaKeyEventDispatchedListener(@NonNull android.media.session.MediaSessionManager.OnMediaKeyEventDispatchedListener);
     method @RequiresPermission(android.Manifest.permission.MEDIA_CONTENT_CONTROL) public void removeOnMediaKeyEventSessionChangedListener(@NonNull android.media.session.MediaSessionManager.OnMediaKeyEventSessionChangedListener);
     method @RequiresPermission(android.Manifest.permission.SET_MEDIA_KEY_LISTENER) public void setOnMediaKeyListener(android.media.session.MediaSessionManager.OnMediaKeyListener, @Nullable android.os.Handler);

media/java/android/media/session/ISessionManager.aidl

@@ -39,6 +39,8 @@ interface ISessionManager {
     ISession createSession(String packageName, in ISessionCallback sessionCb, String tag,
             in Bundle sessionInfo, int userId);
     List<MediaSession.Token> getSessions(in ComponentName compName, int userId);
+    MediaSession.Token getMediaKeyEventSession();
+    String getMediaKeyEventSessionPackageName();
     void dispatchMediaKeyEvent(String packageName, boolean asSystemService, in KeyEvent keyEvent,
             boolean needWakeLock);
     boolean dispatchMediaKeyEventToSessionAsSystemService(String packageName,

media/java/android/media/session/MediaSessionManager.java

@@ -194,6 +194,44 @@ public final class MediaSessionManager {
         return getActiveSessionsForUser(notificationListener, UserHandle.myUserId());
     }
 
+    /**
+     * Gets the media key event session, which would receive a media key event unless specified.
+     * @return The media key event session, which would receive key events by default, unless
+     *          the caller has specified the target. Can be {@code null}.
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(value = android.Manifest.permission.MEDIA_CONTENT_CONTROL)
+    @Nullable
+    public MediaSession.Token getMediaKeyEventSession() {
+        try {
+            return mService.getMediaKeyEventSession();
+        } catch (RemoteException ex) {
+            Log.e(TAG, "Failed to get media key event session", ex);
+        }
+        return null;
+    }
+
+    /**
+     * Gets the package name of the media key event session.
+     * @return The package name of the media key event session or the last session's media button
+     *          receiver if the media key event session is {@code null}.
+     * @see #getMediaKeyEventSession()
+     * @hide
+     */
+    @SystemApi
+    @RequiresPermission(value = android.Manifest.permission.MEDIA_CONTENT_CONTROL)
+    @NonNull
+    public String getMediaKeyEventSessionPackageName() {
+        try {
+            String packageName = mService.getMediaKeyEventSessionPackageName();
+            return (packageName != null) ? packageName : "";
+        } catch (RemoteException ex) {
+            Log.e(TAG, "Failed to get media key event session", ex);
+        }
+        return "";
+    }
+
     /**
      * Get active sessions for the given user.
      * <p>
@@ -856,7 +894,7 @@ public final class MediaSessionManager {
     }
 
     /**
-     * Add a {@link OnMediaKeyEventDispatchedListener}.
+     * Add a {@link OnMediaKeyEventSessionChangedListener}.
      *
      * @param executor The executor on which the listener should be invoked
      * @param listener A {@link OnMediaKeyEventSessionChangedListener}.

services/core/java/com/android/server/media/MediaSessionService.java

@@ -1224,6 +1224,70 @@ public class MediaSessionService extends SystemService implements Monitor {
             }
         }
 
+        @Override
+        public MediaSession.Token getMediaKeyEventSession() {
+            final int pid = Binder.getCallingPid();
+            final int uid = Binder.getCallingUid();
+            final int userId = UserHandle.getUserHandleForUid(uid).getIdentifier();
+            final long token = Binder.clearCallingIdentity();
+            try {
+                if (!hasMediaControlPermission(pid, uid)) {
+                    throw new SecurityException("MEDIA_CONTENT_CONTROL permission is required to"
+                            + " get the media key event session");
+                }
+                MediaSessionRecordImpl record;
+                synchronized (mLock) {
+                    FullUserRecord user = getFullUserRecordLocked(userId);
+                    if (user == null) {
+                        Log.w(TAG, "No matching user record to get the media key event session"
+                                + ", userId=" + userId);
+                        return null;
+                    }
+                    record = user.getMediaButtonSessionLocked();
+                }
+                if (record instanceof MediaSessionRecord) {
+                    return ((MediaSessionRecord) record).getSessionToken();
+                }
+                //TODO: Handle media session 2 case
+                return null;
+            } finally {
+                Binder.restoreCallingIdentity(token);
+            }
+        }
+
+        @Override
+        public String getMediaKeyEventSessionPackageName() {
+            final int pid = Binder.getCallingPid();
+            final int uid = Binder.getCallingUid();
+            final int userId = UserHandle.getUserHandleForUid(uid).getIdentifier();
+            final long token = Binder.clearCallingIdentity();
+            try {
+                if (!hasMediaControlPermission(pid, uid)) {
+                    throw new SecurityException("MEDIA_CONTENT_CONTROL permission is required to"
+                            + " get the media key event session package");
+                }
+                MediaSessionRecordImpl record;
+                synchronized (mLock) {
+                    FullUserRecord user = getFullUserRecordLocked(userId);
+                    if (user == null) {
+                        Log.w(TAG, "No matching user record to get the media key event session"
+                                + " package , userId=" + userId);
+                        return "";
+                    }
+                    record = user.getMediaButtonSessionLocked();
+                    if (record instanceof MediaSessionRecord) {
+                        return record.getPackageName();
+                    //TODO: Handle media session 2 case
+                    } else if (user.mLastMediaButtonReceiverHolder != null) {
+                        return user.mLastMediaButtonReceiverHolder.getPackageName();
+                    }
+                }
+                return "";
+            } finally {
+                Binder.restoreCallingIdentity(token);
+            }
+        }
+
         @Override
         public void addSessionsListener(IActiveSessionsListener listener,
                 ComponentName componentName, int userId) throws RemoteException {