Move media key processing to sessions

Send all media key events over to the MediaSessionService instead
of AudioManager. This does not affect volume handling yet, so it
is possible to get into a state where volume will be handled by
a different thing than media buttons. Except for corner cases
this shouldn't be noticable.

Change-Id: I00a576175d9c82937f0836e509b9a98d5cb77b83

2 files changed, 105 insertions, 7 deletions

diff --git a/services/core/java/com/android/server/media/MediaSessionRecord.java b/services/core/java/com/android/server/media/MediaSessionRecord.java
index 9677577..f6be1ff 100644
--- a/services/core/java/com/android/server/media/MediaSessionRecord.java
+++ b/services/core/java/com/android/server/media/MediaSessionRecord.java
@@ -365,6 +365,10 @@ public class MediaSessionRecord implements IBinder.DeathRecipient {
         return mSessionCb.mCb;
     }
 
+    public void sendMediaButton(KeyEvent ke, ResultReceiver cb) {
+        mSessionCb.sendMediaButton(ke, cb);
+    }
+
     public void dump(PrintWriter pw, String prefix) {
         pw.println(prefix + mTag + " " + this);
 
@@ -645,11 +649,11 @@ public class MediaSessionRecord implements IBinder.DeathRecipient {
             mCb = cb;
         }
 
-        public void sendMediaButton(KeyEvent keyEvent) {
+        public void sendMediaButton(KeyEvent keyEvent, ResultReceiver cb) {
             Intent mediaButtonIntent = new Intent(Intent.ACTION_MEDIA_BUTTON);
             mediaButtonIntent.putExtra(Intent.EXTRA_KEY_EVENT, keyEvent);
             try {
-                mCb.onMediaButton(mediaButtonIntent);
+                mCb.onMediaButton(mediaButtonIntent, cb);
             } catch (RemoteException e) {
                 Slog.e(TAG, "Remote failure in sendMediaRequest.", e);
             }
@@ -785,7 +789,7 @@ public class MediaSessionRecord implements IBinder.DeathRecipient {
 
         @Override
         public void sendMediaButton(KeyEvent mediaButtonIntent) {
-            mSessionCb.sendMediaButton(mediaButtonIntent);
+            mSessionCb.sendMediaButton(mediaButtonIntent, null);
         }
 
         @Override
diff --git a/services/core/java/com/android/server/media/MediaSessionService.java b/services/core/java/com/android/server/media/MediaSessionService.java
index 78f3b5f..a2ca2a1 100644
--- a/services/core/java/com/android/server/media/MediaSessionService.java
+++ b/services/core/java/com/android/server/media/MediaSessionService.java
@@ -17,9 +17,12 @@
 package com.android.server.media;
 
 import android.Manifest;
+import android.app.Activity;
 import android.app.ActivityManager;
+import android.content.BroadcastReceiver;
 import android.content.ComponentName;
 import android.content.Context;
+import android.content.Intent;
 import android.content.pm.PackageManager;
 import android.media.routeprovider.RouteRequest;
 import android.media.session.ISession;
@@ -29,14 +32,18 @@ import android.media.session.RouteInfo;
 import android.media.session.RouteOptions;
 import android.media.session.Session;
 import android.os.Binder;
+import android.os.Bundle;
 import android.os.Handler;
 import android.os.IBinder;
+import android.os.PowerManager;
 import android.os.RemoteException;
+import android.os.ResultReceiver;
 import android.os.UserHandle;
 import android.provider.Settings;
 import android.text.TextUtils;
 import android.util.Log;
 import android.util.SparseArray;
+import android.view.KeyEvent;
 
 import com.android.server.SystemService;
 import com.android.server.Watchdog;
@@ -64,6 +71,7 @@ public class MediaSessionService extends SystemService implements Monitor {
     // = new ArrayList<MediaRouteProviderProxy>();
     private final Object mLock = new Object();
     private final Handler mHandler = new Handler();
+    private final PowerManager.WakeLock mMediaEventWakeLock;
 
     private MediaSessionRecord mPrioritySession;
     private int mCurrentUserId = -1;
@@ -79,6 +87,8 @@ public class MediaSessionService extends SystemService implements Monitor {
         super(context);
         mSessionManagerImpl = new SessionManagerImpl();
         mPriorityStack = new MediaSessionStack();
+        PowerManager pm = (PowerManager) context.getSystemService(Context.POWER_SERVICE);
+        mMediaEventWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "handleMediaEvent");
     }
 
     @Override
@@ -377,7 +387,7 @@ public class MediaSessionService extends SystemService implements Monitor {
 
     /*
      * When a session is created the following things need to happen.
-     * 1. It's callback binder needs a link to death
+     * 1. Its callback binder needs a link to death
      * 2. It needs to be added to all sessions.
      * 3. It needs to be added to the priority stack.
      * 4. It needs to be added to the relevant user record.
@@ -585,9 +595,10 @@ public class MediaSessionService extends SystemService implements Monitor {
     }
 
     class SessionManagerImpl extends ISessionManager.Stub {
-        // TODO add createSessionAsUser, pass user-id to
-        // ActivityManagerNative.handleIncomingUser and stash result for use
-        // when starting services on that session's behalf.
+        private static final String EXTRA_WAKELOCK_ACQUIRED =
+                "android.media.AudioService.WAKELOCK_ACQUIRED";
+        private static final int WAKELOCK_RELEASE_ON_FINISHED = 1980; // magic number
+
         @Override
         public ISession createSession(String packageName, ISessionCallback cb, String tag,
                 int userId) throws RemoteException {
@@ -644,6 +655,59 @@ public class MediaSessionService extends SystemService implements Monitor {
             }
         }
 
+        /**
+         * Handles the dispatching of the media button events to one of the
+         * registered listeners, or if there was none, broadcast an
+         * ACTION_MEDIA_BUTTON intent to the rest of the system.
+         *
+         * @param keyEvent a non-null KeyEvent whose key code is one of the
+         *            supported media buttons
+         * @param needWakeLock true if a PARTIAL_WAKE_LOCK needs to be held
+         *            while this key event is dispatched.
+         */
+        @Override
+        public void dispatchMediaKeyEvent(KeyEvent keyEvent, boolean needWakeLock) {
+            if (keyEvent == null || !KeyEvent.isMediaKey(keyEvent.getKeyCode())) {
+                Log.w(TAG, "Attempted to dispatch null or non-media key event.");
+                return;
+            }
+            final int pid = Binder.getCallingPid();
+            final int uid = Binder.getCallingUid();
+            final long token = Binder.clearCallingIdentity();
+
+            try {
+                if (needWakeLock) {
+                    mMediaEventWakeLock.acquire();
+                }
+                synchronized (mLock) {
+                    MediaSessionRecord mbSession = mPriorityStack
+                            .getDefaultMediaButtonSession(mCurrentUserId);
+                    if (mbSession != null) {
+                        if (DEBUG) {
+                            Log.d(TAG, "Sending media key to " + mbSession.getSessionInfo());
+                        }
+                        mbSession.sendMediaButton(keyEvent,
+                                needWakeLock ? mKeyEventDoneReceiver : null);
+                    } else {
+                        if (DEBUG) {
+                            Log.d(TAG, "Sending media key ordered broadcast");
+                        }
+                        // Fallback to legacy behavior
+                        Intent keyIntent = new Intent(Intent.ACTION_MEDIA_BUTTON, null);
+                        keyIntent.putExtra(Intent.EXTRA_KEY_EVENT, keyEvent);
+                        if (needWakeLock) {
+                            keyIntent.putExtra(EXTRA_WAKELOCK_ACQUIRED,
+                                    WAKELOCK_RELEASE_ON_FINISHED);
+                        }
+                        getContext().sendOrderedBroadcastAsUser(keyIntent, UserHandle.ALL,
+                                null, mKeyEventDone, mHandler, Activity.RESULT_OK, null, null);
+                    }
+                }
+            } finally {
+                Binder.restoreCallingIdentity(token);
+            }
+        }
+
         @Override
         public void dump(FileDescriptor fd, final PrintWriter pw, String[] args) {
             if (getContext().checkCallingOrSelfPermission(Manifest.permission.DUMP)
@@ -678,6 +742,36 @@ public class MediaSessionService extends SystemService implements Monitor {
                 }
             }
         }
+
+        ResultReceiver mKeyEventDoneReceiver = new ResultReceiver(mHandler) {
+            @Override
+            protected void onReceiveResult(int resultCode, Bundle resultData) {
+                synchronized (mLock) {
+                    if (mMediaEventWakeLock.isHeld()) {
+                        mMediaEventWakeLock.release();
+                    }
+                }
+            }
+        };
+
+        BroadcastReceiver mKeyEventDone = new BroadcastReceiver() {
+            @Override
+            public void onReceive(Context context, Intent intent) {
+                if (intent == null) {
+                    return;
+                }
+                Bundle extras = intent.getExtras();
+                if (extras == null) {
+                    return;
+                }
+                synchronized (mLock) {
+                    if (extras.containsKey(EXTRA_WAKELOCK_ACQUIRED)
+                            && mMediaEventWakeLock.isHeld()) {
+                        mMediaEventWakeLock.release();
+                    }
+                }
+            }
+        };
     }
 
 }