Initial round of MediaSession APIs
This is far from complete but puts the basic components in place
for an app to interact with media sessions.
Change-Id: Icfe313f90ad76ae56badbe42b0e43fc5f68db36f
diff --git a/services/core/java/com/android/server/media/MediaSessionService.java b/services/core/java/com/android/server/media/MediaSessionService.java
new file mode 100644
index 0000000..9c96c35
--- /dev/null
+++ b/services/core/java/com/android/server/media/MediaSessionService.java
@@ -0,0 +1,128 @@
+/*
+ * Copyright (C) 2014 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.android.server.media;
+
+import android.content.Context;
+import android.media.IMediaSession;
+import android.media.IMediaSessionCallback;
+import android.media.IMediaSessionManager;
+import android.os.Binder;
+import android.os.RemoteException;
+import android.text.TextUtils;
+import android.util.Log;
+
+import com.android.server.SystemService;
+
+import java.util.ArrayList;
+
+/**
+ * System implementation of MediaSessionManager
+ */
+public class MediaSessionService extends SystemService {
+ private static final String TAG = "MediaSessionService";
+ private static final boolean DEBUG = Log.isLoggable(TAG, Log.DEBUG);
+
+ private final SessionManagerImpl mSessionManagerImpl;
+
+ private final ArrayList<MediaSessionRecord> mSessions
+ = new ArrayList<MediaSessionRecord>();
+ private final Object mLock = new Object();
+
+ public MediaSessionService(Context context) {
+ super(context);
+ mSessionManagerImpl = new SessionManagerImpl();
+ }
+
+ @Override
+ public void onStart() {
+ publishBinderService(Context.MEDIA_SESSION_SERVICE, mSessionManagerImpl);
+ }
+
+ void sessionDied(MediaSessionRecord session) {
+ synchronized (mSessions) {
+ destroySessionLocked(session);
+ }
+ }
+
+ void destroySession(MediaSessionRecord session) {
+ synchronized (mSessions) {
+ destroySessionLocked(session);
+ }
+ }
+
+ private void destroySessionLocked(MediaSessionRecord session) {
+ mSessions.remove(session);
+ }
+
+ private void enforcePackageName(String packageName, int uid) {
+ if (TextUtils.isEmpty(packageName)) {
+ throw new IllegalArgumentException("packageName may not be empty");
+ }
+ String[] packages = getContext().getPackageManager().getPackagesForUid(uid);
+ final int packageCount = packages.length;
+ for (int i = 0; i < packageCount; i++) {
+ if (packageName.equals(packages[i])) {
+ return;
+ }
+ }
+ throw new IllegalArgumentException("packageName is not owned by the calling process");
+ }
+
+ private MediaSessionRecord createSessionInternal(int pid, String packageName,
+ IMediaSessionCallback cb, String tag) {
+ synchronized (mLock) {
+ return createSessionLocked(pid, packageName, cb, tag);
+ }
+ }
+
+ private MediaSessionRecord createSessionLocked(int pid, String packageName,
+ IMediaSessionCallback cb, String tag) {
+ final MediaSessionRecord session = new MediaSessionRecord(pid, packageName, cb, tag, this);
+ try {
+ cb.asBinder().linkToDeath(session, 0);
+ } catch (RemoteException e) {
+ throw new RuntimeException("Media Session owner died prematurely.", e);
+ }
+ synchronized (mSessions) {
+ mSessions.add(session);
+ }
+ if (DEBUG) {
+ Log.d(TAG, "Created session for package " + packageName + " with tag " + tag);
+ }
+ return session;
+ }
+
+ class SessionManagerImpl extends IMediaSessionManager.Stub {
+ @Override
+ public IMediaSession createSession(String packageName, IMediaSessionCallback cb, String tag)
+ throws RemoteException {
+ final int pid = Binder.getCallingPid();
+ final int uid = Binder.getCallingUid();
+ final long token = Binder.clearCallingIdentity();
+ try {
+ enforcePackageName(packageName, uid);
+ if (cb == null) {
+ throw new IllegalArgumentException("Controller callback cannot be null");
+ }
+ return createSessionInternal(pid, packageName, cb, tag).getSessionBinder();
+ } finally {
+ Binder.restoreCallingIdentity(token);
+ }
+ }
+ }
+
+}