| /* |
| * 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.media.session.MediaController.PlaybackInfo; |
| import android.media.session.MediaSession; |
| import android.media.session.PlaybackState; |
| import android.os.Debug; |
| import android.os.UserHandle; |
| import android.util.IntArray; |
| import android.util.Log; |
| import android.util.SparseArray; |
| |
| import java.io.PrintWriter; |
| import java.util.ArrayList; |
| import java.util.List; |
| |
| /** |
| * Keeps track of media sessions and their priority for notifications, media |
| * button dispatch, etc. |
| * <p>This class isn't thread-safe. The caller should take care of the synchronization. |
| */ |
| class MediaSessionStack { |
| private static final boolean DEBUG = MediaSessionService.DEBUG; |
| private static final String TAG = "MediaSessionStack"; |
| |
| /** |
| * Listen the change in the media button session. |
| */ |
| interface OnMediaButtonSessionChangedListener { |
| /** |
| * Called when the media button session is changed. |
| */ |
| void onMediaButtonSessionChanged(MediaSessionRecord oldMediaButtonSession, |
| MediaSessionRecord newMediaButtonSession); |
| } |
| |
| /** |
| * These are states that usually indicate the user took an action and should |
| * bump priority regardless of the old state. |
| */ |
| private static final int[] ALWAYS_PRIORITY_STATES = { |
| PlaybackState.STATE_FAST_FORWARDING, |
| PlaybackState.STATE_REWINDING, |
| PlaybackState.STATE_SKIPPING_TO_PREVIOUS, |
| PlaybackState.STATE_SKIPPING_TO_NEXT }; |
| /** |
| * These are states that usually indicate the user took an action if they |
| * were entered from a non-priority state. |
| */ |
| private static final int[] TRANSITION_PRIORITY_STATES = { |
| PlaybackState.STATE_BUFFERING, |
| PlaybackState.STATE_CONNECTING, |
| PlaybackState.STATE_PLAYING }; |
| |
| /** |
| * Sorted list of the media sessions. |
| * The session of which PlaybackState is changed to ALWAYS_PRIORITY_STATES or |
| * TRANSITION_PRIORITY_STATES comes first. |
| * @see #shouldUpdatePriority |
| */ |
| private final List<MediaSessionRecord> mSessions = new ArrayList<MediaSessionRecord>(); |
| |
| private final AudioPlayerStateMonitor mAudioPlayerStateMonitor; |
| private final OnMediaButtonSessionChangedListener mOnMediaButtonSessionChangedListener; |
| |
| /** |
| * The media button session which receives media key events. |
| * It could be null if the previous media buttion session is released. |
| */ |
| private MediaSessionRecord mMediaButtonSession; |
| |
| private MediaSessionRecord mCachedVolumeDefault; |
| |
| /** |
| * Cache the result of the {@link #getActiveSessions} per user. |
| */ |
| private final SparseArray<ArrayList<MediaSessionRecord>> mCachedActiveLists = |
| new SparseArray<>(); |
| |
| MediaSessionStack(AudioPlayerStateMonitor monitor, OnMediaButtonSessionChangedListener listener) { |
| mAudioPlayerStateMonitor = monitor; |
| mOnMediaButtonSessionChangedListener = listener; |
| } |
| |
| /** |
| * Add a record to the priority tracker. |
| * |
| * @param record The record to add. |
| */ |
| public void addSession(MediaSessionRecord record) { |
| mSessions.add(record); |
| clearCache(record.getUserId()); |
| |
| // Update the media button session. |
| // The added session could be the session from the package with the audio playback. |
| // This can happen if an app starts audio playback before creating media session. |
| updateMediaButtonSessionIfNeeded(); |
| } |
| |
| /** |
| * Remove a record from the priority tracker. |
| * |
| * @param record The record to remove. |
| */ |
| public void removeSession(MediaSessionRecord record) { |
| mSessions.remove(record); |
| if (mMediaButtonSession == record) { |
| // When the media button session is removed, nullify the media button session and do not |
| // search for the alternative media session within the app. It's because the alternative |
| // media session might be a dummy which isn't able to handle the media key events. |
| updateMediaButtonSession(null); |
| } |
| clearCache(record.getUserId()); |
| } |
| |
| /** |
| * Return if the record exists in the priority tracker. |
| */ |
| public boolean contains(MediaSessionRecord record) { |
| return mSessions.contains(record); |
| } |
| |
| /** |
| * Notify the priority tracker that a session's playback state changed. |
| * |
| * @param record The record that changed. |
| * @param oldState Its old playback state. |
| * @param newState Its new playback state. |
| */ |
| public void onPlaystateChanged(MediaSessionRecord record, int oldState, int newState) { |
| if (shouldUpdatePriority(oldState, newState)) { |
| mSessions.remove(record); |
| mSessions.add(0, record); |
| clearCache(record.getUserId()); |
| } else if (!MediaSession.isActiveState(newState)) { |
| // Just clear the volume cache when a state goes inactive |
| mCachedVolumeDefault = null; |
| } |
| |
| // In most cases, playback state isn't needed for finding media button session, |
| // but we only use it as a hint if an app has multiple local media sessions. |
| // In that case, we pick the media session whose PlaybackState matches |
| // the audio playback configuration. |
| if (mMediaButtonSession != null && mMediaButtonSession.getUid() == record.getUid()) { |
| MediaSessionRecord newMediaButtonSession = |
| findMediaButtonSession(mMediaButtonSession.getUid()); |
| if (newMediaButtonSession != mMediaButtonSession) { |
| updateMediaButtonSession(newMediaButtonSession); |
| } |
| } |
| } |
| |
| /** |
| * Handle the change in activeness for a session. |
| * |
| * @param record The record that changed. |
| */ |
| public void onSessionStateChange(MediaSessionRecord record) { |
| // For now just clear the cache. Eventually we'll selectively clear |
| // depending on what changed. |
| clearCache(record.getUserId()); |
| } |
| |
| /** |
| * Update the media button session if needed. |
| * <p>The media button session is the session that will receive the media button events. |
| * <p>We send the media button events to the lastly played app. If the app has the media |
| * session, the session will receive the media button events. |
| */ |
| public void updateMediaButtonSessionIfNeeded() { |
| if (DEBUG) { |
| Log.d(TAG, "updateMediaButtonSessionIfNeeded, callers=" + Debug.getCallers(2)); |
| } |
| IntArray audioPlaybackUids = mAudioPlayerStateMonitor.getSortedAudioPlaybackClientUids(); |
| for (int i = 0; i < audioPlaybackUids.size(); i++) { |
| MediaSessionRecord mediaButtonSession = |
| findMediaButtonSession(audioPlaybackUids.get(i)); |
| if (mediaButtonSession != null) { |
| // Found the media button session. |
| mAudioPlayerStateMonitor.cleanUpAudioPlaybackUids(mediaButtonSession.getUid()); |
| if (mMediaButtonSession != mediaButtonSession) { |
| updateMediaButtonSession(mediaButtonSession); |
| } |
| return; |
| } |
| } |
| } |
| |
| /** |
| * Find the media button session with the given {@param uid}. |
| * If the app has multiple media sessions, the media session whose playback state is not null |
| * and matches the audio playback state becomes the media button session. Otherwise the top |
| * priority session becomes the media button session. |
| * |
| * @return The media button session. Returns {@code null} if the app doesn't have a media |
| * session. |
| */ |
| private MediaSessionRecord findMediaButtonSession(int uid) { |
| MediaSessionRecord mediaButtonSession = null; |
| for (MediaSessionRecord session : mSessions) { |
| if (uid == session.getUid()) { |
| if (session.getPlaybackState() != null && session.isPlaybackActive() == |
| mAudioPlayerStateMonitor.isPlaybackActive(session.getUid())) { |
| // If there's a media session whose PlaybackState matches |
| // the audio playback state, return it immediately. |
| return session; |
| } |
| if (mediaButtonSession == null) { |
| // Among the media sessions whose PlaybackState doesn't match |
| // the audio playback state, pick the top priority. |
| mediaButtonSession = session; |
| } |
| } |
| } |
| return mediaButtonSession; |
| } |
| |
| /** |
| * Get the current priority sorted list of active sessions. The most |
| * important session is at index 0 and the least important at size - 1. |
| * |
| * @param userId The user to check. It can be {@link UserHandle#USER_ALL} to get all sessions |
| * for all users in this {@link MediaSessionStack}. |
| * @return All the active sessions in priority order. |
| */ |
| public ArrayList<MediaSessionRecord> getActiveSessions(int userId) { |
| ArrayList<MediaSessionRecord> cachedActiveList = mCachedActiveLists.get(userId); |
| if (cachedActiveList == null) { |
| cachedActiveList = getPriorityList(true, userId); |
| mCachedActiveLists.put(userId, cachedActiveList); |
| } |
| return cachedActiveList; |
| } |
| |
| /** |
| * Get the media button session which receives the media button events. |
| * |
| * @return The media button session or null. |
| */ |
| public MediaSessionRecord getMediaButtonSession() { |
| return mMediaButtonSession; |
| } |
| |
| private void updateMediaButtonSession(MediaSessionRecord newMediaButtonSession) { |
| MediaSessionRecord oldMediaButtonSession = mMediaButtonSession; |
| mMediaButtonSession = newMediaButtonSession; |
| mOnMediaButtonSessionChangedListener.onMediaButtonSessionChanged( |
| oldMediaButtonSession, newMediaButtonSession); |
| } |
| |
| public MediaSessionRecord getDefaultVolumeSession() { |
| if (mCachedVolumeDefault != null) { |
| return mCachedVolumeDefault; |
| } |
| ArrayList<MediaSessionRecord> records = getPriorityList(true, UserHandle.USER_ALL); |
| int size = records.size(); |
| for (int i = 0; i < size; i++) { |
| MediaSessionRecord record = records.get(i); |
| if (record.isPlaybackActive()) { |
| mCachedVolumeDefault = record; |
| return record; |
| } |
| } |
| return null; |
| } |
| |
| public MediaSessionRecord getDefaultRemoteSession(int userId) { |
| ArrayList<MediaSessionRecord> records = getPriorityList(true, userId); |
| |
| int size = records.size(); |
| for (int i = 0; i < size; i++) { |
| MediaSessionRecord record = records.get(i); |
| if (record.getPlaybackType() == PlaybackInfo.PLAYBACK_TYPE_REMOTE) { |
| return record; |
| } |
| } |
| return null; |
| } |
| |
| public void dump(PrintWriter pw, String prefix) { |
| ArrayList<MediaSessionRecord> sortedSessions = getPriorityList(false, |
| UserHandle.USER_ALL); |
| int count = sortedSessions.size(); |
| pw.println(prefix + "Media button session is " + mMediaButtonSession); |
| pw.println(prefix + "Sessions Stack - have " + count + " sessions:"); |
| String indent = prefix + " "; |
| for (int i = 0; i < count; i++) { |
| MediaSessionRecord record = sortedSessions.get(i); |
| record.dump(pw, indent); |
| pw.println(); |
| } |
| } |
| |
| /** |
| * Get a priority sorted list of sessions. Can filter to only return active |
| * sessions or sessions. |
| * <p>Here's the priority order. |
| * <li>Active sessions whose PlaybackState is active</li> |
| * <li>Active sessions whose PlaybackState is inactive</li> |
| * <li>Inactive sessions</li> |
| * |
| * @param activeOnly True to only return active sessions, false to return |
| * all sessions. |
| * @param userId The user to get sessions for. {@link UserHandle#USER_ALL} |
| * will return sessions for all users. |
| * @return The priority sorted list of sessions. |
| */ |
| public ArrayList<MediaSessionRecord> getPriorityList(boolean activeOnly, int userId) { |
| ArrayList<MediaSessionRecord> result = new ArrayList<MediaSessionRecord>(); |
| int lastPlaybackActiveIndex = 0; |
| int lastActiveIndex = 0; |
| |
| int size = mSessions.size(); |
| for (int i = 0; i < size; i++) { |
| final MediaSessionRecord session = mSessions.get(i); |
| |
| if (userId != UserHandle.USER_ALL && userId != session.getUserId()) { |
| // Filter out sessions for the wrong user |
| continue; |
| } |
| |
| if (!session.isActive()) { |
| if (!activeOnly) { |
| // If we're getting unpublished as well always put them at |
| // the end |
| result.add(session); |
| } |
| continue; |
| } |
| |
| if (session.isPlaybackActive()) { |
| result.add(lastPlaybackActiveIndex++, session); |
| lastActiveIndex++; |
| } else { |
| result.add(lastActiveIndex++, session); |
| } |
| } |
| |
| return result; |
| } |
| |
| private boolean shouldUpdatePriority(int oldState, int newState) { |
| if (containsState(newState, ALWAYS_PRIORITY_STATES)) { |
| return true; |
| } |
| if (!containsState(oldState, TRANSITION_PRIORITY_STATES) |
| && containsState(newState, TRANSITION_PRIORITY_STATES)) { |
| return true; |
| } |
| return false; |
| } |
| |
| private boolean containsState(int state, int[] states) { |
| for (int i = 0; i < states.length; i++) { |
| if (states[i] == state) { |
| return true; |
| } |
| } |
| return false; |
| } |
| |
| private void clearCache(int userId) { |
| mCachedVolumeDefault = null; |
| mCachedActiveLists.remove(userId); |
| // mCachedActiveLists may also include the list of sessions for UserHandle.USER_ALL, |
| // so they also need to be cleared. |
| mCachedActiveLists.remove(UserHandle.USER_ALL); |
| } |
| } |