| /* |
| * 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.PlaybackState; |
| import android.media.session.MediaSession; |
| import android.os.UserHandle; |
| |
| import java.io.PrintWriter; |
| import java.util.ArrayList; |
| |
| /** |
| * Keeps track of media sessions and their priority for notifications, media |
| * button routing, etc. |
| */ |
| public class MediaSessionStack { |
| /** |
| * 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 }; |
| |
| private final ArrayList<MediaSessionRecord> mSessions = new ArrayList<MediaSessionRecord>(); |
| |
| private MediaSessionRecord mGlobalPrioritySession; |
| |
| private MediaSessionRecord mCachedButtonReceiver; |
| private MediaSessionRecord mCachedDefault; |
| private ArrayList<MediaSessionRecord> mCachedActiveList; |
| private ArrayList<MediaSessionRecord> mCachedTransportControlList; |
| |
| /** |
| * Add a record to the priority tracker. |
| * |
| * @param record The record to add. |
| */ |
| public void addSession(MediaSessionRecord record) { |
| mSessions.add(record); |
| if ((record.getFlags() & MediaSession.FLAG_EXCLUSIVE_GLOBAL_PRIORITY) != 0) { |
| mGlobalPrioritySession = record; |
| } |
| clearCache(); |
| } |
| |
| /** |
| * Remove a record from the priority tracker. |
| * |
| * @param record The record to remove. |
| */ |
| public void removeSession(MediaSessionRecord record) { |
| mSessions.remove(record); |
| if (record == mGlobalPrioritySession) { |
| mGlobalPrioritySession = null; |
| } |
| clearCache(); |
| } |
| |
| /** |
| * Notify the priority tracker that a session's state changed. |
| * |
| * @param record The record that changed. |
| * @param oldState Its old playback state. |
| * @param newState Its new playback state. |
| */ |
| public void onPlaystateChange(MediaSessionRecord record, int oldState, int newState) { |
| if (shouldUpdatePriority(oldState, newState)) { |
| mSessions.remove(record); |
| mSessions.add(0, record); |
| clearCache(); |
| } |
| } |
| |
| /** |
| * Handle any stack changes that need to occur in response to a session |
| * state change. TODO add the old and new session state as params |
| * |
| * @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(); |
| } |
| |
| /** |
| * 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. |
| * @return All the active sessions in priority order. |
| */ |
| public ArrayList<MediaSessionRecord> getActiveSessions(int userId) { |
| if (mCachedActiveList == null) { |
| mCachedActiveList = getPriorityListLocked(true, 0, userId); |
| } |
| return mCachedActiveList; |
| } |
| |
| /** |
| * Get the current priority sorted list of active sessions that use |
| * transport controls. The most important session is at index 0 and the |
| * least important at size -1. |
| * |
| * @param userId The user to check. |
| * @return All the active sessions that handle transport controls in |
| * priority order. |
| */ |
| public ArrayList<MediaSessionRecord> getTransportControlSessions(int userId) { |
| if (mCachedTransportControlList == null) { |
| mCachedTransportControlList = getPriorityListLocked(true, |
| MediaSession.FLAG_HANDLES_TRANSPORT_CONTROLS, userId); |
| } |
| return mCachedTransportControlList; |
| } |
| |
| /** |
| * Get the highest priority active session. |
| * |
| * @param userId The user to check. |
| * @return The current highest priority session or null. |
| */ |
| public MediaSessionRecord getDefaultSession(int userId) { |
| if (mCachedDefault != null) { |
| return mCachedDefault; |
| } |
| ArrayList<MediaSessionRecord> records = getPriorityListLocked(true, 0, userId); |
| if (records.size() > 0) { |
| return records.get(0); |
| } |
| return null; |
| } |
| |
| /** |
| * Get the highest priority session that can handle media buttons. |
| * |
| * @param userId The user to check. |
| * @return The default media button session or null. |
| */ |
| public MediaSessionRecord getDefaultMediaButtonSession(int userId) { |
| if (mGlobalPrioritySession != null && mGlobalPrioritySession.isActive()) { |
| return mGlobalPrioritySession; |
| } |
| if (mCachedButtonReceiver != null) { |
| return mCachedButtonReceiver; |
| } |
| ArrayList<MediaSessionRecord> records = getPriorityListLocked(true, |
| MediaSession.FLAG_HANDLES_MEDIA_BUTTONS, userId); |
| if (records.size() > 0) { |
| mCachedButtonReceiver = records.get(0); |
| } |
| return mCachedButtonReceiver; |
| } |
| |
| public void dump(PrintWriter pw, String prefix) { |
| ArrayList<MediaSessionRecord> sortedSessions = getPriorityListLocked(false, 0, |
| UserHandle.USER_ALL); |
| int count = sortedSessions.size(); |
| 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 with specific flags. |
| * |
| * @param activeOnly True to only return active sessions, false to return |
| * all sessions. |
| * @param withFlags Only return sessions with all the specified flags set. 0 |
| * returns 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. |
| */ |
| private ArrayList<MediaSessionRecord> getPriorityListLocked(boolean activeOnly, int withFlags, |
| int userId) { |
| ArrayList<MediaSessionRecord> result = new ArrayList<MediaSessionRecord>(); |
| int lastLocalIndex = 0; |
| int lastActiveIndex = 0; |
| int lastPublishedIndex = 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.getFlags() & withFlags) != withFlags) { |
| // Filter out sessions with the wrong flags |
| 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.isSystemPriority()) { |
| // System priority sessions are special and always go at the |
| // front. We expect there to only be one of these at a time. |
| result.add(0, session); |
| lastLocalIndex++; |
| lastActiveIndex++; |
| lastPublishedIndex++; |
| } else if (session.isPlaybackActive()) { |
| // TODO replace getRoute() == null with real local route check |
| if(session.getRoute() == null) { |
| // Active local sessions get top priority |
| result.add(lastLocalIndex, session); |
| lastLocalIndex++; |
| lastActiveIndex++; |
| lastPublishedIndex++; |
| } else { |
| // Then active remote sessions |
| result.add(lastActiveIndex, session); |
| lastActiveIndex++; |
| lastPublishedIndex++; |
| } |
| } else { |
| // inactive sessions go at the end in order of whoever last did |
| // something. |
| result.add(lastPublishedIndex, session); |
| lastPublishedIndex++; |
| } |
| } |
| |
| 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() { |
| mCachedDefault = null; |
| mCachedButtonReceiver = null; |
| mCachedActiveList = null; |
| mCachedTransportControlList = null; |
| } |
| } |