TestMediaApp/src/com/android/car/media/testmediaapp/TmaPlayer.java - platform/packages/apps/Car/tests - Git at Google

 /*
  * Copyright 2019 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.car.media.testmediaapp;

 import static android.media.AudioManager.AUDIOFOCUS_GAIN;
 import static android.media.AudioManager.AUDIOFOCUS_REQUEST_GRANTED;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_PAUSE;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_PLAY;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_PLAY_FROM_MEDIA_ID;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SEEK_TO;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SKIP_TO_NEXT;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS;
 import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SKIP_TO_QUEUE_ITEM;
 import static android.support.v4.media.session.PlaybackStateCompat.ERROR_CODE_APP_ERROR;
 import static android.support.v4.media.session.PlaybackStateCompat.STATE_ERROR;

 import static com.android.car.media.common.MediaConstants.ERROR_RESOLUTION_ACTION_INTENT;
 import static com.android.car.media.common.MediaConstants.ERROR_RESOLUTION_ACTION_LABEL;

 import androidx.annotation.Nullable;
 import android.app.PendingIntent;
 import android.content.Context;
 import android.content.Intent;
 import android.media.AudioFocusRequest;
 import android.media.AudioManager;
 import android.os.Bundle;
 import android.os.Handler;
 import android.support.v4.media.session.MediaSessionCompat;
 import android.support.v4.media.session.PlaybackStateCompat;
 import android.util.Log;
 import android.widget.Toast;

 import com.android.car.media.testmediaapp.TmaMediaEvent.Action;
 import com.android.car.media.testmediaapp.TmaMediaEvent.EventState;
 import com.android.car.media.testmediaapp.TmaMediaEvent.ResolutionIntent;
 import com.android.car.media.testmediaapp.TmaMediaItem.TmaCustomAction;
 import com.android.car.media.testmediaapp.prefs.TmaEnumPrefs.TmaAccountType;
 import com.android.car.media.testmediaapp.prefs.TmaPrefs;
 import com.android.car.media.testmediaapp.prefs.TmaPrefsActivity;


 /**
  * This class simulates all media interactions (no sound is actually played).
  */
 public class TmaPlayer extends MediaSessionCompat.Callback {

     private static final String TAG = "TmaPlayer";

     private final Context mContext;
     private final TmaPrefs mPrefs;
     private final TmaLibrary mLibrary;
     private final AudioManager mAudioManager;
     private final Handler mHandler;
     private final Runnable mTrackTimer = this::onStop;
     private final Runnable mEventTrigger = this::onProcessMediaEvent;
     private final MediaSessionCompat mSession;
     private final AudioFocusRequest mAudioFocusRequest;

     /** Only updated when the state changes. */
     private long mCurrentPositionMs = 0;
     private float mPlaybackSpeed = 1.0f; // TODO: make variable.
     private long mPlaybackStartTimeMs;
     private boolean mIsPlaying;
     @Nullable
     private TmaMediaItem mActiveItem;
     private int mNextEventIndex = -1;


     TmaPlayer(Context context, TmaLibrary library, AudioManager audioManager, Handler handler,
             MediaSessionCompat session) {
         mContext = context;
         mPrefs = TmaPrefs.getInstance(mContext);
         mLibrary = library;
         mAudioManager = audioManager;
         mHandler = handler;
         mSession = session;

         // TODO add focus listener ?
         mAudioFocusRequest = new AudioFocusRequest.Builder(AUDIOFOCUS_GAIN).build();
     }

     /** Updates the state in the media session based on the given {@link TmaMediaEvent}. */
     void setPlaybackState(TmaMediaEvent event) {
         Log.i(TAG, "setPlaybackState " + event);

         PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
                 .setState(event.mState.mValue, mCurrentPositionMs, mPlaybackSpeed)
                 .setErrorMessage(event.mErrorCode.mValue, event.mErrorMessage)
                 .setActions(addActions(ACTION_PAUSE));
         if (ResolutionIntent.PREFS.equals(event.mResolutionIntent)) {
             Intent prefsIntent = new Intent();
             prefsIntent.setClass(mContext, TmaPrefsActivity.class);
             prefsIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
             PendingIntent pendingIntent = PendingIntent.getActivity(mContext, 0, prefsIntent, 0);

             Bundle extras = new Bundle();
             extras.putString(ERROR_RESOLUTION_ACTION_LABEL, event.mActionLabel);
             extras.putParcelable(ERROR_RESOLUTION_ACTION_INTENT, pendingIntent);
             state.setExtras(extras);
         }

         setActiveItemState(state);
         mSession.setPlaybackState(state.build());
     }

     /** Sets custom action, queue id, etc. */
     private void setActiveItemState(PlaybackStateCompat.Builder state) {
         if (mActiveItem != null) {
             for (TmaCustomAction action : mActiveItem.mCustomActions) {
                 String name = mContext.getResources().getString(action.mNameId);
                 state.addCustomAction(action.mId, name, action.mIcon);
             }
             state.setActiveQueueItemId(mActiveItem.getQueueId());
         }
     }

     private void playItem(@Nullable TmaMediaItem item) {
         if (item != null && item.getParent() != null) {
             if (mIsPlaying) {
                 stopPlayback();
             }
             mActiveItem = item;
             mSession.setQueue(item.getParent().buildQueue());
             startPlayBack(true);
         }
     }

     @Override
     public void onPlayFromMediaId(String mediaId, Bundle extras) {
         super.onPlayFromMediaId(mediaId, extras);
         playItem(mLibrary.getMediaItemById(mediaId));
     }

     @Override
     public void onPrepareFromMediaId(String mediaId, Bundle extras) {
         super.onPrepareFromMediaId(mediaId, extras);

         TmaMediaItem item = mLibrary.getMediaItemById(mediaId);
         prepareMediaItem(item);
     }

     @Override
     public void onPrepare() {
         super.onPrepare();
         if (!mSession.isActive()) {
             mSession.setActive(true);
         }
         // Prepare the first playable item (at root level) as the active item
         if (mActiveItem == null) {
             TmaMediaItem root = mLibrary.getRoot(mPrefs.mRootNodeType.getValue());
             if (root != null) {
                 prepareMediaItem(root.getPlayableByIndex(0));
             }
         }
     }

     void prepareMediaItem(@Nullable TmaMediaItem item) {
         if (item != null && item.getParent() != null) {
             if (mIsPlaying) {
                 stopPlayback();
             }
             mActiveItem = item;
             mActiveItem.updateSessionMetadata(mSession);
             mSession.setQueue(item.getParent().buildQueue());

             PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
                     .setState(PlaybackStateCompat.STATE_PAUSED, mCurrentPositionMs, mPlaybackSpeed)
                     .setActions(addActions(ACTION_PLAY));
             setActiveItemState(state);
             mSession.setPlaybackState(state.build());
         }
     }

     @Override
     public void onSkipToQueueItem(long id) {
         super.onSkipToQueueItem(id);
         if (mActiveItem != null && mActiveItem.getParent() != null) {
             playItem(mActiveItem.getParent().getPlayableByIndex(id));
         }
     }

     @Override
     public void onSkipToNext() {
         super.onSkipToNext();
         if (mActiveItem != null) {
             playItem(mActiveItem.getNext());
         }
     }

     @Override
     public void onSkipToPrevious() {
         super.onSkipToPrevious();
         if (mActiveItem != null) {
             playItem(mActiveItem.getPrevious());
         }
     }

     @Override
     public void onPlay() {
         super.onPlay();
         startPlayBack(true);
     }

     @Override
     public void onSeekTo(long pos) {
         super.onSeekTo(pos);
         boolean wasPlaying = mIsPlaying;
         if (wasPlaying) {
             mHandler.removeCallbacks(mTrackTimer);
         }
         mCurrentPositionMs = pos;
         boolean requestAudioFocus = !wasPlaying;
         startPlayBack(requestAudioFocus);
     }

     @Override
     public void onPause() {
         super.onPause();
         pausePlayback();
     }

     @Override
     public void onStop() {
         super.onStop();
         stopPlayback();
         sendStopPlaybackState();
     }

     @Override
     public void onCustomAction(String action, Bundle extras) {
         super.onCustomAction(action, extras);
         if (mActiveItem != null) {
             if (TmaCustomAction.HEART_PLUS_PLUS.mId.equals(action)) {
                 mActiveItem.mHearts++;
                 toast("" + mActiveItem.mHearts);
             } else if (TmaCustomAction.HEART_LESS_LESS.mId.equals(action)) {
                 mActiveItem.mHearts--;
                 toast("" + mActiveItem.mHearts);
             }
         }
     }

     /** Note: this is for quick feedback implementation, media apps should avoid toasts... */
     private void toast(String message) {
         Toast.makeText(mContext, message, Toast.LENGTH_LONG).show();
     }

     private boolean audioFocusGranted() {
         return mAudioManager.requestAudioFocus(mAudioFocusRequest) == AUDIOFOCUS_REQUEST_GRANTED;
     }

     private void onProcessMediaEvent() {
         if (mActiveItem == null) return;

         TmaMediaEvent event = mActiveItem.mMediaEvents.get(mNextEventIndex);
         event.maybeThrow();

         if (event.premiumAccountRequired() &&
                 TmaAccountType.PAID.equals(mPrefs.mAccountType.getValue())) {
             Log.i(TAG, "Ignoring even for paid account");
             return;
         } else if (Action.RESET_METADATA.equals(event.mAction)) {
             mSession.setMetadata(mSession.getController().getMetadata());
         } else {
             setPlaybackState(event);
         }

         if (event.mState == EventState.PLAYING) {
             if (!mSession.isActive()) {
                 mSession.setActive(true);
             }

             long trackDurationMs = mActiveItem.getDuration();
             if (trackDurationMs > 0) {
                 mPlaybackStartTimeMs = System.currentTimeMillis();
                 long remainingMs = (long) ((trackDurationMs - mCurrentPositionMs) / mPlaybackSpeed);
                 mHandler.postDelayed(mTrackTimer, remainingMs);
             }
             mIsPlaying = true;
         } else if (mIsPlaying) {
             stopPlayback();
         }

         mNextEventIndex++;
         if (mNextEventIndex < mActiveItem.mMediaEvents.size()) {
             mHandler.postDelayed(mEventTrigger,
                     mActiveItem.mMediaEvents.get(mNextEventIndex).mPostDelayMs);
         }
     }

     private void startPlayBack(boolean requestAudioFocus) {
         if (requestAudioFocus && !audioFocusGranted()) return;

         if (mActiveItem == null || mActiveItem.mMediaEvents.size() <= 0) {
             PlaybackStateCompat state = new PlaybackStateCompat.Builder()
                     .setState(STATE_ERROR, mCurrentPositionMs, mPlaybackSpeed)
                     .setErrorMessage(ERROR_CODE_APP_ERROR, "null mActiveItem or empty events")
                     .build();
             mSession.setPlaybackState(state);
             return;
         }

         mActiveItem.updateSessionMetadata(mSession);

         mHandler.removeCallbacks(mEventTrigger);
         mNextEventIndex = 0;
         mHandler.postDelayed(mEventTrigger, mActiveItem.mMediaEvents.get(0).mPostDelayMs);
     }

     private void pausePlayback() {
         mCurrentPositionMs += (System.currentTimeMillis() - mPlaybackStartTimeMs) / mPlaybackSpeed;
         mHandler.removeCallbacks(mTrackTimer);
         PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
                 .setState(PlaybackStateCompat.STATE_PAUSED, mCurrentPositionMs, mPlaybackSpeed)
                 .setActions(addActions(ACTION_PLAY));
         setActiveItemState(state);
         mSession.setPlaybackState(state.build());
         mIsPlaying = false;
     }

     /** Doesn't change the playback state. */
     private void stopPlayback() {
         mCurrentPositionMs = 0;
         mHandler.removeCallbacks(mTrackTimer);
         mIsPlaying = false;
     }

     private void sendStopPlaybackState() {
         PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
                 .setState(PlaybackStateCompat.STATE_STOPPED, mCurrentPositionMs, mPlaybackSpeed)
                 .setActions(addActions(ACTION_PLAY));
         setActiveItemState(state);
         mSession.setPlaybackState(state.build());
     }

     private long addActions(long actions) {
         actions |= ACTION_PLAY_FROM_MEDIA_ID | ACTION_SKIP_TO_QUEUE_ITEM | ACTION_SEEK_TO;

         if (mActiveItem != null) {
             if (mActiveItem.getNext() != null) {
                 actions |= ACTION_SKIP_TO_NEXT;
             }
             if (mActiveItem.getPrevious() != null) {
                 actions |= ACTION_SKIP_TO_PREVIOUS;
             }
         }

         return actions;
     }
 }
	/*
	* Copyright 2019 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.car.media.testmediaapp;

	import static android.media.AudioManager.AUDIOFOCUS_GAIN;
	import static android.media.AudioManager.AUDIOFOCUS_REQUEST_GRANTED;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_PAUSE;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_PLAY;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_PLAY_FROM_MEDIA_ID;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SEEK_TO;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SKIP_TO_NEXT;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS;
	import static android.support.v4.media.session.PlaybackStateCompat.ACTION_SKIP_TO_QUEUE_ITEM;
	import static android.support.v4.media.session.PlaybackStateCompat.ERROR_CODE_APP_ERROR;
	import static android.support.v4.media.session.PlaybackStateCompat.STATE_ERROR;

	import static com.android.car.media.common.MediaConstants.ERROR_RESOLUTION_ACTION_INTENT;
	import static com.android.car.media.common.MediaConstants.ERROR_RESOLUTION_ACTION_LABEL;

	import androidx.annotation.Nullable;
	import android.app.PendingIntent;
	import android.content.Context;
	import android.content.Intent;
	import android.media.AudioFocusRequest;
	import android.media.AudioManager;
	import android.os.Bundle;
	import android.os.Handler;
	import android.support.v4.media.session.MediaSessionCompat;
	import android.support.v4.media.session.PlaybackStateCompat;
	import android.util.Log;
	import android.widget.Toast;

	import com.android.car.media.testmediaapp.TmaMediaEvent.Action;
	import com.android.car.media.testmediaapp.TmaMediaEvent.EventState;
	import com.android.car.media.testmediaapp.TmaMediaEvent.ResolutionIntent;
	import com.android.car.media.testmediaapp.TmaMediaItem.TmaCustomAction;
	import com.android.car.media.testmediaapp.prefs.TmaEnumPrefs.TmaAccountType;
	import com.android.car.media.testmediaapp.prefs.TmaPrefs;
	import com.android.car.media.testmediaapp.prefs.TmaPrefsActivity;


	/**
	* This class simulates all media interactions (no sound is actually played).
	*/
	public class TmaPlayer extends MediaSessionCompat.Callback {

	private static final String TAG = "TmaPlayer";

	private final Context mContext;
	private final TmaPrefs mPrefs;
	private final TmaLibrary mLibrary;
	private final AudioManager mAudioManager;
	private final Handler mHandler;
	private final Runnable mTrackTimer = this::onStop;
	private final Runnable mEventTrigger = this::onProcessMediaEvent;
	private final MediaSessionCompat mSession;
	private final AudioFocusRequest mAudioFocusRequest;

	/** Only updated when the state changes. */
	private long mCurrentPositionMs = 0;
	private float mPlaybackSpeed = 1.0f; // TODO: make variable.
	private long mPlaybackStartTimeMs;
	private boolean mIsPlaying;
	@Nullable
	private TmaMediaItem mActiveItem;
	private int mNextEventIndex = -1;


	TmaPlayer(Context context, TmaLibrary library, AudioManager audioManager, Handler handler,
	MediaSessionCompat session) {
	mContext = context;
	mPrefs = TmaPrefs.getInstance(mContext);
	mLibrary = library;
	mAudioManager = audioManager;
	mHandler = handler;
	mSession = session;

	// TODO add focus listener ?
	mAudioFocusRequest = new AudioFocusRequest.Builder(AUDIOFOCUS_GAIN).build();
	}

	/** Updates the state in the media session based on the given {@link TmaMediaEvent}. */
	void setPlaybackState(TmaMediaEvent event) {
	Log.i(TAG, "setPlaybackState " + event);

	PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
	.setState(event.mState.mValue, mCurrentPositionMs, mPlaybackSpeed)
	.setErrorMessage(event.mErrorCode.mValue, event.mErrorMessage)
	.setActions(addActions(ACTION_PAUSE));
	if (ResolutionIntent.PREFS.equals(event.mResolutionIntent)) {
	Intent prefsIntent = new Intent();
	prefsIntent.setClass(mContext, TmaPrefsActivity.class);
	prefsIntent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK);
	PendingIntent pendingIntent = PendingIntent.getActivity(mContext, 0, prefsIntent, 0);

	Bundle extras = new Bundle();
	extras.putString(ERROR_RESOLUTION_ACTION_LABEL, event.mActionLabel);
	extras.putParcelable(ERROR_RESOLUTION_ACTION_INTENT, pendingIntent);
	state.setExtras(extras);
	}

	setActiveItemState(state);
	mSession.setPlaybackState(state.build());
	}

	/** Sets custom action, queue id, etc. */
	private void setActiveItemState(PlaybackStateCompat.Builder state) {
	if (mActiveItem != null) {
	for (TmaCustomAction action : mActiveItem.mCustomActions) {
	String name = mContext.getResources().getString(action.mNameId);
	state.addCustomAction(action.mId, name, action.mIcon);
	}
	state.setActiveQueueItemId(mActiveItem.getQueueId());
	}
	}

	private void playItem(@Nullable TmaMediaItem item) {
	if (item != null && item.getParent() != null) {
	if (mIsPlaying) {
	stopPlayback();
	}
	mActiveItem = item;
	mSession.setQueue(item.getParent().buildQueue());
	startPlayBack(true);
	}
	}

	@Override
	public void onPlayFromMediaId(String mediaId, Bundle extras) {
	super.onPlayFromMediaId(mediaId, extras);
	playItem(mLibrary.getMediaItemById(mediaId));
	}

	@Override
	public void onPrepareFromMediaId(String mediaId, Bundle extras) {
	super.onPrepareFromMediaId(mediaId, extras);

	TmaMediaItem item = mLibrary.getMediaItemById(mediaId);
	prepareMediaItem(item);
	}

	@Override
	public void onPrepare() {
	super.onPrepare();
	if (!mSession.isActive()) {
	mSession.setActive(true);
	}
	// Prepare the first playable item (at root level) as the active item
	if (mActiveItem == null) {
	TmaMediaItem root = mLibrary.getRoot(mPrefs.mRootNodeType.getValue());
	if (root != null) {
	prepareMediaItem(root.getPlayableByIndex(0));
	}
	}
	}

	void prepareMediaItem(@Nullable TmaMediaItem item) {
	if (item != null && item.getParent() != null) {
	if (mIsPlaying) {
	stopPlayback();
	}
	mActiveItem = item;
	mActiveItem.updateSessionMetadata(mSession);
	mSession.setQueue(item.getParent().buildQueue());

	PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
	.setState(PlaybackStateCompat.STATE_PAUSED, mCurrentPositionMs, mPlaybackSpeed)
	.setActions(addActions(ACTION_PLAY));
	setActiveItemState(state);
	mSession.setPlaybackState(state.build());
	}
	}

	@Override
	public void onSkipToQueueItem(long id) {
	super.onSkipToQueueItem(id);
	if (mActiveItem != null && mActiveItem.getParent() != null) {
	playItem(mActiveItem.getParent().getPlayableByIndex(id));
	}
	}

	@Override
	public void onSkipToNext() {
	super.onSkipToNext();
	if (mActiveItem != null) {
	playItem(mActiveItem.getNext());
	}
	}

	@Override
	public void onSkipToPrevious() {
	super.onSkipToPrevious();
	if (mActiveItem != null) {
	playItem(mActiveItem.getPrevious());
	}
	}

	@Override
	public void onPlay() {
	super.onPlay();
	startPlayBack(true);
	}

	@Override
	public void onSeekTo(long pos) {
	super.onSeekTo(pos);
	boolean wasPlaying = mIsPlaying;
	if (wasPlaying) {
	mHandler.removeCallbacks(mTrackTimer);
	}
	mCurrentPositionMs = pos;
	boolean requestAudioFocus = !wasPlaying;
	startPlayBack(requestAudioFocus);
	}

	@Override
	public void onPause() {
	super.onPause();
	pausePlayback();
	}

	@Override
	public void onStop() {
	super.onStop();
	stopPlayback();
	sendStopPlaybackState();
	}

	@Override
	public void onCustomAction(String action, Bundle extras) {
	super.onCustomAction(action, extras);
	if (mActiveItem != null) {
	if (TmaCustomAction.HEART_PLUS_PLUS.mId.equals(action)) {
	mActiveItem.mHearts++;
	toast("" + mActiveItem.mHearts);
	} else if (TmaCustomAction.HEART_LESS_LESS.mId.equals(action)) {
	mActiveItem.mHearts--;
	toast("" + mActiveItem.mHearts);
	}
	}
	}

	/** Note: this is for quick feedback implementation, media apps should avoid toasts... */
	private void toast(String message) {
	Toast.makeText(mContext, message, Toast.LENGTH_LONG).show();
	}

	private boolean audioFocusGranted() {
	return mAudioManager.requestAudioFocus(mAudioFocusRequest) == AUDIOFOCUS_REQUEST_GRANTED;
	}

	private void onProcessMediaEvent() {
	if (mActiveItem == null) return;

	TmaMediaEvent event = mActiveItem.mMediaEvents.get(mNextEventIndex);
	event.maybeThrow();

	if (event.premiumAccountRequired() &&
	TmaAccountType.PAID.equals(mPrefs.mAccountType.getValue())) {
	Log.i(TAG, "Ignoring even for paid account");
	return;
	} else if (Action.RESET_METADATA.equals(event.mAction)) {
	mSession.setMetadata(mSession.getController().getMetadata());
	} else {
	setPlaybackState(event);
	}

	if (event.mState == EventState.PLAYING) {
	if (!mSession.isActive()) {
	mSession.setActive(true);
	}

	long trackDurationMs = mActiveItem.getDuration();
	if (trackDurationMs > 0) {
	mPlaybackStartTimeMs = System.currentTimeMillis();
	long remainingMs = (long) ((trackDurationMs - mCurrentPositionMs) / mPlaybackSpeed);
	mHandler.postDelayed(mTrackTimer, remainingMs);
	}
	mIsPlaying = true;
	} else if (mIsPlaying) {
	stopPlayback();
	}

	mNextEventIndex++;
	if (mNextEventIndex < mActiveItem.mMediaEvents.size()) {
	mHandler.postDelayed(mEventTrigger,
	mActiveItem.mMediaEvents.get(mNextEventIndex).mPostDelayMs);
	}
	}

	private void startPlayBack(boolean requestAudioFocus) {
	if (requestAudioFocus && !audioFocusGranted()) return;

	if (mActiveItem == null \|\| mActiveItem.mMediaEvents.size() <= 0) {
	PlaybackStateCompat state = new PlaybackStateCompat.Builder()
	.setState(STATE_ERROR, mCurrentPositionMs, mPlaybackSpeed)
	.setErrorMessage(ERROR_CODE_APP_ERROR, "null mActiveItem or empty events")
	.build();
	mSession.setPlaybackState(state);
	return;
	}

	mActiveItem.updateSessionMetadata(mSession);

	mHandler.removeCallbacks(mEventTrigger);
	mNextEventIndex = 0;
	mHandler.postDelayed(mEventTrigger, mActiveItem.mMediaEvents.get(0).mPostDelayMs);
	}

	private void pausePlayback() {
	mCurrentPositionMs += (System.currentTimeMillis() - mPlaybackStartTimeMs) / mPlaybackSpeed;
	mHandler.removeCallbacks(mTrackTimer);
	PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
	.setState(PlaybackStateCompat.STATE_PAUSED, mCurrentPositionMs, mPlaybackSpeed)
	.setActions(addActions(ACTION_PLAY));
	setActiveItemState(state);
	mSession.setPlaybackState(state.build());
	mIsPlaying = false;
	}

	/** Doesn't change the playback state. */
	private void stopPlayback() {
	mCurrentPositionMs = 0;
	mHandler.removeCallbacks(mTrackTimer);
	mIsPlaying = false;
	}

	private void sendStopPlaybackState() {
	PlaybackStateCompat.Builder state = new PlaybackStateCompat.Builder()
	.setState(PlaybackStateCompat.STATE_STOPPED, mCurrentPositionMs, mPlaybackSpeed)
	.setActions(addActions(ACTION_PLAY));
	setActiveItemState(state);
	mSession.setPlaybackState(state.build());
	}

	private long addActions(long actions) {
	actions \|= ACTION_PLAY_FROM_MEDIA_ID \| ACTION_SKIP_TO_QUEUE_ITEM \| ACTION_SEEK_TO;

	if (mActiveItem != null) {
	if (mActiveItem.getNext() != null) {
	actions \|= ACTION_SKIP_TO_NEXT;
	}
	if (mActiveItem.getPrevious() != null) {
	actions \|= ACTION_SKIP_TO_PREVIOUS;
	}
	}

	return actions;
	}
	}