Java tutorial
/* * 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.torrenttunes.android; import android.app.Notification; import android.app.NotificationManager; import android.app.PendingIntent; import android.content.BroadcastReceiver; import android.content.Context; import android.content.Intent; import android.content.IntentFilter; import android.graphics.Bitmap; import android.graphics.BitmapFactory; import android.graphics.Color; import android.os.RemoteException; import android.support.v4.app.NotificationCompat; import android.support.v4.media.MediaDescriptionCompat; import android.support.v4.media.MediaMetadataCompat; import android.support.v4.media.session.MediaControllerCompat; import android.support.v4.media.session.MediaSessionCompat; import android.support.v4.media.session.PlaybackStateCompat; import com.torrenttunes.android.R; import com.torrenttunes.android.ui.MusicPlayerActivity; import com.torrenttunes.android.utils.LogHelper; import com.torrenttunes.android.utils.ResourceHelper; /** * Keeps track of a notification and updates it automatically for a given * MediaSession. Maintaining a visible notification (usually) guarantees that the music service * won't be killed during playback. */ public class MediaNotificationManager extends BroadcastReceiver { private static final String TAG = LogHelper.makeLogTag(MediaNotificationManager.class); private static final int NOTIFICATION_ID = 412; private static final int REQUEST_CODE = 100; public static final String ACTION_PAUSE = "com.example.android.uamp.pause"; public static final String ACTION_PLAY = "com.example.android.uamp.play"; public static final String ACTION_PREV = "com.example.android.uamp.prev"; public static final String ACTION_NEXT = "com.example.android.uamp.next"; public static final String ACTION_STOP_CASTING = "com.example.android.uamp.stop_cast"; private final MusicService mService; private MediaSessionCompat.Token mSessionToken; private MediaControllerCompat mController; private MediaControllerCompat.TransportControls mTransportControls; private PlaybackStateCompat mPlaybackState; private MediaMetadataCompat mMetadata; private NotificationManager mNotificationManager; private PendingIntent mPauseIntent; private PendingIntent mPlayIntent; private PendingIntent mPreviousIntent; private PendingIntent mNextIntent; private PendingIntent mStopCastIntent; private int mNotificationColor; private boolean mStarted = false; public MediaNotificationManager(MusicService service) { mService = service; updateSessionToken(); mNotificationColor = ResourceHelper.getThemeColor(mService, android.R.attr.colorPrimary, Color.DKGRAY); mNotificationManager = (NotificationManager) mService.getSystemService(Context.NOTIFICATION_SERVICE); String pkg = mService.getPackageName(); mPauseIntent = PendingIntent.getBroadcast(mService, REQUEST_CODE, new Intent(ACTION_PAUSE).setPackage(pkg), PendingIntent.FLAG_CANCEL_CURRENT); mPlayIntent = PendingIntent.getBroadcast(mService, REQUEST_CODE, new Intent(ACTION_PLAY).setPackage(pkg), PendingIntent.FLAG_CANCEL_CURRENT); mPreviousIntent = PendingIntent.getBroadcast(mService, REQUEST_CODE, new Intent(ACTION_PREV).setPackage(pkg), PendingIntent.FLAG_CANCEL_CURRENT); mNextIntent = PendingIntent.getBroadcast(mService, REQUEST_CODE, new Intent(ACTION_NEXT).setPackage(pkg), PendingIntent.FLAG_CANCEL_CURRENT); mStopCastIntent = PendingIntent.getBroadcast(mService, REQUEST_CODE, new Intent(ACTION_STOP_CASTING).setPackage(pkg), PendingIntent.FLAG_CANCEL_CURRENT); // Cancel all notifications to handle the case where the Service was killed and // restarted by the system. mNotificationManager.cancelAll(); } /** * Posts the notification and starts tracking the session to keep it * updated. The notification will automatically be removed if the session is * destroyed before {@link #stopNotification} is called. */ public void startNotification() { if (!mStarted) { mMetadata = mController.getMetadata(); mPlaybackState = mController.getPlaybackState(); // The notification must be updated after setting started to true Notification notification = createNotification(); if (notification != null) { mController.registerCallback(mCb); IntentFilter filter = new IntentFilter(); filter.addAction(ACTION_NEXT); filter.addAction(ACTION_PAUSE); filter.addAction(ACTION_PLAY); filter.addAction(ACTION_PREV); filter.addAction(ACTION_STOP_CASTING); mService.registerReceiver(this, filter); mService.startForeground(NOTIFICATION_ID, notification); mStarted = true; } } } /** * Removes the notification and stops tracking the session. If the session * was destroyed this has no effect. */ public void stopNotification() { if (mStarted) { mStarted = false; mController.unregisterCallback(mCb); try { mService.unregisterReceiver(this); } catch (IllegalArgumentException ex) { // ignore if the receiver is not registered. } mService.stopForeground(true); } mNotificationManager.cancel(NOTIFICATION_ID); } @Override public void onReceive(Context context, Intent intent) { final String action = intent.getAction(); LogHelper.d(TAG, "Received intent with action " + action); switch (action) { case ACTION_PAUSE: mTransportControls.pause(); break; case ACTION_PLAY: mTransportControls.play(); break; case ACTION_NEXT: mTransportControls.skipToNext(); break; case ACTION_PREV: mTransportControls.skipToPrevious(); break; case ACTION_STOP_CASTING: Intent i = new Intent(context, MusicService.class); i.setAction(MusicService.ACTION_CMD); i.putExtra(MusicService.CMD_NAME, MusicService.CMD_STOP_CASTING); mService.startService(i); break; default: LogHelper.w(TAG, "Unknown intent ignored. Action=", action); } } /** * Update the state based on a change on the session token. Called either when * we are running for the first time or when the media session owner has destroyed the session * (see {@link android.media.session.MediaController.Callback#onSessionDestroyed()}) */ private void updateSessionToken() { try { MediaSessionCompat.Token freshToken = mService.getSessionToken(); if (mSessionToken == null || !mSessionToken.equals(freshToken)) { if (mController != null) { mController.unregisterCallback(mCb); } mSessionToken = freshToken; mController = new MediaControllerCompat(mService, mSessionToken); mTransportControls = mController.getTransportControls(); if (mStarted) { mController.registerCallback(mCb); } } } catch (RemoteException ex) { } } private PendingIntent createContentIntent(MediaDescriptionCompat description) { Intent openUI = new Intent(mService, MusicPlayerActivity.class); openUI.setFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP); openUI.putExtra(MusicPlayerActivity.EXTRA_START_FULLSCREEN, true); if (description != null) { openUI.putExtra(MusicPlayerActivity.EXTRA_CURRENT_MEDIA_DESCRIPTION, description); } return PendingIntent.getActivity(mService, REQUEST_CODE, openUI, PendingIntent.FLAG_CANCEL_CURRENT); } private final MediaControllerCompat.Callback mCb = new MediaControllerCompat.Callback() { @Override public void onPlaybackStateChanged(PlaybackStateCompat state) { mPlaybackState = state; LogHelper.d(TAG, "Received new playback state", state); if (state != null && (state.getState() == PlaybackStateCompat.STATE_STOPPED || state.getState() == PlaybackStateCompat.STATE_NONE)) { stopNotification(); } else { Notification notification = createNotification(); if (notification != null) { mNotificationManager.notify(NOTIFICATION_ID, notification); } } } @Override public void onMetadataChanged(MediaMetadataCompat metadata) { mMetadata = metadata; LogHelper.d(TAG, "Received new metadata ", metadata); Notification notification = createNotification(); if (notification != null) { mNotificationManager.notify(NOTIFICATION_ID, notification); } } @Override public void onSessionDestroyed() { super.onSessionDestroyed(); LogHelper.d(TAG, "Session was destroyed, resetting to the new session token"); updateSessionToken(); } }; private Notification createNotification() { LogHelper.d(TAG, "updateNotificationMetadata. mMetadata=" + mMetadata); if (mMetadata == null || mPlaybackState == null) { return null; } NotificationCompat.Builder notificationBuilder = new NotificationCompat.Builder(mService); int playPauseButtonPosition = 0; // If skip to previous action is enabled if ((mPlaybackState.getActions() & PlaybackStateCompat.ACTION_SKIP_TO_PREVIOUS) != 0) { notificationBuilder.addAction(R.drawable.ic_skip_previous_white_24dp, mService.getString(R.string.label_previous), mPreviousIntent); // If there is a "skip to previous" button, the play/pause button will // be the second one. We need to keep track of it, because the MediaStyle notification // requires to specify the index of the buttons (actions) that should be visible // when in compact view. playPauseButtonPosition = 1; } addPlayPauseAction(notificationBuilder); // If skip to next action is enabled if ((mPlaybackState.getActions() & PlaybackStateCompat.ACTION_SKIP_TO_NEXT) != 0) { notificationBuilder.addAction(R.drawable.ic_skip_next_white_24dp, mService.getString(R.string.label_next), mNextIntent); } MediaDescriptionCompat description = mMetadata.getDescription(); String fetchArtUrl = null; Bitmap art = null; if (description.getIconUri() != null) { // This sample assumes the iconUri will be a valid URL formatted String, but // it can actually be any valid Android Uri formatted String. // async fetch the album art icon String artUrl = description.getIconUri().toString(); art = AlbumArtCache.getInstance().getBigImage(artUrl); if (art == null) { fetchArtUrl = artUrl; // use a placeholder art while the remote art is being downloaded art = BitmapFactory.decodeResource(mService.getResources(), R.drawable.ic_default_art); } if (art.isRecycled()) { art = null; } } notificationBuilder // .setStyle(new Notification.MediaStyle() // .setShowActionsInCompactView( // new int[]{playPauseButtonPosition}) // show only play/pause in compact view // .setMediaSession(mSessionToken)) .setColor(mNotificationColor).setSmallIcon(R.drawable.ic_notification) .setVisibility(Notification.VISIBILITY_PUBLIC).setUsesChronometer(true) .setContentIntent(createContentIntent(description)).setContentTitle(description.getTitle()) .setContentText(description.getSubtitle()).setLargeIcon(art); if (mController != null && mController.getExtras() != null) { String castName = mController.getExtras().getString(MusicService.EXTRA_CONNECTED_CAST); if (castName != null) { String castInfo = mService.getResources().getString(R.string.casting_to_device, castName); notificationBuilder.setSubText(castInfo); notificationBuilder.addAction(R.drawable.ic_close_black_24dp, mService.getString(R.string.stop_casting), mStopCastIntent); } } setNotificationPlaybackState(notificationBuilder); if (fetchArtUrl != null) { fetchBitmapFromURLAsync(fetchArtUrl, notificationBuilder); } return notificationBuilder.build(); } private void addPlayPauseAction(NotificationCompat.Builder builder) { LogHelper.d(TAG, "updatePlayPauseAction"); String label; int icon; PendingIntent intent; if (mPlaybackState.getState() == PlaybackStateCompat.STATE_PLAYING) { label = mService.getString(R.string.label_pause); icon = R.drawable.ic_pause_white_24dp; intent = mPauseIntent; } else { label = mService.getString(R.string.label_play); icon = R.drawable.ic_play_arrow_white_24dp; intent = mPlayIntent; } builder.addAction(new NotificationCompat.Action(icon, label, intent)); } private void setNotificationPlaybackState(NotificationCompat.Builder builder) { LogHelper.d(TAG, "updateNotificationPlaybackState. mPlaybackState=" + mPlaybackState); if (mPlaybackState == null || !mStarted) { LogHelper.d(TAG, "updateNotificationPlaybackState. cancelling notification!"); mService.stopForeground(true); return; } if (mPlaybackState.getState() == PlaybackStateCompat.STATE_PLAYING && mPlaybackState.getPosition() >= 0) { LogHelper.d(TAG, "updateNotificationPlaybackState. updating playback position to ", (System.currentTimeMillis() - mPlaybackState.getPosition()) / 1000, " seconds"); builder.setWhen(System.currentTimeMillis() - mPlaybackState.getPosition()).setShowWhen(true) .setUsesChronometer(true); } else { LogHelper.d(TAG, "updateNotificationPlaybackState. hiding playback position"); builder.setWhen(0).setShowWhen(false).setUsesChronometer(false); } // Make sure that the notification can be dismissed by the user when we are not playing: builder.setOngoing(mPlaybackState.getState() == PlaybackStateCompat.STATE_PLAYING); } private void fetchBitmapFromURLAsync(final String bitmapUrl, final NotificationCompat.Builder builder) { AlbumArtCache.getInstance().fetch(bitmapUrl, new AlbumArtCache.FetchListener() { @Override public void onFetched(String artUrl, Bitmap bitmap, Bitmap icon) { if (mMetadata != null && mMetadata.getDescription() != null && artUrl.equals(mMetadata.getDescription().getIconUri().toString())) { // If the media is still the same, update the notification: LogHelper.d(TAG, "fetchBitmapFromURLAsync: set bitmap to ", artUrl); if (!bitmap.isRecycled()) { builder.setLargeIcon(bitmap); } mNotificationManager.notify(NOTIFICATION_ID, builder.build()); } } }); } }