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audio_service.dart
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audio_service.dart
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import 'dart:async';
import 'dart:io' show File, Platform;
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:flutter_cache_manager/flutter_cache_manager.dart';
import 'package:flutter_isolate/flutter_isolate.dart';
import 'package:rxdart/rxdart.dart';
/// The different buttons on a headset.
enum MediaButton {
media,
next,
previous,
}
/// The actons associated with playing audio.
enum MediaAction {
stop,
pause,
play,
rewind,
skipToPrevious,
skipToNext,
fastForward,
setRating,
seekTo,
playPause,
playFromMediaId,
playFromSearch,
skipToQueueItem,
playFromUri,
}
/// The different states during audio playback.
enum BasicPlaybackState {
none,
stopped,
paused,
playing,
fastForwarding,
rewinding,
buffering,
error,
connecting,
skippingToPrevious,
skippingToNext,
skippingToQueueItem,
}
/// The playback state for the audio service which includes a basic state such
/// as [BasicPlaybackState.paused], the playback position and the currently
/// supported actions.
class PlaybackState {
/// The basic state e.g. [BasicPlaybackState.paused]
final BasicPlaybackState basicState;
/// The set of actions currently supported by the audio service e.g.
/// [MediaAction.play]
final Set<MediaAction> actions;
/// The playback position in milliseconds at the last update time
final int position;
/// The current playback speed where 1.0 means normal speed
final double speed;
/// The time at which the playback position was last updated
final int updateTime;
const PlaybackState({
@required this.basicState,
@required this.actions,
this.position,
this.speed,
this.updateTime,
});
/// The current playback position in milliseconds
int get currentPosition {
if (basicState == BasicPlaybackState.playing) {
return (position +
((DateTime.now().millisecondsSinceEpoch - updateTime) *
(speed ?? 1.0)))
.toInt();
} else {
return position;
}
}
}
enum RatingStyle {
/// Indicates a rating style is not supported.
///
/// A Rating will never have this type, but can be used by other classes
/// to indicate they do not support Rating.
none,
/// A rating style with a single degree of rating, "heart" vs "no heart".
///
/// Can be used to indicate the content referred to is a favorite (or not).
heart,
/// A rating style for "thumb up" vs "thumb down".
thumbUpDown,
/// A rating style with 0 to 3 stars.
range3stars,
/// A rating style with 0 to 4 stars.
range4stars,
/// A rating style with 0 to 5 stars.
range5stars,
/// A rating style expressed as a percentage.
percentage,
}
/// A rating to attach to a MediaItem.
class Rating {
final RatingStyle _type;
final dynamic _value;
const Rating._internal(this._type, this._value);
/// Create a new heart rating.
const Rating.newHeartRating(bool hasHeart)
: this._internal(RatingStyle.heart, hasHeart);
/// Create a new percentage rating.
factory Rating.newPercentageRating(double percent) {
if (percent < 0 || percent > 100) throw ArgumentError();
return Rating._internal(RatingStyle.percentage, percent);
}
/// Create a new star rating.
factory Rating.newStartRating(RatingStyle starRatingStyle, int starRating) {
if (starRatingStyle != RatingStyle.range3stars &&
starRatingStyle != RatingStyle.range4stars &&
starRatingStyle != RatingStyle.range5stars) {
throw ArgumentError();
}
if (starRating > starRatingStyle.index || starRating < 0)
throw ArgumentError();
return Rating._internal(starRatingStyle, starRating);
}
/// Create a new thumb rating.
const Rating.newThumbRating(bool isThumbsUp)
: this._internal(RatingStyle.thumbUpDown, isThumbsUp);
/// Create a new unrated rating.
const Rating.newUnratedRating(RatingStyle ratingStyle)
: this._internal(ratingStyle, null);
/// Return the rating style.
RatingStyle getRatingStyle() => _type;
/// Returns a percentage rating value greater or equal to 0.0f, or a
/// negative value if the rating style is not percentage-based, or
/// if it is unrated.
double getPercentRating() {
if (_type != RatingStyle.percentage) return -1;
if (_value < 0 || _value > 100) return -1;
return _value ?? -1;
}
/// Returns a rating value greater or equal to 0.0f, or a negative
/// value if the rating style is not star-based, or if it is
/// unrated.
int getStarRating() {
if (_type != RatingStyle.range3stars &&
_type != RatingStyle.range4stars &&
_type != RatingStyle.range5stars) return -1;
return _value ?? -1;
}
/// Returns true if the rating is "heart selected" or false if the
/// rating is "heart unselected", if the rating style is not [heart]
/// or if it is unrated.
bool hasHeart() {
if (_type != RatingStyle.heart) return false;
return _value ?? false;
}
/// Returns true if the rating is "thumb up" or false if the rating
/// is "thumb down", if the rating style is not [thumbUpDown] or if
/// it is unrated.
bool isThumbUp() {
if (_type != RatingStyle.thumbUpDown) return false;
return _value ?? false;
}
/// Return whether there is a rating value available.
bool isRated() => _value != null;
Map<String, dynamic> _toRaw() {
return <String, dynamic>{
'type': _type.index,
'value': _value,
};
}
// Even though this should take a Map<String, dynamic>, that makes an error.
Rating._fromRaw(Map<dynamic, dynamic> raw)
: this._internal(RatingStyle.values[raw['type']], raw['value']);
}
/// Metadata about an audio item that can be played, or a folder containing
/// audio items.
class MediaItem {
/// A unique id
final String id;
/// The album this media item belongs to
final String album;
/// The title of this media item
final String title;
/// The artist of this media item
final String artist;
/// The genre of this media item
final String genre;
/// The duration in milliseconds
final int duration;
/// The artwork for this media item as a uri
final String artUri;
/// Whether this is playable (i.e. not a folder)
final bool playable;
/// Override the default title for display purposes
final String displayTitle;
/// Override the default subtitle for display purposes
final String displaySubtitle;
/// Override the default description for display purposes
final String displayDescription;
/// The rating of the MediaItem.
final Rating rating;
/// A map of additional metadata for the media item.
///
/// The values must be integers or strings.
final Map<String, dynamic> extras;
/// Creates a [MediaItem].
///
/// [id], [album] and [title] must not be null, and [id] must be unique for
/// each instance.
const MediaItem({
@required this.id,
@required this.album,
@required this.title,
this.artist,
this.genre,
this.duration,
this.artUri,
this.playable = true,
this.displayTitle,
this.displaySubtitle,
this.displayDescription,
this.rating,
this.extras,
});
MediaItem copyWith({
String id,
String album,
String title,
String artist,
String genre,
int duration,
String artUri,
bool playable,
String displayTitle,
String displaySubtitle,
String displayDescription,
Rating rating,
Map extras,
}) =>
MediaItem(
id: id ?? this.id,
album: album ?? this.album,
title: title ?? this.title,
artist: artist ?? this.artist,
genre: genre ?? this.genre,
duration: duration ?? this.duration,
artUri: artUri ?? this.artUri,
playable: playable ?? this.playable,
displayTitle: displayTitle ?? this.displayTitle,
displaySubtitle: displaySubtitle ?? this.displaySubtitle,
displayDescription: displayDescription ?? this.displayDescription,
rating: rating ?? this.rating,
extras: extras ?? this.extras,
);
@override
int get hashCode => id.hashCode;
@override
bool operator ==(dynamic other) => other is MediaItem && other.id == id;
}
/// A media action that can be controlled by a client.
///
/// The set of media controls available at any moment depends on the current
/// playback state as set by [AudioServiceBackground.setState]. For example, a
/// "pause" control should be available in the [BasicPlaybackState.playing]
/// state but not in the [BasicPlaybackState.paused] state.
///
/// A button for each media control will be shown in your app's notification,
/// Wear OS and Android Auto devices.
class MediaControl {
/// A reference to an Android icon resource for the control (e.g.
/// `"drawable/ic_action_pause"`)
final String androidIcon;
/// A label for the control
final String label;
/// The action to be executed by this control
final MediaAction action;
const MediaControl({
this.androidIcon,
@required this.label,
@required this.action,
});
}
const MethodChannel _channel =
const MethodChannel('ryanheise.com/audioService');
Map _mediaItem2raw(MediaItem mediaItem) => {
'id': mediaItem.id,
'album': mediaItem.album,
'title': mediaItem.title,
'artist': mediaItem.artist,
'genre': mediaItem.genre,
'duration': mediaItem.duration,
'artUri': mediaItem.artUri,
'playable': mediaItem.playable,
'displayTitle': mediaItem.displayTitle,
'displaySubtitle': mediaItem.displaySubtitle,
'displayDescription': mediaItem.displayDescription,
'rating': mediaItem.rating?._toRaw(),
'extras': mediaItem.extras,
};
MediaItem _raw2mediaItem(Map raw) => MediaItem(
id: raw['id'],
album: raw['album'],
title: raw['title'],
artist: raw['artist'],
genre: raw['genre'],
duration: raw['duration'],
artUri: raw['artUri'],
displayTitle: raw['displayTitle'],
displaySubtitle: raw['displaySubtitle'],
displayDescription: raw['displayDescription'],
rating: raw['rating'] != null ? Rating._fromRaw(raw['rating']) : null,
extras: _raw2extras(raw['extras']),
);
Map<String, dynamic> _raw2extras(Map raw) {
if (raw == null) return null;
final extras = <String, dynamic>{};
for (var key in raw.keys) {
extras[key as String] = raw[key];
}
return extras;
}
const String _CUSTOM_PREFIX = 'custom_';
/// Client API to start and interact with the audio service.
///
/// This class is used from your UI code to establish a connection with the
/// audio service. While connected to the service, your UI may invoke methods
/// of this class to start/pause/stop/etc. playback and listen to changes in
/// playback state and playing media.
///
/// Your UI must disconnect from the audio service when it is no longer visible
/// although the audio service will continue to run in the background. If your
/// UI once again becomes visible, you should reconnect to the audio service.
/// Use [AudioServiceWidget] to manage this connection automatically.
class AudioService {
/// The root media ID for browsing media provided by the background
/// task.
static const String MEDIA_ROOT_ID = "root";
static final _browseMediaChildrenSubject = BehaviorSubject<List<MediaItem>>();
/// An instance of flutter isolate
static FlutterIsolate _flutterIsolate;
/// A stream that broadcasts the children of the current browse
/// media parent.
static Stream<List<MediaItem>> get browseMediaChildrenStream =>
_browseMediaChildrenSubject.stream;
static final _playbackStateSubject = BehaviorSubject<PlaybackState>();
/// A stream that broadcasts the playback state.
static Stream<PlaybackState> get playbackStateStream =>
_playbackStateSubject.stream;
static final _currentMediaItemSubject = BehaviorSubject<MediaItem>();
/// A stream that broadcasts the current [MediaItem].
static Stream<MediaItem> get currentMediaItemStream =>
_currentMediaItemSubject.stream;
static final _queueSubject = BehaviorSubject<List<MediaItem>>();
/// A stream that broadcasts the queue.
static Stream<List<MediaItem>> get queueStream => _queueSubject.stream;
/// The children of the current browse media parent.
static List<MediaItem> get browseMediaChildren => _browseMediaChildren;
static List<MediaItem> _browseMediaChildren;
/// The current playback state.
static PlaybackState get playbackState => _playbackState;
static PlaybackState _playbackState;
/// The current media item.
static MediaItem get currentMediaItem => _currentMediaItem;
static MediaItem _currentMediaItem;
/// The current queue.
static List<MediaItem> get queue => _queue;
static List<MediaItem> _queue;
/// True after service stopped and !running.
static bool _afterStop = false;
/// Connects to the service from your UI so that audio playback can be
/// controlled.
///
/// This method should be called when your UI becomes visible, and
/// [disconnect] should be called when your UI is no longer visible. All
/// other methods in this class will work only while connected.
///
/// Use [AudioServiceWidget] to handle this automatically.
static Future<void> connect() async {
_channel.setMethodCallHandler((MethodCall call) async {
switch (call.method) {
case 'onChildrenLoaded':
final List<Map> args = List<Map>.from(call.arguments[0]);
_browseMediaChildren = args.map(_raw2mediaItem).toList();
_browseMediaChildrenSubject.add(_browseMediaChildren);
break;
case 'onPlaybackStateChanged':
// If this event arrives too late, ignore it.
if (_afterStop) return;
final List args = call.arguments;
int actionBits = args[1];
_playbackState = PlaybackState(
basicState: BasicPlaybackState.values[args[0]],
actions: MediaAction.values
.where((action) => (actionBits & (1 << action.index)) != 0)
.toSet(),
position: args[2],
speed: args[3],
updateTime: args[4],
);
_playbackStateSubject.add(_playbackState);
break;
case 'onMediaChanged':
_currentMediaItem = call.arguments[0] != null
? _raw2mediaItem(call.arguments[0])
: null;
_currentMediaItemSubject.add(_currentMediaItem);
break;
case 'onQueueChanged':
final List<Map> args = call.arguments[0] != null
? List<Map>.from(call.arguments[0])
: null;
_queue = args?.map(_raw2mediaItem)?.toList();
_queueSubject.add(_queue);
break;
case 'onStopped':
_browseMediaChildren = null;
_browseMediaChildrenSubject.add(null);
_playbackState = null;
_playbackStateSubject.add(null);
_currentMediaItem = null;
_currentMediaItemSubject.add(null);
_queue = null;
_queueSubject.add(null);
_running = false;
_afterStop = true;
break;
}
});
await _channel.invokeMethod("connect");
_running = await _channel.invokeMethod("isRunning");
_connected = true;
}
/// Disconnects your UI from the service.
///
/// This method should be called when the UI is no longer visible.
///
/// Use [AudioServiceWidget] to handle this automatically.
static Future<void> disconnect() async {
_channel.setMethodCallHandler(null);
await _channel.invokeMethod("disconnect");
_connected = false;
}
/// True if the UI is connected.
static bool get connected => _connected;
static bool _connected = false;
/// True if the background audio task is running.
static bool _running = false;
static bool get running => _running;
/// Starts a background audio task which will continue running even when the
/// UI is not visible or the screen is turned off.
///
/// While the background task is running, it will display a system
/// notification showing information about the current media item being
/// played (see [AudioServiceBackground.setMediaItem]) along with any media
/// controls to perform any media actions that you want to support (see
/// [AudioServiceBackground.setState]).
///
/// The background task is specified by [backgroundTaskEntrypoint] which will
/// be run within a background isolate. This function must be a top-level or
/// static function, and it must initiate execution by calling
/// [AudioServiceBackground.run]. Because the background task runs in an
/// isolate, no memory is shared between the background isolate and your main
/// UI isolate and so all communication between the background task and your
/// UI is achieved through message passing.
///
/// The [androidNotificationIcon] is specified like an XML resource reference
/// and defaults to `"mipmap/ic_launcher"`.
static Future<bool> start({
@required Function backgroundTaskEntrypoint,
String androidNotificationChannelName = "Notifications",
String androidNotificationChannelDescription,
int notificationColor,
String androidNotificationIcon = 'mipmap/ic_launcher',
bool androidNotificationClickStartsActivity = true,
bool androidNotificationOngoing = false,
bool resumeOnClick = true,
bool androidStopForegroundOnPause = false,
bool enableQueue = false,
bool androidStopOnRemoveTask = false,
int fastForwardInterval = 0,
int rewindInterval = 0,
}) async {
if (_running) return false;
_running = true;
_afterStop = false;
final ui.CallbackHandle handle =
ui.PluginUtilities.getCallbackHandle(backgroundTaskEntrypoint);
if (handle == null) {
return false;
}
var callbackHandle = handle.toRawHandle();
if (Platform.isIOS) {
// NOTE: to maintain compatibility between the Android and iOS
// implementations, we ensure that the iOS background task also runs in
// an isolate. Currently, the standard Isolate API does not allow
// isolates to invoke methods on method channels. That may be fixed in
// the future, but until then, we use the flutter_isolate plugin which
// creates a FlutterNativeView for us, similar to what the Android
// implementation does.
// TODO: remove dependency on flutter_isolate by either using the
// FlutterNativeView API directly or by waiting until Flutter allows
// regular isolates to use method channels.
AudioService._flutterIsolate =
await FlutterIsolate.spawn(_iosIsolateEntrypoint, callbackHandle);
}
final success = await _channel.invokeMethod('start', {
'callbackHandle': callbackHandle,
'androidNotificationChannelName': androidNotificationChannelName,
'androidNotificationChannelDescription':
androidNotificationChannelDescription,
'notificationColor': notificationColor,
'androidNotificationIcon': androidNotificationIcon,
'androidNotificationClickStartsActivity':
androidNotificationClickStartsActivity,
'androidNotificationOngoing': androidNotificationOngoing,
'resumeOnClick': resumeOnClick,
'androidStopForegroundOnPause': androidStopForegroundOnPause,
'enableQueue': enableQueue,
'androidStopOnRemoveTask': androidStopOnRemoveTask,
'fastForwardInterval': fastForwardInterval,
'rewindInterval': rewindInterval,
});
_running = await _channel.invokeMethod("isRunning");
return success;
}
/// Sets the parent of the children that [browseMediaChildrenStream] broadcasts.
/// If unspecified, the root parent will be used.
static Future<void> setBrowseMediaParent(
[String parentMediaId = MEDIA_ROOT_ID]) async {
await _channel.invokeMethod('setBrowseMediaParent', parentMediaId);
}
/// Passes through to `onAddQueueItem` in the background task.
static Future<void> addQueueItem(MediaItem mediaItem) async {
await _channel.invokeMethod('addQueueItem', _mediaItem2raw(mediaItem));
}
/// Passes through to `onAddQueueItemAt` in the background task.
static Future<void> addQueueItemAt(MediaItem mediaItem, int index) async {
await _channel
.invokeMethod('addQueueItemAt', [_mediaItem2raw(mediaItem), index]);
}
/// Passes through to `onRemoveQueueItem` in the background task.
static Future<void> removeQueueItem(MediaItem mediaItem) async {
await _channel.invokeMethod('removeQueueItem', _mediaItem2raw(mediaItem));
}
/// Programmatically simulates a click of a media button on the headset.
///
/// This passes through to `onClick` in the background task.
static Future<void> click([MediaButton button = MediaButton.media]) async {
await _channel.invokeMethod('click', button.index);
}
/// Passes through to `onPrepare` in the background task.
static Future<void> prepare() async {
await _channel.invokeMethod('prepare');
}
/// Passes through to `onPrepareFromMediaId` in the background task.
static Future<void> prepareFromMediaId(String mediaId) async {
await _channel.invokeMethod('prepareFromMediaId', mediaId);
}
//static Future<void> prepareFromSearch(String query, Bundle extras) async {}
//static Future<void> prepareFromUri(Uri uri, Bundle extras) async {}
/// Passes through to 'onPlay' in the background task.
static Future<void> play() async {
await _channel.invokeMethod('play');
}
/// Passes through to 'onPlayFromMediaId' in the background task.
static Future<void> playFromMediaId(String mediaId) async {
await _channel.invokeMethod('playFromMediaId', mediaId);
}
//static Future<void> playFromSearch(String query, Bundle extras) async {}
//static Future<void> playFromUri(Uri uri, Bundle extras) async {}
/// Passes through to `skipToQueueItem` in the background task.
static Future<void> skipToQueueItem(String mediaId) async {
await _channel.invokeMethod('skipToQueueItem', mediaId);
}
/// Passes through to `onPause` in the background task.
static Future<void> pause() async {
await _channel.invokeMethod('pause');
}
/// Passes through to `onStop` in the background task.
static Future<void> stop() async {
await _channel.invokeMethod('stop');
}
/// Passes through to `onSeekTo` in the background task.
static Future<void> seekTo(int pos) async {
await _channel.invokeMethod('seekTo', pos);
}
/// Passes through to `onSkipToNext` in the background task.
static Future<void> skipToNext() async {
await _channel.invokeMethod('skipToNext');
}
/// Passes through to `onSkipToPrevious` in the background task.
static Future<void> skipToPrevious() async {
await _channel.invokeMethod('skipToPrevious');
}
/// Passes through to `onFastForward` in the background task.
static Future<void> fastForward() async {
await _channel.invokeMethod('fastForward');
}
/// Passes through to `onRewind` in the background task.
static Future<void> rewind() async {
await _channel.invokeMethod('rewind');
}
/// Passes through to `onSetRating` in the background task.
/// The extras map must *only* contain primitive types!
static Future<void> setRating(Rating rating,
[Map<String, dynamic> extras]) async {
await _channel.invokeMethod('setRating', {
"rating": rating._toRaw(),
"extras": extras,
});
}
//static Future<void> setCaptioningEnabled(boolean enabled) async {}
//static Future<void> setRepeatMode(@PlaybackStateCompat.RepeatMode int repeatMode) async {}
//static Future<void> setShuffleMode(@PlaybackStateCompat.ShuffleMode int shuffleMode) async {}
//static Future<void> sendCustomAction(PlaybackStateCompat.CustomAction customAction,
//static Future<void> sendCustomAction(String action, Bundle args) async {}
/// Passes through to `onCustomAction` in the background task.
///
/// This may be used for your own purposes.
static Future customAction(String name, [dynamic arguments]) async {
return await _channel.invokeMethod('$_CUSTOM_PREFIX$name', arguments);
}
}
/// Background API to be used by your background audio task.
///
/// The entry point of your background task that you passed to
/// [AudioService.start] is executed in an isolate that will run independently
/// of the view. Aside from its primary job of playing audio, your background
/// task should also use methods of this class to initialise the isolate,
/// broadcast state changes to any UI that may be connected, and to also handle
/// playback actions initiated by the UI.
class AudioServiceBackground {
static final PlaybackState _noneState =
PlaybackState(basicState: BasicPlaybackState.none, actions: Set());
static MethodChannel _backgroundChannel;
static PlaybackState _state = _noneState;
static MediaItem _mediaItem;
static BaseCacheManager _cacheManager;
/// The current media playback state.
///
/// This is the value most recently set via [setState].
static PlaybackState get state => _state;
/// Runs the background audio task within the background isolate.
///
/// This must be the first method called by the entrypoint of your background
/// task that you passed into [AudioService.start]. The [BackgroundAudioTask]
/// parameter defines callbacks to handle the initialization and distruction
/// of the task, as well as any requests by the client to play, pause and
/// otherwise control audio playback.
static Future<void> run(BackgroundAudioTask taskBuilder()) async {
_backgroundChannel =
const MethodChannel('ryanheise.com/audioServiceBackground');
WidgetsFlutterBinding.ensureInitialized();
final task = taskBuilder();
_cacheManager = task.cacheManager;
_backgroundChannel.setMethodCallHandler((MethodCall call) async {
switch (call.method) {
case 'onLoadChildren':
final List args = call.arguments;
String parentMediaId = args[0];
List<MediaItem> mediaItems = await task.onLoadChildren(parentMediaId);
List<Map> rawMediaItems = mediaItems.map(_mediaItem2raw).toList();
return rawMediaItems as dynamic;
case 'onAudioFocusGained':
task.onAudioFocusGained();
break;
case 'onAudioFocusLost':
task.onAudioFocusLost();
break;
case 'onAudioFocusLostTransient':
task.onAudioFocusLostTransient();
break;
case 'onAudioFocusLostTransientCanDuck':
task.onAudioFocusLostTransientCanDuck();
break;
case 'onAudioBecomingNoisy':
task.onAudioBecomingNoisy();
break;
case 'onClick':
final List args = call.arguments;
MediaButton button = MediaButton.values[args[0]];
task.onClick(button);
break;
case 'onStop':
task.onStop();
break;
case 'onPause':
task.onPause();
break;
case 'onPrepare':
task.onPrepare();
break;
case 'onPrepareFromMediaId':
final List args = call.arguments;
String mediaId = args[0];
task.onPrepareFromMediaId(mediaId);
break;
case 'onPlay':
task.onPlay();
break;
case 'onPlayFromMediaId':
final List args = call.arguments;
String mediaId = args[0];
task.onPlayFromMediaId(mediaId);
break;
case 'onAddQueueItem':
task.onAddQueueItem(_raw2mediaItem(call.arguments[0]));
break;
case 'onAddQueueItemAt':
final List args = call.arguments;
MediaItem mediaItem = _raw2mediaItem(args[0]);
int index = args[1];
task.onAddQueueItemAt(mediaItem, index);
break;
case 'onRemoveQueueItem':
task.onRemoveQueueItem(_raw2mediaItem(call.arguments[0]));
break;
case 'onSkipToNext':
task.onSkipToNext();
break;
case 'onSkipToPrevious':
task.onSkipToPrevious();
break;
case 'onFastForward':
task.onFastForward();
break;
case 'onRewind':
task.onRewind();
break;
case 'onSkipToQueueItem':
final List args = call.arguments;
String mediaId = args[0];
task.onSkipToQueueItem(mediaId);
break;
case 'onSeekTo':
final List args = call.arguments;
int pos = args[0];
task.onSeekTo(pos);
break;
case 'onSetRating':
task.onSetRating(
Rating._fromRaw(call.arguments[0]), call.arguments[1]);
break;
default:
if (call.method.startsWith(_CUSTOM_PREFIX)) {
task.onCustomAction(
call.method.substring(_CUSTOM_PREFIX.length), call.arguments);
}
break;
}
});
await _backgroundChannel.invokeMethod('ready');
await task.onStart();
await _backgroundChannel.invokeMethod('stopped');
if (Platform.isIOS) {
AudioService._flutterIsolate?.kill();
}
_backgroundChannel.setMethodCallHandler(null);
_state = _noneState;
}
/// Sets the current playback state and dictates which media actions can be
/// controlled by clients and which media controls and actions should be
/// enabled in the notification, Wear OS and Android Auto. Each control
/// listed in [controls] will appear as a button in the notification and its
/// action will also be made available to all clients such as Wear OS and
/// Android Auto. Any additional actions that you would like to enable for
/// clients that do not correspond to a button can be listed in
/// [systemActions]. For example, include [MediaAction.seekTo] in
/// [systemActions] and the system will provide a seek bar in the
/// notification.
///
/// All clients will be notified so they can update their display.
///
/// The playback [position] should be explicitly updated only when the normal
/// continuity of time is disrupted, such as when the user performs a seek,
/// or buffering occurs, etc. Thus, the [position] parameter indicates the
/// playback position in milliseconds at the time the state was updated while
/// the [updateTime] parameter indicates the precise time of that update.
///
/// The playback [speed] is given as a double where 1.0 means normal speed.
static Future<void> setState({
@required List<MediaControl> controls,
List<MediaAction> systemActions = const [],
@required BasicPlaybackState basicState,
int position = 0,
double speed = 1.0,
int updateTime,
List<int> androidCompactActions,
}) async {
_state = PlaybackState(
basicState: basicState,
actions: controls.map((control) => control.action).toSet(),
position: position,
speed: speed,
updateTime: updateTime,
);
List<Map> rawControls = controls
.map((control) => {
'androidIcon': control.androidIcon,
'label': control.label,
'action': control.action.index,
})
.toList();
final rawSystemActions =
systemActions.map((action) => action.index).toList();
await _backgroundChannel.invokeMethod('setState', [
rawControls,
rawSystemActions,
basicState.index,
position,
speed,
updateTime,
androidCompactActions
]);
}
/// Sets the current queue and notifies all clients.
static Future<void> setQueue(List<MediaItem> queue,
{bool preloadArtwork = false}) async {
if (preloadArtwork) {
_loadAllArtwork(queue);
}
await _backgroundChannel.invokeMethod(
'setQueue', queue.map(_mediaItem2raw).toList());
}
/// Sets the currently playing media item and notifies all clients.
static Future<void> setMediaItem(MediaItem mediaItem) async {
_mediaItem = mediaItem;
if (mediaItem.artUri != null) {
// We potentially need to fetch the art.
final fileInfo = await _cacheManager.getFileFromMemory(mediaItem.artUri);
String filePath = fileInfo?.file?.path;
if (filePath == null) {
// We haven't fetched the art yet, so show the metadata now, and again
// after we load the art.
await _backgroundChannel.invokeMethod(
'setMediaItem', _mediaItem2raw(mediaItem));
// Load the art
filePath = await _loadArtwork(mediaItem);
// If we failed to download the art, abort.
if (filePath == null) return;
// If we've already set a new media item, cancel this request.
if (mediaItem != _mediaItem) return;
}
final extras = Map.of(mediaItem.extras ?? <String, dynamic>{});
extras['artCacheFile'] = filePath;
final platformMediaItem = mediaItem.copyWith(extras: extras);
// Show the media item after the art is loaded.
await _backgroundChannel.invokeMethod(
'setMediaItem', _mediaItem2raw(platformMediaItem));
} else {
await _backgroundChannel.invokeMethod(
'setMediaItem', _mediaItem2raw(mediaItem));
}
}
static Future<void> _loadAllArtwork(List<MediaItem> queue) async {
for (var mediaItem in queue) {
await _loadArtwork(mediaItem);
}
}
static Future<String> _loadArtwork(MediaItem mediaItem) async {
try {
final artUri = mediaItem.artUri;
if (artUri != null) {
const prefix = 'file://';
if (artUri.toLowerCase().startsWith(prefix)) {
return artUri.substring(prefix.length);
} else {
final file = await _cacheManager.getSingleFile(mediaItem.artUri);
return file.path;
}
}
} catch (e) {}
return null;
}
/// Notify clients that the child media items of [parentMediaId] have
/// changed.
///
/// If [parentMediaId] is unspecified, the root parent will be used.
static Future<void> notifyChildrenChanged(
[String parentMediaId = AudioService.MEDIA_ROOT_ID]) async {
await _backgroundChannel.invokeMethod(
'notifyChildrenChanged', parentMediaId);
}
/// In Android, forces media button events to be routed to your active media
/// session.
///
/// This is necessary if you want to play TextToSpeech in the background and