gnome-shell/js/ui/mpris.js
Bryan Dunsmore f526e592fe mpris: Prevent DBus race when creating media players
Sometimes an MPRIS media player will create and then destroy an object
before the signals that handle the object's destruction can be created.
This verifies that the object still exists after the necessary signals
have been created.

https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2776
2020-05-13 19:46:24 +02:00

306 lines
9.5 KiB
JavaScript

/* exported MediaSection */
const { Gio, GObject, Shell, St } = imports.gi;
const Signals = imports.signals;
const Calendar = imports.ui.calendar;
const Main = imports.ui.main;
const MessageList = imports.ui.messageList;
const { loadInterfaceXML } = imports.misc.fileUtils;
const DBusIface = loadInterfaceXML('org.freedesktop.DBus');
const DBusProxy = Gio.DBusProxy.makeProxyWrapper(DBusIface);
const MprisIface = loadInterfaceXML('org.mpris.MediaPlayer2');
const MprisProxy = Gio.DBusProxy.makeProxyWrapper(MprisIface);
const MprisPlayerIface = loadInterfaceXML('org.mpris.MediaPlayer2.Player');
const MprisPlayerProxy = Gio.DBusProxy.makeProxyWrapper(MprisPlayerIface);
const MPRIS_PLAYER_PREFIX = 'org.mpris.MediaPlayer2.';
var MediaMessage = GObject.registerClass(
class MediaMessage extends MessageList.Message {
_init(player) {
super._init('', '');
this._player = player;
this._icon = new St.Icon({ style_class: 'media-message-cover-icon' });
this.setIcon(this._icon);
this._prevButton = this.addMediaControl('media-skip-backward-symbolic',
() => {
this._player.previous();
});
this._playPauseButton = this.addMediaControl(null,
() => {
this._player.playPause();
});
this._nextButton = this.addMediaControl('media-skip-forward-symbolic',
() => {
this._player.next();
});
this._updateHandlerId =
this._player.connect('changed', this._update.bind(this));
this._closedHandlerId =
this._player.connect('closed', this.close.bind(this));
this._update();
}
_onDestroy() {
super._onDestroy();
this._player.disconnect(this._updateHandlerId);
this._player.disconnect(this._closedHandlerId);
}
vfunc_clicked() {
this._player.raise();
Main.panel.closeCalendar();
}
_updateNavButton(button, sensitive) {
button.reactive = sensitive;
}
_update() {
this.setTitle(this._player.trackArtists.join(', '));
this.setBody(this._player.trackTitle);
if (this._player.trackCoverUrl) {
let file = Gio.File.new_for_uri(this._player.trackCoverUrl);
this._icon.gicon = new Gio.FileIcon({ file });
this._icon.remove_style_class_name('fallback');
} else {
this._icon.icon_name = 'audio-x-generic-symbolic';
this._icon.add_style_class_name('fallback');
}
let isPlaying = this._player.status == 'Playing';
let iconName = isPlaying
? 'media-playback-pause-symbolic'
: 'media-playback-start-symbolic';
this._playPauseButton.child.icon_name = iconName;
this._updateNavButton(this._prevButton, this._player.canGoPrevious);
this._updateNavButton(this._nextButton, this._player.canGoNext);
}
});
var MprisPlayer = class MprisPlayer {
constructor(busName) {
this._mprisProxy = new MprisProxy(Gio.DBus.session, busName,
'/org/mpris/MediaPlayer2',
this._onMprisProxyReady.bind(this));
this._playerProxy = new MprisPlayerProxy(Gio.DBus.session, busName,
'/org/mpris/MediaPlayer2',
this._onPlayerProxyReady.bind(this));
this._visible = false;
this._trackArtists = [];
this._trackTitle = '';
this._trackCoverUrl = '';
this._busName = busName;
}
get status() {
return this._playerProxy.PlaybackStatus;
}
get trackArtists() {
return this._trackArtists;
}
get trackTitle() {
return this._trackTitle;
}
get trackCoverUrl() {
return this._trackCoverUrl;
}
playPause() {
this._playerProxy.PlayPauseRemote();
}
get canGoNext() {
return this._playerProxy.CanGoNext;
}
next() {
this._playerProxy.NextRemote();
}
get canGoPrevious() {
return this._playerProxy.CanGoPrevious;
}
previous() {
this._playerProxy.PreviousRemote();
}
raise() {
// The remote Raise() method may run into focus stealing prevention,
// so prefer activating the app via .desktop file if possible
let app = null;
if (this._mprisProxy.DesktopEntry) {
let desktopId = '%s.desktop'.format(this._mprisProxy.DesktopEntry);
app = Shell.AppSystem.get_default().lookup_app(desktopId);
}
if (app)
app.activate();
else if (this._mprisProxy.CanRaise)
this._mprisProxy.RaiseRemote();
}
_close() {
this._mprisProxy.disconnect(this._ownerNotifyId);
this._mprisProxy = null;
this._playerProxy.disconnect(this._propsChangedId);
this._playerProxy = null;
this.emit('closed');
}
_onMprisProxyReady() {
this._ownerNotifyId = this._mprisProxy.connect('notify::g-name-owner',
() => {
if (!this._mprisProxy.g_name_owner)
this._close();
});
// It is possible for the bus to disappear before the previous signal
// is connected, so we must ensure that the bus still exists at this
// point.
if (!this._mprisProxy.g_name_owner)
this._close();
}
_onPlayerProxyReady() {
this._propsChangedId = this._playerProxy.connect('g-properties-changed',
this._updateState.bind(this));
this._updateState();
}
_updateState() {
let metadata = {};
for (let prop in this._playerProxy.Metadata)
metadata[prop] = this._playerProxy.Metadata[prop].deep_unpack();
// Validate according to the spec; some clients send buggy metadata:
// https://www.freedesktop.org/wiki/Specifications/mpris-spec/metadata
this._trackArtists = metadata['xesam:artist'];
if (!Array.isArray(this._trackArtists) ||
!this._trackArtists.every(artist => typeof artist === 'string')) {
if (typeof this._trackArtists !== 'undefined') {
log(('Received faulty track artist metadata from %s; ' +
'expected an array of strings, got %s (%s)').format(
this._busName, this._trackArtists, typeof this._trackArtists));
}
this._trackArtists = [_("Unknown artist")];
}
this._trackTitle = metadata['xesam:title'];
if (typeof this._trackTitle !== 'string') {
if (typeof this._trackTitle !== 'undefined') {
log(('Received faulty track title metadata from %s; ' +
'expected a string, got %s (%s)').format(
this._busName, this._trackTitle, typeof this._trackTitle));
}
this._trackTitle = _("Unknown title");
}
this._trackCoverUrl = metadata['mpris:artUrl'];
if (typeof this._trackCoverUrl !== 'string') {
if (typeof this._trackCoverUrl !== 'undefined') {
log(('Received faulty track cover art metadata from %s; ' +
'expected a string, got %s (%s)').format(
this._busName, this._trackCoverUrl, typeof this._trackCoverUrl));
}
this._trackCoverUrl = '';
}
this.emit('changed');
let visible = this._playerProxy.CanPlay;
if (this._visible != visible) {
this._visible = visible;
if (visible)
this.emit('show');
else
this.emit('hide');
}
}
};
Signals.addSignalMethods(MprisPlayer.prototype);
var MediaSection = GObject.registerClass(
class MediaSection extends MessageList.MessageListSection {
_init() {
super._init();
this._players = new Map();
this._proxy = new DBusProxy(Gio.DBus.session,
'org.freedesktop.DBus',
'/org/freedesktop/DBus',
this._onProxyReady.bind(this));
}
_shouldShow() {
return !this.empty && Calendar.isToday(this._date);
}
get allowed() {
return !Main.sessionMode.isGreeter;
}
_addPlayer(busName) {
if (this._players.get(busName))
return;
let player = new MprisPlayer(busName);
let message = null;
player.connect('closed',
() => {
this._players.delete(busName);
});
player.connect('show', () => {
message = new MediaMessage(player);
this.addMessage(message, true);
});
player.connect('hide', () => {
this.removeMessage(message, true);
message = null;
});
this._players.set(busName, player);
}
_onProxyReady() {
this._proxy.ListNamesRemote(([names]) => {
names.forEach(name => {
if (!name.startsWith(MPRIS_PLAYER_PREFIX))
return;
this._addPlayer(name);
});
});
this._proxy.connectSignal('NameOwnerChanged',
this._onNameOwnerChanged.bind(this));
}
_onNameOwnerChanged(proxy, sender, [name, oldOwner, newOwner]) {
if (!name.startsWith(MPRIS_PLAYER_PREFIX))
return;
if (newOwner && !oldOwner)
this._addPlayer(name);
}
});