Separate the audio player app from Files.app

ui/file_manager/file_manager/audio_player/elements/audio_player.js

-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-'use strict';
-
-Polymer('audio-player', {
-  /**
-   * Child Elements
-   */
-  audioController: null,
-  audioElement: null,
-  trackList: null,
-
-  // Attributes of the element (lower characters only).
-  // These values must be used only to data binding and shouldn't be assigned
-  // any value nowhere except in the handler.
-  publish: {
-    playing: {
-      value: true,
-      reflect: true
-    },
-    currenttrackurl: {
-      value: '',
-      reflect: true
-    },
-    playcount: {
-      value: 0,
-      reflect: true
-    }
-  },
-
-  /**
-   * Model object of the Audio Player.
-   * @type {AudioPlayerModel}
-   */
-  model: null,
-
-  /**
-   * Initializes an element. This method is called automatically when the
-   * element is ready.
-   */
-  ready: function() {
-    this.audioController = this.$.audioController;
-    this.audioElement = this.$.audio;
-    this.trackList = this.$.trackList;
-
-    this.addEventListener('keydown', this.onKeyDown_.bind(this));
-
-    this.audioElement.volume = 0;  // Temporary initial volume.
-    this.audioElement.addEventListener('ended', this.onAudioEnded.bind(this));
-    this.audioElement.addEventListener('error', this.onAudioError.bind(this));
-
-    var onAudioStatusUpdatedBound = this.onAudioStatusUpdate_.bind(this);
-    this.audioElement.addEventListener('timeupdate', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('ended', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('play', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('pause', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('suspend', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('abort', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('error', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('emptied', onAudioStatusUpdatedBound);
-    this.audioElement.addEventListener('stalled', onAudioStatusUpdatedBound);
-  },
-
-  /**
-   * Registers handlers for changing of external variables
-   */
-  observe: {
-    'trackList.currentTrackIndex': 'onCurrentTrackIndexChanged',
-    'audioController.playing': 'onControllerPlayingChanged',
-    'audioController.time': 'onControllerTimeChanged',
-    'model.volume': 'onVolumeChanged',
-  },
-
-  /**
-   * Invoked when trackList.currentTrackIndex is changed.
-   * @param {number} oldValue old value.
-   * @param {number} newValue new value.
-   */
-  onCurrentTrackIndexChanged: function(oldValue, newValue) {
-    var currentTrackUrl = '';
-
-    if (oldValue != newValue) {
-      var currentTrack = this.trackList.getCurrentTrack();
-      if (currentTrack && currentTrack.url != this.audioElement.src) {
-        this.audioElement.src = currentTrack.url;
-        currentTrackUrl = this.audioElement.src;
-        if (this.audioController.playing)
-          this.audioElement.play();
-      }
-    }
-
-    // The attributes may be being watched, so we change it at the last.
-    this.currenttrackurl = currentTrackUrl;
-  },
-
-  /**
-   * Invoked when audioController.playing is changed.
-   * @param {boolean} oldValue old value.
-   * @param {boolean} newValue new value.
-   */
-  onControllerPlayingChanged: function(oldValue, newValue) {
-    this.playing = newValue;
-
-    if (newValue) {
-      if (!this.audioElement.src) {
-        var currentTrack = this.trackList.getCurrentTrack();
-        if (currentTrack && currentTrack.url != this.audioElement.src) {
-          this.audioElement.src = currentTrack.url;
-        }
-      }
-
-      if (this.audioElement.src) {
-        this.currenttrackurl = this.audioElement.src;
-        this.audioElement.play();
-        return;
-      }
-    }
-
-    // When the new status is "stopped".
-    this.cancelAutoAdvance_();
-    this.audioElement.pause();
-    this.currenttrackurl = '';
-    this.lastAudioUpdateTime_ = null;
-  },
-
-  /**
-   * Invoked when audioController.volume is changed.
-   * @param {number} oldValue old value.
-   * @param {number} newValue new value.
-   */
-  onVolumeChanged: function(oldValue, newValue) {
-    this.audioElement.volume = newValue / 100;
-  },
-
-  /**
-   * Invoked when the model changed.
-   * @param {AudioPlayerModel} oldValue Old Value.
-   * @param {AudioPlayerModel} newValue New Value.
-   */
-  modelChanged: function(oldValue, newValue) {
-    this.trackList.model = newValue;
-    this.audioController.model = newValue;
-
-    // Invoke the handler manually.
-    this.onVolumeChanged(0, newValue.volume);
-  },
-
-  /**
-   * Invoked when audioController.time is changed.
-   * @param {number} oldValue old time (in ms).
-   * @param {number} newValue new time (in ms).
-   */
-  onControllerTimeChanged: function(oldValue, newValue) {
-    // Ignores updates from the audio element.
-    if (this.lastAudioUpdateTime_ === newValue)
-      return;
-
-    if (this.audioElement.readyState !== 0)
-      this.audioElement.currentTime = this.audioController.time / 1000;
-  },
-
-  /**
-   * Invoked when the next button in the controller is clicked.
-   * This handler is registered in the 'on-click' attribute of the element.
-   */
-  onControllerNextClicked: function() {
-    this.advance_(true /* forward */, true /* repeat */);
-  },
-
-  /**
-   * Invoked when the previous button in the controller is clicked.
-   * This handler is registered in the 'on-click' attribute of the element.
-   */
-  onControllerPreviousClicked: function() {
-    this.advance_(false /* forward */, true /* repeat */);
-  },
-
-  /**
-   * Invoked when the playback in the audio element is ended.
-   * This handler is registered in this.ready().
-   */
-  onAudioEnded: function() {
-    this.playcount++;
-    this.advance_(true /* forward */, this.model.repeat);
-  },
-
-  /**
-   * Invoked when the playback in the audio element gets error.
-   * This handler is registered in this.ready().
-   */
-  onAudioError: function() {
-    this.scheduleAutoAdvance_(true /* forward */, this.model.repeat);
-  },
-
-  /**
-   * Invoked when the time of playback in the audio element is updated.
-   * This handler is registered in this.ready().
-   * @private
-   */
-  onAudioStatusUpdate_: function() {
-    this.audioController.time =
-        (this.lastAudioUpdateTime_ = this.audioElement.currentTime * 1000);
-    this.audioController.duration = this.audioElement.duration * 1000;
-    this.audioController.playing = !this.audioElement.paused;
-  },
-
-  /**
-   * Invoked when receiving a request to replay the current music from the track
-   * list element.
-   */
-  onReplayCurrentTrack: function() {
-    // Changes the current time back to the beginning, regardless of the current
-    // status (playing or paused).
-    this.audioElement.currentTime = 0;
-    this.audioController.time = 0;
-  },
-
-  /**
-   * Goes to the previous or the next track.
-   * @param {boolean} forward True if next, false if previous.
-   * @param {boolean} repeat True if repeat-mode is enabled. False otherwise.
-   * @private
-   */
-  advance_: function(forward, repeat) {
-    this.cancelAutoAdvance_();
-
-    var nextTrackIndex = this.trackList.getNextTrackIndex(forward, true);
-    var isNextTrackAvailable =
-        (this.trackList.getNextTrackIndex(forward, repeat) !== -1);
-
-    this.audioController.playing = isNextTrackAvailable;
-
-    // If there is only a single file in the list, 'currentTrackInde' is not
-    // changed and the handler is not invoked. Instead, plays here.
-    // TODO(yoshiki): clean up the code around here.
-    if (isNextTrackAvailable &&
-        this.trackList.currentTrackIndex == nextTrackIndex) {
-      this.audioElement.play();
-    }
-
-    this.trackList.currentTrackIndex = nextTrackIndex;
-
-    Platform.performMicrotaskCheckpoint();
-  },
-
-  /**
-   * Timeout ID of auto advance. Used internally in scheduleAutoAdvance_() and
-   *     cancelAutoAdvance_().
-   * @type {number}
-   * @private
-   */
-  autoAdvanceTimer_: null,
-
-  /**
-   * Schedules automatic advance to the next track after a timeout.
-   * @param {boolean} forward True if next, false if previous.
-   * @param {boolean} repeat True if repeat-mode is enabled. False otherwise.
-   * @private
-   */
-  scheduleAutoAdvance_: function(forward, repeat) {
-    this.cancelAutoAdvance_();
-    var currentTrackIndex = this.currentTrackIndex;
-
-    var timerId = setTimeout(
-        function() {
-          // If the other timer is scheduled, do nothing.
-          if (this.autoAdvanceTimer_ !== timerId)
-            return;
-
-          this.autoAdvanceTimer_ = null;
-
-          // If the track has been changed since the advance was scheduled, do
-          // nothing.
-          if (this.currentTrackIndex !== currentTrackIndex)
-            return;
-
-          // We are advancing only if the next track is not known to be invalid.
-          // This prevents an endless auto-advancing in the case when all tracks
-          // are invalid (we will only visit each track once).
-          this.advance_(forward, repeat, true /* only if valid */);
-        }.bind(this),
-        3000);
-
-    this.autoAdvanceTimer_ = timerId;
-  },
-
-  /**
-   * Cancels the scheduled auto advance.
-   * @private
-   */
-  cancelAutoAdvance_: function() {
-    if (this.autoAdvanceTimer_) {
-      clearTimeout(this.autoAdvanceTimer_);
-      this.autoAdvanceTimer_ = null;
-    }
-  },
-
-  /**
-   * The index of the current track.
-   * If the list has no tracks, the value must be -1.
-   *
-   * @type {number}
-   */
-  get currentTrackIndex() {
-    return this.trackList.currentTrackIndex;
-  },
-  set currentTrackIndex(value) {
-    this.trackList.currentTrackIndex = value;
-  },
-
-  /**
-   * The list of the tracks in the playlist.
-   *
-   * When it changed, current operation including playback is stopped and
-   * restarts playback with new tracks if necessary.
-   *
-   * @type {Array.<AudioPlayer.TrackInfo>}
-   */
-  get tracks() {
-    return this.trackList ? this.trackList.tracks : null;
-  },
-  set tracks(tracks) {
-    if (this.trackList.tracks === tracks)
-      return;
-
-    this.cancelAutoAdvance_();
-
-    this.trackList.tracks = tracks;
-    var currentTrack = this.trackList.getCurrentTrack();
-    if (currentTrack && currentTrack.url != this.audioElement.src) {
-      this.audioElement.src = currentTrack.url;
-      this.audioElement.play();
-    }
-  },
-
-  /**
-   * Invoked when the audio player is being unloaded.
-   */
-  onPageUnload: function() {
-    this.audioElement.src = '';  // Hack to prevent crashing.
-  },
-
-  /**
-   * Invoked when the 'keydown' event is fired.
-   * @param {Event} event The event object.
-   */
-  onKeyDown_: function(event) {
-    switch (event.keyIdentifier) {
-      case 'Up':
-        if (this.audioController.volumeSliderShown && this.model.volume < 100)
-          this.model.volume += 1;
-        break;
-      case 'Down':
-        if (this.audioController.volumeSliderShown && this.model.volume > 0)
-          this.model.volume -= 1;
-        break;
-      case 'PageUp':
-        if (this.audioController.volumeSliderShown && this.model.volume < 91)
-          this.model.volume += 10;
-        break;
-      case 'PageDown':
-        if (this.audioController.volumeSliderShown && this.model.volume > 9)
-          this.model.volume -= 10;
-        break;
-      case 'MediaNextTrack':
-        this.onControllerNextClicked();
-        break;
-      case 'MediaPlayPause':
-        var playing = this.audioController.playing;
-        this.onControllerPlayingChanged(playing, !playing);
-        break;
-      case 'MediaPreviousTrack':
-        this.onControllerPreviousClicked();
-        break;
-      case 'MediaStop':
-        // TODO: Define "Stop" behavior.
-        break;
-    }
-  },
-});