Support to repeat one song in Audio Player.

ui/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.
 
 Polymer({
   is: 'audio-player',
 
   listeners: {
     'toggle-pause-event': 'onTogglePauseEvent_',
     'small-forward-skip-event': 'onSmallForwardSkipEvent_',
@@ skipping 23 matching lines @@
 
     /**
      * Whether the shuffle button is ON.
      */
     shuffle: {
       type: Boolean,
       notify: true
     },
 
     /**
-     * Whether the repeat button is ON.
+     * What mode the repeat button idicates.
+     * repeat-modes can be "repeat-none", "repeat-all", "repeat-one".
      */
     repeat: {
-      type: Boolean,
+      type: String,
       notify: true
     },
 
     /**
      * The audio volume. 0 is silent, and 100 is maximum loud.
      */
     volume: {
       type: Number,
       notify: true
     },
@@ skipping 141 matching lines @@
 
     if (this.$.audio.readyState !== 0)
       this.$.audio.currentTime = this.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 */);
+    this.advance_(true /* forward */, "repeat-all");
   },
 
   /**
    * 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 */);
+    this.advance_(false /* forward */, "repeat-all");
   },
 
   /**
    * 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.repeat);
   },
@@ skipping 32 matching lines @@
     // Changes the current time back to the beginning, regardless of the current
     // status (playing or paused).
     this.$.audio.currentTime = 0;
     this.time = 0;
     this.$.audio.play();
   },
 
   /**
    * 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.
+   * @param {string} repeatMode Repeat mode name.
    * @private
    */
-  advance_: function(forward, repeat) {
+  advance_: function(forward, repeatMode) {

[fukino, 2016/09/02 12:11:48]

I think we don't need to change this advance_ function.
Actually, in repeat-one mode, we don't advance to the next song.

Maybe we can handle the repeat-one case in scheduleAutoAdvance_.

[harukam, 2016/09/05 04:35:03]

scheduleAutoAdvance_ is called only when error happens.
So, I think we have to change not only scheduleAutoAdvance_, but also
onAudioEnded if we do not change advance_ function.
Do you think I should change these two parts, or create a new function like
repeat_or_advance_(repeatMode)?

[fukino, 2016/09/05 11:44:13]

I think this should work:
1) On onAudioEnded, we repeat the current song if repeat mode is repeat-one.
2) On onAudioError, we should stop playing, instead of schedule auto advance, if
repeat mode is repeat-one.

[harukam, 2016/09/09 04:54:50]

OK. Thanks.

+    console.assert(repeatMode == "repeat-none" || repeatMode === "repeat-all" ||
+        repeatMode == "repeat-one");
+
     this.cancelAutoAdvance_();
 
+    if(repeatMode === "repeat-one") {
+      this.playing = true;
+      this.$.audio.currentTime = 0;
+      this.$.trackList.fire('current-track-index-changed');

[harukam, 2016/09/02 11:27:27]

Question, do you think this line is necessary?
According to the definition of 'currentTrackIndexChanged' in
'audio_player/elements/track_list.js' (observer of currentTrackIndex), it
doesn't seem do anything when the index doesn't change.

[fukino, 2016/09/02 12:11:48]

According to https://codereview.chromium.org/1681843002,
the current-track-index-changed event is fired to restart playback when there is
only one song.

Please check if it works without the event firing when the mode is repeat-one
and there is only one song and the user press next/prev button.

[harukam, 2016/09/05 04:35:03]

Thanks for the link. It works without the event firing in all three modes when
there is only one song.

I don't understand why we need to fire the event though currentTrackIndexChanged
function doesn't do anything when both new value and old one are same.
In addition, currentTrackIndexChanged isn't called when we do
"this.$.trackList.fire('current-track-index-changed')".

[fukino, 2016/09/05 11:44:13]

Maybe we can drop the current-track-index-changed from advance_, but let's keep
it as it is until we can understand why it is added in the previous CL.

[harukam, 2016/09/09 04:54:50]

Acknowledged.

+      return;
+    }
+
+    var repeat = repeatMode === "repeat-all";
     var nextTrackIndex = this.$.trackList.getNextTrackIndex(forward, true);
     var isNextTrackAvailable =
         (this.$.trackList.getNextTrackIndex(forward, repeat) !== -1);
 
     this.playing = isNextTrackAvailable;
 
     var shouldFireEvent = this.$.trackList.currentTrackIndex === nextTrackIndex;
     this.$.trackList.currentTrackIndex = nextTrackIndex;
     this.$.audio.currentTime = 0;
     // If the next track and current track is the same,
     // the event will not be fired.
     // So we will fire the event here.
     // This happenes if there is only one song.
     if (shouldFireEvent) {
       this.$.trackList.fire('current-track-index-changed');
     }
   },
 
   /**
    * 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.
+   * @param {string} repeatMode Repeat mode name.
    * @private
    */
-  scheduleAutoAdvance_: function(forward, repeat) {
+  scheduleAutoAdvance_: function(forward, repeatMode) {
     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);
+          this.advance_(forward, repeatMode);
         }.bind(this),
         3000);
 
     this.autoAdvanceTimer_ = timerId;
   },
 
   /**
    * Cancels the scheduled auto advance.
    * @private
    */
@@ skipping 147 matching lines @@
   },
 
   /**
    * Big skip backword.
    * @private
    */
   onBigBackwordSkipEvent_: function(event) {
     this.$.audioController.bigSkip(false);
   },
 });