Separate the audio player app from Files.app

ui/file_manager/audio_player/js/background.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';
+
+/**
+ * Icon of the audio player.
+ * TODO(yoshiki): Consider providing an exact size icon, instead of relying
+ * on downsampling by ash.
+ *
+ * @type {string}
+ * @const
+ */
+var AUDIO_PLAYER_ICON = 'audio_player/icons/audio-player-64.png';
+
+/**
+ * Configuration of the audio player panel.
+ * @type {Object}
+ */
+var audioPlayerCreateOptions = {
+  id: 'audio-player',
+  type: 'panel',
+  minHeight: 44 + 73,  // 44px: track, 73px: controller
+  minWidth: 292,
+  height: 44 + 73,  // collapsed
+  width: 292
+};
+
+/**
+ * Backgound object. This is necessary for AppWindowWrapper.
+ * @type {BackgroundBase}
+ */
+var background = new BackgroundBase();
+
+/**
+ * Wrapper of audio player window.
+ * @type {SingletonAppWindowWrapper}
+ */
+var audioPlayer = new SingletonAppWindowWrapper('audio_player.html',
+                                                audioPlayerCreateOptions);
+
+/**
+ * Queue to serialize initialization.
+ * @type {AsyncUtil.Queue}
+ */
+var initializeQueue = new AsyncUtil.Queue();
+
+// Initializes the strings. This needs for the volume manager.
+initializeQueue.run(function(fulfill) {
+  chrome.fileManagerPrivate.getStrings(function(stringData) {
+    loadTimeData.data = stringData;
+    fulfill();
+  });
+});
+
+// Initializes the volume manager. This needs for isolated entries.
+initializeQueue.run(function(fulfill) {
+  VolumeManager.getInstance(fulfill);
+});
+
+// Registers the handlers.
+chrome.app.runtime.onLaunched.addListener(onLaunched);
+chrome.app.runtime.onRestarted.addListener(onRestarted);
+
+/**
+ * Called when an app is launched.
+ * @param {Object} launchData Launch data.
+ */
+function onLaunched(launchData) {
+  if (!launchData || !launchData.items || launchData.items.length == 0)
+    return;
+
+  var playlist = {};
+
+  initializeQueue.run(function(fulfill) {
+    var isolatedEntries = launchData.items.map(function(item) {
+      return item.entry;
+    });
+
+    chrome.fileManagerPrivate.resolveIsolatedEntries(isolatedEntries,
+        function(externalEntries) {
+          var urls = util.entriesToURLs(externalEntries);
+          playlist = {items: urls, position: 0};
+          fulfill();
+        });
+  });
+
+  initializeQueue.run(function(fulfill) {
+    open(playlist, false);
+    fulfill();
+  });
+}
+
+/**
+ * Called when an app is restarted.
+ */
+function onRestarted() {
+  audioPlayer.reopen(function() {
+    // If the audioPlayer is reopened, change its window's icon. Otherwise
+    // there is no reopened window so just skip the call of setIcon.
+    if (audioPlayer.rawAppWindow)
+      audioPlayer.setIcon(AUDIO_PLAYER_ICON);
+  });
+}
+
+/**
+ * Opens player window.
+ * @param {Object} playlist List of audios to play and index to start playing.
+ * @param {Promise} Promise to be fulfilled on success, or rejected on error.
+ */
+function open(playlist, reopen) {
+  var items = playlist.items;
+  var position = playlist.position;
+  var startUrl = (position < items.length) ? items[position] : '';
+
+  return new Promise(function(fulfill, reject) {
+    if (items.length === 0) {
+      reject('No file to open.');
+      return;
+    }
+
+    // Gets the current list of the children of the parent.
+    window.webkitResolveLocalFileSystemURL(items[0], function(fileEntry) {
+      fileEntry.getParent(function(parentEntry) {
+        var dirReader = parentEntry.createReader();
+        var entries = [];
+
+        // Call the reader.readEntries() until no more results are returned.
+        var readEntries = function() {
+           dirReader.readEntries(function(results) {
+            if (!results.length) {
+              fulfill(entries.sort(util.compareName));
+            } else {
+              entries = entries.concat(Array.prototype.slice.call(results, 0));
+              readEntries();
+            }
+          }, reject);
+        };
+
+        // Start reading.
+        readEntries();
+      }, reject);
+    }, reject);
+  }).then(function(entries) {
+    // Omits non-audio files.
+    var audioEntries = entries.filter(FileType.isAudio);
+
+    // Adjusts the position to start playing.
+    var maybePosition = util.entriesToURLs(audioEntries).indexOf(startUrl);
+    if (maybePosition !== -1)
+      position = maybePosition;
+
+    // Opens the audio player panel.
+    return new Promise(function(fulfill, reject) {
+      var urls = util.entriesToURLs(audioEntries);
+      audioPlayer.launch({items: urls, position: position}, reopen, fulfill);
+    });
+  }).then(function() {
+    audioPlayer.setIcon('icons/audio-player-64.png');
+    AppWindowWrapper.focusOnDesktop(audioPlayer.rawAppWindow);
+  }).catch(function(error) {
+    console.error('Launch failed' + error.stack || error);
+    return Promise.reject(error);
+  });
+}