Use resolveIsolatedEntries in the separated new Gallery.app.

ui/file_manager/gallery/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';
 
-var stringData = new Promise(function(fulfill) {
-  chrome.fileBrowserPrivate.getStrings(function(stringData) {
-    loadTimeData.data = stringData;
-    fulfill(stringData);
+/**
+ * @param {Object.<string, string>} stringData String data.
+ * @param {VolumeManager} volumeManager Volume manager.
+ */
+function BackgroundComponents(stringData, volumeManager) {
+  /**
+   * String data.
+   * @type {Object.<string, string>}
+   */
+  this.stringData = stringData;
+
+  /**
+   * Volume manager.
+   * @type {VolumeManager}
+   */
+  this.volumeManager = volumeManager;
+
+  Object.freeze(this);
+}
+
+/**
+ * Loads background component.
+ * @return {Promise} Promise fulfilled with BackgroundComponents.
+ */
+BackgroundComponents.load = function() {
+  var stringDataPromise = new Promise(function(fulfill) {
+    chrome.fileBrowserPrivate.getStrings(function(stringData) {
+      loadTimeData.data = stringData;
+      fulfill(stringData);
+    });
   });
-});
 
-// VolumeManager should be obtained after stringData initialized.
-var volumeManager = stringData.then(function() {
-  return new Promise(function(fulfill) {
-    VolumeManager.getInstance(fulfill);
+  // VolumeManager should be obtained after stringData initialized.
+  var volumeManagerPromise = stringDataPromise.then(function() {
+    return new Promise(function(fulfill) {
+      VolumeManager.getInstance(fulfill);
+    });
   });
-});
 
-var backgroundComponent = Promise.all([stringData, volumeManager]).
-    then(function(args) {
-      return {
-        stringData: args[0],
-        volumeManager: args[1]
-      };
+  return Promise.all([stringDataPromise, volumeManagerPromise]).then(
+      function(args) {
+        return new BackgroundComponents(args[0], args[1]);
+      });
+};
+
+/**
+ * Promise to be fulfilled with singleton instance of background components.
+ * @type {Promise}
+ */
+var backgroundComponentPromise = BackgroundComponents.load();

[mtomasz, 2014/05/16 03:29:21]

nit: backgroundComponentPromise -> backgroundComponentsPromise

[hirono, 2014/05/16 04:12:48]

Done.

+
+/**
+ * Resolves file system names and obtains entries.
+ * @param {Array.<FileEntry>} entries Names of isolated file system.
+ * @return {Promise} Promise to be fulfilled with an entry array.
+ */
+function resolveEntries(entries) {
+  return new Promise(function(fulfill, reject) {
+    chrome.fileBrowserPrivate.resolveIsolatedEntries(entries,
+                                                     function(externalEntries) {
+      if (!chrome.runtime.lastError)
+        fulfill(externalEntries);
+      else
+        reject(chrome.runtime.lastError);
     });
+  });
+}
+
+/**
+ * Obtains child entries.
+ * @param {DirectoryEntry} entry Directory entry.
+ * @return {Promise} Promise to be fulfilled with child entries.
+ */
+function getChildren(entry) {
+  var reader = entry.createReader();
+  var readEntries = function() {
+    return new Promise(reader.readEntries.bind(reader)).then(function(entries) {
+      if (entries.length === 0)
+        return [];
+      return readEntries().then(function(nextEntries) {
+        return entries.concat(nextEntries);
+      });
+    });
+  };
+  return readEntries();
+}
 
 chrome.app.runtime.onLaunched.addListener(function(launchData) {
   // Skip if files are not selected.
   if (!launchData || !launchData.items || launchData.items.length == 0)
     return;
 
+  // Obtains entries in non-isolated file systems.
+  // The entries in launchData is stored in the isolated file system.

[mtomasz, 2014/05/16 03:29:21]

nit: is -> are

[hirono, 2014/05/16 04:12:48]

Done.

+  // We need to map the isolated entries to the normal entries to retrieve their
+  // parent directory.
+  var isolatedEntries = launchData.items.map(function(item) {
+    return item.entry;
+  });
+  var selectedEntriesPromise = backgroundComponentPromise.then(function() {
+    return resolveEntries(isolatedEntries);
+  });
+
+  // If only 1 entry is selected, retrieve entries in the same directory.
+  // Otherwise, just use the selectedEntries as an entry set.
+  var allEntriesPromise = selectedEntriesPromise.then(function(entries) {
+    if (entries.length === 1) {
+      var parent = new Promise(entries[0].getParent.bind(entries[0]));
+      return parent.then(getChildren).then(function(entries) {
+        return entries.filter(FileType.isImageOrVideo);
+      });
+    } else {
+      return entries;
+    }
+  });
+
+  // Store the selected and all entries to the launchData.
+  launchData.entriesPromise = Promise.all([selectedEntriesPromise,
+                                           allEntriesPromise]).then(
+      function(args) {
+        return Object.freeze({
+          selectedEntries: args[0],
+          allEntries: args[1]
+        });
+      });
+
   // Open application window.
   chrome.app.window.create(
       'gallery.html',
       {
-        id: 'video',
+        id: 'gallery',
         minWidth: 160,
         minHeight: 100,
         frame: 'none'
       },
       function(appWindow) {
         appWindow.contentWindow.launchData = launchData;
-        appWindow.contentWindow.backgroundComponent = backgroundComponent;
+        appWindow.contentWindow.backgroundComponentPromise =
+            backgroundComponentPromise;
       });
 });