[File Manager] Properly enable/disable Copy and Open for GData files in the offline mode.

chrome/browser/resources/file_manager/js/file_transfer_controller.js

 // Copyright (c) 2012 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.
 
 var MAX_DRAG_THUMBAIL_COUNT = 4;
 
 /**
  * TODO(olege): Fix style warnings.
  */
 function FileTransferController(fileList,
@@ skipping 57 matching lines @@
    * @param {HTMLDocument} doc Command dispatcher.
    */
   attachCopyPasteHandlers: function(doc) {
     this.document_ = doc;
     doc.addEventListener('beforecopy', this.onBeforeCopy_.bind(this));
     doc.addEventListener('copy', this.onCopy_.bind(this));
     doc.addEventListener('beforecut', this.onBeforeCut_.bind(this));
     doc.addEventListener('cut', this.onCut_.bind(this));
     doc.addEventListener('beforepaste', this.onBeforePaste_.bind(this));
     doc.addEventListener('paste', this.onPaste_.bind(this));
+    this.copyCommand_ = doc.querySelector('command#copy');
   },
 
   /**
    * Write the current selection to system clipboard.
    *
    * @param {Clipboard} clipboard Clipboard from the event.
    * @param {string} effectAllowed Value must be valid for the
    *     |dataTransfer.effectAllowed| property ('move', 'copy', 'copyMove').
    */
   cutOrCopy: function(dataTransfer, effectAllowed) {
-    var directories  = [];
+    var directories = [];
     var files = [];
     var entries = this.selectedEntries_;
     for (var i = 0; i < entries.length; i++) {
       (entries[i].isDirectory ? directories : files).push(entries[i].fullPath);
     }
 
     // Tag to check it's filemanager data.
     dataTransfer.setData('fs/tag', 'filemanager-data');
 
     dataTransfer.setData('fs/isOnGData', this.isOnGData);
@@ skipping 158 matching lines @@
 
   onBeforeCopy_: function(event) {
     if (!this.isDocumentWideEvent_(event))
       return;
 
     // queryCommandEnabled returns true if event.returnValue is false.
     event.returnValue = !this.canCopyOrDrag_();
   },
 
   canCopyOrDrag_: function() {
+    if (this.isOnGData && util.isOffline() && !this.allGDataFilesAvailable)
+      return false;
     return this.selectedEntries_.length > 0;
   },
 
   onCut_: function(event) {
     if (!this.isDocumentWideEvent_(event) ||
         !this.canCutOrDrag_()) {
       return;
     }
     event.preventDefault();
     this.cutOrCopy(event.clipboardData, 'move');
@@ skipping 99 matching lines @@
       // asynchronous operations.
       if (!this.isOnGData && entries[i].isFile)
         entries[i].file(function(file) { files.push(file); });
 
       // Items to drag are created in advance. Images must be loaded
       // at the time the 'dragstart' event comes. Otherwise draggable
       // image will be rendered without IMG tags.
       if (dragNodes.length < MAX_DRAG_THUMBAIL_COUNT)
         dragNodes.push(new this.dragNodeConstructor_(entries[i]));
     }
+
+    if (this.isOnGData) {
+      this.allGDataFilesAvailable = false;
+      var urls = entries.map(function(e) { return e.toURL() });
+      this.directoryModel_.getMetadataCache().get(
+          urls, 'gdata', function(props) {
+        // We consider directories not available offline for the purposes of
+        // file transfer since we cannot afford to recursive traversal.
+        this.allGDataFilesAvailable =
+            entries.filter(function(e) {return e.isDirectory}).length == 0 &&
+            props.filter(function(p) {return !p.availableOffline}).length == 0;
+        // |Copy| is the only menu item affected by allGDataFilesAvailable.
+        // It could be open right now, update its UI.
+        this.copyCommand_.disabled = !this.canCopyOrDrag_();
+      }.bind(this));
+    }
   },
 
   get currentDirectory() {
     return this.directoryModel_.getCurrentDirEntry();
   },
 
   get readonly() {
     return this.directoryModel_.isReadOnly();
   },
 
@@ skipping 13 matching lines @@
    * @type {Array.<Entry>}
    */
   get selectedEntries_() {
     var list = this.fileList_;
     return this.fileListSelection_.selectedIndexes.map(function(index) {
       return list.item(index);
     });
   }
 };