[File Manager]Disable "Copy" command if selection contains dimmed GData files

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;
 
 function FileTransferController(fileList,
                                 fileListSelection,
                                 dragNodeConstructor,
                                 copyManager,
                                 directoryModel) {
   this.fileList_ = fileList;
   this.fileListSelection_ = fileListSelection;
   this.dragNodeConstructor_ = dragNodeConstructor;
   this.copyManager_ = copyManager;
   this.directoryModel_ = directoryModel;
 
   this.fileListSelection_.addEventListener('change',
       this.onSelectionChanged_.bind(this));
 
   /**
    * DOM elements to represent selected files in drag operation.
    * @type {Array.<Element>}
    */
   this.dragNodes_ = [];
 
   /**
-   * File objects for seletced files.
+   * File objects for selected files.
    * @type {Array.<File>}
    */
   this.files_ = [];
 
 }
 
 FileTransferController.prototype = {
   __proto__: cr.EventTarget.prototype,
 
   /**
@@ skipping 32 matching lines @@
   },
 
   /**
    * 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);
     dataTransfer.setData('fs/sourceDir',
                          this.currentDirectory.fullPath);
     dataTransfer.setData('fs/directories', directories.join('\n'));
     dataTransfer.setData('fs/files', files.join('\n'));
     dataTransfer.effectAllowed = effectAllowed;
     dataTransfer.setData('fs/effectallowed', effectAllowed);
 
     for (var i = 0; i < this.files_.length; i++) {
       dataTransfer.items.add(this.files_[i]);
     }
   },
 
   /**
    * Queue up a file copy operation based on the current system clipboard.
    * @param {DataTransfer} dataTransfer System data transfer object.
    * @param {DirectoryEntry=} opt_destination Paste destination.
+   * @return {string} "move"|"copy"
    */
   paste: function(dataTransfer, opt_destination) {
     var destination = opt_destination || this.currentDirectory;
     // effectAllowed set in copy/pase handlers stay uninitialized. DnD handlers
     // work fine.
     var effectAllowed = dataTransfer.effectAllowed != 'uninitialized' ?
         dataTransfer.effectAllowed : dataTransfer.getData('fs/effectallowed');
 
     var toMove = effectAllowed == 'move' ||
         (effectAllowed == 'copyMove' && dataTransfer.dropEffect != 'copy');
@@ skipping 129 matching lines @@
 
   onBeforeCopy_: function(event) {
     if (!this.isDocumentWideEvent_(event))
       return;
 
     // queryCommandEnabled returns true if event.returnValue is false.
     event.returnValue = !this.canCopyOrDrag_();
   },
 
   canCopyOrDrag_: function() {
-    return this.selectedEntries_.length > 0;
+    return this.selectionAvailable_ && this.selectedEntries_.length > 0;
   },
 
   onCut_: function(event) {
     if (!this.isDocumentWideEvent_(event) ||
         !this.canCutOrDrag_()) {
       return;
     }
     event.preventDefault();
     this.cutOrCopy(event.clipboardData, 'move');
     this.notify_('selection-cut');
@@ skipping 106 matching lines @@
   },
 
   get currentDirectory() {
     return this.directoryModel_.currentEntry;
   },
 
   get readonly() {
     return this.directoryModel_.readonly;
   },
 
+  set selectionAvailable(available) {
+    this.selectionAvailable_ = available;

[dgozman, 2012/04/18 16:07:37]

I don't like this 'set from outside to work properly' approach. Maybe, we can
ask file manager instead?

[Vladislav Kaznacheev, 2012/04/18 16:36:24]

Yeah, I hate it myself. But asking the file manager is not any better. 

How about this:
1. I remove the "change" listener from the selection
2. I add a method like "updateSelection"
3. When the selection changes in the file manager I call this method with an
empty array
4. When the selection is summarized AND it is OK to Copy I call this method with
the actual selected items array.

On 2012/04/18 16:07:37, dgozman wrote:

+  },
+
   get isOnGData() {
     return this.directoryModel_.rootType == DirectoryModel.RootType.GDATA;
   },
 
   notify_: function(eventName) {
     var self = this;
     // Set timeout to avoid recursive events.
     setTimeout(function() {
       cr.dispatchSimpleEvent(self, eventName);
     }, 0);
   },
 
   /**
    * @type {Array.<Entry>}
    */
   get selectedEntries_() {
     var list = this.fileList_;
     return this.fileListSelection_.selectedIndexes.map(function(index) {
       return list.item(index);
     });
   }
 };