Disabling "Select all" chechbox when the dir is empty.

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

 // Copyright (c) 2011 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.
 
 // Setting the src of an img to an empty string can crash the browser, so we
 // use an empty 1x1 gif instead.
 const EMPTY_IMAGE_URI = 'data:image/gif;base64,'
         + 'R0lGODlhAQABAPABAP///wAAACH5BAEKAAAALAAAAAABAAEAAAICRAEAOw%3D%3D';
 
 var g_slideshow_data = null;
@@ skipping 732 matching lines @@
     this.dataModel_.prepareSort = this.prepareSort_.bind(this);
 
     if (this.dialogType_ == FileManager.DialogType.SELECT_OPEN_FILE ||
         this.dialogType_ == FileManager.DialogType.SELECT_OPEN_FOLDER ||
         this.dialogType_ == FileManager.DialogType.SELECT_SAVEAS_FILE) {
       this.selectionModelClass_ = cr.ui.ListSingleSelectionModel;
     } else {
       this.selectionModelClass_ = cr.ui.ListSelectionModel;
     }
 
+    this.dataModel_.addEventListener('splice',
+                                     this.onDataModelSplice_.bind(this));
+
     this.initTable_();
     this.initGrid_();
 
     this.setListType(FileManager.ListType.DETAIL);
 
     this.onResize_();
 
     this.textSearchState_ = {text: '', date: new Date()};
   };
 
@@ skipping 83 matching lines @@
    * @param {Entry} entry An HTML5 Entry object.
    * @param {function(Entry)} successCallback The function to invoke once the
    *     icon type is known.
    */
   FileManager.prototype.cacheEntryIconType = function(entry, successCallback) {
     this.getIconType(entry);
     if (successCallback)
       setTimeout(function() { successCallback(entry) }, 0);
   };
 
+  FileManager.prototype.onDataModelSplice_ = function(event) {
+    var checkbox = this.document_.querySelector('#select-all-checkbox');
+    if (checkbox)
+      this.updateSelectAllCheckboxState_(checkbox);
+  };
+
   /**
    * Get the file type of the entry, caching the result.
    *
    * When this method completes, the entry object will get a
    * 'cachedIconType_' property (if it doesn't already have one) containing the
    * icon type of the file as a string.
    *
    * @param {Entry} entry An HTML5 Entry object.
    * @param {function(Entry)} successCallback The function to invoke once the
    *     file size is known.
@@ skipping 687 matching lines @@
     }
 
     return input;
   };
 
   FileManager.prototype.renderNameColumnHeader_ = function(name, table) {
     var input = this.document_.createElement('input');
     input.setAttribute('type', 'checkbox');
     input.setAttribute('tabindex', -1);
     input.id = 'select-all-checkbox';
-    input.checked = this.areAllItemsSelected();
+    this.updateSelectAllCheckboxState_(input);
 
-    var self = this;
     input.addEventListener('click', function(event) {
-      if (self.areAllItemsSelected())
+      if (input.checked)
+        table.selectionModel.selectAll();
+      else
         table.selectionModel.unselectAll();
-      else
-        table.selectionModel.selectAll();
       event.preventDefault();
       event.stopPropagation();
     });
 
     var fragment = this.document_.createDocumentFragment();
     fragment.appendChild(input);
     fragment.appendChild(this.document_.createTextNode(name));
     return fragment;
   };
 
   /**
-   * Check if all items in the current list are selected.
-   * @return {boolean} True if all items are selected.
+   * Update check and disable states of the 'Select all' checkbox.
    */
-  FileManager.prototype.areAllItemsSelected = function() {
-    return this.selection && this.dataModel_.length > 0 &&
-           this.dataModel_.length == this.selection.totalCount;
+  FileManager.prototype.updateSelectAllCheckboxState_ = function(checkbox) {
+    checkbox.checked = this.selection && this.dataModel_.length > 0 &&
+                       this.dataModel_.length == this.selection.totalCount;
+    checkbox.disabled = this.dataModel_.length == 0;
   };
 
   /**
    * Update the thumbnail image to fit/fill the square container.
    *
    * Using webkit center packing does not align the image properly, so we need
    * to wait until the image loads and its proportions are known, then manually
    * position it at the center.
    *
    * @param {CSSStyleDeclaration} style Style object of the image.
@@ skipping 1336 matching lines @@
       for (var i = 0; i < this.selection.entries.length; i++) {
         var selectedIndex = this.selection.indexes[i];
         var listItem = this.currentList_.getListItemByIndex(selectedIndex);
         if (listItem)
           listItem.querySelector('input[type="checkbox"]').checked = true;
       }
     }
     var selectAllCheckbox =
         this.document_.getElementById('select-all-checkbox');
     if (selectAllCheckbox)
-      selectAllCheckbox.checked = this.areAllItemsSelected();
+      this.updateSelectAllCheckboxState_(selectAllCheckbox);
   };
 
   FileManager.prototype.updateOkButton_ = function(event) {
     var selectable;
 
     if (this.dialogType_ == FileManager.DialogType.SELECT_FOLDER) {
       selectable = this.selection.directoryCount == 1 &&
           this.selection.fileCount == 0;
     } else if (this.dialogType_ == FileManager.DialogType.SELECT_OPEN_FILE) {
       selectable = (this.selection.directoryCount == 0 &&
@@ skipping 1027 matching lines @@
           });
       }, onError);
 
       function onError(err) {
         console.log('Error while checking free space: ' + err);
         setTimeout(doCheck, 1000 * 60);
       }
     }
   }
 })();