MD Bookmarks: Add keyboard shortcut support to bookmarks-command-manager

chrome/browser/resources/md_bookmarks/command_manager.js

 // Copyright 2017 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.
 
 Polymer({
   is: 'bookmarks-command-manager',
 
   behaviors: [
     bookmarks.StoreClient,
   ],
 
   properties: {
     /** @type {Set<string>} */
     menuIds_: Object,
   },
 
   attached: function() {
     /** @private {function(!Event)} */
     this.boundOnOpenItemMenu_ = this.onOpenItemMenu_.bind(this);
     document.addEventListener('open-item-menu', this.boundOnOpenItemMenu_);
+
+    /** @private {function(!Event)} */
+    this.boundOnKeydown_ = this.onKeydown_.bind(this);
+    document.addEventListener('keydown', this.boundOnKeydown_);
+
+    /** @private {Object<Command, string>} */
+    this.shortcuts_ = {};
+    this.shortcuts_[Command.EDIT] = cr.isMac ? 'enter' : 'f2';
+    this.shortcuts_[Command.COPY] = cr.isMac ? 'meta+c' : 'ctrl+c';
+    this.shortcuts_[Command.DELETE] = cr.isMac ? 'delete backspace' : 'delete';
   },
 
   detached: function() {
     document.removeEventListener('open-item-menu', this.boundOnOpenItemMenu_);
+    document.removeEventListener('keydown', this.boundOnKeydown_);
   },
 
   /**
    * Display the command context menu at (|x|, |y|) in window co-ordinates.
    * Commands will execute on the currently selected items.
    * @param {number} x
    * @param {number} y
    */
   openCommandMenuAtPosition: function(x, y) {
     this.menuIds_ = this.getState().selection.items;
@@ skipping 26 matching lines @@
   canExecute: function(command, itemIds) {
     switch (command) {
       case Command.EDIT:
         return itemIds.size == 1;
       case Command.COPY:
         return itemIds.size == 1 &&
             this.containsMatchingNode_(itemIds, function(node) {
               return !!node.url;
             });
       case Command.DELETE:
-        return true;
+        return itemIds.size > 0;
       default:
         return false;
     }
   },
 
   /**
    * @param {Command} command
    * @param {!Set<string>} itemIds
    */
   handle: function(command, itemIds) {
@@ skipping 53 matching lines @@
   /**
    * @param {Event} e
    * @private
    */
   onCommandClick_: function(e) {
     this.closeCommandMenu();
     this.handle(e.target.getAttribute('command'), assert(this.menuIds_));
   },
 
   /**
+   * @param {!Event} e
+   * @private
+   */
+  onKeydown_: function(e) {
+    var selection = this.getState().selection.items;
+    // TODO(tsergeant): Prevent keyboard shortcuts when a dialog is open or text
+    // field is focused.
+    for (var commandName in this.shortcuts_) {
+      var shortcut = this.shortcuts_[commandName];
+      if (Polymer.IronA11yKeysBehavior.keyboardEventMatchesKeys(e, shortcut) &&
+          this.canExecute(commandName, selection)) {
+        this.handle(commandName, selection);
+
+        e.stopPropagation();
+        e.preventDefault();
+        return;
+      }
+    }
+  },
+
+  /**
    * Close the menu on mousedown so clicks can propagate to the underlying UI.
    * This allows the user to right click the list while a context menu is
    * showing and get another context menu.
    * @param {Event} e
    * @private
    */
   onMenuMousedown_: function(e) {
     if (e.path[0] != this.$.dropdown)
       return;
 
     this.$.dropdown.close();
   },
 
   /** @private */
   getEditActionLabel_: function() {
     if (this.menuIds_.size > 1)
       return;
 
     var id = Array.from(this.menuIds_)[0];
     var itemUrl = this.getState().nodes[id].url;
     var label = itemUrl ? 'menuEdit' : 'menuRename';
     return loadTimeData.getString(label);
   },
 });