MD Bookmarks: Support policies for disabling bookmark editing

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.
 
 /**
  * @fileoverview Element which shows context menus and handles keyboard
  * shortcuts.
  */
 cr.define('bookmarks', function() {
 
@@ skipping 14 matching lines @@
             Command.COPY,
             Command.DELETE,
             // <hr>
             Command.OPEN_NEW_TAB,
             Command.OPEN_NEW_WINDOW,
             Command.OPEN_INCOGNITO,
           ];
         },
       },
 
-      /** @type {Set<string>} */
+      /** @private {Set<string>} */
       menuIds_: Object,
+
+      /** @private */
+      canEdit_: Boolean,
     },
 
     attached: function() {
       assert(CommandManager.instance_ == null);
       CommandManager.instance_ = this;
 
+      this.watch('canEdit_', function(state) {
+        return state.prefs.canEdit;
+      });
+      this.updateFromStore();
+
       /** @private {function(!Event)} */
       this.boundOnOpenItemMenu_ = this.onOpenItemMenu_.bind(this);
       document.addEventListener('open-item-menu', this.boundOnOpenItemMenu_);
 
       /** @private {function()} */
       this.boundOnCommandUndo_ = function() {
         this.handle(Command.UNDO, new Set());
       }.bind(this);
       document.addEventListener('command-undo', this.boundOnCommandUndo_);
 
@@ skipping 60 matching lines @@
      * @param {Command} command
      * @param {!Set<string>} itemIds
      * @return {boolean}
      */
     canExecute: function(command, itemIds) {
       switch (command) {
         case Command.OPEN:
           return itemIds.size > 0;
         case Command.UNDO:
         case Command.REDO:
-          return true;
+          return this.canEdit_;

[calamity, 2017/06/09 06:47:31]

Does anything bad happen if this is true?

[tsergeant, 2017/06/13 03:13:10]

The call to chrome.bookmarkManagerPrivate.undo() will throw an exception, but
nothing bad really happens.

[calamity, 2017/06/13 05:13:53]

Acknowledged.

         default:
           return this.isCommandVisible_(command, itemIds) &&
               this.isCommandEnabled_(command, itemIds);
       }
     },
 
     /**
      * @param {Command} command
      * @param {!Set<string>} itemIds
      * @return {boolean} True if the command should be visible in the context
      *     menu.
      */
     isCommandVisible_: function(command, itemIds) {
       switch (command) {
         case Command.EDIT:
-          return itemIds.size == 1;
+          return itemIds.size == 1 && this.canEdit_;
         case Command.COPY:
-          return itemIds.size == 1 &&
-              this.containsMatchingNode_(itemIds, function(node) {
-                return !!node.url;
-              });
+          return this.isSingleBookmark_(itemIds);
         case Command.DELETE:
+          return itemIds.size > 0 && this.canEdit_;
         case Command.OPEN_NEW_TAB:
         case Command.OPEN_NEW_WINDOW:
         case Command.OPEN_INCOGNITO:
           return itemIds.size > 0;
         default:
           return false;
       }
     },
 
     /**
      * @param {Command} command
      * @param {!Set<string>} itemIds
      * @return {boolean} True if the command should be clickable in the context
      *     menu.
      */
     isCommandEnabled_: function(command, itemIds) {
       switch (command) {
+        case Command.EDIT:
+        case Command.DELETE:
+          var state = this.getState();
+          return !this.containsMatchingNode_(itemIds, function(node) {
+            return bookmarks.util.isNodeUnmodifiable(state, node.id);
+          });
         case Command.OPEN_NEW_TAB:
         case Command.OPEN_NEW_WINDOW:
           return this.expandUrls_(itemIds).length > 0;
         case Command.OPEN_INCOGNITO:
           return this.expandUrls_(itemIds).length > 0 &&
               this.getState().prefs.incognitoAvailability !=
               IncognitoAvailability.DISABLED;
         default:
           return true;
       }
@@ skipping 178 matching lines @@
      */
     containsMatchingNode_: function(itemIds, predicate) {
       var nodes = this.getState().nodes;
 
       return Array.from(itemIds).some(function(id) {
         return predicate(nodes[id]);
       });
     },
 
     /**
+     * @param {!Set<string>} itemIds
+     * @return {boolean} True if |itemIds| is a single bookmark (non-folder)
+     *     node.
+     */
+    isSingleBookmark_: function(itemIds) {
+      return itemIds.size == 1 &&
+          this.containsMatchingNode_(itemIds, function(node) {
+            return !!node.url;
+          });
+    },
+
+    /**
      * @param {Event} e
      * @private
      */
     onOpenItemMenu_: function(e) {
       if (e.detail.targetElement) {
         this.openCommandMenuAtElement(e.detail.targetElement);
       } else {
         this.openCommandMenuAtPosition(e.detail.x, e.detail.y);
       }
     },
@@ skipping 69 matching lines @@
       }
 
       return loadTimeData.getString(assert(label));
     },
 
     /**
      * @param {Command} command
      * @return {boolean}
      * @private
      */
-    showDividerAfter_: function(command) {
-      return command == Command.DELETE;
+    showDividerAfter_: function(command, itemIds) {
+      return command == Command.DELETE &&
+          (this.canEdit_ || this.isSingleBookmark_(itemIds));
     },
   });
 
   /** @private {bookmarks.CommandManager} */
   CommandManager.instance_ = null;
 
   /** @return {!bookmarks.CommandManager} */
   CommandManager.getInstance = function() {
     return assert(CommandManager.instance_);
   };
 
   return {
     CommandManager: CommandManager,
   };
 });