MD Bookmarks: Support policies for disabling bookmark editing

chrome/browser/resources/md_bookmarks/util.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 Utility functions for the Bookmarks page.
  */
 
 cr.define('bookmarks.util', function() {
   /**
@@ skipping 53 matching lines @@
     return nodeMap;
   }
 
   /** @return {!BookmarksPageState} */
   function createEmptyState() {
     return {
       nodes: {},
       selectedFolder: '0',
       closedFolders: new Set(),
       prefs: {
+        canEdit: true,
         incognitoAvailability: IncognitoAvailability.ENABLED,
       },
       search: {
         term: '',
         inProgress: false,
         results: [],
       },
       selection: {
         items: new Set(),
         anchor: null,
       },
     };
   }
 
   /**
    * @param {BookmarksPageState} state
    * @return {boolean}
    */
   function isShowingSearch(state) {
     return !!state.search.term && !state.search.inProgress;
   }
 
   /**
+   * Returns true if the node with ID |itemId| is modifiable, allowing
+   * the node to be renamed, moved or deleted. Note that if a node is
+   * uneditable, it may still have editable children (for example, the top-level
+   * folders).

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

Might also be worth mentioning that the unmodifiable nodes are going to be top
level folders and anything beneath the managed bookmarks folder (if that's all
that this will ever apply to).

[tsergeant, 2017/06/13 05:32:16]

I think that comment will probably just end up restating the actual code, which
I'd probably rather avoid.

+   * @param {BookmarksPageState} state
+   * @param {string} itemId
+   * @return {boolean}
+   */
+  function canEditNode(state, itemId) {
+    return itemId != ROOT_NODE_ID &&
+        state.nodes[itemId].parentId != ROOT_NODE_ID &&
+        !state.nodes[itemId].unmodifiable && state.prefs.canEdit;
+  }
+
+  /**
+   * Returns true if it is possible to modify the children list of the node with
+   * ID |itemId|. This includes rearranging the children or adding new ones.
+   * @param {BookmarksPageState} state
+   * @param {string} itemId
+   * @return {boolean}
+   */
+  function canReorderChildren(state, itemId) {
+    return itemId != ROOT_NODE_ID && !state.nodes[itemId].unmodifiable &&
+        state.prefs.canEdit;
+  }
+
+  /**
    * @param {string} id
    * @param {NodeMap} nodes
    * @return {boolean}
    */
   function hasChildFolders(id, nodes) {
     var children = nodes[id].children;
     for (var i = 0; i < children.length; i++) {
       if (nodes[children[i]].children)
         return true;
     }
@@ skipping 52 matching lines @@
    */
   function removeIdsFromSet(set, ids) {
     var difference = new Set(set);
     ids.forEach(function(id) {
       difference.delete(id);
     });
     return difference;
   }
 
   return {
+    canEditNode: canEditNode,
+    canReorderChildren: canReorderChildren,
     createEmptyState: createEmptyState,
     getDescendants: getDescendants,
     getDisplayedList: getDisplayedList,
     hasChildFolders: hasChildFolders,
     isShowingSearch: isShowingSearch,
     normalizeNode: normalizeNode,
     normalizeNodes: normalizeNodes,
     removeIdsFromMap: removeIdsFromMap,
     removeIdsFromSet: removeIdsFromSet,
   };
 });