[MD Bookmarks] Double Click

chrome/browser/resources/md_bookmarks/store.js

 // Copyright 2016 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 BookmarksStore = Polymer({
   is: 'bookmarks-store',
 
   properties: {
     /** @type {BookmarkTreeNode} */
     rootNode: {
@@ skipping 342 matching lines @@
     // Deselect the old folder if defined.
     if (this.selectedId && this.idToNodeMap_[this.selectedId])
       this.set(
           this.idToNodeMap_[this.selectedId].path + '.isSelectedFolder', false);
 
     // Check if the selected id is that of a defined folder.
     var id = /** @type {string} */ (e.detail);
     if (!this.idToNodeMap_[id] || this.idToNodeMap_[id].url)
       id = this.rootNode.children[0].id;
 
-    var newFolder = this.idToNodeMap_[id];
-    this.set(newFolder.path + '.isSelectedFolder', true);
+    var folder = this.idToNodeMap_[id];
+    this.set(folder.path + '.isSelectedFolder', true);
     this.selectedId = id;
+    while (folder.parentId) {
+      folder = this.idToNodeMap_[folder.parentId];
+      if (folder.isOpen)
+        continue;
+
+      this.fire('folder-open-changed', {
+        id: folder.id,
+        open: true,
+      });
+    }

[calamity, 2017/02/03 04:12:22]

I'm not a super fan of the loop structure here and the reuse of the folder
variable (if someone wants to use folder beneath this line, they might get
bitten by the fact it's changed from the selected folder to the root node).

I think you should just stop when something is a child of the root node. This
loop will actually tell the root node to open itself too.

I'm also just used to loop variable updates at the end of the loop.

How about:

var parent = this.idToNodeMap_[folder.parentId];
while (parent.id != this.rootNode.id) {
  if (!parent.isOpen)
    this.fire(...);

  parent = this.idToNodeMap_[parent.parentId];
}

[jiaxi, 2017/02/06 05:11:03]

This will return a "cannot read id of undefined" if we're selecting the
rootNode. Also I don't think this loop tell the root node to open itselt cause
it stops when parent  == rootNode. I've made some changes to this loop. Please
take a look.

   },
 
   /**
    * Handles events that open and close folders.
    * @param {CustomEvent} e
    * @private
    */
   onFolderOpenChanged_: function(e) {
     var folder = this.idToNodeMap_[e.detail.id];
     this.set(folder.path + '.isOpen', e.detail.open);
@@ skipping 49 matching lines @@
     idToNodeMap[bookmarkNode.id] = bookmarkNode;
 
   if (bookmarkNode.url)
     return;
 
   bookmarkNode.isSelectedFolder = false;
   bookmarkNode.isOpen = true;
   for (var i = 0; i < bookmarkNode.children.length; i++)
     BookmarksStore.initNodes(bookmarkNode.children[i], idToNodeMap);
 };