[MD Extensions] Update subpages when the backing extension data changes

chrome/browser/resources/md_extensions/manager.js

 // Copyright 2015 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.
 
 /**
  * The different pages that can be shown at a time.
  * Note: This must remain in sync with the order in manager.html!
  * @enum {string}
  */
 var Page = {
@@ skipping 45 matching lines @@
       inDevMode: {
         type: Boolean,
         value: false,
       },
 
       filter: {
         type: String,
         value: '',
       },
 
+      /**
+       * The item currently displayed in the error subpage. We use a separate
+       * item for different pages (rather than a single subpageItem_ property)
+       * so that hidden subpages don't update when an item updates. That is, we
+       * don't want the details view subpage to update when the item shown in
+       * the errors page updates, and vice versa.
+       * @private {!chrome.developerPrivate.ExtensionInfo|undefined}
+       */
+      errorPageItem_: Object,
+
+      /**
+       * The item currently displayed in the details view subpage. See also
+       * errorPageItem_.
+       * @private {!chrome.developerPrivate.ExtensionInfo|undefined}
+       */
+      detailViewItem_: Object,
+
       /** @type {!Array<!chrome.developerPrivate.ExtensionInfo>} */
       extensions: {
         type: Array,
         value: function() { return []; },
       },
 
       /** @type {!Array<!chrome.developerPrivate.ExtensionInfo>} */
       apps: {
         type: Array,
         value: function() { return []; },
@@ skipping 33 matching lines @@
     get errorPage() {
       return this.$['error-page'];
     },
 
     /**
      * Shows the details view for a given item.
      * @param {!chrome.developerPrivate.ExtensionInfo} data
      */
     showItemDetails: function(data) {
       this.$['items-list'].willShowItemSubpage(data.id);
-      this.$['details-view'].data = data;
+      this.detailViewItem_ = data;
       this.changePage(Page.DETAIL_VIEW);
     },
 
     /**
      * @param {!CustomEvent} event
      * @private
      */
     onFilterChanged_: function(event) {
       this.filter = /** @type {string} */ (event.detail);
     },
@@ skipping 66 matching lines @@
     /**
      * @param {!chrome.developerPrivate.ExtensionInfo} item The data for the
      *     item to update.
      */
     updateItem: function(item) {
       var listId = this.getListId_(item.type);
       var index = this.getIndexInList_(listId, item.id);
       // We should never try and update a non-existent item.
       assert(index >= 0);
       this.set([listId, index], item);
+
+      // Update the subpage if it is open and displaying the item. If it's not
+      // open, we don't update the data even if it's displaying that item. We'll
+      // set the item correctly before opening the page. It's a little weird
+      // that the DOM will have stale data, but there's no point in causing the
+      // extra work.
+      if (this.detailViewItem_ && this.detailViewItem_.id == item.id &&
+          this.$.pages.selected == Page.DETAIL_VIEW) {
+        this.detailViewItem_ = item;
+      } else if (this.errorPageItem_ && this.errorPageItem_.id == item.id &&
+                 this.$.pages.selected == Page.ERROR_PAGE) {
+        this.errorPageItem_ = item;
+      }
     },
 
     /**
      * @param {!chrome.developerPrivate.ExtensionInfo} item The data for the
      *     item to remove.
      */
     removeItem: function(item) {
       var listId = this.getListId_(item.type);
       var index = this.getIndexInList_(listId, item.id);
       // We should never try and remove a non-existent item.
@@ skipping 60 matching lines @@
     },
 
     /**
      * Handles the event for the user clicking on the errors button.
      * @param {!CustomEvent} e
      * @private
      */
     onShouldShowItemErrors_: function(e) {
       var data = e.detail.data;
       this.$['items-list'].willShowItemSubpage(data.id);
-      this.$['error-page'].data = data;
+      this.errorPageItem_ = data;
       this.changePage(Page.ERROR_PAGE);
     },
 
     /** @private */
     onDetailsViewClose_: function() {
+      // Note: we don't reset detailViewItem_ here because doing so just causes
+      // extra work for the data-bound details view.
       this.changePage(Page.ITEM_LIST);
     },
 
     /** @private */
     onErrorPageClose_: function() {
+      // Note: we don't reset errorPageItem_ here because doing so just causes
+      // extra work for the data-bound error page.
       this.changePage(Page.ITEM_LIST);
     }
   });
 
   /**
    * @param {extensions.Manager} manager
    * @constructor
    * @implements {extensions.SidebarListDelegate}
    */
   function ListHelper(manager) {
@@ skipping 23 matching lines @@
     },
 
     /** @override */
     showPackDialog: function() {
       this.manager_.packDialog.show();
     }
   };
 
   return {Manager: Manager};
 });