DevTools: TabbedLocations only materialize tabs when needed

third_party/WebKit/Source/devtools/front_end/ui/View.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.
 /**
  * @interface
  */
 UI.View = function() {};
 
 UI.View.prototype = {
   /**
@@ skipping 424 matching lines @@
       var shouldFocus = this.element.hasFocus();
       this.setDefaultFocusedElement(null);
       this._view[UI.View._widgetSymbol] = widget;
       widget.show(this.element);
       if (shouldFocus)
         widget.focus();
     }));
     this._materializePromise = Promise.all(promises);
     return this._materializePromise;
   }
+
+  /**
+   * @override
+   */
+  wasShown() {
+    this._materialize();
+  }
 };
 
 /**
  * @unrestricted
  */
 UI.ViewManager._ExpandableContainerWidget = class extends UI.VBox {
   /**
    * @param {!UI.View} view
    */
   constructor(view) {
@@ skipping 247 matching lines @@
   /**
    * @override
    * @param {!UI.View} view
    * @param {?UI.View=} insertBefore
    * @return {!Promise}
    */
   showView(view, insertBefore) {
     this.appendView(view, insertBefore);
     this._tabbedPane.selectTab(view.viewId());
     this._tabbedPane.focus();
-    return this._materializeWidget(view);
+    var widget = /** @type {!UI.ViewManager._ContainerWidget} */ (this._tabbedPane.tabView(view.viewId()));
+    return widget._materialize();
   }
 
   /**
    * @param {!UI.View} view
    * @override
    */
   removeView(view) {
     if (!this._tabbedPane.hasTab(view.viewId()))
       return;
 
     delete view[UI.ViewManager._Location.symbol];
     this._manager._views.delete(view.viewId());
     this._views.delete(view.viewId());
     this._tabbedPane.closeTab(view.viewId());
   }
 
   /**
    * @param {!Common.Event} event
    */
   _tabSelected(event) {
     var tabId = /** @type {string} */ (event.data.tabId);
     if (this._lastSelectedTabSetting && event.data['isUserGesture'])
       this._lastSelectedTabSetting.set(tabId);
     var view = this._views.get(tabId);
     if (!view)
       return;
 
-    this._materializeWidget(view);
-
     if (view.isCloseable()) {
       var tabs = this._closeableTabSetting.get();
       if (!tabs[tabId]) {
         tabs[tabId] = true;
         this._closeableTabSetting.set(tabs);
       }
     }
   }
 
   /**
    * @param {!Common.Event} event
    */
   _tabClosed(event) {
     var id = /** @type {string} */ (event.data['tabId']);
     var tabs = this._closeableTabSetting.get();
     if (tabs[id]) {
       delete tabs[id];
       this._closeableTabSetting.set(tabs);
     }
   }
 
   /**
-   * @param {!UI.View} view
-   * @return {!Promise}
-   */
-  _materializeWidget(view) {
-    var widget = /** @type {!UI.ViewManager._ContainerWidget} */ (this._tabbedPane.tabView(view.viewId()));
-    return widget._materialize();
-  }
-
-  /**
    * @param {!Common.Event} event
    */
   _persistTabOrder(event) {
     var tabIds = this._tabbedPane.tabIds();
     var tabOrders = {};
     for (var i = 0; i < tabIds.length; i++)
       tabOrders[tabIds[i]] = (i + 1) * UI.ViewManager._TabbedLocation.orderStep;
     this._tabOrderSetting.set(tabOrders);
   }
 };
@@ skipping 77 matching lines @@
   appendApplicableItems(locationName) {
     for (var view of this._manager._viewsForLocation(locationName))
       this.appendView(view);
   }
 };
 
 /**
  * @type {!UI.ViewManager}
  */
 UI.viewManager;