DevTools: traverse widget hierarchy to reveal views.

third_party/WebKit/Source/devtools/front_end/sources/ThreadsSidebarPane.js

 // Copyright 2014 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.
 
 /**
  * @constructor
  * @extends {WebInspector.View}
  * @implements {WebInspector.TargetManager.Observer}
  */
 WebInspector.ThreadsSidebarPane = function()
 {
     WebInspector.View.call(this, WebInspector.UIString("Threads"));
-    this.requestSetVisible(false);
 
     /** @type {!Map.<!WebInspector.DebuggerModel, !WebInspector.UIList.Item>} */
     this._debuggerModelToListItems = new Map();
     /** @type {!Map.<!WebInspector.UIList.Item, !WebInspector.Target>} */
     this._listItemsToTargets = new Map();
     /** @type {?WebInspector.UIList.Item} */
     this._selectedListItem = null;
     this.threadList = new WebInspector.UIList();
     this.threadList.show(this.element);
     WebInspector.targetManager.addModelListener(WebInspector.DebuggerModel, WebInspector.DebuggerModel.Events.DebuggerPaused, this._onDebuggerStateChanged, this);
     WebInspector.targetManager.addModelListener(WebInspector.DebuggerModel, WebInspector.DebuggerModel.Events.DebuggerResumed, this._onDebuggerStateChanged, this);
     WebInspector.targetManager.addModelListener(WebInspector.RuntimeModel, WebInspector.RuntimeModel.Events.ExecutionContextChanged, this._onExecutionContextChanged, this);
     WebInspector.context.addFlavorChangeListener(WebInspector.Target, this._targetChanged, this);
     WebInspector.targetManager.observeTargets(this);
 }
 
 WebInspector.ThreadsSidebarPane.prototype = {
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetAdded: function(target)
     {
         var debuggerModel = WebInspector.DebuggerModel.fromTarget(target)
-        if (!debuggerModel) {
-            this._updateVisibility();
+        if (!debuggerModel)
             return;
-        }
 
         var executionContext = target.runtimeModel.defaultExecutionContext();
         var label = executionContext && executionContext.label() ? executionContext.label() : target.name();
         var listItem = new WebInspector.UIList.Item(label, "");
         listItem.element.addEventListener("click", this._onListItemClick.bind(this, listItem), false);
         var currentTarget = WebInspector.context.flavor(WebInspector.Target);
         if (currentTarget === target)
             this._selectListItem(listItem);
 
         this._debuggerModelToListItems.set(debuggerModel, listItem);
         this._listItemsToTargets.set(listItem, target);
         this.threadList.addItem(listItem);
         this._updateDebuggerState(debuggerModel);
-        this._updateVisibility();
-    },
-
-    _updateVisibility: function()
-    {
-        this._wasVisibleAtLeastOnce = this._wasVisibleAtLeastOnce || this._debuggerModelToListItems.size > 1;
-        this.requestSetVisible(this._wasVisibleAtLeastOnce);
     },
 
     /**
      * @override
      * @param {!WebInspector.Target} target
      */
     targetRemoved: function(target)
     {
         var debuggerModel = WebInspector.DebuggerModel.fromTarget(target)
         if (!debuggerModel)
             return;
         var listItem = this._debuggerModelToListItems.remove(debuggerModel);
         if (listItem) {
             this._listItemsToTargets.remove(listItem);
             this.threadList.removeItem(listItem);
         }
-        this._updateVisibility();
     },
 
     /**
      * @param {!WebInspector.Event} event
      */
     _targetChanged: function(event)
     {
         var newTarget = /** @type {!WebInspector.Target} */(event.data);
         var debuggerModel = WebInspector.DebuggerModel.fromTarget(newTarget)
         if (!debuggerModel)
@@ skipping 54 matching lines @@
      */
     _onListItemClick: function(listItem)
     {
         WebInspector.context.setFlavor(WebInspector.Target, this._listItemsToTargets.get(listItem));
         listItem.element.scrollIntoViewIfNeeded();
     },
 
 
     __proto__: WebInspector.View.prototype
 }