DevTools: Remember the last focused widget.

third_party/WebKit/Source/devtools/front_end/ui/Widget.js

 /*
  * Copyright (C) 2008 Apple Inc. All Rights Reserved.
  * Copyright (C) 2011 Google Inc. All Rights Reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 30 matching lines @@
     }
     this._isWebComponent = isWebComponent;
     this.element.__widget = this;
     this._visible = false;
     this._isRoot = false;
     this._isShowing = false;
     this._children = [];
     this._hideOnDetach = false;
     this._notificationDepth = 0;
     this._invalidationsSuspended = 0;
+    this._boundWasFocused = this.wasFocused.bind(this);
+    this._lastFocusedChild = null;
 }
 
 WebInspector.Widget.prototype = {
     markAsRoot: function()
     {
         WebInspector.Widget.__assert(!this.element.parentElement, "Attempt to mark as root attached node");
         this._isRoot = true;
     },
 
     /**
@@ skipping 170 matching lines @@
      * @param {!WebInspector.Widget} parentWidget
      */
     attach: function(parentWidget)
     {
         if (parentWidget === this._parentWidget)
             return;
         if (this._parentWidget)
             this.detach();
         this._parentWidget = parentWidget;
         this._parentWidget._children.push(this);
+        if (!this._parentWidget._lastFocusedChild)
+            this._parentWidget._lastFocusedChild = this;
+        this._updateDefaultFocusedElementListener();
         this._isRoot = false;
     },
 
     /**
      * @param {!Element} parentElement
      * @param {?Element=} insertBefore
      */
     showWidget: function(parentElement, insertBefore)
     {
         var currentParent = parentElement;
@@ skipping 74 matching lines @@
             return;
 
         if (this._visible)
             this._hideWidget(true);
 
         // Update widget hierarchy.
         if (this._parentWidget) {
             var childIndex = this._parentWidget._children.indexOf(this);
             WebInspector.Widget.__assert(childIndex >= 0, "Attempt to remove non-child widget");
             this._parentWidget._children.splice(childIndex, 1);
+            if (this._parentWidget._lastFocusedChild === this)
+                this._parentWidget._lastFocusedChild = this._parentWidget._children[0] || null;
             this._parentWidget.childWasDetached(this);
             var parent = this._parentWidget;
             this._parentWidget = null;
+            this._updateDefaultFocusedElementListener();
         } else {
             WebInspector.Widget.__assert(this._isRoot, "Removing non-root widget from DOM");
         }
     },
 
     detachChildWidgets: function()
     {
         var children = this._children.slice();
         for (var i = 0; i < children.length; ++i)
             children[i].detach();
@@ skipping 70 matching lines @@
 
         if (this._children.length)
             lines.push(prefix + "}");
     },
 
     /**
      * @param {!Element} element
      */
     setDefaultFocusedElement: function(element)
     {
+        if (this._defaultFocusedElement)
+            this._defaultFocusedElement.removeEventListener("focus", this._boundWasFocused);
         this._defaultFocusedElement = element;
+        this._updateDefaultFocusedElementListener();
+        if (this._defaultFocusedElement.ownerDocument.activeElement.isSelfOrDescendant(this._defaultFocusedElement))
+            this.wasFocused();
+    },
+
+    _updateDefaultFocusedElementListener: function()
+    {
+        if (!this._defaultFocusedElement)
+            return;
+        if (this._parentWidget)
+            this._defaultFocusedElement.addEventListener("focus", this._boundWasFocused, true);
+        else
+            this._defaultFocusedElement.removeEventListener("focus", this._boundWasFocused);

[luoe, 2016/09/08 20:48:56]

Should this and L437 also get useCapture == true, same as L449?

[einbinder, 2016/09/09 01:32:16]

This was removed in the next patch.

     },
 
     focus: function()
     {
         var element = this._defaultFocusedElement;
         if (element && !element.isAncestor(this.element.ownerDocument.activeElement)) {
             WebInspector.setCurrentFocusElement(element);
+            this.wasFocused();
             return;
         }
 
-        if (this._children.length)
-            this._children[0].focus();
+        if (this._lastFocusedChild)
+            this._lastFocusedChild.focus();
     },
 
     /**
+     * @final
+     */
+    wasFocused: function()
+    {
+        var widget = this;
+        while (widget._parentWidget) {
+            widget._parentWidget._lastFocusedChild = widget;
+            widget = widget._parentWidget;
+        }
+    },
+
+    /**
      * @return {boolean}
      */
     hasFocus: function()
     {
         var activeElement = this.element.ownerDocument.activeElement;
         return activeElement && activeElement.isSelfOrDescendant(this.element);
     },
 
     /**
      * @return {!Size}
@@ skipping 272 matching lines @@
 {
     WebInspector.Widget.__assert(!child.__widgetCounter && !child.__widget, "Attempt to remove element containing widget via regular DOM operation");
     return WebInspector.Widget._originalRemoveChild.call(this, child);
 }
 
 Element.prototype.removeChildren = function()
 {
     WebInspector.Widget.__assert(!this.__widgetCounter, "Attempt to remove element containing widget via regular DOM operation");
     WebInspector.Widget._originalRemoveChildren.call(this);
 }