DevTools: keep widgets in widget hierarchy upon hide, split attach/detach cycle from show/hide.

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

Index: third_party/WebKit/Source/devtools/front_end/ui/Widget.js
diff --git a/third_party/WebKit/Source/devtools/front_end/ui/Widget.js b/third_party/WebKit/Source/devtools/front_end/ui/Widget.js
index 5558f589144f8b9e4e97f525bef41f9e0d87a232..5f7f7aa8d339bf4316a63035c01bcd7459355cc5 100644
--- a/third_party/WebKit/Source/devtools/front_end/ui/Widget.js
+++ b/third_party/WebKit/Source/devtools/front_end/ui/Widget.js
@@ -41,7 +41,7 @@ WebInspector.Widget = function(isWebComponent)
     }
     this._isWebComponent = isWebComponent;
     this.element.__widget = this;
-    this._visible = true;
+    this._visible = false;
     this._isRoot = false;
     this._isShowing = false;
     this._children = [];
@@ -119,7 +119,7 @@ WebInspector.Widget.prototype = {
     {
         if (this._isRoot)
             return true;
-        return this._parentWidget && this._parentWidget.isShowing();
+        return !!this._parentWidget && this._parentWidget.isShowing();
     },
 
     /**
@@ -210,27 +210,48 @@ WebInspector.Widget.prototype = {
      */
     show: function(parentElement, insertBefore)
     {
+        this.attach(parentElement, insertBefore);
+        this.showWidget();
+    },
+
+    /**
+     * @param {?Element} parentElement

[dgozman, 2016/07/20 23:48:22]

!Element

[pfeldman, 2016/07/20 23:57:52]

Done.

+     * @param {?Element=} insertBefore
+     */
+    attach: function(parentElement, insertBefore)

[dgozman, 2016/07/20 23:48:22]

Let's move the parameters to showWidget instead!

[pfeldman, 2016/07/20 23:57:52]

Acknowledged.

+    {
         WebInspector.Widget.__assert(parentElement, "Attempt to attach widget with no parent element");
 
         // Update widget hierarchy.
-        if (this.element.parentElement !== parentElement) {
-            if (this.element.parentElement)
-                this.detach();
-
-            var currentParent = parentElement;
-            while (currentParent && !currentParent.__widget)
-                currentParent = currentParent.parentElementOrShadowHost();
+        var currentParent = parentElement;
+        while (currentParent && !currentParent.__widget)
+            currentParent = currentParent.parentElementOrShadowHost();
+        var newParentWidget = currentParent ? currentParent.__widget : null;
+
+        if (this._parentWidget && newParentWidget !== this._parentWidget) {
+            // Reparent.
+            this.detach();
+        }
 
-            if (currentParent) {
-                this._parentWidget = currentParent.__widget;
+        if (newParentWidget) {
+            if (this._parentWidget !== newParentWidget) {
+                this._parentWidget = newParentWidget;
                 this._parentWidget._children.push(this);
-                this._isRoot = false;
-            } else
-                WebInspector.Widget.__assert(this._isRoot, "Attempt to attach widget to orphan node");
-        } else if (this._visible) {
-            return;
+            }
+            this._isRoot = false;
+        } else {
+            WebInspector.Widget.__assert(this._isRoot, "Attempt to attach widget to orphan node");
         }
 
+        this._parentElement = parentElement;
+        this._insertBeforeElement = insertBefore;
+    },
+
+    showWidget: function()
+    {
+        WebInspector.Widget.__assert(this._parentElement, "Attempt to show detached widget");
+        if (this._visible)
+            return;
         this._visible = true;
 
         if (this._parentIsShowing())
@@ -239,12 +260,12 @@ WebInspector.Widget.prototype = {
         this.element.classList.remove("hidden");
 
         // Reparent
-        if (this.element.parentElement !== parentElement) {
-            WebInspector.Widget._incrementWidgetCounter(parentElement, this.element);
-            if (insertBefore)
-                WebInspector.Widget._originalInsertBefore.call(parentElement, this.element, insertBefore);
+        if (this.element.parentElement !== this._parentElement) {
+            WebInspector.Widget._incrementWidgetCounter(this._parentElement, this.element);
+            if (this._insertBeforeElement)
+                WebInspector.Widget._originalInsertBefore.call(this._parentElement, this.element, this._insertBeforeElement);
             else
-                WebInspector.Widget._originalAppendChild.call(parentElement, this.element);
+                WebInspector.Widget._originalAppendChild.call(this._parentElement, this.element);
         }
 
         if (this._parentIsShowing())
@@ -256,35 +277,51 @@ WebInspector.Widget.prototype = {
             this._processOnResize();
     },
 
+    hideWidget: function()
+    {
+        this._hideWidget();
+    },
+
     /**
      * @param {boolean=} overrideHideOnDetach
+     * @return {boolean}

[dgozman, 2016/07/20 23:48:22]

Remove the return value.

[pfeldman, 2016/07/20 23:57:52]

Done.

      */
-    detach: function(overrideHideOnDetach)
+    _hideWidget: function(overrideHideOnDetach)
     {
-        var parentElement = this.element.parentElement;
-        if (!parentElement)
-            return;
+        WebInspector.Widget.__assert(this._parentElement, "Attempt to hide detached widget");
+        if (!this._visible)
+            return false;
+        this._visible = false;
+        var parentElement = this._parentElement;
 
         if (this._parentIsShowing())
             this._processWillHide();
 
         if (!overrideHideOnDetach && this.shouldHideOnDetach()) {
             this.element.classList.add("hidden");
-            this._visible = false;
             if (this._parentIsShowing())
                 this._processWasHidden();
             if (this._parentWidget && this._hasNonZeroConstraints())
                 this._parentWidget.invalidateConstraints();
-            return;
+            return true;
         }
 
         // Force legal removal
         WebInspector.Widget._decrementWidgetCounter(parentElement, this.element);
         WebInspector.Widget._originalRemoveChild.call(parentElement, this.element);
 
-        this._visible = false;
         if (this._parentIsShowing())
             this._processWasHidden();
+        return true;
+    },
+
+    detach: function()
+    {
+        if (!this._parentWidget)
+            return;
+        var wasShown = this._hideWidget(true);
+        if (!wasShown)
+            return;
 
         // Update widget hierarchy.
         if (this._parentWidget) {
@@ -294,10 +331,13 @@ WebInspector.Widget.prototype = {
             this._parentWidget.childWasDetached(this);
             var parent = this._parentWidget;
             this._parentWidget = null;
+            this._parentElement = null;
+            this._insertBeforeElement = null;
             if (this._hasNonZeroConstraints())
                 parent.invalidateConstraints();

[dgozman, 2016/07/20 23:48:22]

This should be in hide.

[pfeldman, 2016/07/20 23:57:52]

Done.

-        } else
+        } else {
             WebInspector.Widget.__assert(this._isRoot, "Removing non-root widget from DOM");
+        }
     },
 
     detachChildWidgets: function()