Merge branch 'material' into 'master'

improve detachRootWidget

See merge request upm-packages/ui-widgets/com.unity.uiwidgets!144

Runtime/widgets/binding.cs

         RenderObjectToWidgetElement<RenderBox> _renderViewElement;
 
         public void detachRootWidget() {
-            this.pipelineOwner.rootNode = null;
-
-            void unMountAll(Element element) {
-                element.visitChildren(unMountAll);
-                element.deactivate();
-                element.unmount();
-            }
-
-            if (this._renderViewElement != null) {
-                this._renderViewElement.visitChildren(unMountAll);
-                this._renderViewElement.deactivate();
-                this._renderViewElement.unmount();
-                this._renderViewElement = null;
+            if (this._renderViewElement == null) {
+                return;
+            
+            this.attachRootWidget(null);
+            this.buildOwner.buildScope(this._renderViewElement);
+            this.buildOwner.finalizeTree();
+            
+            this.pipelineOwner.rootNode = null;
+            this._renderViewElement.deactivate();
+            this._renderViewElement.unmount();
+            this._renderViewElement = null;
         }
 
         public void attachRootWidget(Widget rootWidget) {

Runtime/widgets/framework.cs

                 return true;
             }
 
-            return ReferenceEquals(this.componentKey1, other.componentKey1) &&
-                   ReferenceEquals(this.componentKey2, other.componentKey2);
+            return Equals(this.componentKey1, other.componentKey1) &&
+                   Equals(this.componentKey2, other.componentKey2);
         }
 
         public override bool Equals(object obj) {
 
                 return true;
             });
-            if (_registry.getOrDefault(compKey) == element) {
+            if (_registry[compKey] == element) {
                 _registry.Remove(compKey);
                 _removedKeys.Add(compKey);
             }