Create a unified UIElement interface for Widget, View and Window.

ash/devtools/ash_devtools_dom_agent.h

 // 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.
 
 #ifndef ASH_DEVTOOLS_ASH_DEVTOOLS_DOM_AGENT_H_
 #define ASH_DEVTOOLS_ASH_DEVTOOLS_DOM_AGENT_H_
 
 #include "ash/ash_export.h"
+#include "ash/devtools/ui_element_delegate.h"
 #include "base/macros.h"
-#include "base/observer_list.h"
 #include "components/ui_devtools/DOM.h"
 #include "components/ui_devtools/devtools_base_agent.h"
-#include "ui/aura/window_observer.h"
 #include "ui/views/view.h"
-#include "ui/views/view_observer.h"
 #include "ui/views/widget/widget.h"
-#include "ui/views/widget/widget_observer.h"
-#include "ui/views/widget/widget_removals_observer.h"
 
 namespace aura {
 class Window;
 }
 
 namespace ash {
 
 namespace devtools {
 
+class UIElement;
+
 class ASH_EXPORT AshDevToolsDOMAgentObserver {
  public:
-  virtual void OnWindowBoundsChanged(aura::Window* window) {}
-  virtual void OnWidgetBoundsChanged(views::Widget* widget) {}
-  virtual void OnViewBoundsChanged(views::View* view) {}
+  virtual void OnNodeBoundsChanged(int node_id);
 };
 
 class ASH_EXPORT AshDevToolsDOMAgent
     : public NON_EXPORTED_BASE(ui::devtools::UiDevToolsBaseAgent<
                                ui::devtools::protocol::DOM::Metainfo>),
-      public aura::WindowObserver,
-      public views::WidgetObserver,
-      public views::WidgetRemovalsObserver,
-      public views::ViewObserver {
+      public UIElementDelegate,
+      public AshDevToolsDOMAgentObserver {
  public:
   AshDevToolsDOMAgent();
   ~AshDevToolsDOMAgent() override;
+  void RemoveUIElementTree(UIElement* root);
 
-  // DOM::Backend
+  // DOM::Backend:
   ui::devtools::protocol::Response disable() override;
   ui::devtools::protocol::Response getDocument(
       std::unique_ptr<ui::devtools::protocol::DOM::Node>* out_root) override;
   ui::devtools::protocol::Response highlightNode(
       std::unique_ptr<ui::devtools::protocol::DOM::HighlightConfig>
           highlight_config,
       ui::devtools::protocol::Maybe<int> node_id) override;
   ui::devtools::protocol::Response hideHighlight() override;
 
-  // WindowObserver
-  void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
-  void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
-  void OnWindowStackingChanged(aura::Window* window) override;
-  void OnWindowBoundsChanged(aura::Window* window,
-                             const gfx::Rect& old_bounds,
-                             const gfx::Rect& new_bounds) override;
-
-  // views::WidgetRemovalsObserver
-  void OnWillRemoveView(views::Widget* widget, views::View* view) override;
-
-  // views::WidgetObserver
-  void OnWidgetBoundsChanged(views::Widget* widget,
-                             const gfx::Rect& new_bounds) override;
-
-  // views::ViewObserver
-  void OnChildViewRemoved(views::View* parent, views::View* view) override;
-  void OnChildViewAdded(views::View* parent, views::View* view) override;
-  void OnChildViewReordered(views::View* parent, views::View*) override;
-  void OnViewBoundsChanged(views::View* view) override;
-
-  aura::Window* GetWindowFromNodeId(int nodeId);
-  views::Widget* GetWidgetFromNodeId(int nodeId);
-  views::View* GetViewFromNodeId(int nodeId);
-
-  int GetNodeIdFromWindow(aura::Window* window);
-  int GetNodeIdFromWidget(views::Widget* widget);
-  int GetNodeIdFromView(views::View* view);
+  // UIElementDelegate:
+  void OnUIElementAdded(
+      int node_id,
+      UIElement* child_ui_element,
+      std::vector<UIElement*>::iterator prev_sibling_position) override;
+  // Return iterator of the next siblings of node_id.
+  std::vector<UIElement*>::iterator OnUIElementRemoved(int node_id) override;
+  void OnUIElementBoundsChanged(int node_id) override;
 
   void AddObserver(AshDevToolsDOMAgentObserver* observer);
   void RemoveObserver(AshDevToolsDOMAgentObserver* observer);
+  UIElement* GetElementFromNodeId(int node_id);
+  UIElement* GetWindowElementRoot();
 
  private:
+  // AshDevToolsDOMAgentObserver:
+  void OnNodeBoundsChanged(int node_id) override;
+
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildInitialTree();
+  std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForUIElement(
+      UIElement* ui_element);
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForWindow(
+      UIElement* window_element_root,
       aura::Window* window);
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForRootWidget(
+      UIElement* widget_element,
       views::Widget* widget);
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForView(
+      UIElement* view_element,
       views::View* view);
-
-  void AddWindowTree(aura::Window* window);
-  // |remove_observer| ensures that we don't add a duplicate observer in any
-  // observer callback. For example, |remove_observer| is false when rebuilding
-  // the tree in OnWindowStackingChanged so that the observer is not removed and
-  // re-added, thus causing endless calls on the observer.
-  void RemoveWindowTree(aura::Window* window, bool remove_observer);
-  void RemoveWindowNode(aura::Window* window, bool remove_observer);
-
-  // Don't need AddWidgetTree because |widget| will always be inside a window,
-  // so when windows are created, their widget nodes are created as well.
-  void RemoveWidgetTree(views::Widget* widget, bool remove_observer);
-  void RemoveWidgetNode(views::Widget* widget, bool remove_observer);
-
-  void AddViewTree(views::View* view);
-  void RemoveViewTree(views::View* view,
-                      views::View* parent,
-                      bool remove_observer);
-  void RemoveViewNode(views::View* view,
-                      views::View* parent,
-                      bool remove_observer);
-
-  void DestroyHighlightingWidget();
-  void RemoveObservers();
+  void RemoveDomNode(UIElement* ui_element);
   void Reset();
-
-  using WindowAndBoundsPair = std::pair<aura::Window*, gfx::Rect>;
-  WindowAndBoundsPair GetNodeWindowAndBounds(int node_id);
   void InitializeHighlightingWidget();
-  void UpdateHighlight(const WindowAndBoundsPair& window_and_bounds,
-                       SkColor background,
-                       SkColor border);
+  void UpdateHighlight(
+      const std::pair<aura::Window*, gfx::Rect>& window_and_bounds,
+      SkColor background,
+      SkColor border);
   ui::devtools::protocol::Response HighlightNode(
       std::unique_ptr<ui::devtools::protocol::DOM::HighlightConfig>
           highlight_config,
       int node_id);
   bool IsHighlightingWindow(aura::Window* window);
 
+  UIElement* window_element_root;
+  std::unordered_map<int, UIElement*> node_id_to_ui_element_;
   std::unique_ptr<views::Widget> widget_for_highlighting_;
-
-  using WindowToNodeIdMap = std::unordered_map<aura::Window*, int>;
-  WindowToNodeIdMap window_to_node_id_map_;
-  using NodeIdToWindowMap = std::unordered_map<int, aura::Window*>;
-  NodeIdToWindowMap node_id_to_window_map_;
-
-  using WidgetToNodeIdMap = std::unordered_map<views::Widget*, int>;
-  WidgetToNodeIdMap widget_to_node_id_map_;
-  using NodeIdToWidgetMap = std::unordered_map<int, views::Widget*>;
-  NodeIdToWidgetMap node_id_to_widget_map_;
-
-  using ViewToNodeIdMap = std::unordered_map<views::View*, int>;
-  ViewToNodeIdMap view_to_node_id_map_;
-  using NodeIdToViewMap = std::unordered_map<int, views::View*>;
-  NodeIdToViewMap node_id_to_view_map_;
-
   base::ObserverList<AshDevToolsDOMAgentObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(AshDevToolsDOMAgent);
 };
 
 }  // namespace devtools
 }  // namespace ash
 
 #endif  // ASH_DEVTOOLS_ASH_DEVTOOLS_DOM_AGENT_H_