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

ash/devtools/ash_devtools_dom_agent.cc

Index: ash/devtools/ash_devtools_dom_agent.cc
diff --git a/ash/devtools/ash_devtools_dom_agent.cc b/ash/devtools/ash_devtools_dom_agent.cc
index 00272f56284bd0d4d979eff610d7ce6a7537d73c..2b6cef0583bc01a71fa1f0d287a40b446418ecbc 100644
--- a/ash/devtools/ash_devtools_dom_agent.cc
+++ b/ash/devtools/ash_devtools_dom_agent.cc
@@ -4,6 +4,10 @@
 
 #include "ash/devtools/ash_devtools_dom_agent.h"
 
+#include "ash/devtools/ui_element.h"
+#include "ash/devtools/view_element.h"
+#include "ash/devtools/widget_element.h"
+#include "ash/devtools/window_element.h"
 #include "ash/public/cpp/shell_window_ids.h"
 #include "ash/root_window_controller.h"
 #include "ash/shell.h"
@@ -13,6 +17,8 @@
 #include "ui/display/display.h"
 #include "ui/views/background.h"
 #include "ui/views/border.h"
+#include "ui/views/view.h"
+#include "ui/views/widget/widget.h"
 #include "ui/wm/core/window_util.h"
 
 namespace ash {
@@ -64,27 +70,6 @@ std::unique_ptr<Array<std::string>> GetAttributes(const views::View* view) {
   return attributes;
 }
 
-aura::Window* FindPreviousSibling(aura::Window* window) {
-  const aura::Window::Windows& siblings = window->parent()->children();
-  auto it = std::find(siblings.begin(), siblings.end(), window);
-  DCHECK(it != siblings.end());
-  // If this is the first child of its parent, the previous sibling is null
-  return it == siblings.begin() ? nullptr : *std::prev(it);
-}
-
-views::View* FindPreviousSibling(views::View* view) {
-  views::View* parent = view->parent();
-  int view_index = -1;
-  for (int i = 0, count = parent->child_count(); i < count; i++) {
-    if (view == parent->child_at(i)) {
-      view_index = i;
-      break;
-    }
-  }
-  DCHECK_GE(view_index, 0);
-  return view_index == 0 ? nullptr : parent->child_at(view_index - 1);
-}
-
 int MaskColor(int value) {
   return value & 0xff;
 }
@@ -108,7 +93,14 @@ views::Widget* GetWidgetFromWindow(aura::Window* window) {
 AshDevToolsDOMAgent::AshDevToolsDOMAgent() {}
 
 AshDevToolsDOMAgent::~AshDevToolsDOMAgent() {
-  RemoveObservers();
+  RemoveUIElementTree(window_element_root);
+}
+
+void AshDevToolsDOMAgent::RemoveUIElementTree(UIElement* root) {
+  for (auto* child : root->GetChildren())
+    RemoveUIElementTree(child);
+  root->GetChildren().clear();
+  root->Destroy();
 }
 
 ui::devtools::protocol::Response AshDevToolsDOMAgent::disable() {
@@ -135,335 +127,191 @@ ui::devtools::protocol::Response AshDevToolsDOMAgent::hideHighlight() {
   return ui::devtools::protocol::Response::OK();
 }
 
-// Handles removing windows.
-void AshDevToolsDOMAgent::OnWindowHierarchyChanging(
-    const HierarchyChangeParams& params) {
-  // Only trigger this when params.receiver == params.old_parent.
-  // Only removals are handled here. Removing a node can occur as a result of
-  // reorganizing a window or just destroying it. OnWindowHierarchyChanged
-  // is only called if there is a new_parent. The only case this method isn't
-  // called is when adding a node because old_parent is then null.
-  // Finally, We only trigger this  0 or 1 times as an old_parent will
-  // either exist and only call this callback once, or not at all.
-  if (params.receiver == params.old_parent)
-    RemoveWindowTree(params.target, true);
-}
-
-// Handles adding windows.
-void AshDevToolsDOMAgent::OnWindowHierarchyChanged(
-    const HierarchyChangeParams& params) {
-  // Only trigger this when params.receiver == params.new_parent.
-  // If there is an old_parent + new_parent, then this window's node was
-  // removed in OnWindowHierarchyChanging and will now be added to the
-  // new_parent. If there is only a new_parent, OnWindowHierarchyChanging is
-  // never called and the window is only added here.
-  if (params.receiver == params.new_parent)
-    AddWindowTree(params.target);
-}
-
-void AshDevToolsDOMAgent::OnWindowStackingChanged(aura::Window* window) {
-  RemoveWindowTree(window, false);
-  AddWindowTree(window);
-}
-
-void AshDevToolsDOMAgent::OnWindowBoundsChanged(aura::Window* window,
-                                                const gfx::Rect& old_bounds,
-                                                const gfx::Rect& new_bounds) {
-  for (auto& observer : observers_)
-    observer.OnWindowBoundsChanged(window);
-}
-
-void AshDevToolsDOMAgent::OnWillRemoveView(views::Widget* widget,
-                                           views::View* view) {
-  if (view == widget->GetRootView())
-    RemoveViewTree(view, nullptr, true);
-}
-
-void AshDevToolsDOMAgent::OnWidgetBoundsChanged(views::Widget* widget,
-                                                const gfx::Rect& new_bounds) {
-  for (auto& observer : observers_)
-    observer.OnWidgetBoundsChanged(widget);
-}
-
-void AshDevToolsDOMAgent::OnChildViewRemoved(views::View* parent,
-                                             views::View* view) {
-  RemoveViewTree(view, parent, true);
+void AshDevToolsDOMAgent::OnUIElementAdded(
+    int parent_node_id,
+    UIElement* child_ui_element,
+    std::vector<UIElement*>::iterator prev_sibling_position) {
+  if (child_ui_element->GetType() == UIElementType::WINDOW &&
+      IsHighlightingWindow(
+          UIElement::GetBackingElement<aura::Window, WindowElement>(
+              child_ui_element))) {
+    child_ui_element->Destroy();
+    return;
+  }
+  DCHECK(node_id_to_ui_element_.count(parent_node_id));
+  UIElement* parent_ui_element = node_id_to_ui_element_[parent_node_id];
+  DCHECK(parent_ui_element);
+  child_ui_element->SetParent(parent_ui_element);
+
+  int prev_node_id = 0;
+  if (parent_ui_element->GetChildren().empty())
+    parent_ui_element->GetChildren().push_back(child_ui_element);
+  else {
+    prev_node_id = (*prev_sibling_position)->GetNodeId();
+    parent_ui_element->GetChildren().insert(prev_sibling_position,
+                                            child_ui_element);
+  }
+  frontend()->childNodeInserted(parent_node_id, prev_node_id,
+                                BuildTreeForUIElement(child_ui_element));
 }
 
-void AshDevToolsDOMAgent::OnChildViewAdded(views::View* parent,
-                                           views::View* view) {
-  AddViewTree(view);
-}
+std::vector<UIElement*>::iterator AshDevToolsDOMAgent::OnUIElementRemoved(
+    int node_id) {
+  DCHECK(node_id_to_ui_element_.count(node_id));
+  UIElement* ui_element = node_id_to_ui_element_[node_id];
+  DCHECK(ui_element);
 
-void AshDevToolsDOMAgent::OnChildViewReordered(views::View* parent,
-                                               views::View* view) {
-  RemoveViewTree(view, parent, false);
-  AddViewTree(view);
+  if (ui_element->GetType() == UIElementType::WINDOW &&
+      IsHighlightingWindow(static_cast<WindowElement*>(ui_element)->window()))
+    return ui_element->GetParent()->GetChildren().end();
+  RemoveDomNode(ui_element);
+  return ui_element->RemoveChild();
 }
 
-void AshDevToolsDOMAgent::OnViewBoundsChanged(views::View* view) {
+void AshDevToolsDOMAgent::OnUIElementBoundsChanged(int node_id) {
   for (auto& observer : observers_)
-    observer.OnViewBoundsChanged(view);
-}
-
-aura::Window* AshDevToolsDOMAgent::GetWindowFromNodeId(int nodeId) {
-  return node_id_to_window_map_.count(nodeId) ? node_id_to_window_map_[nodeId]
-                                              : nullptr;
+    observer.OnNodeBoundsChanged(node_id);
 }
 
-views::Widget* AshDevToolsDOMAgent::GetWidgetFromNodeId(int nodeId) {
-  return node_id_to_widget_map_.count(nodeId) ? node_id_to_widget_map_[nodeId]
-                                              : nullptr;
-}
-
-views::View* AshDevToolsDOMAgent::GetViewFromNodeId(int nodeId) {
-  return node_id_to_view_map_.count(nodeId) ? node_id_to_view_map_[nodeId]
-                                            : nullptr;
-}
-
-int AshDevToolsDOMAgent::GetNodeIdFromWindow(aura::Window* window) {
-  DCHECK(window_to_node_id_map_.count(window));
-  return window_to_node_id_map_[window];
+void AshDevToolsDOMAgent::AddObserver(AshDevToolsDOMAgentObserver* observer) {
+  observers_.AddObserver(observer);
 }
 
-int AshDevToolsDOMAgent::GetNodeIdFromWidget(views::Widget* widget) {
-  DCHECK(widget_to_node_id_map_.count(widget));
-  return widget_to_node_id_map_[widget];
+void AshDevToolsDOMAgent::RemoveObserver(
+    AshDevToolsDOMAgentObserver* observer) {
+  observers_.RemoveObserver(observer);
 }
 
-int AshDevToolsDOMAgent::GetNodeIdFromView(views::View* view) {
-  DCHECK(view_to_node_id_map_.count(view));
-  return view_to_node_id_map_[view];
+UIElement* AshDevToolsDOMAgent::GetElementFromNodeId(int node_id) {
+  return node_id_to_ui_element_[node_id];
 }
 
-void AshDevToolsDOMAgent::AddObserver(AshDevToolsDOMAgentObserver* observer) {
-  observers_.AddObserver(observer);
+UIElement* AshDevToolsDOMAgent::GetWindowElementRoot() {
+  return window_element_root;
 }
 
-void AshDevToolsDOMAgent::RemoveObserver(
-    AshDevToolsDOMAgentObserver* observer) {
-  observers_.RemoveObserver(observer);
+void AshDevToolsDOMAgent::OnNodeBoundsChanged(int node_id) {
+  for (auto& observer : observers_)
+    observer.OnNodeBoundsChanged(node_id);
 }
 
 std::unique_ptr<ui::devtools::protocol::DOM::Node>
 AshDevToolsDOMAgent::BuildInitialTree() {
   std::unique_ptr<Array<DOM::Node>> children = Array<DOM::Node>::create();
-  for (aura::Window* window : Shell::GetAllRootWindows())
-    children->addItem(BuildTreeForWindow(window));
-  return BuildNode("root", nullptr, std::move(children));
+  window_element_root = new WindowElement(nullptr, this, nullptr);
+  for (aura::Window* window : Shell::GetAllRootWindows()) {
+    UIElement* window_element =
+        new WindowElement(window, this, window_element_root);
+    window_element->SetParent(window_element_root);
+
+    children->addItem(BuildTreeForUIElement(window_element));
+    window_element_root->GetChildren().push_back(window_element);
+  }
+  std::unique_ptr<ui::devtools::protocol::DOM::Node> root_node =
+      BuildNode("root", nullptr, std::move(children));
+  window_element_root->SetNodeId(root_node->getNodeId());
+  node_id_to_ui_element_[window_element_root->GetNodeId()] =
+      window_element_root;
+  return root_node;
+}
+
+std::unique_ptr<ui::devtools::protocol::DOM::Node>
+AshDevToolsDOMAgent::BuildTreeForUIElement(UIElement* ui_element) {
+  if (ui_element->GetType() == UIElementType::WINDOW)
+    return BuildTreeForWindow(
+        ui_element,
+        UIElement::GetBackingElement<aura::Window, WindowElement>(ui_element));
+  else if (ui_element->GetType() == UIElementType::WIDGET)
+    return BuildTreeForRootWidget(
+        ui_element,
+        UIElement::GetBackingElement<views::Widget, WidgetElement>(ui_element));
+  else if (ui_element->GetType() == UIElementType::VIEW)
+    return BuildTreeForView(
+        ui_element,
+        UIElement::GetBackingElement<views::View, ViewElement>(ui_element));
+  return nullptr;
 }
 
 std::unique_ptr<DOM::Node> AshDevToolsDOMAgent::BuildTreeForWindow(
+    UIElement* window_element_root,
     aura::Window* window) {
-  DCHECK(!window_to_node_id_map_.count(window));
   std::unique_ptr<Array<DOM::Node>> children = Array<DOM::Node>::create();
   views::Widget* widget = GetWidgetFromWindow(window);
-  if (widget)
-    children->addItem(BuildTreeForRootWidget(widget));
-  for (aura::Window* child : window->children()) {
-    if (!IsHighlightingWindow(child))
-      children->addItem(BuildTreeForWindow(child));
+  if (widget) {
+    UIElement* widget_element =
+        new WidgetElement(widget, this, window_element_root);
+
+    children->addItem(BuildTreeForRootWidget(widget_element, widget));
+    window_element_root->GetChildren().push_back(widget_element);
   }
+  for (aura::Window* child : window->children()) {
+    if (!IsHighlightingWindow(child)) {
+      UIElement* window_element =
+          new WindowElement(child, this, window_element_root);
 
+      children->addItem(BuildTreeForWindow(window_element, child));
+      window_element_root->GetChildren().push_back(window_element);
+    }
+  }
   std::unique_ptr<ui::devtools::protocol::DOM::Node> node =
       BuildNode("Window", GetAttributes(window), std::move(children));
-  if (!window->HasObserver(this))
-    window->AddObserver(this);
-  window_to_node_id_map_[window] = node->getNodeId();
-  node_id_to_window_map_[node->getNodeId()] = window;
+  window_element_root->SetNodeId(node->getNodeId());
+  node_id_to_ui_element_[node->getNodeId()] = window_element_root;
   return node;
 }
 
 std::unique_ptr<DOM::Node> AshDevToolsDOMAgent::BuildTreeForRootWidget(
+    UIElement* widget_element,
     views::Widget* widget) {
-  DCHECK(!widget_to_node_id_map_.count(widget));
   std::unique_ptr<Array<DOM::Node>> children = Array<DOM::Node>::create();
-  children->addItem(BuildTreeForView(widget->GetRootView()));
+
+  UIElement* view_element =
+      new ViewElement(widget->GetRootView(), this, widget_element);
+
+  children->addItem(BuildTreeForView(view_element, widget->GetRootView()));
+  widget_element->GetChildren().push_back(view_element);
+
   std::unique_ptr<ui::devtools::protocol::DOM::Node> node =
       BuildNode("Widget", GetAttributes(widget), std::move(children));
-  if (!widget->HasRemovalsObserver(this))
-    widget->AddRemovalsObserver(this);
-  widget_to_node_id_map_[widget] = node->getNodeId();
-  node_id_to_widget_map_[node->getNodeId()] = widget;
+  widget_element->SetNodeId(node->getNodeId());
+  node_id_to_ui_element_[node->getNodeId()] = widget_element;
   return node;
 }
 
 std::unique_ptr<DOM::Node> AshDevToolsDOMAgent::BuildTreeForView(
+    UIElement* view_element,
     views::View* view) {
-  DCHECK(!view_to_node_id_map_.count(view));
   std::unique_ptr<Array<DOM::Node>> children = Array<DOM::Node>::create();
-  for (int i = 0, count = view->child_count(); i < count; i++)
-    children->addItem(BuildTreeForView(view->child_at(i)));
+
+  for (int i = 0, count = view->child_count(); i < count; i++) {
+    UIElement* view_element_child =
+        new ViewElement(view->child_at(i), this, view_element);
+
+    children->addItem(BuildTreeForView(view_element_child, view->child_at(i)));
+    view_element->GetChildren().push_back(view_element_child);
+  }
   std::unique_ptr<ui::devtools::protocol::DOM::Node> node =
       BuildNode("View", GetAttributes(view), std::move(children));
-  if (!view->HasObserver(this))
-    view->AddObserver(this);
-  view_to_node_id_map_[view] = node->getNodeId();
-  node_id_to_view_map_[node->getNodeId()] = view;
+  view_element->SetNodeId(node->getNodeId());
+  node_id_to_ui_element_[node->getNodeId()] = view_element;
   return node;
 }
 
-void AshDevToolsDOMAgent::AddWindowTree(aura::Window* window) {
-  if (IsHighlightingWindow(window))
-    return;
-
-  DCHECK(window_to_node_id_map_.count(window->parent()));
-  aura::Window* prev_sibling = FindPreviousSibling(window);
-  frontend()->childNodeInserted(
-      window_to_node_id_map_[window->parent()],
-      prev_sibling ? window_to_node_id_map_[prev_sibling] : 0,
-      BuildTreeForWindow(window));
-}
+void AshDevToolsDOMAgent::RemoveDomNode(UIElement* ui_element) {
+  node_id_to_ui_element_[ui_element->GetNodeId()] = 0;
 
-void AshDevToolsDOMAgent::RemoveWindowTree(aura::Window* window,
-                                           bool remove_observer) {
-  DCHECK(window);
-  if (IsHighlightingWindow(window))
-    return;
+  for (auto* child_element : ui_element->GetChildren())
+    if (child_element)
+      RemoveDomNode(child_element);
 
-  if (GetWidgetFromWindow(window))
-    RemoveWidgetTree(GetWidgetFromWindow(window), remove_observer);
-
-  for (aura::Window* child : window->children())
-    RemoveWindowTree(child, remove_observer);
-
-  RemoveWindowNode(window, remove_observer);
-}
-
-void AshDevToolsDOMAgent::RemoveWindowNode(aura::Window* window,
-                                           bool remove_observer) {
-  WindowToNodeIdMap::iterator window_to_node_id_it =
-      window_to_node_id_map_.find(window);
-  DCHECK(window_to_node_id_it != window_to_node_id_map_.end());
-
-  int node_id = window_to_node_id_it->second;
-  int parent_id = GetNodeIdFromWindow(window->parent());
-
-  NodeIdToWindowMap::iterator node_id_to_window_it =
-      node_id_to_window_map_.find(node_id);
-  DCHECK(node_id_to_window_it != node_id_to_window_map_.end());
-
-  if (remove_observer)
-    window->RemoveObserver(this);
-
-  node_id_to_window_map_.erase(node_id_to_window_it);
-  window_to_node_id_map_.erase(window_to_node_id_it);
-  frontend()->childNodeRemoved(parent_id, node_id);
-}
-
-void AshDevToolsDOMAgent::RemoveWidgetTree(views::Widget* widget,
-                                           bool remove_observer) {
-  DCHECK(widget);
-  if (widget->GetRootView())
-    RemoveViewTree(widget->GetRootView(), nullptr, remove_observer);
-  RemoveWidgetNode(widget, remove_observer);
-}
-
-void AshDevToolsDOMAgent::RemoveWidgetNode(views::Widget* widget,
-                                           bool remove_observer) {
-  WidgetToNodeIdMap::iterator widget_to_node_id_it =
-      widget_to_node_id_map_.find(widget);
-  DCHECK(widget_to_node_id_it != widget_to_node_id_map_.end());
-
-  int node_id = widget_to_node_id_it->second;
-  int parent_id = GetNodeIdFromWindow(widget->GetNativeWindow());
-
-  if (remove_observer)
-    widget->RemoveRemovalsObserver(this);
-
-  NodeIdToWidgetMap::iterator node_id_to_widget_it =
-      node_id_to_widget_map_.find(node_id);
-  DCHECK(node_id_to_widget_it != node_id_to_widget_map_.end());
-
-  widget_to_node_id_map_.erase(widget_to_node_id_it);
-  node_id_to_widget_map_.erase(node_id_to_widget_it);
-  frontend()->childNodeRemoved(parent_id, node_id);
-}
-
-void AshDevToolsDOMAgent::AddViewTree(views::View* view) {
-  DCHECK(view_to_node_id_map_.count(view->parent()));
-  views::View* prev_sibling = FindPreviousSibling(view);
-  frontend()->childNodeInserted(
-      view_to_node_id_map_[view->parent()],
-      prev_sibling ? view_to_node_id_map_[prev_sibling] : 0,
-      BuildTreeForView(view));
-}
-
-void AshDevToolsDOMAgent::RemoveViewTree(views::View* view,
-                                         views::View* parent,
-                                         bool remove_observer) {
-  DCHECK(view);
-  for (int i = 0, count = view->child_count(); i < count; i++)
-    RemoveViewTree(view->child_at(i), view, remove_observer);
-  RemoveViewNode(view, parent, remove_observer);
-}
-
-void AshDevToolsDOMAgent::RemoveViewNode(views::View* view,
-                                         views::View* parent,
-                                         bool remove_observer) {
-  ViewToNodeIdMap::iterator view_to_node_id_it =
-      view_to_node_id_map_.find(view);
-  DCHECK(view_to_node_id_it != view_to_node_id_map_.end());
-
-  int node_id = view_to_node_id_it->second;
-  int parent_id = 0;
-  if (parent)
-    parent_id = GetNodeIdFromView(parent);
-  else  // views::RootView
-    parent_id = GetNodeIdFromWidget(view->GetWidget());
-
-  if (remove_observer)
-    view->RemoveObserver(this);
-
-  NodeIdToViewMap::iterator node_id_to_view_it =
-      node_id_to_view_map_.find(node_id);
-  DCHECK(node_id_to_view_it != node_id_to_view_map_.end());
-
-  view_to_node_id_map_.erase(view_to_node_id_it);
-  node_id_to_view_map_.erase(node_id_to_view_it);
-  frontend()->childNodeRemoved(parent_id, node_id);
-}
-
-void AshDevToolsDOMAgent::RemoveObservers() {
-  for (auto& pair : window_to_node_id_map_)
-    pair.first->RemoveObserver(this);
-  for (auto& pair : widget_to_node_id_map_)
-    pair.first->RemoveRemovalsObserver(this);
-  for (auto& pair : view_to_node_id_map_)
-    pair.first->RemoveObserver(this);
+  frontend()->childNodeRemoved(ui_element->GetParent()->GetNodeId(),
+                               ui_element->GetNodeId());
 }
 
 void AshDevToolsDOMAgent::Reset() {
-  RemoveObservers();
   widget_for_highlighting_.reset();
-  window_to_node_id_map_.clear();
-  widget_to_node_id_map_.clear();
-  view_to_node_id_map_.clear();
-  node_id_to_window_map_.clear();
-  node_id_to_widget_map_.clear();
-  node_id_to_view_map_.clear();
-  node_ids = 1;
-}
-
-AshDevToolsDOMAgent::WindowAndBoundsPair
-AshDevToolsDOMAgent::GetNodeWindowAndBounds(int node_id) {
-  aura::Window* window = GetWindowFromNodeId(node_id);
-  if (window)
-    return std::make_pair(window, window->GetBoundsInScreen());
-
-  views::Widget* widget = GetWidgetFromNodeId(node_id);
-  if (widget) {
-    return std::make_pair(widget->GetNativeWindow(),
-                          widget->GetWindowBoundsInScreen());
-  }
-
-  views::View* view = GetViewFromNodeId(node_id);
-  if (view) {
-    gfx::Rect bounds = view->GetBoundsInScreen();
-    return std::make_pair(view->GetWidget()->GetNativeWindow(), bounds);
-  }
-
-  return std::make_pair(nullptr, gfx::Rect());
+  RemoveUIElementTree(window_element_root);
+  node_id_to_ui_element_.clear();
 }
 
 void AshDevToolsDOMAgent::InitializeHighlightingWidget() {
@@ -485,7 +333,7 @@ void AshDevToolsDOMAgent::InitializeHighlightingWidget() {
 }
 
 void AshDevToolsDOMAgent::UpdateHighlight(
-    const WindowAndBoundsPair& window_and_bounds,
+    const std::pair<aura::Window*, gfx::Rect>& window_and_bounds,
     SkColor background,
     SkColor border) {
   constexpr int kBorderThickness = 1;
@@ -507,7 +355,13 @@ ui::devtools::protocol::Response AshDevToolsDOMAgent::HighlightNode(
   if (!widget_for_highlighting_)
     InitializeHighlightingWidget();
 
-  WindowAndBoundsPair window_and_bounds(GetNodeWindowAndBounds(node_id));
+  std::pair<aura::Window*, gfx::Rect> window_and_bounds;
+  if (node_id_to_ui_element_.count(node_id))
+    window_and_bounds =
+        node_id_to_ui_element_[node_id]->GetNodeWindowAndBounds();
+  else
+    window_and_bounds =
+        std::make_pair<aura::Window*, gfx::Rect>(nullptr, gfx::Rect());
 
   if (!window_and_bounds.first)
     return ui::devtools::protocol::Response::Error(