Show corresponding window/widget/view in UIElement tree when clicking on a UI element.

components/ui_devtools/views/ui_devtools_overlay_agent.cc

+// Copyright 2017 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.
+
+#include "components/ui_devtools/views/ui_devtools_overlay_agent.h"
+
+#include "ui/aura/env.h"
+
+namespace ui_devtools {
+
+UIDevToolsOverlayAgent::UIDevToolsOverlayAgent(UIDevToolsDOMAgent* dom_agent)
+    : dom_agent_(dom_agent) {
+  DCHECK(dom_agent_);
+}
+
+UIDevToolsOverlayAgent::~UIDevToolsOverlayAgent() {}
+
+ui_devtools::protocol::Response UIDevToolsOverlayAgent::enable() {
+  dom_agent_->AddObserver(this);
+  return ui_devtools::protocol::Response::OK();
+}
+
+ui_devtools::protocol::Response UIDevToolsOverlayAgent::disable() {
+  dom_agent_->RemoveObserver(this);
+  return ui_devtools::protocol::Response::OK();
+}
+
+ui_devtools::protocol::Response UIDevToolsOverlayAgent::setInspectMode(
+    const String& in_mode,
+    protocol::Maybe<protocol::Overlay::HighlightConfig> in_highlightConfig) {
+  if (in_mode.compare("searchForNode") == 0)
+    aura::Env::GetInstance()->PrependPreTargetHandler(this);
+  else if (in_mode.compare("none") == 0)
+    aura::Env::GetInstance()->RemovePreTargetHandler(this);
+  return ui_devtools::protocol::Response::OK();
+}
+
+ui_devtools::protocol::Response UIDevToolsOverlayAgent::highlightNode(
+    std::unique_ptr<ui_devtools::protocol::Overlay::HighlightConfig>
+        highlight_config,
+    ui_devtools::protocol::Maybe<int> node_id) {
+  return dom_agent_->HighlightNode(std::move(highlight_config),
+                                   node_id.fromJust());
+}
+
+ui_devtools::protocol::Response UIDevToolsOverlayAgent::hideHighlight() {
+  return dom_agent_->hideHighlight();
+}
+
+void UIDevToolsOverlayAgent::OnNodeBoundsChanged(int node_id) {}
+
+void UIDevToolsOverlayAgent::OnMouseEvent(ui::MouseEvent* event) {
+  if (!dom_agent_->window_element_root())
+    return;
+
+  // Find node id of element whose bounds contain the mouse pointer location.
+  int element_id = 0;
+  dom_agent_->FindElementByEventHandler(event->root_location(), &element_id);
+
+  if (event->type() == ui::ET_MOUSE_PRESSED) {
+    event->SetHandled();
+    aura::Env::GetInstance()->RemovePreTargetHandler(this);
+    if (element_id) {
+      frontend()->inspectNodeRequested(element_id);
+      dom_agent_->setInspectedNode(element_id);
+    }
+  } else if (element_id) {
+    frontend()->nodeHighlightRequested(element_id);
+  }
+}
+
+}  // namespace ui_devtools