Implement surface-based browser process hit testing for Mac and Aura

content/browser/renderer_host/render_widget_host_input_event_router.cc

+// Copyright 2015 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 "content/browser/renderer_host/render_widget_host_input_event_router.h"
+
+#include "cc/surfaces/surface_manager.h"
+#include "content/browser/renderer_host/render_widget_host_view_base.h"
+#include "third_party/WebKit/public/web/WebInputEvent.h"
+
+namespace content {
+
+RenderWidgetHostInputEventRouter::RenderWidgetHostInputEventRouter() {}
+
+RenderWidgetHostInputEventRouter::~RenderWidgetHostInputEventRouter() {
+  owner_map_.clear();
+}
+
+RenderWidgetHostViewBase* RenderWidgetHostInputEventRouter::FindEventTarget(
+    RenderWidgetHostViewBase* root_view,
+    const gfx::Point& point,
+    gfx::Point* transformed_point) {
+  // Short circuit if owner_map has only one RenderWidgetHostView, no need for
+  // hit testing.
+  if (owner_map_.size() <= 1) {
+    *transformed_point = point;
+    return root_view;
+  }
+
+  // The conversion of point to transform_point is done over the course of the
+  // hit testing, and reflect transformations that would normally be applied in
+  // the renderer process if the event was being routed between frames within a
+  // single process with only one RenderWidgetHost.
+  uint32_t surface_id_namespace =
+      root_view->SurfaceIdNamespaceAtPoint(point, transformed_point);
+  const SurfaceIdNamespaceOwnerMap::iterator iter =
+      owner_map_.find(surface_id_namespace);
+  // If the point hit a Surface whose namspace is no longer in the map, then
+  // it likely means the RenderWidgetHostView has been destroyed but its
+  // parent frame has not sent a new compositor frame since that happened.
+  if (iter == owner_map_.end())
+    return root_view;
+  return iter->second;
+}
+
+void RenderWidgetHostInputEventRouter::RouteMouseEvent(
+    RenderWidgetHostViewBase* root_view,
+    blink::WebMouseEvent* event) {
+  gfx::Point transformed_point;
+  RenderWidgetHostViewBase* target = FindEventTarget(
+      root_view, gfx::Point(event->x, event->y), &transformed_point);
+  event->x = transformed_point.x();
+  event->y = transformed_point.y();
+
+  target->ProcessMouseEvent(*event);
+}
+
+void RenderWidgetHostInputEventRouter::RouteMouseWheelEvent(
+    RenderWidgetHostViewBase* root_view,
+    blink::WebMouseWheelEvent* event) {
+  gfx::Point transformed_point;
+  RenderWidgetHostViewBase* target = FindEventTarget(
+      root_view, gfx::Point(event->x, event->y), &transformed_point);
+  event->x = transformed_point.x();
+  event->y = transformed_point.y();
+
+  target->ProcessMouseWheelEvent(*event);
+}
+
+void RenderWidgetHostInputEventRouter::AddSurfaceIdNamespaceOwner(
+    uint32_t id,
+    RenderWidgetHostViewBase* owner) {
+  DCHECK(owner_map_.find(id) == owner_map_.end());
+  owner_map_.insert(std::make_pair(id, owner));
+}
+
+void RenderWidgetHostInputEventRouter::RemoveSurfaceIdNamespaceOwner(
+    uint32_t id) {
+  owner_map_.erase(id);
+}
+
+}  // namespace content