mus: Let clients set the cursor of their window.

components/mus/ws/event_dispatcher.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 "components/mus/ws/event_dispatcher.h"
 
 #include <set>
 
 #include "cc/surfaces/surface_hittest.h"
 #include "components/mus/surfaces/surfaces_state.h"
@@ skipping 123 matching lines @@
   mojom::EventType event_type_;
   mojom::EventFlags event_flags_;
   mojom::KeyboardCode keyboard_code_;
   mojom::PointerKind pointer_kind_;
   gfx::RectF pointer_region_;
 };
 
 ////////////////////////////////////////////////////////////////////////////////
 
 EventDispatcher::EventDispatcher(EventDispatcherDelegate* delegate)
-    : delegate_(delegate), root_(nullptr) {}
+    : delegate_(delegate),
+      root_(nullptr),
+      last_pointer_target_window_(nullptr) {}
 
 EventDispatcher::~EventDispatcher() {
   std::set<ServerWindow*> pointer_targets;
   for (const auto& pair : pointer_targets_) {
     if (pair.second.window &&
         pointer_targets.insert(pair.second.window).second) {
       pair.second.window->RemoveObserver(this);
     }
   }
 }
@@ skipping 101 matching lines @@
     if (target && !IsObservingWindow(target))
       target->RemoveObserver(this);
   }
 }
 
 void EventDispatcher::DispatchToPointerTarget(const PointerTarget& target,
                                               mojom::EventPtr event) {
   if (!target.window)
     return;
 
+  if (event->pointer_data->kind == mojom::PointerKind::POINTER_KIND_MOUSE)
+    last_pointer_target_window_ = target.window;
+
   gfx::Point location(EventLocationToPoint(*event));
   gfx::Transform transform(GetTransformToWindow(surface_id_, target.window));
   transform.TransformPoint(&location);
   event->pointer_data->location->x = location.x();
   event->pointer_data->location->y = location.y();
   delegate_->DispatchInputEventToWindow(target.window, target.in_nonclient_area,
                                         event.Pass());
 }
 
 void EventDispatcher::CancelPointerEventsToTarget(ServerWindow* window) {
@@ skipping 30 matching lines @@
                                                   ServerWindow* old_parent) {
   CancelPointerEventsToTarget(window);
 }
 
 void EventDispatcher::OnWindowVisibilityChanged(ServerWindow* window) {
   CancelPointerEventsToTarget(window);
 }
 
 void EventDispatcher::OnWindowDestroyed(ServerWindow* window) {
   CancelPointerEventsToTarget(window);
+
+  if (last_pointer_target_window_ == window)
+    last_pointer_target_window_ = nullptr;
 }
 
 }  // namespace ws
 }  // namespace mus