mus: Let clients set the cursor of their window.

components/mus/ws/window_tree_host_impl.h

 // 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.
 
 #ifndef COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_
 #define COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_
 
 #include <queue>
 
 #include "base/macros.h"
@@ skipping 75 matching lines @@
   const ServerWindow* root_window() const { return root_.get(); }
 
   void SetFocusedWindow(ServerWindow* window);
   ServerWindow* GetFocusedWindow();
   void DestroyFocusController();
 
   void UpdateTextInputState(ServerWindow* window,
                             const ui::TextInputState& state);
   void SetImeVisibility(ServerWindow* window, bool visible);
 
+  // Called when a client updates a cursor. This will update the cursor on the
+  // native display if the cursor is currently under |window|.
+  void OnCursorUpdated(ServerWindow* window);
+
   // WindowTreeHost:
   void SetSize(mojo::SizePtr size) override;
   void SetTitle(const mojo::String& title) override;
   void AddAccelerator(uint32_t id,
                       mojom::EventMatcherPtr event_matcher,
                       const AddAcceleratorCallback& callback) override;
   void RemoveAccelerator(uint32_t id) override;
   void AddActivationParent(uint32_t window_id) override;
   void RemoveActivationParent(uint32_t window_id) override;
   void ActivateNextWindow() override;
   void SetUnderlaySurfaceOffsetAndExtendedHitArea(
       Id window_id,
       int32_t x_offset,
       int32_t y_offset,
       mojo::InsetsPtr hit_area) override;
 
   void OnEventAck(mojom::WindowTree* tree);
 
  private:
   friend class WindowTreeTest;
 
   void OnClientClosed();
   void OnEventAckTimeout();
   void DispatchNextEventFromQueue();
 
+  void UpdateNativeCursor(int32_t cursor_id);
+
   // DisplayManagerDelegate:
   ServerWindow* GetRootWindow() override;
   void OnEvent(mojom::EventPtr event) override;
   void OnDisplayClosed() override;
   void OnViewportMetricsChanged(
       const mojom::ViewportMetrics& old_metrics,
       const mojom::ViewportMetrics& new_metrics) override;
   void OnTopLevelSurfaceChanged(cc::SurfaceId surface_id) override;
   void OnCompositorFrameDrawn() override;
 
@@ skipping 21 matching lines @@
   WindowTreeHostDelegate* delegate_;
   ConnectionManager* const connection_manager_;
   mojom::WindowTreeHostClientPtr client_;
   EventDispatcher event_dispatcher_;
   scoped_ptr<ServerWindow> root_;
   scoped_ptr<DisplayManager> display_manager_;
   scoped_ptr<FocusController> focus_controller_;
   mojom::WindowManagerPtr window_manager_;
   mojom::WindowTree* tree_awaiting_input_ack_;
 
+  // The last cursor set. Used to track whether we need to change the cursor.
+  int32_t last_cursor_;
+
   std::set<WindowId> activation_parents_;
 
   // Set of windows with surfaces that need to be destroyed once the frame
   // draws.
   std::set<ServerWindow*> windows_needing_frame_destruction_;
 
   std::queue<mojom::EventPtr> event_queue_;
   base::OneShotTimer event_ack_timer_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowTreeHostImpl);
 };
 
 }  // namespace ws
 }  // namespace mus
 
 #endif  // COMPONENTS_MUS_WS_WINDOW_TREE_HOST_IMPL_H_