cros: Laser pointer fades out on release, do not cover palette.

ash/laser/laser_pointer_controller.h

 // Copyright 2016 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 ASH_LASER_LASER_POINTER_CONTROLLER_H_
 #define ASH_LASER_LASER_POINTER_CONTROLLER_H_
 
 #include <memory>
 
 #include "ash/ash_export.h"
@@ skipping 36 matching lines @@
   void OnWindowDestroying(aura::Window* window) override;
 
   // Reparent, recreate or destroy LaserPointerView instance as needed based on
   // the current window and the widgets window.
   void SwitchTargetRootWindowIfNeeded(aura::Window* root_window);
 
   // Timer callback which adds a point where the mouse was last seen. This
   // allows the trail to fade away when the mouse is stationary.
   void AddStationaryPoint();
 
+  // Updates |laser_pointer_view_| by changing its root window or creating it if
+  // needed. Also adds the latest point at |event_location| and stops
+  // propagation of |event|.
+  void UpdateLaserPointerView(aura::Window* current_window,
+                              const gfx::Point& event_location,
+                              ui::MouseEvent* event);
+
+  // Destroys |laser_pointer_view_|, if it exists.
+  void DestroyLaserPointerView();
+
+  void RestartTimer();
+
   // Timer which will add a new stationary point when the mouse stops moving.
   // This will remove points that are too old.
   std::unique_ptr<base::Timer> stationary_timer_;
   int stationary_timer_repeat_count_ = 0;
 
   bool enabled_ = false;
 
+  // |is_fading_away_| determines whether the laser pointer view should accept
+  // points normally, or just advance the |laser_points_| time so that current
+  // points start fading away. This should be set to true when the view is about
+  // to be destroyed, such as when the stylus is released.
+  bool is_fading_away_ = false;
+
   // The last seen mouse location in screen coordinates.
   gfx::Point current_mouse_location_;
 
   // |laser_pointer_view_| will only hold an instance when the laser pointer is
   // enabled and activated (pressed or dragged).
   std::unique_ptr<LaserPointerView> laser_pointer_view_;
 
   DISALLOW_COPY_AND_ASSIGN(LaserPointerController);
 };
 
 }  // namespace ash
 
 #endif  // ASH_LASER_LASER_POINTER_CONTROLLER_H_