Pointer watcher modifications to support laser pointer.

ash/common/system/chromeos/palette/tools/laser_pointer_mode.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_COMMON_SYSTEM_CHROMEOS_PALETTE_TOOLS_LASER_POINTER_MODE_H_
+#define ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_TOOLS_LASER_POINTER_MODE_H_
+
+#include "ash/common/system/chromeos/palette/common_palette_tool.h"
+#include "ash/common/system/chromeos/palette/tools/laser_pointer_points.h"
+#include "ash/common/system/chromeos/palette/tools/laser_pointer_view.h"
+
+namespace ash {
+
+class LaserPointerMode : public CommonPaletteTool, public ui::EventHandler {
+ public:
+  explicit LaserPointerMode(Delegate* delegate);
+  ~LaserPointerMode() override;
+
+ protected:
+  // Timer which will add a new stationary point when the mouse stops moving.
+  // This will remove points past a certain threshold.
+  std::unique_ptr<base::Timer> timer_;
+  base::Lock points_lock_;
+  int timer_repeat_count_;
+
+  gfx::Point current_mouse_location_;
+  LaserPointerPoints laser_points_;
+  LaserPointerView* laser_pointer_view_ = nullptr;
+
+ private:
+  // PaletteTool overrides.
+  PaletteGroup GetGroup() const override;
+  PaletteToolId GetToolId() const override;
+  void OnEnable() override;
+  void OnDisable() override;
+  gfx::VectorIconId GetActiveTrayIcon() override;
+
+  // CommonPaletteTool overrides.
+  gfx::VectorIconId GetPaletteIconId() override;
+
+  // EventHandler overrides.
+  void OnMouseEvent(ui::MouseEvent* event) override;
+  void OnKeyEvent(ui::KeyEvent* event) override;
+  void OnTouchEvent(ui::TouchEvent* event) override;
+  void OnGestureEvent(ui::GestureEvent* event) override;
+  void OnScrollEvent(ui::ScrollEvent* event) override;
+
+  void InitializeTimer();
+  void StartTimer();
+  void StopTimer();
+  // Timer callback which adds a point where the mouse was last seen. This takes
+  // care of fading away the tail of the laser when the mouse is stationary.
+  void AddStationaryPoint();
+
+  static const int kAddStationaryPointsDelayMs;
+  static const int kPointLifeDurationMs;
+
+  DISALLOW_COPY_AND_ASSIGN(LaserPointerMode);
+};
+
+}  // namespace ash
+
+#endif  // ASH_COMMON_SYSTEM_CHROMEOS_PALETTE_TOOLS_LASER_POINTER_MODE_H_