Separate projection mode from rest of touch HUD

ash/touch/touch_hud_projection.h

+// Copyright (c) 2013 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_TOUCH_TOUCH_HUD_PROJECTION_H_
+#define ASH_TOUCH_TOUCH_HUD_PROJECTION_H_
+
+#include <map>
+
+#include "ash/touch/touch_observer_hud.h"
+
+namespace ash {
+namespace internal {
+
+class TouchPointView;
+
+// A heads-up display to show active touch points on the screen. As a derivative
+// of TouchObserverHUD, objects of this class manage their own lifetime.
+class TouchHudProjection : public TouchObserverHUD {
+ public:
+  explicit TouchHudProjection(aura::RootWindow* initial_root);
+
+  // Overriden from TouchObserverHUD.
+  virtual void Clear() OVERRIDE;
+
+ private:
+  virtual ~TouchHudProjection();
+
+  // Overriden from TouchObserverHUD.
+  virtual void OnTouchEvent(ui::TouchEvent* event) OVERRIDE;
+  virtual void SetHudForRootWindowController(
+      RootWindowController* controller) OVERRIDE;
+  virtual void UnsetHudForRootWindowController(
+      RootWindowController* controller) OVERRIDE;
+
+  std::map<int, TouchPointView*> points_;
+
+  DISALLOW_COPY_AND_ASSIGN(TouchHudProjection);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_TOUCH_TOUCH_HUD_PROJECTION_H_