chromeos: Notify power manager about user activity.

ash/wm/user_activity_detector.h

+// Copyright (c) 2012 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_WM_USER_ACTIVITY_DETECTOR_H_
+#define ASH_WM_USER_ACTIVITY_DETECTOR_H_
+#pragma once
+
+#include "ash/ash_export.h"
+#include "base/basictypes.h"
+#include "base/compiler_specific.h"
+#include "base/observer_list.h"
+#include "base/time.h"
+#include "ui/aura/event_filter.h"
+
+namespace ash {
+
+class UserActivityObserver;
+
+// Watches for input events and notifies observers that the user is active.
+class ASH_EXPORT UserActivityDetector : public aura::EventFilter {
+ public:
+  // Minimum amount of time between notifications to observers that a video is
+  // playing.
+  static const double kNotifyIntervalSec;
+
+  UserActivityDetector();
+  virtual ~UserActivityDetector();
+
+  void AddObserver(UserActivityObserver* observer);
+  void RemoveObserver(UserActivityObserver* observer);
+
+  // aura::EventFilter implementation.
+  virtual bool PreHandleKeyEvent(
+      aura::Window* target,
+      aura::KeyEvent* event) OVERRIDE;
+  virtual bool PreHandleMouseEvent(
+      aura::Window* target,
+      aura::MouseEvent* event) OVERRIDE;
+  virtual ui::TouchStatus PreHandleTouchEvent(
+      aura::Window* target,
+      aura::TouchEvent* event) OVERRIDE;
+  virtual ui::GestureStatus PreHandleGestureEvent(
+      aura::Window* target,
+      aura::GestureEvent* event) OVERRIDE;
+
+ private:
+  // Notifies observers if enough time has passed since the last notification.
+  void MaybeNotify();
+
+  ObserverList<UserActivityObserver> observers_;
+
+  // Last time at which we notified observers that the user was active.
+  base::TimeTicks last_observer_notification_time_;
+
+  DISALLOW_COPY_AND_ASSIGN(UserActivityDetector);
+};
+
+}  // namespace ash
+
+#endif  // ASH_WM_USER_ACTIVITY_DETECTOR_H_