| // Copyright 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 MEDIA_BASE_USER_INPUT_MONITOR_H_ |
| #define MEDIA_BASE_USER_INPUT_MONITOR_H_ |
| |
| #include <stddef.h> |
| |
| #include <memory> |
| |
| #include "base/macros.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/synchronization/lock.h" |
| #include "media/base/media_export.h" |
| |
| namespace base { |
| class SingleThreadTaskRunner; |
| } // namespace base |
| |
| namespace media { |
| |
| // Monitors and notifies about keyboard events. |
| // Thread safe. |
| class MEDIA_EXPORT UserInputMonitor { |
| public: |
| UserInputMonitor(); |
| virtual ~UserInputMonitor(); |
| |
| // Creates a platform-specific instance of UserInputMonitor. |
| // |io_task_runner| is the task runner for an IO thread. |
| // |ui_task_runner| is the task runner for a UI thread. |
| static std::unique_ptr<UserInputMonitor> Create( |
| const scoped_refptr<base::SingleThreadTaskRunner>& io_task_runner, |
| const scoped_refptr<base::SingleThreadTaskRunner>& ui_task_runner); |
| |
| // A caller must call EnableKeyPressMonitoring and |
| // DisableKeyPressMonitoring in pair. |
| void EnableKeyPressMonitoring(); |
| void DisableKeyPressMonitoring(); |
| |
| // Returns the number of keypresses. The starting point from when it is |
| // counted is not guaranteed, but consistent within the pair of calls of |
| // EnableKeyPressMonitoring and DisableKeyPressMonitoring. So a caller can |
| // use the difference between the values returned at two times to get the |
| // number of keypresses happened within that time period, but should not make |
| // any assumption on the initial value. |
| virtual size_t GetKeyPressCount() const = 0; |
| |
| private: |
| virtual void StartKeyboardMonitoring() = 0; |
| virtual void StopKeyboardMonitoring() = 0; |
| |
| base::Lock lock_; |
| size_t key_press_counter_references_; |
| |
| DISALLOW_COPY_AND_ASSIGN(UserInputMonitor); |
| }; |
| |
| } // namespace media |
| |
| #endif // MEDIA_BASE_USER_INPUT_MONITOR_H_ |