1 // Copyright (c) 2011 The Chromium Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style license that can be 3 // found in the LICENSE file. 4 5 #ifndef CHROME_BROWSER_CHROMEOS_CAMERA_DETECTOR_H_ 6 #define CHROME_BROWSER_CHROMEOS_CAMERA_DETECTOR_H_ 7 8 #include "base/callback.h" 9 10 namespace chromeos { 11 12 // Class used to check for camera presence. 13 class CameraDetector { 14 public: 15 enum CameraPresence { 16 kCameraPresenceUnknown = 0, 17 kCameraAbsent, 18 kCameraPresent 19 }; 20 21 // Returns result of the last presence check. If no check has been performed 22 // yet, returns |kCameraPresenceUnknown|. camera_presence()23 static CameraPresence camera_presence() { 24 return camera_presence_; 25 } 26 27 // Checks asynchronously for camera device presence. Only one 28 // presence check can be running at a time. Calls |check_done| 29 // on current thread when the check has been completed. 30 static void StartPresenceCheck(const base::Closure& check_done); 31 32 private: 33 // Called back on UI thread after check has been performed. 34 static void OnPresenceCheckDone(const base::Closure& callback, bool present); 35 36 // Checks for camera presence. Runs on a thread that allows I/O. 37 static bool CheckPresence(); 38 39 // Result of the last presence check. 40 static CameraPresence camera_presence_; 41 42 static bool presence_check_in_progress_; 43 44 DISALLOW_COPY_AND_ASSIGN(CameraDetector); 45 }; 46 47 } // namespace chromeos 48 49 #endif // CHROME_BROWSER_CHROMEOS_CAMERA_DETECTOR_H_ 50