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      1 // Copyright (c) 2012 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 // VideoCaptureImplManager manages video capture devices in renderer process.
      6 // The video capture clients use AddDevice() to get a pointer to
      7 // video capture device. VideoCaputreImplManager supports multiple clients
      8 // accessing same device.
      9 
     10 #ifndef CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
     11 #define CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
     12 
     13 #include <list>
     14 #include <map>
     15 
     16 #include "base/message_loop/message_loop_proxy.h"
     17 #include "base/threading/thread.h"
     18 #include "base/synchronization/lock.h"
     19 #include "content/common/content_export.h"
     20 #include "media/video/capture/video_capture.h"
     21 
     22 namespace content {
     23 
     24 class VideoCaptureImpl;
     25 class VideoCaptureMessageFilter;
     26 
     27 class CONTENT_EXPORT VideoCaptureImplManager
     28     : public base::RefCountedThreadSafe<VideoCaptureImplManager> {
     29  public:
     30   VideoCaptureImplManager();
     31 
     32   // Called by video capture client |handler| to add device referenced
     33   // by |id| to VideoCaptureImplManager's list of opened device list.
     34   // A pointer to VideoCapture is returned to client so that client can
     35   // operate on that pointer, such as StartCaptrue, StopCapture.
     36   virtual media::VideoCapture* AddDevice(
     37       media::VideoCaptureSessionId id,
     38       media::VideoCapture::EventHandler* handler);
     39 
     40   // Called by video capture client |handler| to remove device referenced
     41   // by |id| from VideoCaptureImplManager's list of opened device list.
     42   virtual void RemoveDevice(media::VideoCaptureSessionId id,
     43                             media::VideoCapture::EventHandler* handler);
     44 
     45   // Make all existing VideoCaptureImpl instances stop/resume delivering
     46   // video frames to their clients, depends on flag |suspend|.
     47   virtual void SuspendDevices(bool suspend);
     48 
     49   VideoCaptureMessageFilter* video_capture_message_filter() const {
     50     return filter_.get();
     51   }
     52 
     53  protected:
     54   virtual ~VideoCaptureImplManager();
     55 
     56  private:
     57   friend class base::RefCountedThreadSafe<VideoCaptureImplManager>;
     58 
     59   struct Device {
     60     Device(VideoCaptureImpl* device,
     61            media::VideoCapture::EventHandler* handler);
     62     ~Device();
     63 
     64     VideoCaptureImpl* vc;
     65     std::list<media::VideoCapture::EventHandler*> clients;
     66   };
     67 
     68   void FreeDevice(VideoCaptureImpl* vc);
     69 
     70   typedef std::map<media::VideoCaptureSessionId, Device*> Devices;
     71   Devices devices_;
     72   base::Lock lock_;
     73   scoped_refptr<VideoCaptureMessageFilter> filter_;
     74   base::Thread thread_;
     75   scoped_refptr<base::MessageLoopProxy> message_loop_proxy_;
     76 
     77   DISALLOW_COPY_AND_ASSIGN(VideoCaptureImplManager);
     78 };
     79 
     80 }  // namespace content
     81 
     82 #endif  // CONTENT_RENDERER_MEDIA_VIDEO_CAPTURE_IMPL_MANAGER_H_
     83