Use factory method to create screen capturer

src/screen_capturer/windows/screen_capturer_wgc.h

@@ -0,0 +1,57 @@
+#ifndef _SCREEN_CAPTURER_WGC_H_
+#define _SCREEN_CAPTURER_WGC_H_
+
+#include <atomic>
+#include <functional>
+#include <string>
+#include <thread>
+
+#include "screen_capturer.h"
+#include "wgc_session.h"
+#include "wgc_session_impl.h"
+
+class ScreenCapturerWgc : public ScreenCapturer,
+                          public WgcSession::wgc_session_observer {
+ public:
+  ScreenCapturerWgc();
+  ~ScreenCapturerWgc();
+
+ public:
+  bool IsWgcSupported();
+
+  virtual int Init(const RECORD_DESKTOP_RECT &rect, const int fps,
+                   cb_desktop_data cb);
+  virtual int Destroy();
+
+  virtual int Start();
+
+  int Pause();
+  int Resume();
+  int Stop();
+
+  void OnFrame(const WgcSession::wgc_session_frame &frame);
+
+ protected:
+  void CleanUp();
+
+ private:
+  WgcSession *session_ = nullptr;
+
+  std::atomic_bool _running;
+  std::atomic_bool _paused;
+  std::atomic_bool _inited;
+
+  std::thread _thread;
+
+  std::string _device_name;
+
+  RECORD_DESKTOP_RECT _rect;
+
+  int _fps;
+
+  cb_desktop_data _on_data;
+
+  unsigned char *nv12_frame_ = nullptr;
+};
+
+#endif