text: // 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.
  
  #include "remoting/host/curtain_mode.h"
  
  #include "base/logging.h"
  #include "base/single_thread_task_runner.h"
  #include "base/win/windows_version.h"
  #include "remoting/host/client_session_control.h"
  
  namespace remoting {
  
  class CurtainModeWin : public CurtainMode {
   public:
    CurtainModeWin();
  
    // Overriden from CurtainMode.
    virtual bool Activate() OVERRIDE;
  
   private:
    DISALLOW_COPY_AND_ASSIGN(CurtainModeWin);
  };
  
  CurtainModeWin::CurtainModeWin() {
  }
  
  bool CurtainModeWin::Activate() {
    if (base::win::GetVersion() < base::win::VERSION_VISTA) {
      LOG(ERROR) << "Curtain mode is not supported on Windows XP/2003";
      return false;
    }
  
    DWORD session_id;
    if (!ProcessIdToSessionId(GetCurrentProcessId(), &session_id)) {
      PLOG(ERROR) << "Failed to map the current PID to session ID";
      return false;
    }
  
    // The current session is curtained if it is not attached to the local
    // console.
    return WTSGetActiveConsoleSessionId() != session_id;
  }
  
  // static
  scoped_ptr<CurtainMode> CurtainMode::Create(
      scoped_refptr<base::SingleThreadTaskRunner> caller_task_runner,
      scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner,
      base::WeakPtr<ClientSessionControl> client_session_control) {
    // |client_session_control| is not used because the client session is
    // disconnected as soon as the session is re-attached to the local console.
    // See RdpDesktopSession for more details.
    return scoped_ptr<CurtainMode>(new CurtainModeWin());
  }
  
  }  // namespace remoting
  