src/win32/base/imm_util.h

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#ifndef MOZC_WIN32_BASE_IMM_UTIL_H_
#define MOZC_WIN32_BASE_IMM_UTIL_H_

#include <windows.h>
#include <string>

#include "base/port.h"

namespace mozc {
namespace win32 {

class ImeUtil {
 public:
  // Returns true if Google Japanese Input is selected as the default IME.
  static bool IsDefault();

  // Sets Google Japanese Input as the default IME and update the runtime
  // keyboard setting of the current session.
  // Returns true if the operation completed successfully.
  // NOTE: This function internally calls LoadKeyboardLayout on Windows XP.
  // Loading the specified keyboard layout might result in loading
  // corresponding IME module (*.ime) into the current process, although I
  // have not tested. If this is true, you cannot freely call SetDefault()
  // in some special situations like CustomAction.
  static bool SetDefault();

  // Enables or disables CUAS (Cicero Unaware Application Support).
  // Returns true if the operation completed successfully.
  static bool SetCuasEnabled(bool enable);

  // Returns true if cfmon.exe is running.
  // ctfmon.exe is running if TSF (Text Service Framework) is enabled.
  static bool IsCtfmonRunning();

  // Activates the IMM32 version of Google Japanese Input for the current
  // process.
  // Returns true if the operation completed successfully.
  static bool ActivateForCurrentProcess();

  // Looks like the TSF needs to rebuild a certain cache after changing the
  // input details. This task usually takes a few hundreds msec. However,
  // if we broadcast WM_INPUTLANGCHANGEREQUEST message to all the desktop
  // UI threads before the TSF finishes rebuilding its internal cache, all
  // the UI threads which receive the WM_INPUTLANGCHANGEREQUEST message start
  // waiting for "MSCTF.AsmCacheReady.<desktop name><session #>" event and
  // later waiting for an IMM critical section that the former threads own.
  // Perhaps TSF's rebuiding process is not resilient enough for a relatively
  // lot of threads. As a result, all the desktop UI threads will be blocked
  // for about a minute, as reported in b/5765783.
  //
  // This method waits for
  //   "Local\MSCTF.AsmCacheReady.<desktop name><session #>"
  // event to cope with the above TSF's behavior.
  // You can pass INFINITE to |timeout_msec| to wait for the event forever.
  // Returns true if the operation completed successfully.
  // Returns true if "MSCTF.AsmCacheReady.<desktop name><session #>" event does
  // not exist.
  // Otherwise returns false.
  static bool WaitForAsmCacheReady(uint32 timeout_msec);

  // Activates the IMM32 version of Google Japanese Input for all existing
  // applications running in the current session.
  // Returns true if the operation completed successfully.
  static bool ActivateForCurrentSession();

 private:
  DISALLOW_COPY_AND_ASSIGN(ImeUtil);
};

}  // namespace win32
}  // namespace mozc

#endif  // MOZC_WIN32_BASE_IMM_UTIL_H_