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#ifndef MOZC_WIN32_BASE_INPUT_DLL_H_
#define MOZC_WIN32_BASE_INPUT_DLL_H_

#include <windows.h>

#include "base/port.h"
#include "testing/base/public/gunit_prod.h"
// for FRIEND_TEST()

// Structures and flags bellow have not been included header files in Windows
// SDK.  You can see the original source of this information at the following
// page.
// - http://msdn.microsoft.com/en-us/library/bb847907.aspx
// - http://msdn.microsoft.com/en-us/library/bb847908.aspx

// Flags used in LAYOUTORTIP::dwFlags.
// Also might be used in LAYOUTORTIP::dwFlags based on observations.
#define LOT_DEFAULT    0x0001
#define LOT_DISABLED   0x0002

// Flags used in LAYOUTORTIPPROFILE::dwProfileType
#define LOTP_INPUTPROCESSOR  1
#define LOTP_KEYBOARDLAYOUT  2

// Flags used with InstallLayoutOrTipUserReg.
#define ILOT_UNINSTALL                 0x00000001
#define ILOT_DEFPROFILE                0x00000002
#define ILOT_NOAPPLYTOCURRENTSESSION   0x00000020
#define ILOT_CLEANINSTALL              0x00000040
#define ILOT_DISABLED                  0x00000080

// Flags used with SetDefaultLayoutOrTip.
#define SDLOT_NOAPPLYTOCURRENTSESSION  0x00000001
#define SDLOT_APPLYTOCURRENTTHREAD     0x00000002

// Structure used with EnumLayoutOrTipForSetup API.
typedef struct tagLAYOUTORTIP {
  DWORD dwFlags;
  WCHAR szId[MAX_PATH];
  WCHAR szName[MAX_PATH];
} LAYOUTORTIP;

// Structure used with EnumEnabledLayoutOrTip API.
typedef struct tagLAYOUTORTIPPROFILE {
  DWORD  dwProfileType;
  LANGID langid;
  CLSID  clsid;
  GUID   guidProfile;
  GUID   catid;
  DWORD  dwSubstituteLayout;
  DWORD  dwFlags;
  WCHAR  szId[MAX_PATH];
} LAYOUTORTIPPROFILE;

namespace mozc {
namespace win32 {

// With these function, you no longer need to manipulate undocumented registry
// entries such as "Keyboard Layout/Preload".
// TODO(yukawa): Add mock injection mechanism to support unit tests.
class InputDll {
 public:
  // Ensures input.dll is loaded into the process so that its export functions
  // become available. When this method returns true, the returned value of
  // each accessor method like |set_default_layout_or_tip()| is the same to
  // the returned address of GetProcAddress API.  If |EnsureInitialized()|
  // returns true but the accessor method returns nullptr, it means that the DLL
  // exists on the system but the expected function is not exported.
  // You can call this method multiple times from multiple threads.  In other
  // words, you can use this method like 'IsInizialized'.
  // This method fails if input.dll is not available on the system.  This
  // method also fails if the caller thread owns loader lock.
  static bool EnsureInitialized();

  // Returns a function pointer to the EnumEnabledLayoutOrTip API, which
  // is available on Vista or later via input.dll to enumerates all enabled
  // keyboard layouts or text services of the specified user setting.
  //
  // EnumEnabledLayoutOrTip:
  //   URL:
  //     http://msdn.microsoft.com/en-us/library/bb847907.aspx
  //   Return Value:
  //     TRUE: The function was successful.
  //     FALSE: An unspecified error occurred.
  typedef UINT (CALLBACK *FPEnumEnabledLayoutOrTip)(
      __in_opt  LPCWSTR pszUserReg,
      __in_opt  LPCWSTR pszSystemReg,
      __in_opt  LPCWSTR pszSoftwareReg,
      __out     LAYOUTORTIPPROFILE *pLayoutOrTipProfile,
      __in      UINT uBufLength);
  static FPEnumEnabledLayoutOrTip enum_enabled_layout_or_tip();

  // Returns a function pointer to the EnumEnabledLayoutOrTip API, which
  // is available on Vista or later via input.dll to enumerates the installed
  // keyboard layouts and text services.
  //
  // EnumLayoutOrTipForSetup:
  //   URL:
  //     http://msdn.microsoft.com/en-us/library/bb847908.aspx
  //   Return Value:
  //     |pLayoutOrTip == nullptr|
  //        The number of elements to be returned.
  //     |pLayoutOrTip != nullptr|
  //        The number of elements actually copied to |pLayoutOrTip|.
  typedef UINT (CALLBACK *FPEnumLayoutOrTipForSetup)(
    __in                     LANGID langid,
    __out_ecount(uBufLength) LAYOUTORTIP *pLayoutOrTip,
    __in                     UINT uBufLength,
    __in                     DWORD dwFlags);
  static FPEnumLayoutOrTipForSetup enum_layout_or_tip_for_setup();

  // Returns a function pointer to the InstallLayoutOrTip API, which is
  // available on Vista or later via input.dll to enable the specified
  // keyboard layouts or text services for the current user.
  //
  // InstallLayoutOrTip:
  //   URL:
  //     http://msdn.microsoft.com/en-us/library/bb847909.aspx
  //   Remarks:
  //     The string format of the layout list is:
  //       <LangID 1>:<KLID 1>;[...<LangID N>:<KLID N>
  //     The string format of the text service profile list is:
  //       <LangID 1>:{CLSID of TIP}{GUID of LanguageProfile};
  //     where GUID should be like {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}.
  //     This format seems to be corresponding to the registry key, e.g.
  //       HKLM\SOFTWARE\Microsoft\CTF\TIP\{CLSID of TIP}\LanguageProfile\
  //       {Land ID}\{GUID of LanguageProfile}
  //   Return Value:
  //     TRUE: The function was successful.
  //     FALSE: An unspecified error occurred.
  typedef BOOL (CALLBACK *FPInstallLayoutOrTip)(
    __in      LPCWSTR psz,
    __in      DWORD dwFlags);
  static FPInstallLayoutOrTip install_layout_or_tip();

  // Returns a function pointer to the InstallLayoutOrTipUserReg API, which
  // is available on Vista or later via input.dll to enable the specified
  // keyboard layouts or text services for the specified user.
  //
  // InstallLayoutOrTipUserReg:
  //   URL:
  //     http://msdn.microsoft.com/en-us/library/bb847910.aspx
  //   Remarks:
  //     The string format of the layout list is:
  //       <LangID 1>:<KLID 1>;[...<LangID N>:<KLID N>
  //     The string format of the text service profile list is:
  //       <LangID 1>:{CLSID of TIP}{GUID of LanguageProfile};
  //     where GUID should be like {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}.
  //     This format seems to be corresponding to the registry key, e.g.
  //       HKLM\SOFTWARE\Microsoft\CTF\TIP\{CLSID of TIP}\LanguageProfile\
  //       {Land ID}\{GUID of LanguageProfile}
  //   Return Value:
  //     TRUE: The function was successful.
  //     FALSE: An unspecified error occurred.
  //   Observational Facts:
  //     Like ImmInstallIME API, calling InstallLayoutOrTipUserReg from 32-bit
  //     process to install x64 binaries is not recommended.  Otherwise, we
  //     will see some weird issues like b/2931871.
  typedef BOOL (CALLBACK *FPInstallLayoutOrTipUserReg)(
    __in_opt  LPCWSTR pszUserReg,
    __in_opt  LPCWSTR pszSystemReg,
    __in_opt  LPCWSTR pszSoftwareReg,
    __in      LPCWSTR psz,
    __in      DWORD dwFlags);
  static FPInstallLayoutOrTipUserReg install_layout_or_tip_user_reg();

  // Returns a function pointer to the SetDefaultLayoutOrTip API, which sets
  // the specified keyboard layout or a text service as the default input item
  // of the current user.
  //
  // SetDefaultLayoutOrTip:
  //   URL:
  //     http://msdn.microsoft.com/en-us/library/bb847915.aspx
  //   Remarks:
  //     The string format of the layout list is:
  //       <LangID 1>:<KLID 1>;[...<LangID N>:<KLID N>
  //     The string format of the text service profile list is:
  //       <LangID 1>:{CLSID of TIP}{GUID of LanguageProfile};
  //     where GUID should be like {xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}.
  //     This format seems to be corresponding to the registry key, e.g.
  //       HKLM\SOFTWARE\Microsoft\CTF\TIP\{CLSID of TIP}\LanguageProfile\
  //       {Land ID}\{GUID of LanguageProfile}
  //   Return Value:
  //     TRUE: The function was successful.
  //     FALSE: An unspecified error occurred.
  //   Observational Facts:
  //     This API seems to be designed to modify per user settings, like HKCU,
  //     so that the current user can modify it with his/her privileges.  In
  //     oother words, no administrative privilege is required.
  //     SetDefaultLayoutOrTipUserReg might be a phantom, which only exists in
  //     MSDN Library.
  //     This function returns fail if it is called to install an IME which is
  //     not enabled (if we use undocumented terms to explain the condition,
  //     "The IME is not listed in the Preload key").  It seems that the caller
  //     is responsible to enable (e.g. calling InstallLayoutOrTipUserReg)
  //     the target IME before call this function to set the IME default.
  typedef BOOL (CALLBACK *FPSetDefaultLayoutOrTip)(
      __in  LPCWSTR psz,
      DWORD dwFlags);
  static FPSetDefaultLayoutOrTip set_default_layout_or_tip();

 private:
  static volatile HMODULE module_;
  static bool not_found_;
  static FPEnumEnabledLayoutOrTip enum_enabled_layout_or_tip_;
  static FPEnumLayoutOrTipForSetup enum_layout_or_tip_for_setup_;
  static FPInstallLayoutOrTip install_layout_or_tip_;
  static FPInstallLayoutOrTipUserReg install_layout_or_tip_user_reg_;
  static FPSetDefaultLayoutOrTip set_default_layout_or_tip_;

  FRIEND_TEST(InputDllTest, EnsureInitializedTest);

  DISALLOW_IMPLICIT_CONSTRUCTORS(InputDll);
};
}  // namespace win32
}  // namespace mozc
#endif  // MOZC_WIN32_BASE_INPUT_DLL_H_