src/video/windows/SDL_windowskeyboard.c

/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2010 Sam Lantinga

    This library is free software; you can redistribute it and/or
    modify it under the terms of the GNU Lesser General Public
    License as published by the Free Software Foundation; either
    version 2.1 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    Lesser General Public License for more details.

    You should have received a copy of the GNU Lesser General Public
    License along with this library; if not, write to the Free Software
    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

    Sam Lantinga
    slouken@libsdl.org
*/
#include "SDL_config.h"

#ifdef _WIN32_WCE
#define SDL_DISABLE_WINDOWS_IME
#endif

#include "SDL_windowsvideo.h"

#include "../../events/SDL_keyboard_c.h"
#include "../../events/scancodes_windows.h"

#include <imm.h>
#include <oleauto.h>

#ifndef SDL_DISABLE_WINDOWS_IME
static void IME_Init(SDL_VideoData *videodata, HWND hwnd);
static void IME_Enable(SDL_VideoData *videodata, HWND hwnd);
static void IME_Disable(SDL_VideoData *videodata, HWND hwnd);
static void IME_Quit(SDL_VideoData *videodata);
#endif /* !SDL_DISABLE_WINDOWS_IME */

#ifndef MAPVK_VK_TO_VSC
#define MAPVK_VK_TO_VSC     0
#endif
#ifndef MAPVK_VSC_TO_VK
#define MAPVK_VSC_TO_VK     1
#endif
#ifndef MAPVK_VK_TO_CHAR
#define MAPVK_VK_TO_CHAR    2
#endif

/* Alphabetic scancodes for PC keyboards */
BYTE alpha_scancodes[26] = {
    30, 48, 46, 32, 18, 33, 34, 35, 23, 36, 37, 38, 50, 49, 24,
    25, 16, 19, 31, 20, 22, 47, 17, 45, 21, 44
};

BYTE keypad_scancodes[10] = {
    82, 79, 80, 81, 75, 76, 77, 71, 72, 73
};

void
WIN_InitKeyboard(_THIS)
{
    SDL_VideoData *data = (SDL_VideoData *) _this->driverdata;
    int i;

    /* Make sure the alpha scancodes are correct.  T isn't usually remapped */
    if (MapVirtualKey('T', MAPVK_VK_TO_VSC) != alpha_scancodes['T' - 'A']) {
#if 0
        printf
            ("Fixing alpha scancode map, assuming US QWERTY layout!\nPlease send the following 26 lines of output to the SDL mailing list <sdl@libsdl.org>, including a description of your keyboard hardware.\n");
#endif
        for (i = 0; i < SDL_arraysize(alpha_scancodes); ++i) {
            alpha_scancodes[i] = MapVirtualKey('A' + i, MAPVK_VK_TO_VSC);
#if 0
            printf("%d = %d\n", i, alpha_scancodes[i]);
#endif
        }
    }
    if (MapVirtualKey(VK_NUMPAD0, MAPVK_VK_TO_VSC) != keypad_scancodes[0]) {
#if 0
        printf
            ("Fixing keypad scancode map!\nPlease send the following 10 lines of output to the SDL mailing list <sdl@libsdl.org>, including a description of your keyboard hardware.\n");
#endif
        for (i = 0; i < SDL_arraysize(keypad_scancodes); ++i) {
            keypad_scancodes[i] =
                MapVirtualKey(VK_NUMPAD0 + i, MAPVK_VK_TO_VSC);
#if 0
            printf("%d = %d\n", i, keypad_scancodes[i]);
#endif
        }
    }

    data->key_layout = windows_scancode_table;

    data->ime_com_initialized = SDL_FALSE;
    data->ime_threadmgr = 0;
    data->ime_initialized = SDL_FALSE;
    data->ime_enabled = SDL_FALSE;
    data->ime_available = SDL_FALSE;
    data->ime_hwnd_main = 0;
    data->ime_hwnd_current = 0;
    data->ime_himc = 0;
    data->ime_composition[0] = 0;
    data->ime_readingstring[0] = 0;
    data->ime_cursor = 0;

    data->ime_candlist = SDL_FALSE;
    SDL_memset(data->ime_candidates, 0, sizeof(data->ime_candidates));
    data->ime_candcount = 0;
    data->ime_candref = 0;
    data->ime_candsel = 0;
    data->ime_candpgsize = 0;
    data->ime_candlistindexbase = 0;
    data->ime_candvertical = SDL_TRUE;

    data->ime_candtex = NULL;
    data->ime_dirty = SDL_FALSE;
    SDL_memset(&data->ime_rect, 0, sizeof(data->ime_rect));
    SDL_memset(&data->ime_candlistrect, 0, sizeof(data->ime_candlistrect));
    data->ime_winwidth = 0;
    data->ime_winheight = 0;

    data->ime_hkl = 0;
    data->ime_himm32 = 0;
    data->GetReadingString = 0;
    data->ShowReadingWindow = 0;
    data->ImmLockIMC = 0;
    data->ImmUnlockIMC = 0;
    data->ImmLockIMCC = 0;
    data->ImmUnlockIMCC = 0;
    data->ime_uiless = SDL_FALSE;
    data->ime_threadmgrex = 0;
    data->ime_uielemsinkcookie = TF_INVALID_COOKIE;
    data->ime_alpnsinkcookie = TF_INVALID_COOKIE;
    data->ime_openmodesinkcookie = TF_INVALID_COOKIE;
    data->ime_convmodesinkcookie = TF_INVALID_COOKIE;
    data->ime_uielemsink = 0;
    data->ime_ippasink = 0;

    WIN_UpdateKeymap();

    SDL_SetScancodeName(SDL_SCANCODE_APPLICATION, "Menu");
    SDL_SetScancodeName(SDL_SCANCODE_LGUI, "Left Windows");
    SDL_SetScancodeName(SDL_SCANCODE_RGUI, "Right Windows");
}

void
WIN_UpdateKeymap()
{
    int i;
    SDL_ScanCode scancode;
    SDLKey keymap[SDL_NUM_SCANCODES];

    SDL_GetDefaultKeymap(keymap);

    for (i = 0; i < SDL_arraysize(windows_scancode_table); i++) {

        /* Make sure this scancode is a valid character scancode */
        scancode = windows_scancode_table[i];
        if (scancode == SDL_SCANCODE_UNKNOWN || keymap[scancode] >= 127) {
            continue;
        }

        /* Alphabetic keys are handled specially, since Windows remaps them */
        if (i >= 'A' && i <= 'Z') {
            BYTE vsc = alpha_scancodes[i - 'A'];
            keymap[scancode] = MapVirtualKey(vsc, MAPVK_VSC_TO_VK) + 0x20;
        } else {
            keymap[scancode] = (MapVirtualKey(i, MAPVK_VK_TO_CHAR) & 0x7FFF);
        }
    }
    SDL_SetKeymap(0, keymap, SDL_NUM_SCANCODES);
}

void
WIN_QuitKeyboard(_THIS)
{
#ifndef SDL_DISABLE_WINDOWS_IME
    IME_Quit((SDL_VideoData *)_this->driverdata);
#endif
}

void
WIN_StartTextInput(_THIS)
{
#ifndef SDL_DISABLE_WINDOWS_IME
    SDL_Window *window = SDL_GetKeyboardFocus();
    if (window) {
        HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
        SDL_VideoData *videodata = (SDL_VideoData *)_this->driverdata;
        SDL_GetWindowSize(window, &videodata->ime_winwidth, &videodata->ime_winheight);
        IME_Init(videodata, hwnd);
        IME_Enable(videodata, hwnd);
    }
#endif /* !SDL_DISABLE_WINDOWS_IME */
}

void
WIN_StopTextInput(_THIS)
{
#ifndef SDL_DISABLE_WINDOWS_IME
    SDL_Window *window = SDL_GetKeyboardFocus();
    if (window) {
        HWND hwnd = ((SDL_WindowData *) window->driverdata)->hwnd;
        SDL_VideoData *videodata = (SDL_VideoData *)_this->driverdata;
        IME_Init(videodata, hwnd);
        IME_Disable(videodata, hwnd);
    }
#endif /* !SDL_DISABLE_WINDOWS_IME */
}

void
WIN_SetTextInputRect(_THIS, SDL_Rect *rect)
{
    SDL_VideoData *videodata = (SDL_VideoData *)_this->driverdata;
    videodata->ime_rect = *rect;
}

#ifdef SDL_DISABLE_WINDOWS_IME


SDL_bool
IME_HandleMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM *lParam, SDL_VideoData *videodata)
{
    return SDL_FALSE;
}

void IME_Present(SDL_VideoData *videodata)
{
}

#else

#ifdef __GNUC__
#undef DEFINE_GUID
#define DEFINE_GUID(n,l,w1,w2,b1,b2,b3,b4,b5,b6,b7,b8) static const GUID n = {l,w1,w2,{b1,b2,b3,b4,b5,b6,b7,b8}}
DEFINE_GUID(IID_ITfInputProcessorProfileActivationSink,        0x71C6E74E,0x0F28,0x11D8,0xA8,0x2A,0x00,0x06,0x5B,0x84,0x43,0x5C);
DEFINE_GUID(IID_ITfUIElementSink,                              0xEA1EA136,0x19DF,0x11D7,0xA6,0xD2,0x00,0x06,0x5B,0x84,0x43,0x5C);
DEFINE_GUID(GUID_TFCAT_TIP_KEYBOARD,                           0x34745C63,0xB2F0,0x4784,0x8B,0x67,0x5E,0x12,0xC8,0x70,0x1A,0x31);
DEFINE_GUID(IID_ITfSource,                                     0x4EA48A35,0x60AE,0x446F,0x8F,0xD6,0xE6,0xA8,0xD8,0x24,0x59,0xF7);
DEFINE_GUID(IID_ITfUIElementMgr,                               0xEA1EA135,0x19DF,0x11D7,0xA6,0xD2,0x00,0x06,0x5B,0x84,0x43,0x5C);
DEFINE_GUID(IID_ITfCandidateListUIElement,                     0xEA1EA138,0x19DF,0x11D7,0xA6,0xD2,0x00,0x06,0x5B,0x84,0x43,0x5C);
DEFINE_GUID(IID_ITfReadingInformationUIElement,                0xEA1EA139,0x19DF,0x11D7,0xA6,0xD2,0x00,0x06,0x5B,0x84,0x43,0x5C);
DEFINE_GUID(IID_ITfThreadMgr,                                  0xAA80E801,0x2021,0x11D2,0x93,0xE0,0x00,0x60,0xB0,0x67,0xB8,0x6E);
DEFINE_GUID(CLSID_TF_ThreadMgr,                                0x529A9E6B,0x6587,0x4F23,0xAB,0x9E,0x9C,0x7D,0x68,0x3E,0x3C,0x50);
DEFINE_GUID(IID_ITfThreadMgrEx,                                0x3E90ADE3,0x7594,0x4CB0,0xBB,0x58,0x69,0x62,0x8F,0x5F,0x45,0x8C);
#endif

#define LANG_CHT MAKELANGID(LANG_CHINESE, SUBLANG_CHINESE_TRADITIONAL)
#define LANG_CHS MAKELANGID(LANG_CHINESE, SUBLANG_CHINESE_SIMPLIFIED)

#define MAKEIMEVERSION(major,minor) ((DWORD) (((BYTE)(major) << 24) | ((BYTE)(minor) << 16) ))
#define IMEID_VER(id) ((id) & 0xffff0000)
#define IMEID_LANG(id) ((id) & 0x0000ffff)

#define CHT_HKL_DAYI            ((HKL)0xE0060404)
#define CHT_HKL_NEW_PHONETIC    ((HKL)0xE0080404)
#define CHT_HKL_NEW_CHANG_JIE   ((HKL)0xE0090404)
#define CHT_HKL_NEW_QUICK       ((HKL)0xE00A0404)
#define CHT_HKL_HK_CANTONESE    ((HKL)0xE00B0404)
#define CHT_IMEFILENAME1        "TINTLGNT.IME"
#define CHT_IMEFILENAME2        "CINTLGNT.IME"
#define CHT_IMEFILENAME3        "MSTCIPHA.IME"
#define IMEID_CHT_VER42         (LANG_CHT | MAKEIMEVERSION(4, 2))
#define IMEID_CHT_VER43         (LANG_CHT | MAKEIMEVERSION(4, 3))
#define IMEID_CHT_VER44         (LANG_CHT | MAKEIMEVERSION(4, 4))
#define IMEID_CHT_VER50         (LANG_CHT | MAKEIMEVERSION(5, 0))
#define IMEID_CHT_VER51         (LANG_CHT | MAKEIMEVERSION(5, 1))
#define IMEID_CHT_VER52         (LANG_CHT | MAKEIMEVERSION(5, 2))
#define IMEID_CHT_VER60         (LANG_CHT | MAKEIMEVERSION(6, 0))
#define IMEID_CHT_VER_VISTA     (LANG_CHT | MAKEIMEVERSION(7, 0))

#define CHS_HKL                 ((HKL)0xE00E0804)
#define CHS_IMEFILENAME1        "PINTLGNT.IME"
#define CHS_IMEFILENAME2        "MSSCIPYA.IME"
#define IMEID_CHS_VER41         (LANG_CHS | MAKEIMEVERSION(4, 1))
#define IMEID_CHS_VER42         (LANG_CHS | MAKEIMEVERSION(4, 2))
#define IMEID_CHS_VER53         (LANG_CHS | MAKEIMEVERSION(5, 3))

#define LANG() LOWORD((videodata->ime_hkl))
#define PRIMLANG() ((WORD)PRIMARYLANGID(LANG()))
#define SUBLANG() SUBLANGID(LANG())

static void IME_UpdateInputLocale(SDL_VideoData *videodata);
static void IME_ClearComposition(SDL_VideoData *videodata);
static void IME_SetWindow(SDL_VideoData* videodata, HWND hwnd);
static void IME_SetupAPI(SDL_VideoData *videodata);
static DWORD IME_GetId(SDL_VideoData *videodata, UINT uIndex);
static void IME_SendEditingEvent(SDL_VideoData *videodata);
static void IME_DestroyTextures(SDL_VideoData *videodata);

#define SDL_IsEqualIID(riid1, riid2) SDL_IsEqualGUID(riid1, riid2)
#define SDL_IsEqualGUID(rguid1, rguid2) (!SDL_memcmp(rguid1, rguid2, sizeof(GUID)))

static SDL_bool UILess_SetupSinks(SDL_VideoData *videodata);
static void UILess_ReleaseSinks(SDL_VideoData *videodata);
static void UILess_EnableUIUpdates(SDL_VideoData *videodata);
static void UILess_DisableUIUpdates(SDL_VideoData *videodata);

static void
IME_Init(SDL_VideoData *videodata, HWND hwnd)
{
    if (videodata->ime_initialized)
        return;

    videodata->ime_hwnd_main = hwnd;
    if (SUCCEEDED(CoInitializeEx(NULL, COINIT_APARTMENTTHREADED))) {
        videodata->ime_com_initialized = SDL_TRUE;
        CoCreateInstance(&CLSID_TF_ThreadMgr, NULL, CLSCTX_INPROC_SERVER, &IID_ITfThreadMgr, (LPVOID *)&videodata->ime_threadmgr);
    }
    videodata->ime_initialized = SDL_TRUE;
    videodata->ime_himm32 = SDL_LoadObject("imm32.dll");
    if (!videodata->ime_himm32) {
        videodata->ime_available = SDL_FALSE;
        return;
    }
    videodata->ImmLockIMC = (LPINPUTCONTEXT2 (WINAPI *)(HIMC))SDL_LoadFunction(videodata->ime_himm32, "ImmLockIMC");
    videodata->ImmUnlockIMC = (BOOL (WINAPI *)(HIMC))SDL_LoadFunction(videodata->ime_himm32, "ImmUnlockIMC");
    videodata->ImmLockIMCC = (LPVOID (WINAPI *)(HIMCC))SDL_LoadFunction(videodata->ime_himm32, "ImmLockIMCC");
    videodata->ImmUnlockIMCC = (BOOL (WINAPI *)(HIMCC))SDL_LoadFunction(videodata->ime_himm32, "ImmUnlockIMCC");

    IME_SetWindow(videodata, hwnd);
    videodata->ime_himc = ImmGetContext(hwnd);
    ImmReleaseContext(hwnd, videodata->ime_himc);
    if (!videodata->ime_himc) {
        videodata->ime_available = SDL_FALSE;
        IME_Disable(videodata, hwnd);
        return;
    }
    videodata->ime_available = SDL_TRUE;
    IME_UpdateInputLocale(videodata);
    IME_SetupAPI(videodata);
    videodata->ime_uiless = UILess_SetupSinks(videodata);
    IME_UpdateInputLocale(videodata);
    IME_Disable(videodata, hwnd);
}

static void
IME_Enable(SDL_VideoData *videodata, HWND hwnd)
{
    if (!videodata->ime_initialized || !videodata->ime_hwnd_current)
        return;

    if (!videodata->ime_available) {
        IME_Disable(videodata, hwnd);
        return;
    }
    if (videodata->ime_hwnd_current == videodata->ime_hwnd_main)
        ImmAssociateContext(videodata->ime_hwnd_current, videodata->ime_himc);

    videodata->ime_enabled = SDL_TRUE;
    IME_UpdateInputLocale(videodata);
    UILess_EnableUIUpdates(videodata);
}

static void
IME_Disable(SDL_VideoData *videodata, HWND hwnd)
{
    if (!videodata->ime_initialized || !videodata->ime_hwnd_current)
        return;

    IME_ClearComposition(videodata);
    if (videodata->ime_hwnd_current == videodata->ime_hwnd_main)
        ImmAssociateContext(videodata->ime_hwnd_current, (HIMC)0);

    videodata->ime_enabled = SDL_FALSE;
    UILess_DisableUIUpdates(videodata);
}

static void
IME_Quit(SDL_VideoData *videodata)
{
    if (!videodata->ime_initialized)
        return;

    UILess_ReleaseSinks(videodata);
    if (videodata->ime_hwnd_main)
        ImmAssociateContext(videodata->ime_hwnd_main, videodata->ime_himc);

    videodata->ime_hwnd_main = 0;
    videodata->ime_himc = 0;
    if (videodata->ime_himm32) {
        SDL_UnloadObject(videodata->ime_himm32);
        videodata->ime_himm32 = 0;
    }
    if (videodata->ime_threadmgr) {
        videodata->ime_threadmgr->lpVtbl->Release(videodata->ime_threadmgr);
        videodata->ime_threadmgr = 0;
    }
    if (videodata->ime_com_initialized) {
        CoUninitialize();
        videodata->ime_com_initialized = SDL_FALSE;
    }
    IME_DestroyTextures(videodata);
    videodata->ime_initialized = SDL_FALSE;
}

static void
IME_GetReadingString(SDL_VideoData *videodata, HWND hwnd)
{
    DWORD id = 0;
    HIMC himc = 0;
    WCHAR buffer[16];
    WCHAR *s = buffer;
    DWORD len = 0;
    INT err = 0;
    BOOL vertical = FALSE;
    UINT maxuilen = 0;
    static OSVERSIONINFOA osversion = {0};
    if (videodata->ime_uiless)
        return;

    videodata->ime_readingstring[0] = 0;
    if (!osversion.dwOSVersionInfoSize) {
        osversion.dwOSVersionInfoSize = sizeof(osversion);
        GetVersionExA(&osversion);
    }
    id = IME_GetId(videodata, 0);
    if (!id)
        return;

    himc = ImmGetContext(hwnd);
    if (!himc)
        return;

    if (videodata->GetReadingString) {
        len = videodata->GetReadingString(himc, 0, 0, &err, &vertical, &maxuilen);
        if (len) {
            if (len > SDL_arraysize(buffer))
                len = SDL_arraysize(buffer);

            len = videodata->GetReadingString(himc, len, s, &err, &vertical, &maxuilen);
        }
        SDL_wcslcpy(videodata->ime_readingstring, s, len);
    }
    else {
        LPINPUTCONTEXT2 lpimc = videodata->ImmLockIMC(himc);
        LPBYTE p = 0;
        s = 0;
        switch (id)
        {
        case IMEID_CHT_VER42:
        case IMEID_CHT_VER43:
        case IMEID_CHT_VER44:
            p = *(LPBYTE *)((LPBYTE)videodata->ImmLockIMCC(lpimc->hPrivate) + 24);
            if (!p)
                break;

            len = *(DWORD *)(p + 7*4 + 32*4);
            s = (WCHAR *)(p + 56);
            break;
        case IMEID_CHT_VER51:
        case IMEID_CHT_VER52:
        case IMEID_CHS_VER53:
            p = *(LPBYTE *)((LPBYTE)videodata->ImmLockIMCC(lpimc->hPrivate) + 4);
            if (!p)
                break;

            p = *(LPBYTE *)((LPBYTE)p + 1*4 + 5*4);
            if (!p)
                break;

            len = *(DWORD *)(p + 1*4 + (16*2+2*4) + 5*4 + 16*2);
            s = (WCHAR *)(p + 1*4 + (16*2+2*4) + 5*4);
            break;
        case IMEID_CHS_VER41:
            {
                int offset = (IME_GetId(videodata, 1) >= 0x00000002) ? 8 : 7;
                p = *(LPBYTE *)((LPBYTE)videodata->ImmLockIMCC(lpimc->hPrivate) + offset * 4);
                if (!p)
                    break;

                len = *(DWORD *)(p + 7*4 + 16*2*4);
                s = (WCHAR *)(p + 6*4 + 16*2*1);
            }
            break;
        case IMEID_CHS_VER42:
            if (osversion.dwPlatformId != VER_PLATFORM_WIN32_NT)
                break;

            p = *(LPBYTE *)((LPBYTE)videodata->ImmLockIMCC(lpimc->hPrivate) + 1*4 + 1*4 + 6*4);
            if (!p)
                break;

            len = *(DWORD *)(p + 1*4 + (16*2+2*4) + 5*4 + 16*2);
            s = (WCHAR *)(p + 1*4 + (16*2+2*4) + 5*4);
            break;
        }
        if (s)
            SDL_wcslcpy(videodata->ime_readingstring, s, len + 1);

        videodata->ImmUnlockIMCC(lpimc->hPrivate);
        videodata->ImmUnlockIMC(himc);
    }
    ImmReleaseContext(hwnd, himc);
    IME_SendEditingEvent(videodata);
}

static void
IME_InputLangChanged(SDL_VideoData *videodata)
{
    UINT lang = PRIMLANG();
    IME_UpdateInputLocale(videodata);
    if (!videodata->ime_uiless)
        videodata->ime_candlistindexbase = (videodata->ime_hkl == CHT_HKL_DAYI) ? 0 : 1;

    IME_SetupAPI(videodata);
    if (lang != PRIMLANG()) {
        IME_ClearComposition(videodata);
    }
}

static DWORD
IME_GetId(SDL_VideoData *videodata, UINT uIndex)
{
    static HKL hklprev = 0;
    static DWORD dwRet[2] = {0};
    DWORD dwVerSize = 0;
    DWORD dwVerHandle = 0;
    LPVOID lpVerBuffer = 0;
    LPVOID lpVerData = 0;
    UINT cbVerData = 0;
    char szTemp[256];
    HKL hkl = 0;
    DWORD dwLang = 0;
    if (uIndex >= sizeof(dwRet) / sizeof(dwRet[0]))
        return 0;

    hkl = videodata->ime_hkl;
    if (hklprev == hkl)
        return dwRet[uIndex];

    hklprev = hkl;
    dwLang = ((DWORD_PTR)hkl & 0xffff);
    if (videodata->ime_uiless && LANG() == LANG_CHT) {
        dwRet[0] = IMEID_CHT_VER_VISTA;
        dwRet[1] = 0;
        return dwRet[0];
    }
    if (hkl != CHT_HKL_NEW_PHONETIC
        && hkl != CHT_HKL_NEW_CHANG_JIE
        && hkl != CHT_HKL_NEW_QUICK
        && hkl != CHT_HKL_HK_CANTONESE
        && hkl != CHS_HKL) {
        dwRet[0] = dwRet[1] = 0;
        return dwRet[uIndex];
    }
    if (ImmGetIMEFileNameA(hkl, szTemp, sizeof(szTemp) - 1) <= 0) {
        dwRet[0] = dwRet[1] = 0;
        return dwRet[uIndex];
    }
    if (!videodata->GetReadingString) {
        #define LCID_INVARIANT MAKELCID(MAKELANGID(LANG_ENGLISH, SUBLANG_ENGLISH_US), SORT_DEFAULT)
        if (CompareStringA(LCID_INVARIANT, NORM_IGNORECASE, szTemp, -1, CHT_IMEFILENAME1, -1) != 2
            && CompareStringA(LCID_INVARIANT, NORM_IGNORECASE, szTemp, -1, CHT_IMEFILENAME2, -1) != 2
            && CompareStringA(LCID_INVARIANT, NORM_IGNORECASE, szTemp, -1, CHT_IMEFILENAME3, -1) != 2
            && CompareStringA(LCID_INVARIANT, NORM_IGNORECASE, szTemp, -1, CHS_IMEFILENAME1, -1) != 2
            && CompareStringA(LCID_INVARIANT, NORM_IGNORECASE, szTemp, -1, CHS_IMEFILENAME2, -1) != 2) {
            dwRet[0] = dwRet[1] = 0;
            return dwRet[uIndex];
        }
        #undef LCID_INVARIANT
        dwVerSize = GetFileVersionInfoSizeA(szTemp, &dwVerHandle);
        if (dwVerSize) {
            lpVerBuffer = SDL_malloc(dwVerSize);
            if (lpVerBuffer) {
                if (GetFileVersionInfoA(szTemp, dwVerHandle, dwVerSize, lpVerBuffer)) {
                    if (VerQueryValueA(lpVerBuffer, "\\", &lpVerData, &cbVerData)) {
                        #define pVerFixedInfo   ((VS_FIXEDFILEINFO FAR*)lpVerData)
                        DWORD dwVer = pVerFixedInfo->dwFileVersionMS;
                        dwVer = (dwVer & 0x00ff0000) << 8 | (dwVer & 0x000000ff) << 16;
                        if (videodata->GetReadingString ||
                            dwLang == LANG_CHT && (
                            dwVer == MAKEIMEVERSION(4, 2) ||
                            dwVer == MAKEIMEVERSION(4, 3) ||
                            dwVer == MAKEIMEVERSION(4, 4) ||
                            dwVer == MAKEIMEVERSION(5, 0) ||
                            dwVer == MAKEIMEVERSION(5, 1) ||
                            dwVer == MAKEIMEVERSION(5, 2) ||
                            dwVer == MAKEIMEVERSION(6, 0))
                            ||
                            dwLang == LANG_CHS && (
                            dwVer == MAKEIMEVERSION(4, 1) ||
                            dwVer == MAKEIMEVERSION(4, 2) ||
                            dwVer == MAKEIMEVERSION(5, 3))) {
                            dwRet[0] = dwVer | dwLang;
                            dwRet[1] = pVerFixedInfo->dwFileVersionLS;
                            SDL_free(lpVerBuffer);
                            return dwRet[0];
                        }
                        #undef pVerFixedInfo
                    }
                }
            }
            SDL_free(lpVerBuffer);
        }
    }
    dwRet[0] = dwRet[1] = 0;
    return dwRet[uIndex];
}

static void
IME_SetupAPI(SDL_VideoData *videodata)
{
    char ime_file[MAX_PATH + 1];
    void* hime = 0;
    HKL hkl = 0;
    videodata->GetReadingString = 0;
    videodata->ShowReadingWindow = 0;
    if (videodata->ime_uiless)
        return;

    hkl = videodata->ime_hkl;
    if (ImmGetIMEFileNameA(hkl, ime_file, sizeof(ime_file) - 1) <= 0)
        return;

    hime = SDL_LoadObject(ime_file);
    if (!hime)
        return;

    videodata->GetReadingString = (UINT (WINAPI *)(HIMC, UINT, LPWSTR, PINT, BOOL*, PUINT))
        SDL_LoadFunction(hime, "GetReadingString");
    videodata->ShowReadingWindow = (BOOL (WINAPI *)(HIMC, BOOL))
        SDL_LoadFunction(hime, "ShowReadingWindow");

    if (videodata->ShowReadingWindow) {
        HIMC himc = ImmGetContext(videodata->ime_hwnd_current);
        if (himc) {
            videodata->ShowReadingWindow(himc, FALSE);
            ImmReleaseContext(videodata->ime_hwnd_current, himc);
        }
    }
}

static void
IME_SetWindow(SDL_VideoData* videodata, HWND hwnd)
{
    videodata->ime_hwnd_current = hwnd;
    if (videodata->ime_threadmgr) {
        struct ITfDocumentMgr *document_mgr = 0;
        if (SUCCEEDED(videodata->ime_threadmgr->lpVtbl->AssociateFocus(videodata->ime_threadmgr, hwnd, NULL, &document_mgr))) {
            if (document_mgr)
                document_mgr->lpVtbl->Release(document_mgr);
        }
    }
}

static void
IME_UpdateInputLocale(SDL_VideoData *videodata)
{
    static HKL hklprev = 0;
    videodata->ime_hkl = GetKeyboardLayout(0);
    if (hklprev == videodata->ime_hkl)
        return;

    hklprev = videodata->ime_hkl;
    switch (PRIMLANG()) {
    case LANG_CHINESE:
        videodata->ime_candvertical = SDL_TRUE;
        if (SUBLANG() == SUBLANG_CHINESE_SIMPLIFIED)
            videodata->ime_candvertical = SDL_FALSE;

        break;
    case LANG_JAPANESE:
        videodata->ime_candvertical = SDL_TRUE;
        break;
    case LANG_KOREAN:
        videodata->ime_candvertical = SDL_FALSE;
        break;
    }
}

static void
IME_ClearComposition(SDL_VideoData *videodata)
{
    HIMC himc = 0;
    if (!videodata->ime_initialized)
        return;

    himc = ImmGetContext(videodata->ime_hwnd_current);
    if (!himc)
        return;

    ImmNotifyIME(himc, NI_COMPOSITIONSTR, CPS_CANCEL, 0);
    if (videodata->ime_uiless)
        ImmSetCompositionString(himc, SCS_SETSTR, TEXT(""), sizeof(TCHAR), TEXT(""), sizeof(TCHAR));

    ImmNotifyIME(himc, NI_CLOSECANDIDATE, 0, 0);
    ImmReleaseContext(videodata->ime_hwnd_current, himc);
    SDL_SendEditingText("", 0, 0);
}

static void
IME_GetCompositionString(SDL_VideoData *videodata, HIMC himc, DWORD string)
{
    LONG length = ImmGetCompositionStringW(himc, string, videodata->ime_composition, sizeof(videodata->ime_composition));
    if (length < 0)
        length = 0;

    length /= sizeof(videodata->ime_composition[0]);
    videodata->ime_cursor = LOWORD(ImmGetCompositionStringW(himc, GCS_CURSORPOS, 0, 0));
    if (videodata->ime_composition[videodata->ime_cursor] == 0x3000) {
        int i;
        for (i = videodata->ime_cursor + 1; i < length; ++i)
            videodata->ime_composition[i - 1] = videodata->ime_composition[i];

        --length;
    }
    videodata->ime_composition[length] = 0;
}

static void
IME_SendInputEvent(SDL_VideoData *videodata)
{
    char *s = 0;
    s = WIN_StringToUTF8(videodata->ime_composition);
    SDL_SendKeyboardText(s);
    SDL_free(s);

    videodata->ime_composition[0] = 0;
    videodata->ime_readingstring[0] = 0;
    videodata->ime_cursor = 0;
}

static void
IME_SendEditingEvent(SDL_VideoData *videodata)
{
    char *s = 0;
    WCHAR buffer[SDL_TEXTEDITINGEVENT_TEXT_SIZE];
    buffer[0] = 0;
    if (videodata->ime_readingstring[0]) {
        size_t len = SDL_min(SDL_wcslen(videodata->ime_composition), (size_t)videodata->ime_cursor);
        SDL_wcslcpy(buffer, videodata->ime_composition, len + 1);
        SDL_wcslcat(buffer, videodata->ime_readingstring, sizeof(buffer));
        SDL_wcslcat(buffer, &videodata->ime_composition[len], sizeof(buffer) - len);
    }
    else {
        SDL_wcslcpy(buffer, videodata->ime_composition, sizeof(videodata->ime_composition));
    }
    s = WIN_StringToUTF8(buffer);
    SDL_SendEditingText(s, videodata->ime_cursor + SDL_wcslen(videodata->ime_readingstring), 0);
    SDL_free(s);
}

static void
IME_AddCandidate(SDL_VideoData *videodata, UINT i, LPCWSTR candidate)
{
    LPWSTR dst = videodata->ime_candidates[i];
    *dst++ = (WCHAR)(TEXT('0') + ((i + videodata->ime_candlistindexbase) % 10));
    if (videodata->ime_candvertical)
        *dst++ = TEXT(' ');

    while (*candidate && (SDL_arraysize(videodata->ime_candidates[i]) > (dst - videodata->ime_candidates[i])))
        *dst++ = *candidate++;

    *dst = (WCHAR)'\0';
}

static void
IME_GetCandidateList(HIMC himc, SDL_VideoData *videodata)
{
    LPCANDIDATELIST cand_list = 0;
    DWORD size = ImmGetCandidateListW(himc, 0, 0, 0);
    if (size) {
        cand_list = (LPCANDIDATELIST)SDL_malloc(size);
        if (cand_list) {
            size = ImmGetCandidateListW(himc, 0, cand_list, size);
            if (size) {
                int i = 0;
                int j = 0;
                int page_start = 0;
                videodata->ime_candsel = cand_list->dwSelection;
                videodata->ime_candcount = cand_list->dwCount;

                if (LANG() == LANG_CHS && IME_GetId(videodata, 0)) {
                    const UINT maxcandchar = 18;
                    UINT i = 0;
                    UINT cchars = 0;

                    for (; i < videodata->ime_candcount; ++i) {
                        UINT len = SDL_wcslen((LPWSTR)((DWORD_PTR)cand_list + cand_list->dwOffset[i])) + 1;
                        if (len + cchars > maxcandchar) {
                            if (i > cand_list->dwSelection)
                                break;

                            page_start = i;
                            cchars = len;
                        }
                        else {
                            cchars += len;
                        }
                    }
                    videodata->ime_candpgsize = i - page_start;
                }
                else {
                    videodata->ime_candpgsize = SDL_min(cand_list->dwPageSize, MAX_CANDLIST);
                    page_start = (cand_list->dwSelection / videodata->ime_candpgsize) * videodata->ime_candpgsize;
                }
                SDL_memset(&videodata->ime_candidates, 0, sizeof(videodata->ime_candidates));
                for (i = page_start, j = 0; (DWORD)i < cand_list->dwCount && j < (int)videodata->ime_candpgsize; i++, j++) {
                    LPCWSTR candidate = (LPCWSTR)((DWORD_PTR)cand_list + cand_list->dwOffset[i]);
                    IME_AddCandidate(videodata, j, candidate);
                }
                if (PRIMLANG() == LANG_KOREAN || (PRIMLANG() == LANG_CHT && !IME_GetId(videodata, 0)))
                    videodata->ime_candsel = -1;

            }
            SDL_free(cand_list);
        }
    }
}

static void
IME_ShowCandidateList(SDL_VideoData *videodata)
{
    videodata->ime_dirty = SDL_TRUE;
    videodata->ime_candlist = SDL_TRUE;
    IME_DestroyTextures(videodata);
    IME_SendEditingEvent(videodata);
}

static void
IME_HideCandidateList(SDL_VideoData *videodata)
{
    videodata->ime_dirty = SDL_FALSE;
    videodata->ime_candlist = SDL_FALSE;
    IME_DestroyTextures(videodata);
    IME_SendEditingEvent(videodata);
}

SDL_bool
IME_HandleMessage(HWND hwnd, UINT msg, WPARAM wParam, LPARAM *lParam, SDL_VideoData *videodata)
{
    SDL_bool trap = SDL_FALSE;
    HIMC himc = 0;
    if (!videodata->ime_initialized || !videodata->ime_available || !videodata->ime_enabled)
        return SDL_FALSE;

    switch (msg) {
    case WM_INPUTLANGCHANGE:
        IME_InputLangChanged(videodata);
        break;
    case WM_IME_SETCONTEXT:
        *lParam = 0;
        break;
    case WM_IME_STARTCOMPOSITION:
        trap = SDL_TRUE;
        break;
    case WM_IME_COMPOSITION:
        trap = SDL_TRUE;
        himc = ImmGetContext(hwnd);
        if (*lParam & GCS_RESULTSTR) {
            IME_GetCompositionString(videodata, himc, GCS_RESULTSTR);
            IME_SendInputEvent(videodata);
        }
        if (*lParam & GCS_COMPSTR) {
            if (!videodata->ime_uiless)
                videodata->ime_readingstring[0] = 0;

            IME_GetCompositionString(videodata, himc, GCS_COMPSTR);
            IME_SendEditingEvent(videodata);
        }
        ImmReleaseContext(hwnd, himc);
        break;
    case WM_IME_ENDCOMPOSITION:
        videodata->ime_composition[0] = 0;
        videodata->ime_readingstring[0] = 0;
        videodata->ime_cursor = 0;
        SDL_SendEditingText("", 0, 0);
        break;
    case WM_IME_NOTIFY:
        switch (wParam) {
        case IMN_SETCONVERSIONMODE:
        case IMN_SETOPENSTATUS:
            IME_UpdateInputLocale(videodata);
            break;
        case IMN_OPENCANDIDATE:
        case IMN_CHANGECANDIDATE:
            if (videodata->ime_uiless)
                break;

            trap = SDL_TRUE;
            IME_ShowCandidateList(videodata);
            himc = ImmGetContext(hwnd);
            if (!himc)
                break;

            IME_GetCandidateList(himc, videodata);
            ImmReleaseContext(hwnd, himc);
            break;
        case IMN_CLOSECANDIDATE:
            trap = SDL_TRUE;
            IME_HideCandidateList(videodata);
            break;
        case IMN_PRIVATE:
            {
                DWORD dwId = IME_GetId(videodata, 0);
                IME_GetReadingString(videodata, hwnd);
                switch (dwId)
                {
                case IMEID_CHT_VER42:
                case IMEID_CHT_VER43:
                case IMEID_CHT_VER44:
                case IMEID_CHS_VER41:
                case IMEID_CHS_VER42:
                    if (*lParam == 1 || *lParam == 2)
                        trap = SDL_TRUE;

                    break;
                case IMEID_CHT_VER50:
                case IMEID_CHT_VER51:
                case IMEID_CHT_VER52:
                case IMEID_CHT_VER60:
                case IMEID_CHS_VER53:
                    if (*lParam == 16
                        || *lParam == 17
                        || *lParam == 26
                        || *lParam == 27
                        || *lParam == 28)
                        trap = SDL_TRUE;
                    break;
                }
            }
            break;
        default:
            trap = SDL_TRUE;
            break;
        }
        break;
    }
    return trap;
}

static void
IME_CloseCandidateList(SDL_VideoData *videodata)
{
    IME_HideCandidateList(videodata);
    videodata->ime_candcount = 0;
    SDL_memset(videodata->ime_candidates, 0, sizeof(videodata->ime_candidates));
}

static void
UILess_GetCandidateList(SDL_VideoData *videodata, ITfCandidateListUIElement *pcandlist)
{
    UINT selection = 0;
    UINT count = 0;
    UINT page = 0;
    UINT pgcount = 0;
    DWORD pgstart = 0;
    DWORD pgsize = 0;
    UINT i, j;
    pcandlist->lpVtbl->GetSelection(pcandlist, &selection);
    pcandlist->lpVtbl->GetCount(pcandlist, &count);
    pcandlist->lpVtbl->GetCurrentPage(pcandlist, &page);

    videodata->ime_candsel = selection;
    videodata->ime_candcount = count;
    IME_ShowCandidateList(videodata);

    pcandlist->lpVtbl->GetPageIndex(pcandlist, 0, 0, &pgcount);
    if (pgcount > 0) {
        UINT *idxlist = SDL_malloc(sizeof(UINT) * pgcount);
        if (idxlist) {
            pcandlist->lpVtbl->GetPageIndex(pcandlist, idxlist, pgcount, &pgcount);
            pgstart = idxlist[page];
            if (page < pgcount - 1)
                pgsize = SDL_min(count, idxlist[page + 1]) - pgstart;
            else
                pgsize = count - pgstart;

            SDL_free(idxlist);
        }
    }
    videodata->ime_candpgsize = SDL_min(pgsize, MAX_CANDLIST);
    videodata->ime_candsel = videodata->ime_candsel - pgstart;

    SDL_memset(videodata->ime_candidates, 0, sizeof(videodata->ime_candidates));
    for (i = pgstart, j = 0; (DWORD)i < count && j < videodata->ime_candpgsize; i++, j++) {
        BSTR bstr;
        if (SUCCEEDED(pcandlist->lpVtbl->GetString(pcandlist, i, &bstr))) {
            if (bstr) {
                IME_AddCandidate(videodata, j, bstr);
                SysFreeString(bstr);
            }
        }
    }
    if (PRIMLANG() == LANG_KOREAN)
        videodata->ime_candsel = -1;
}

STDMETHODIMP_(ULONG) TSFSink_AddRef(TSFSink *sink)
{
    return ++sink->refcount;
}

STDMETHODIMP_(ULONG)TSFSink_Release(TSFSink *sink)
{
    --sink->refcount;
    if (sink->refcount == 0) {
        SDL_free(sink);
        return 0;
    }
    return sink->refcount;
}

STDMETHODIMP UIElementSink_QueryInterface(TSFSink *sink, REFIID riid, PVOID *ppv)
{
    if (!ppv)
        return E_INVALIDARG;

    *ppv = 0;
    if (SDL_IsEqualIID(riid, &IID_IUnknown))
        *ppv = (IUnknown *)sink;
    else if (SDL_IsEqualIID(riid, &IID_ITfUIElementSink))
        *ppv = (ITfUIElementSink *)sink;

    if (*ppv) {
        TSFSink_AddRef(sink);
        return S_OK;
    }
    return E_NOINTERFACE;
}

ITfUIElement *UILess_GetUIElement(SDL_VideoData *videodata, DWORD dwUIElementId)
{
    ITfUIElementMgr *puiem = 0;
    ITfUIElement *pelem = 0;
    ITfThreadMgrEx *threadmgrex = videodata->ime_threadmgrex;

    if (SUCCEEDED(threadmgrex->lpVtbl->QueryInterface(threadmgrex, &IID_ITfUIElementMgr, (LPVOID *)&puiem))) {
        puiem->lpVtbl->GetUIElement(puiem, dwUIElementId, &pelem);
        puiem->lpVtbl->Release(puiem);
    }
    return pelem;
}

STDMETHODIMP UIElementSink_BeginUIElement(TSFSink *sink, DWORD dwUIElementId, BOOL *pbShow)
{
    ITfUIElement *element = UILess_GetUIElement((SDL_VideoData *)sink->data, dwUIElementId);
    ITfReadingInformationUIElement *preading = 0;
    ITfCandidateListUIElement *pcandlist = 0;
    SDL_VideoData *videodata = (SDL_VideoData *)sink->data;
    if (!element)
        return E_INVALIDARG;

    *pbShow = FALSE;
    if (SUCCEEDED(element->lpVtbl->QueryInterface(element, &IID_ITfReadingInformationUIElement, (LPVOID *)&preading))) {
        BSTR bstr;
        if (SUCCEEDED(preading->lpVtbl->GetString(preading, &bstr)) && bstr) {
            WCHAR *s = (WCHAR *)bstr;
            SysFreeString(bstr);
        }
        preading->lpVtbl->Release(preading);
    }
    else if (SUCCEEDED(element->lpVtbl->QueryInterface(element, &IID_ITfCandidateListUIElement, (LPVOID *)&pcandlist)))	{
        videodata->ime_candref++;
        UILess_GetCandidateList(videodata, pcandlist);
        pcandlist->lpVtbl->Release(pcandlist);
    }
    return S_OK;
}

STDMETHODIMP UIElementSink_UpdateUIElement(TSFSink *sink, DWORD dwUIElementId)
{
    ITfUIElement *element = UILess_GetUIElement((SDL_VideoData *)sink->data, dwUIElementId);
    ITfReadingInformationUIElement *preading = 0;
    ITfCandidateListUIElement *pcandlist = 0;
    SDL_VideoData *videodata = (SDL_VideoData *)sink->data;
    if (!element)
        return E_INVALIDARG;

    if (SUCCEEDED(element->lpVtbl->QueryInterface(element, &IID_ITfReadingInformationUIElement, (LPVOID *)&preading))) {
        BSTR bstr;
        if (SUCCEEDED(preading->lpVtbl->GetString(preading, &bstr)) && bstr) {
            WCHAR *s = (WCHAR *)bstr;
            SDL_wcslcpy(videodata->ime_readingstring, s, sizeof(videodata->ime_readingstring));
            IME_SendEditingEvent(videodata);
            SysFreeString(bstr);
        }
        preading->lpVtbl->Release(preading);
    }
    else if (SUCCEEDED(element->lpVtbl->QueryInterface(element, &IID_ITfCandidateListUIElement, (LPVOID *)&pcandlist)))	{
        UILess_GetCandidateList(videodata, pcandlist);
        pcandlist->lpVtbl->Release(pcandlist);
    }
    return S_OK;
}

STDMETHODIMP UIElementSink_EndUIElement(TSFSink *sink, DWORD dwUIElementId)
{
    ITfUIElement *element = UILess_GetUIElement((SDL_VideoData *)sink->data, dwUIElementId);
    ITfReadingInformationUIElement *preading = 0;
    ITfCandidateListUIElement *pcandlist = 0;
    SDL_VideoData *videodata = (SDL_VideoData *)sink->data;
    if (!element)
        return E_INVALIDARG;

    if (SUCCEEDED(element->lpVtbl->QueryInterface(element, &IID_ITfReadingInformationUIElement, (LPVOID *)&preading))) {
        videodata->ime_readingstring[0] = 0;
        IME_SendEditingEvent(videodata);
        preading->lpVtbl->Release(preading);
    }
    if (SUCCEEDED(element->lpVtbl->QueryInterface(element, &IID_ITfCandidateListUIElement, (LPVOID *)&pcandlist))) {
        videodata->ime_candref--;
        if (videodata->ime_candref == 0)
            IME_CloseCandidateList(videodata);

        pcandlist->lpVtbl->Release(pcandlist);
    }
    return S_OK;
}

STDMETHODIMP IPPASink_QueryInterface(TSFSink *sink, REFIID riid, PVOID *ppv)
{
    if (!ppv)
        return E_INVALIDARG;

    *ppv = 0;
    if (SDL_IsEqualIID(riid, &IID_IUnknown))
        *ppv = (IUnknown *)sink;
    else if (SDL_IsEqualIID(riid, &IID_ITfInputProcessorProfileActivationSink))
        *ppv = (ITfInputProcessorProfileActivationSink *)sink;

    if (*ppv) {
        TSFSink_AddRef(sink);
        return S_OK;
    }
    return E_NOINTERFACE;
}

STDMETHODIMP IPPASink_OnActivated(TSFSink *sink, DWORD dwProfileType, LANGID langid, REFCLSID clsid, REFGUID catid, REFGUID guidProfile, HKL hkl, DWORD dwFlags)
{
    static GUID TF_PROFILE_DAYI = {0x037B2C25, 0x480C, 0x4D7F, 0xB0, 0x27, 0xD6, 0xCA, 0x6B, 0x69, 0x78, 0x8A};
    SDL_VideoData *videodata = (SDL_VideoData *)sink->data;
    videodata->ime_candlistindexbase = SDL_IsEqualGUID(&TF_PROFILE_DAYI, guidProfile) ? 0 : 1;
    if (SDL_IsEqualIID(catid, &GUID_TFCAT_TIP_KEYBOARD) && (dwFlags & TF_IPSINK_FLAG_ACTIVE))
        IME_InputLangChanged((SDL_VideoData *)sink->data);

    IME_HideCandidateList(videodata);
    return S_OK;
}

static void *vtUIElementSink[] = {
    (void *)(UIElementSink_QueryInterface),
    (void *)(TSFSink_AddRef),
    (void *)(TSFSink_Release),
    (void *)(UIElementSink_BeginUIElement),
    (void *)(UIElementSink_UpdateUIElement),
    (void *)(UIElementSink_EndUIElement)
};

static void *vtIPPASink[] = {
    (void *)(IPPASink_QueryInterface),
    (void *)(TSFSink_AddRef),
    (void *)(TSFSink_Release),
    (void *)(IPPASink_OnActivated)
};

static void
UILess_EnableUIUpdates(SDL_VideoData *videodata)
{
    ITfSource *source = 0;
    if (!videodata->ime_threadmgrex || videodata->ime_uielemsinkcookie != TF_INVALID_COOKIE)
        return;

    if (SUCCEEDED(videodata->ime_threadmgrex->lpVtbl->QueryInterface(videodata->ime_threadmgrex, &IID_ITfSource, (LPVOID *)&source))) {
        source->lpVtbl->AdviseSink(source, &IID_ITfUIElementSink, (IUnknown *)videodata->ime_uielemsink, &videodata->ime_uielemsinkcookie);
        source->lpVtbl->Release(source);
    }
}

static void
UILess_DisableUIUpdates(SDL_VideoData *videodata)
{
    ITfSource *source = 0;
    if (!videodata->ime_threadmgrex || videodata->ime_uielemsinkcookie == TF_INVALID_COOKIE)
        return;

    if (SUCCEEDED(videodata->ime_threadmgrex->lpVtbl->QueryInterface(videodata->ime_threadmgrex, &IID_ITfSource, (LPVOID *)&source))) {
        source->lpVtbl->UnadviseSink(source, videodata->ime_uielemsinkcookie);
        videodata->ime_uielemsinkcookie = TF_INVALID_COOKIE;
        source->lpVtbl->Release(source);
    }
}

static SDL_bool
UILess_SetupSinks(SDL_VideoData *videodata)
{
    TfClientId clientid = 0;
    SDL_bool result = SDL_FALSE;
    ITfSource *source = 0;
    if (FAILED(CoCreateInstance(&CLSID_TF_ThreadMgr, NULL, CLSCTX_INPROC_SERVER, &IID_ITfThreadMgrEx, (LPVOID *)&videodata->ime_threadmgrex)))
        return SDL_FALSE;

    if (FAILED(videodata->ime_threadmgrex->lpVtbl->ActivateEx(videodata->ime_threadmgrex, &clientid, TF_TMAE_UIELEMENTENABLEDONLY)))
        return SDL_FALSE;

    videodata->ime_uielemsink = SDL_malloc(sizeof(TSFSink));
    videodata->ime_ippasink = SDL_malloc(sizeof(TSFSink));

    videodata->ime_uielemsink->lpVtbl = vtUIElementSink;
    videodata->ime_uielemsink->refcount = 1;
    videodata->ime_uielemsink->data = videodata;

    videodata->ime_ippasink->lpVtbl = vtIPPASink;
    videodata->ime_ippasink->refcount = 1;
    videodata->ime_ippasink->data = videodata;

    if (SUCCEEDED(videodata->ime_threadmgrex->lpVtbl->QueryInterface(videodata->ime_threadmgrex, &IID_ITfSource, (LPVOID *)&source))) {
        if (SUCCEEDED(source->lpVtbl->AdviseSink(source, &IID_ITfUIElementSink, (IUnknown *)videodata->ime_uielemsink, &videodata->ime_uielemsinkcookie))) {
            if (SUCCEEDED(source->lpVtbl->AdviseSink(source, &IID_ITfInputProcessorProfileActivationSink, (IUnknown *)videodata->ime_ippasink, &videodata->ime_alpnsinkcookie))) {
                result = SDL_TRUE;
            }
        }
        source->lpVtbl->Release(source);
    }
    return result;
}

#define SAFE_RELEASE(p)                             \
{                                                   \
    if (p) {                                        \
        (p)->lpVtbl->Release((p));                  \
        (p) = 0;                                    \
    }                                               \
}

static void
UILess_ReleaseSinks(SDL_VideoData *videodata)
{
    ITfSource *source = 0;
    if (videodata->ime_threadmgrex && SUCCEEDED(videodata->ime_threadmgrex->lpVtbl->QueryInterface(videodata->ime_threadmgrex, &IID_ITfSource, (LPVOID *)&source))) {
        source->lpVtbl->UnadviseSink(source, videodata->ime_uielemsinkcookie);
        source->lpVtbl->UnadviseSink(source, videodata->ime_alpnsinkcookie);
        SAFE_RELEASE(source);
        videodata->ime_threadmgrex->lpVtbl->Deactivate(videodata->ime_threadmgrex);
        SAFE_RELEASE(videodata->ime_threadmgrex);
        TSFSink_Release(videodata->ime_uielemsink);
        videodata->ime_uielemsink = 0;
        TSFSink_Release(videodata->ime_ippasink);
        videodata->ime_ippasink = 0;
    }
}

static void *
StartDrawToBitmap(HDC hdc, HBITMAP *hhbm, int width, int height)
{
    BITMAPINFO info = {0};
    BITMAPINFOHEADER *infoHeader = &info.bmiHeader;
    BYTE *bits = NULL;
    if (hhbm) {
        infoHeader->biSize = sizeof(BITMAPINFOHEADER);
        infoHeader->biWidth = width;
        infoHeader->biHeight = -1 * SDL_abs(height);
        infoHeader->biPlanes = 1;
        infoHeader->biBitCount = 32;
        infoHeader->biCompression = BI_RGB;
        *hhbm = CreateDIBSection(hdc, &info, DIB_RGB_COLORS, (void **)&bits, 0, 0);
        if (*hhbm)
            SelectObject(hdc, *hhbm);
    }
    return bits;
}

static void
StopDrawToBitmap(HDC hdc, HBITMAP *hhbm)
{
    if (hhbm && *hhbm) {
        DeleteObject(*hhbm);
        *hhbm = NULL;
    }
}

static void
BitmapToTexture(HBITMAP hbm, BYTE *bits, int width, int height, SDL_Texture **texture)
{
    SDL_Surface *surface = NULL;
    BITMAP bm = {0};

    if (GetObject(hbm, sizeof(bm), &bm) == 0)
        return;

    if (bits && texture) {
        /*
            For transparency:

            const Uint8 alpha = 130;
            unsigned long *p = (unsigned long *)bits;
            unsigned long *end = (unsigned long *)(bits + (bm.bmWidthBytes * bm.bmHeight));
            while (p < end) {
                *p = RGB(GetRValue(*p), GetGValue(*p), GetBValue(*p)) | (alpha << 24);
                ++p;
            }
            surface = SDL_CreateRGBSurfaceFrom(bits, width, height, bm.bmBitsPixel, bm.bmWidthBytes, 0x00ff0000, 0x0000ff00, 0x000000ff, 0xff000000);
        */
        surface = SDL_CreateRGBSurfaceFrom(bits, width, height, bm.bmBitsPixel, bm.bmWidthBytes, 0x00ff0000, 0x0000ff00, 0x000000ff, 0);
        if (surface) {
            *texture = SDL_CreateTextureFromSurface(0, surface);
            SDL_FreeSurface(surface);
        }
    }
}

/* This draws only within the specified area and fills the entire region. */
static void
DrawRect(HDC hdc, int left, int top, int right, int bottom, int pensize)
{
    /* The case of no pen (PenSize = 0) is automatically taken care of. */
    const int penadjust = (int)SDL_floor(pensize / 2.0f - 0.5f);
    left += pensize / 2;
    top += pensize / 2;
    right -= penadjust;
    bottom -= penadjust;
    Rectangle(hdc, left, top, right, bottom);
}

static void
DestroyTexture(SDL_Texture **texture)
{
    if (texture && *texture) {
        SDL_DestroyTexture(*texture);
        *texture = NULL;
    }
}

static void
IME_DestroyTextures(SDL_VideoData *videodata)
{
    DestroyTexture(&videodata->ime_candtex);
}

#define SDL_swap(a,b) { \
    int c = (a);        \
    (a) = (b);          \
    (b) = c;            \
    }

static void
IME_PositionCandidateList(SDL_VideoData *videodata, SIZE size)
{
    int left, top, right, bottom;
    SDL_bool ok = SDL_FALSE;
    int winw = videodata->ime_winwidth;
    int winh = videodata->ime_winheight;

    /* Bottom */
    left = videodata->ime_rect.x;
    top = videodata->ime_rect.y + videodata->ime_rect.h;
    right = left + size.cx;
    bottom = top + size.cy;
    if (right >= winw) {
        left -= right - winw;
        right = winw;
    }
    if (bottom < winh)
        ok = SDL_TRUE;

    /* Top */
    if (!ok) {
        left = videodata->ime_rect.x;
        top = videodata->ime_rect.y - size.cy;
        right = left + size.cx;
        bottom = videodata->ime_rect.y;
        if (right >= winw) {
            left -= right - winw;
            right = winw;
        }
        if (top >= 0)
            ok = SDL_TRUE;
    }

    /* Right */
    if (!ok) {
        left = videodata->ime_rect.x + size.cx;
        top = 0;
        right = left + size.cx;
        bottom = size.cy;
        if (right < winw)
            ok = SDL_TRUE;
    }

    /* Left */
    if (!ok) {
        left = videodata->ime_rect.x - size.cx;
        top = 0;
        right = videodata->ime_rect.x;
        bottom = size.cy;
        if (right >= 0)
            ok = SDL_TRUE;
    }

    /* Window too small, show at (0,0) */
    if (!ok) {
        left = 0;
        top = 0;
        right = size.cx;
        bottom = size.cy;
    }

    videodata->ime_candlistrect.x = left;
    videodata->ime_candlistrect.y = top;
    videodata->ime_candlistrect.w = right - left;
    videodata->ime_candlistrect.h = bottom - top;
}

static void
IME_RenderCandidateList(SDL_VideoData *videodata, HDC hdc)
{
    int i, j;
    SIZE size = {0};
    SIZE candsizes[MAX_CANDLIST];
    SIZE maxcandsize = {0};
    HBITMAP hbm = NULL;
    BYTE *bits = NULL;
    const int candcount = SDL_min(SDL_min(MAX_CANDLIST, videodata->ime_candcount), videodata->ime_candpgsize);
    SDL_bool vertical = videodata->ime_candvertical;

    const int listborder = 1;
    const int listpadding = 0;
    const int listbordercolor = RGB(0xB4, 0xC7, 0xAA);
    const int listfillcolor = RGB(255, 255, 255);

    const int candborder = 1;
    const int candpadding = 0;
    const int candmargin = 1;
    const COLORREF candbordercolor = RGB(255, 255, 255);
    const COLORREF candfillcolor = RGB(255, 255, 255);
    const COLORREF candtextcolor = RGB(0, 0, 0);
    const COLORREF selbordercolor = RGB(0x84, 0xAC, 0xDD);
    const COLORREF selfillcolor = RGB(0xD2, 0xE6, 0xFF);
    const COLORREF seltextcolor = RGB(0, 0, 0);
    const int horzcandspacing = 5;

    HPEN listpen = listborder != 0 ? CreatePen(PS_SOLID, listborder, listbordercolor) : (HPEN)GetStockObject(NULL_PEN);
    HBRUSH listbrush = CreateSolidBrush(listfillcolor);
    HPEN candpen = candborder != 0 ? CreatePen(PS_SOLID, candborder, candbordercolor) : (HPEN)GetStockObject(NULL_PEN);
    HBRUSH candbrush = CreateSolidBrush(candfillcolor);
    HPEN selpen = candborder != 0 ? CreatePen(PS_DOT, candborder, selbordercolor) : (HPEN)GetStockObject(NULL_PEN);
    HBRUSH selbrush = CreateSolidBrush(selfillcolor);
    HFONT font = CreateFont((int)(1 + videodata->ime_rect.h * 0.75f), 0, 0, 0, FW_NORMAL, FALSE, FALSE, FALSE, DEFAULT_CHARSET, OUT_CHARACTER_PRECIS, CLIP_DEFAULT_PRECIS, PROOF_QUALITY, VARIABLE_PITCH | FF_SWISS, TEXT("Microsoft Sans Serif"));

    SetBkMode(hdc, TRANSPARENT);
    SelectObject(hdc, font);

    for (i = 0; i < candcount; ++i) {
        const WCHAR *s = videodata->ime_candidates[i];
        if (!*s)
            break;

        GetTextExtentPoint32W(hdc, s, SDL_wcslen(s), &candsizes[i]);
        maxcandsize.cx = SDL_max(maxcandsize.cx, candsizes[i].cx);
        maxcandsize.cy = SDL_max(maxcandsize.cy, candsizes[i].cy);

    }
    if (vertical) {
        size.cx =
            (listborder * 2) +
            (listpadding * 2) +
            (candmargin * 2) +
            (candborder * 2) +
            (candpadding * 2) +
            (maxcandsize.cx)
            ;
        size.cy =
            (listborder * 2) +
            (listpadding * 2) +
            ((candcount + 1) * candmargin) +
            (candcount * candborder * 2) +
            (candcount * candpadding * 2) +
            (candcount * maxcandsize.cy)
            ;
    }
    else {
        size.cx =
            (listborder * 2) +
            (listpadding * 2) +
            ((candcount + 1) * candmargin) +
            (candcount * candborder * 2) +
            (candcount * candpadding * 2) +
            ((candcount - 1) * horzcandspacing);
        ;

        for (i = 0; i < candcount; ++i)
            size.cx += candsizes[i].cx;

        size.cy =
            (listborder * 2) +
            (listpadding * 2) +
            (candmargin * 2) +
            (candborder * 2) +
            (candpadding * 2) +
            (maxcandsize.cy)
            ;
    }

    bits = StartDrawToBitmap(hdc, &hbm, size.cx, size.cy);

    SelectObject(hdc, listpen);
    SelectObject(hdc, listbrush);
    DrawRect(hdc, 0, 0, size.cx, size.cy, listborder);

    SelectObject(hdc, candpen);
    SelectObject(hdc, candbrush);
    SetTextColor(hdc, candtextcolor);
    SetBkMode(hdc, TRANSPARENT);

    for (i = 0; i < candcount; ++i) {
        const WCHAR *s = videodata->ime_candidates[i];
        int left, top, right, bottom;
        if (!*s)
            break;

        if (vertical) {
            left = listborder + listpadding + candmargin;
            top = listborder + listpadding + (i * candborder * 2) + (i * candpadding * 2) + ((i + 1) * candmargin) + (i * maxcandsize.cy);
            right = size.cx - listborder - listpadding - candmargin;
            bottom = top + maxcandsize.cy + (candpadding * 2) + (candborder * 2);
        }
        else {
            left = listborder + listpadding + (i * candborder * 2) + (i * candpadding * 2) + ((i + 1) * candmargin) + (i * horzcandspacing);

            for (j = 0; j < i; ++j)
                left += candsizes[j].cx;

            top = listborder + listpadding + candmargin;
            right = left + candsizes[i].cx + (candpadding * 2) + (candborder * 2);
            bottom = size.cy - listborder - listpadding - candmargin;
        }

        if (i == videodata->ime_candsel) {
            SelectObject(hdc, selpen);
            SelectObject(hdc, selbrush);
            SetTextColor(hdc, seltextcolor);
        }
        else {
            SelectObject(hdc, candpen);
            SelectObject(hdc, candbrush);
            SetTextColor(hdc, candtextcolor);
        }

        DrawRect(hdc, left, top, right, bottom, candborder);
        ExtTextOutW(hdc, left + candborder + candpadding, top + candborder + candpadding, 0, NULL, s, SDL_wcslen(s), NULL);
    }
    BitmapToTexture(hbm, bits, size.cx, size.cy, &videodata->ime_candtex);
    StopDrawToBitmap(hdc, &hbm);

    DeleteObject(listpen);
    DeleteObject(listbrush);
    DeleteObject(candpen);
    DeleteObject(candbrush);
    DeleteObject(selpen);
    DeleteObject(selbrush);
    DeleteObject(font);

    IME_PositionCandidateList(videodata, size);
}

static void
IME_Render(SDL_VideoData *videodata)
{
    HDC hdc = CreateCompatibleDC(NULL);

    if (videodata->ime_candlist)
        IME_RenderCandidateList(videodata, hdc);

    DeleteDC(hdc);

    videodata->ime_dirty = SDL_FALSE;
}

void IME_Present(SDL_VideoData *videodata)
{
    if (videodata->ime_dirty)
        IME_Render(videodata);

    SDL_RenderCopy(videodata->ime_candtex, NULL, &videodata->ime_candlistrect);
}

#endif /* SDL_DISABLE_WINDOWS_IME */

/* vi: set ts=4 sw=4 expandtab: */