stgsharp/StgSharp.Native/sdl-src/video/windows/SDL_windowsclipboard.c

/*
  Simple DirectMedia Layer
  Copyright (C) 1997-2025 Sam Lantinga <slouken@libsdl.org>

  This software is provided 'as-is', without any express or implied
  warranty.  In no event will the authors be held liable for any damages
  arising from the use of this software.

  Permission is granted to anyone to use this software for any purpose,
  including commercial applications, and to alter it and redistribute it
  freely, subject to the following restrictions:

  1. The origin of this software must not be misrepresented; you must not
     claim that you wrote the original software. If you use this software
     in a product, an acknowledgment in the product documentation would be
     appreciated but is not required.
  2. Altered source versions must be plainly marked as such, and must not be
     misrepresented as being the original software.
  3. This notice may not be removed or altered from any source distribution.
*/
#include "SDL_internal.h"

#if defined(SDL_VIDEO_DRIVER_WINDOWS) && !defined(SDL_PLATFORM_XBOXONE) && !defined(SDL_PLATFORM_XBOXSERIES)

#include "SDL_windowsvideo.h"
#include "SDL_windowswindow.h"
#include "../SDL_clipboard_c.h"
#include "../../events/SDL_events_c.h"
#include "../../events/SDL_clipboardevents_c.h"

#ifdef UNICODE
#define TEXT_FORMAT CF_UNICODETEXT
#else
#define TEXT_FORMAT CF_TEXT
#endif

#define IMAGE_FORMAT CF_DIB
#define IMAGE_MIME_TYPE "image/bmp"
#define BFT_BITMAP 0x4d42 // 'BM'

// Assume we can directly read and write BMP fields without byte swapping
SDL_COMPILE_TIME_ASSERT(verify_byte_order, SDL_BYTEORDER == SDL_LIL_ENDIAN);

static BOOL WIN_OpenClipboard(SDL_VideoDevice *_this)
{
    // Retry to open the clipboard in case another application has it open
    const int MAX_ATTEMPTS = 3;
    int attempt;
    HWND hwnd = NULL;

    if (_this->windows) {
        hwnd = _this->windows->internal->hwnd;
    }
    for (attempt = 0; attempt < MAX_ATTEMPTS; ++attempt) {
        if (OpenClipboard(hwnd)) {
            return TRUE;
        }
        SDL_Delay(10);
    }
    return FALSE;
}

static void WIN_CloseClipboard(void)
{
    CloseClipboard();
}

static HANDLE WIN_ConvertBMPtoDIB(const void *bmp, size_t bmp_size)
{
    HANDLE hMem = NULL;

    if (bmp && bmp_size > sizeof(BITMAPFILEHEADER) && ((BITMAPFILEHEADER *)bmp)->bfType == BFT_BITMAP) {
        BITMAPFILEHEADER *pbfh = (BITMAPFILEHEADER *)bmp;
        BITMAPINFOHEADER *pbih = (BITMAPINFOHEADER *)((Uint8 *)bmp + sizeof(BITMAPFILEHEADER));
        size_t bih_size = pbih->biSize + pbih->biClrUsed * sizeof(RGBQUAD);
        size_t pixels_size = pbih->biSizeImage;

        if (pbfh->bfOffBits >= (sizeof(BITMAPFILEHEADER) + bih_size) &&
            (pbfh->bfOffBits + pixels_size) <= bmp_size) {
            const Uint8 *pixels = (const Uint8 *)bmp + pbfh->bfOffBits;
            size_t dib_size = bih_size + pixels_size;
            hMem = GlobalAlloc(GMEM_MOVEABLE, dib_size);
            if (hMem) {
                LPVOID dst = GlobalLock(hMem);
                if (dst) {
                    SDL_memcpy(dst, pbih, bih_size);
                    SDL_memcpy((Uint8 *)dst + bih_size, pixels, pixels_size);
                    GlobalUnlock(hMem);
                } else {
                    WIN_SetError("GlobalLock()");
                    GlobalFree(hMem);
                    hMem = NULL;
                }
            } else {
                SDL_OutOfMemory();
            }
        } else {
            SDL_SetError("Invalid BMP data");
        }
    } else {
        SDL_SetError("Invalid BMP data");
    }
    return hMem;
}

static void *WIN_ConvertDIBtoBMP(HANDLE hMem, size_t *size)
{
    void *bmp = NULL;
    size_t mem_size = GlobalSize(hMem);

    if (mem_size > sizeof(BITMAPINFOHEADER)) {
        LPVOID dib = GlobalLock(hMem);
        if (dib) {
            BITMAPINFOHEADER *pbih = (BITMAPINFOHEADER *)dib;

            // https://learn.microsoft.com/en-us/windows/win32/api/wingdi/ns-wingdi-bitmapinfoheader#color-tables
            size_t color_table_size;
            switch (pbih->biCompression) {
            case BI_RGB:
                if (pbih->biBitCount <= 8) {
                    color_table_size = sizeof(RGBQUAD) * (pbih->biClrUsed == 0 ? 1 << pbih->biBitCount : pbih->biClrUsed);
                } else {
                    color_table_size = 0;
                }
                break;
            case BI_BITFIELDS:
                color_table_size = 3 * sizeof(DWORD);
                break;
            case 6 /* BI_ALPHABITFIELDS */:
                // https://learn.microsoft.com/en-us/previous-versions/windows/embedded/aa452885(v=msdn.10)
                color_table_size = 4 * sizeof(DWORD);
                break;
            default: // FOURCC
                color_table_size = sizeof(RGBQUAD) * pbih->biClrUsed;
            }

            size_t bih_size = pbih->biSize + color_table_size;
            size_t dib_size = bih_size + pbih->biSizeImage;
            if (dib_size <= mem_size) {
                size_t bmp_size = sizeof(BITMAPFILEHEADER) + mem_size;
                bmp = SDL_malloc(bmp_size);
                if (bmp) {
                    BITMAPFILEHEADER *pbfh = (BITMAPFILEHEADER *)bmp;
                    pbfh->bfType = BFT_BITMAP;
                    pbfh->bfSize = (DWORD)bmp_size;
                    pbfh->bfReserved1 = 0;
                    pbfh->bfReserved2 = 0;
                    pbfh->bfOffBits = (DWORD)(sizeof(BITMAPFILEHEADER) + pbih->biSize + color_table_size);
                    SDL_memcpy((Uint8 *)bmp + sizeof(BITMAPFILEHEADER), dib, dib_size);
                    *size = bmp_size;
                }
            } else {
                SDL_SetError("Invalid BMP data");
            }
            GlobalUnlock(hMem);
        } else {
            WIN_SetError("GlobalLock()");
        }
    } else {
        SDL_SetError("Invalid BMP data");
    }
    return bmp;
}

static bool WIN_SetClipboardImage(SDL_VideoDevice *_this)
{
    HANDLE hMem;
    size_t clipboard_data_size;
    const void *clipboard_data;
    bool result = true;

    clipboard_data = _this->clipboard_callback(_this->clipboard_userdata, IMAGE_MIME_TYPE, &clipboard_data_size);
    hMem = WIN_ConvertBMPtoDIB(clipboard_data, clipboard_data_size);
    if (hMem) {
        // Save the image to the clipboard
        if (!SetClipboardData(IMAGE_FORMAT, hMem)) {
            result = WIN_SetError("Couldn't set clipboard data");
        }
    } else {
        // WIN_ConvertBMPtoDIB() set the error
        result = false;
    }
    return result;
}

static bool WIN_SetClipboardText(SDL_VideoDevice *_this, const char *mime_type)
{
    HANDLE hMem;
    size_t clipboard_data_size;
    const void *clipboard_data;
    bool result = true;

    clipboard_data = _this->clipboard_callback(_this->clipboard_userdata, mime_type, &clipboard_data_size);
    if (clipboard_data && clipboard_data_size > 0) {
        SIZE_T i, size;
        LPWSTR tstr = (WCHAR *)SDL_iconv_string("UTF-16LE", "UTF-8", (const char *)clipboard_data, clipboard_data_size);
        if (!tstr) {
            return SDL_SetError("Couldn't convert text from UTF-8");
        }

        // Find out the size of the data
        for (size = 0, i = 0; tstr[i]; ++i, ++size) {
            if (tstr[i] == '\n' && (i == 0 || tstr[i - 1] != '\r')) {
                // We're going to insert a carriage return
                ++size;
            }
        }
        size = (size + 1) * sizeof(*tstr);

        // Save the data to the clipboard
        hMem = GlobalAlloc(GMEM_MOVEABLE, size);
        if (hMem) {
            LPWSTR dst = (LPWSTR)GlobalLock(hMem);
            if (dst) {
                // Copy the text over, adding carriage returns as necessary
                for (i = 0; tstr[i]; ++i) {
                    if (tstr[i] == '\n' && (i == 0 || tstr[i - 1] != '\r')) {
                        *dst++ = '\r';
                    }
                    *dst++ = tstr[i];
                }
                *dst = 0;
                GlobalUnlock(hMem);
            }

            if (!SetClipboardData(TEXT_FORMAT, hMem)) {
                result = WIN_SetError("Couldn't set clipboard data");
            }
        } else {
            result = SDL_OutOfMemory();
        }
        SDL_free(tstr);
    }
    return result;
}

bool WIN_SetClipboardData(SDL_VideoDevice *_this)
{
    SDL_VideoData *data = _this->internal;
    size_t i;
    bool result = true;

    /* I investigated delayed clipboard rendering, and at least with text and image
     * formats you have to use an output window, not SDL_HelperWindow, and the system
     * requests them being rendered immediately, so there isn't any benefit.
     */

    if (WIN_OpenClipboard(_this)) {
        EmptyClipboard();

        // Set the clipboard text
        for (i = 0; i < _this->num_clipboard_mime_types; ++i) {
            const char *mime_type = _this->clipboard_mime_types[i];

            if (SDL_IsTextMimeType(mime_type)) {
                if (!WIN_SetClipboardText(_this, mime_type)) {
                    result = false;
                }
                // Only set the first clipboard text
                break;
            }
        }

        // Set the clipboard image
        for (i = 0; i < _this->num_clipboard_mime_types; ++i) {
            const char *mime_type = _this->clipboard_mime_types[i];

            if (SDL_strcmp(mime_type, IMAGE_MIME_TYPE) == 0) {
                if (!WIN_SetClipboardImage(_this)) {
                    result = false;
                }
                break;
            }
        }

        data->clipboard_count = GetClipboardSequenceNumber();
        WIN_CloseClipboard();
    } else {
        result = WIN_SetError("Couldn't open clipboard");
    }
    return result;
}

void *WIN_GetClipboardData(SDL_VideoDevice *_this, const char *mime_type, size_t *size)
{
    void *data = NULL;

    if (SDL_IsTextMimeType(mime_type)) {
        char *text = NULL;

        if (IsClipboardFormatAvailable(TEXT_FORMAT)) {
            if (WIN_OpenClipboard(_this)) {
                HANDLE hMem;
                LPTSTR tstr;

                hMem = GetClipboardData(TEXT_FORMAT);
                if (hMem) {
                    tstr = (LPTSTR)GlobalLock(hMem);
                    if (tstr) {
                        text = WIN_StringToUTF8(tstr);
                        GlobalUnlock(hMem);
                    } else {
                        WIN_SetError("Couldn't lock clipboard data");
                    }
                } else {
                    WIN_SetError("Couldn't get clipboard data");
                }
                WIN_CloseClipboard();
            }
        }
        if (!text) {
            text = SDL_strdup("");
        }
        data = text;
        *size = SDL_strlen(text);

    } else if (SDL_strcmp(mime_type, IMAGE_MIME_TYPE) == 0) {
        if (IsClipboardFormatAvailable(IMAGE_FORMAT)) {
            if (WIN_OpenClipboard(_this)) {
                HANDLE hMem;

                hMem = GetClipboardData(IMAGE_FORMAT);
                if (hMem) {
                    data = WIN_ConvertDIBtoBMP(hMem, size);
                } else {
                    WIN_SetError("Couldn't get clipboard data");
                }
                WIN_CloseClipboard();
            }
        }
    } else {
        data = SDL_GetInternalClipboardData(_this, mime_type, size);
    }
    return data;
}

bool WIN_HasClipboardData(SDL_VideoDevice *_this, const char *mime_type)
{
    if (SDL_IsTextMimeType(mime_type)) {
        if (IsClipboardFormatAvailable(TEXT_FORMAT)) {
            return true;
        }
    } else if (SDL_strcmp(mime_type, IMAGE_MIME_TYPE) == 0) {
        if (IsClipboardFormatAvailable(IMAGE_FORMAT)) {
            return true;
        }
    } else {
        if (SDL_HasInternalClipboardData(_this, mime_type)) {
            return true;
        }
    }
    return false;
}

static int GetClipboardFormatMimeType(UINT format, char *name)
{
    static struct
    {
        UINT format;
        const char *mime_type;
    } mime_types[] = {
        { TEXT_FORMAT, "text/plain;charset=utf-8" },
        { IMAGE_FORMAT, IMAGE_MIME_TYPE },
    };

    for (int i = 0; i < SDL_arraysize(mime_types); ++i) {
        if (format == mime_types[i].format) {
            size_t len = SDL_strlen(mime_types[i].mime_type) + 1;
            if (name) {
                SDL_memcpy(name, mime_types[i].mime_type, len);
            }
            return (int)len;
        }
    }
    return 0;
}

static char **GetMimeTypes(int *pnformats)
{
    char **new_mime_types = NULL;

    *pnformats = 0;

    if (WIN_OpenClipboard(SDL_GetVideoDevice())) {
        int nformats = 0;
        UINT format = 0;
        int formatsSz = 0;
        for ( ; ; ) {
            format = EnumClipboardFormats(format);
            if (!format) {
                break;
            }

            int len = GetClipboardFormatMimeType(format, NULL);
            if (len > 0) {
                ++nformats;
                formatsSz += len;
            }
        }

        new_mime_types = SDL_AllocateTemporaryMemory((nformats + 1) * sizeof(char *) + formatsSz);
        if (new_mime_types) {
            format = 0;
            char *strPtr = (char *)(new_mime_types + nformats + 1);
            int i = 0;
            for ( ; ; ) {
                format = EnumClipboardFormats(format);
                if (!format) {
                    break;
                }

                int len = GetClipboardFormatMimeType(format, strPtr);
                if (len > 0) {
                    new_mime_types[i++] = strPtr;
                    strPtr += len;
                }
            }

            new_mime_types[nformats] = NULL;
            *pnformats = nformats;
        }
        WIN_CloseClipboard();
    }
    return new_mime_types;
}

void WIN_CheckClipboardUpdate(struct SDL_VideoData *data)
{
    DWORD count = GetClipboardSequenceNumber();
    if (count != data->clipboard_count) {
        if (count) {
            int nformats = 0;
            char **new_mime_types = GetMimeTypes(&nformats);
            if (new_mime_types) {
                SDL_SendClipboardUpdate(false, new_mime_types, nformats);
            }
        }
        data->clipboard_count = count;
    }
}

#endif // SDL_VIDEO_DRIVER_WINDOWS