CMSWindowsClipboardBitmapConverter.cpp

/*
 * synergy -- mouse and keyboard sharing utility
 * Copyright (C) 2012 Bolton Software Ltd.
 * Copyright (C) 2004 Chris Schoeneman
 * 
 * This package is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * found in the file COPYING that should have accompanied this file.
 * 
 * This package 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include "CMSWindowsClipboardBitmapConverter.h"
#include "CLog.h"

//
// CMSWindowsClipboardBitmapConverter
//

CMSWindowsClipboardBitmapConverter::CMSWindowsClipboardBitmapConverter()
{
    // do nothing
}

CMSWindowsClipboardBitmapConverter::~CMSWindowsClipboardBitmapConverter()
{
    // do nothing
}

IClipboard::EFormat
CMSWindowsClipboardBitmapConverter::getFormat() const
{
    return IClipboard::kBitmap;
}

UINT
CMSWindowsClipboardBitmapConverter::getWin32Format() const
{
    return CF_DIB;
}

HANDLE
CMSWindowsClipboardBitmapConverter::fromIClipboard(const CString& data) const
{
    // copy to memory handle
    HGLOBAL gData = GlobalAlloc(GMEM_MOVEABLE | GMEM_DDESHARE, data.size());
    if (gData != NULL) {
        // get a pointer to the allocated memory
        char* dst = (char*)GlobalLock(gData);
        if (dst != NULL) {
            memcpy(dst, data.data(), data.size());
            GlobalUnlock(gData);
        }
        else {
            GlobalFree(gData);
            gData = NULL;
        }
    }

    return gData;
}

CString
CMSWindowsClipboardBitmapConverter::toIClipboard(HANDLE data) const
{
    // get datator
    const char* src = (const char*)GlobalLock(data);
    if (src == NULL) {
        return CString();
    }
    UInt32 srcSize = (UInt32)GlobalSize(data);

    // check image type
    const BITMAPINFO* bitmap = reinterpret_cast<const BITMAPINFO*>(src);
    LOG((CLOG_INFO "bitmap: %dx%d %d", bitmap->bmiHeader.biWidth, bitmap->bmiHeader.biHeight, (int)bitmap->bmiHeader.biBitCount));
    if (bitmap->bmiHeader.biPlanes == 1 &&
        (bitmap->bmiHeader.biBitCount == 24 ||
        bitmap->bmiHeader.biBitCount == 32) &&
        bitmap->bmiHeader.biCompression == BI_RGB) {
        // already in canonical form
        CString image(src, srcSize);
        GlobalUnlock(data);
        return image;
    }

    // create a destination DIB section
    LOG((CLOG_INFO "convert image from: depth=%d comp=%d", bitmap->bmiHeader.biBitCount, bitmap->bmiHeader.biCompression));
    void* raw;
    BITMAPINFOHEADER info;
    LONG w               = bitmap->bmiHeader.biWidth;
    LONG h               = bitmap->bmiHeader.biHeight;
    info.biSize          = sizeof(BITMAPINFOHEADER);
    info.biWidth         = w;
    info.biHeight        = h;
    info.biPlanes        = 1;
    info.biBitCount      = 32;
    info.biCompression   = BI_RGB;
    info.biSizeImage     = 0;
    info.biXPelsPerMeter = 1000;
    info.biYPelsPerMeter = 1000;
    info.biClrUsed       = 0;
    info.biClrImportant  = 0;
    HDC dc      = GetDC(NULL);
    HBITMAP dst = CreateDIBSection(dc, (BITMAPINFO*)&info,
                            DIB_RGB_COLORS, &raw, NULL, 0);

    // find the start of the pixel data
    const char* srcBits = (const char*)bitmap + bitmap->bmiHeader.biSize;
    if (bitmap->bmiHeader.biBitCount >= 16) {
        if (bitmap->bmiHeader.biCompression == BI_BITFIELDS &&
            (bitmap->bmiHeader.biBitCount == 16 ||
            bitmap->bmiHeader.biBitCount == 32)) {
            srcBits += 3 * sizeof(DWORD);
        }
    }
    else if (bitmap->bmiHeader.biClrUsed != 0) {
        srcBits += bitmap->bmiHeader.biClrUsed * sizeof(RGBQUAD);
    }
    else {
        //http://msdn.microsoft.com/en-us/library/ke55d167(VS.80).aspx
        srcBits += (1i64 << bitmap->bmiHeader.biBitCount) * sizeof(RGBQUAD);
    }

    // copy source image to destination image
    HDC dstDC         = CreateCompatibleDC(dc);
    HGDIOBJ oldBitmap = SelectObject(dstDC, dst);
    SetDIBitsToDevice(dstDC, 0, 0, w, h, 0, 0, 0, h,
                            srcBits, bitmap, DIB_RGB_COLORS);
    SelectObject(dstDC, oldBitmap);
    DeleteDC(dstDC);
    GdiFlush();

    // extract data
    CString image((const char*)&info, info.biSize);
    image.append((const char*)raw, 4 * w * h);

    // clean up GDI
    DeleteObject(dst);
    ReleaseDC(NULL, dc);

    // release handle
    GlobalUnlock(data);

    return image;
}