source: trunk/synergy/lib/platform/CXWindowsClipboardBMPConverter.cpp

/*
 * synergy -- mouse and keyboard sharing utility
 * 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.
 */

#include "CXWindowsClipboardBMPConverter.h"

// BMP file header structure
struct CBMPHeader {
public:
        UInt16                          type;
        UInt32                          size;
        UInt16                          reserved1;
        UInt16                          reserved2;
        UInt32                          offset;
};

// BMP is little-endian
static inline
UInt32
fromLEU32(const UInt8* data)
{
        return static_cast<UInt32>(data[0]) |
                        (static_cast<UInt32>(data[1]) <<  8) |
                        (static_cast<UInt32>(data[2]) << 16) |
                        (static_cast<UInt32>(data[3]) << 24);
}

static
void
toLE(UInt8*& dst, char src)
{
        dst[0] = static_cast<UInt8>(src);
        dst += 1;
}

static
void
toLE(UInt8*& dst, UInt16 src)
{
        dst[0] = static_cast<UInt8>(src & 0xffu);
        dst[1] = static_cast<UInt8>((src >> 8) & 0xffu);
        dst += 2;
}

static
void
toLE(UInt8*& dst, UInt32 src)
{
        dst[0] = static_cast<UInt8>(src & 0xffu);
        dst[1] = static_cast<UInt8>((src >>  8) & 0xffu);
        dst[2] = static_cast<UInt8>((src >> 16) & 0xffu);
        dst[3] = static_cast<UInt8>((src >> 24) & 0xffu);
        dst += 4;
}

//
// CXWindowsClipboardBMPConverter
//

CXWindowsClipboardBMPConverter::CXWindowsClipboardBMPConverter(
                                Display* display) :
        m_atom(XInternAtom(display, "image/bmp", False))
{
        // do nothing
}

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

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

Atom
CXWindowsClipboardBMPConverter::getAtom() const
{
        return m_atom;
}

int
CXWindowsClipboardBMPConverter::getDataSize() const
{
        return 8;
}

CString
CXWindowsClipboardBMPConverter::fromIClipboard(const CString& bmp) const
{
        // create BMP image
        UInt8 header[14];
        UInt8* dst = header;
        toLE(dst, 'B');
        toLE(dst, 'M');
        toLE(dst, static_cast<UInt32>(14 + bmp.size()));
        toLE(dst, static_cast<UInt16>(0));
        toLE(dst, static_cast<UInt16>(0));
        toLE(dst, static_cast<UInt32>(14 + 40));
        return CString(reinterpret_cast<const char*>(header), 14) + bmp;
}

CString
CXWindowsClipboardBMPConverter::toIClipboard(const CString& bmp) const
{
        // make sure data is big enough for a BMP file
        if (bmp.size() <= 14 + 40) {
                return CString();
        }

        // check BMP file header
        const UInt8* rawBMPHeader = reinterpret_cast<const UInt8*>(bmp.data());
        if (rawBMPHeader[0] != 'B' || rawBMPHeader[1] != 'M') {
                return CString();
        }

        // get offset to image data
        UInt32 offset = fromLEU32(rawBMPHeader + 10);

        // construct BMP
        if (offset == 14 + 40) {
                return bmp.substr(14);
        }
        else {
                return bmp.substr(14, 40) + bmp.substr(offset, bmp.size() - offset);
        }
}