/****************************************************************************
**
** Copyright (C) 1992-2006 Trolltech ASA. All rights reserved.
**
** This file is part of the QtGui module of the Qt Toolkit.
**
** This file may be used under the terms of the GNU General Public
** License version 2.0 as published by the Free Software Foundation
** and appearing in the file LICENSE.GPL included in the packaging of
** this file.  Please review the following information to ensure GNU
** General Public Licensing requirements will be met:
** http://www.trolltech.com/products/qt/opensource.html
**
** If you are unsure which license is appropriate for your use, please
** review the following information:
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** sales department at sales@trolltech.com.
**
** This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
** WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
**
****************************************************************************/

#include "qpixmap.h"
#include "qpixmap_p.h"

#include "qbitmap.h"
#include "qimage.h"
#include "qwidget.h"
#include "qpainter.h"
#include "qdatastream.h"
#include "qbuffer.h"
#include "qapplication.h"
#include <private/qinternal_p.h>
#include "qevent.h"
#include "qfile.h"
#include "qfileinfo.h"
#include "qdatetime.h"
#include "qpixmapcache.h"
#include "qimagereader.h"
#include "qimagewriter.h"
#include "qdebug.h"
#include "qt_windows.h"

QPixmap QPixmap::grabWindow(WId winId, int x, int y, int w, int h )
{
    RECT r;
    GetClientRect(winId, &r);

    if (w < 0) w = r.right - r.left;
    if (h < 0) h = r.bottom - r.top;

    // Create and setup bitmap
    HDC bitmap_dc = CreateCompatibleDC(qt_win_display_dc());
    HBITMAP bitmap = CreateCompatibleBitmap(qt_win_display_dc(), w, h);
    HGDIOBJ null_bitmap = SelectObject(bitmap_dc, bitmap);

    // copy data
    HDC window_dc = GetDC(winId);
    BitBlt(bitmap_dc, 0, 0, w, h, window_dc, x, y, SRCCOPY);

    // clean up all but bitmap
    ReleaseDC(winId, window_dc);
    SelectObject(bitmap_dc, null_bitmap);
    DeleteDC(bitmap_dc);

    QPixmap pixmap = QPixmap::fromWinHBITMAP(bitmap);

    DeleteObject(bitmap);

    return pixmap;
}



/*!
    \enum QPixmap::HBitmapFormat

    This enum defines how the conversion between \c HBITMAP
    and QPixmap is performed.

    \warning This enum is only available on Windows.

    \value NoAlpha The alpha channel is ignored and always treated as
    being set to fully opaque. This is preferred if the \c HBITMAP is
    used with standard GDI calls, such as \c BitBlt().

    \value PremultipliedAlpha The \c HBITMAP is treated as having a
    alpha channel and premultiplied colors. This is preferred if the
    \c HBITMAP is accessed through the \c AlphaBlend() GDI function.

    \sa fromWinHBITMAP(), toWinHBITMAP()
*/

/*!
    Creates a \c HBITMAP equivalent to the QPixmap, based on the given
    \a format. Returns the \c HBITMAP handle.

    It is the caller's responsibility to free the \c HBITMAP data
    after use.

    \warning This function is only available on Windows.

    \sa fromWinHBITMAP()
*/
HBITMAP QPixmap::toWinHBITMAP(HBitmapFormat format) const
{
    int w = data->image.width();
    int h = data->image.height();

    HDC display_dc = qt_win_display_dc();

    // Define the header
    BITMAPINFO bmi;
    memset(&bmi, 0, sizeof(bmi));
    bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);
    bmi.bmiHeader.biWidth       = w;
    bmi.bmiHeader.biHeight      = -h;
    bmi.bmiHeader.biPlanes      = 1;
    bmi.bmiHeader.biBitCount    = 32;
    bmi.bmiHeader.biCompression = BI_RGB;
    bmi.bmiHeader.biSizeImage   = w * h * 4;

    // Create the pixmap
    uchar *pixels = 0;
    HBITMAP bitmap = CreateDIBSection(display_dc, &bmi, DIB_RGB_COLORS, (void **) &pixels, 0, 0);
    if (!bitmap) {
        qErrnoWarning("QPixmap::toWinHBITMAP(), failed to create dibsection");
        return 0;
    }
    if (!pixels) {
        qErrnoWarning("QPixmap::toWinHBITMAP(), did not allocate pixel data");
        return 0;
    }

    // Copy over the data
    QImage::Format imageFormat = format == NoAlpha
                                 ? QImage::Format_RGB32
                                 : QImage::Format_ARGB32_Premultiplied;
    const QImage image = data->image.convertToFormat(imageFormat);
    int bytes_per_line = w * 4;
    for (int y=0; y<h; ++y)
        memcpy(pixels + y * bytes_per_line, image.scanLine(y), bytes_per_line);

    return bitmap;
}

/*!
    Returns a QPixmap that is equivalent to the given \a bitmap. The
    conversion is based on the specified \a format.

    \warning This function is only available on Windows.

    \sa toWinHBITMAP(), {QPixmap#Pixmap Conversion}{Pixmap Conversion}

*/
QPixmap QPixmap::fromWinHBITMAP(HBITMAP bitmap, HBitmapFormat format)
{
    // Verify size
    BITMAP bitmap_info;
    memset(&bitmap_info, 0, sizeof(BITMAP));

    int res;
    QT_WA({
        res = GetObjectW(bitmap, sizeof(BITMAP), &bitmap_info);
    } , {
        res = GetObjectA(bitmap, sizeof(BITMAP), &bitmap_info);
    });

    if (!res) {
        qErrnoWarning("QPixmap::fromWinHBITMAP(), failed to get bitmap info");
        return QPixmap();
    }
    int w = bitmap_info.bmWidth;
    int h = bitmap_info.bmHeight;

    BITMAPINFO bmi;
    memset(&bmi, 0, sizeof(bmi));
    bmi.bmiHeader.biSize        = sizeof(BITMAPINFOHEADER);
    bmi.bmiHeader.biWidth       = w;
    bmi.bmiHeader.biHeight      = -h;
    bmi.bmiHeader.biPlanes      = 1;
    bmi.bmiHeader.biBitCount    = 32;
    bmi.bmiHeader.biCompression = BI_RGB;
    bmi.bmiHeader.biSizeImage   = w * h * 4;

    QImage result;
    // Get bitmap bits
    uchar *data = (uchar *) qMalloc(bmi.bmiHeader.biSizeImage);
    if (GetDIBits(qt_win_display_dc(), bitmap, 0, h, data, &bmi, DIB_RGB_COLORS)) {

        QImage::Format imageFormat = QImage::Format_ARGB32_Premultiplied;
        uint mask = 0;
        if (format == NoAlpha) {
            imageFormat = QImage::Format_RGB32;
            mask = 0xff000000;
        }

        // Create image and copy data into image.
        QImage image(w, h, imageFormat);
        int bytes_per_line = w * sizeof(QRgb);
        for (int y=0; y<h; ++y) {
            QRgb *dest = (QRgb *) image.scanLine(y);
            const QRgb *src = (const QRgb *) (data + y * bytes_per_line);
            for (int x=0; x<w; ++x) {
                dest[x] = src[x] | mask;
            }
        }
        result = image;
    } else {
        qWarning("QPixmap::fromWinHBITMAP(), failed to get bitmap bits");
    }
    qFree(data);
    return fromImage(result);
}
