Converting from HBitmap to a QPixmap

[qtUser500]

I am using Qt3.
Would like to know how I can convert a HBitmap to a QPixmap?

Is it possible in Qt3? If not what are the alternatives?

[ComaWhite]

Why don't you use Qt4 instead of old abandon Qt3?

[zgulser]

Hi,

try this;

yourPixmap = QPixmap::fromWinHBitmap( pixmap, QPixmap::PremultipliedAlpha);

[spirit]

Hi,

try this;

yourPixmap = QPixmap::fromWinHBitmap( pixmap, QPixmap::PremultipliedAlpha);

there is no such method in Qt3.

[qtUser500]

there is no such method in Qt3.

Yes I noticed no method like that in Qt3.

Any suggestions on how to convert a HBitmap to some other image form after which it can be converted to QPixmap.

[spirit]

this is code from Qt 4.4.3

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);
        if (!image.isNull()) { // failed to alloc?
            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);
}

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);
        if (!image.isNull()) { // failed to alloc?
            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);
}

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[qtUser500]

Thanks Spirit for the information, I was able to resolve it.
Appreciate the time of everyone who replied to my post