Carbon : Setting palette brush to a pixmap does not work.

//set a png file in MyWidget constructor
#include <QtGui>

class MyWidget: public QWidget
{
public:
    MyWidget(QWidget *parent = 0);
protected:
    virtual void paintEvent ( QPaintEvent * event );

private:
   QImage img;
   QPixmap pixmap;
};        

MyWidget::MyWidget(QWidget *parent) : QWidget(parent) 
{
    setWindowTitle("Qt Tester paintEvent");
    img.load("../../../qt-logo.png");
    pixmap = QPixmap::fromImage(img);

    //setting a pixmap as the brush on carbon does not show the image.
            QBrush brush;
            brush.setTexture(pixmap);
            brush.setStyle(Qt::TexturePattern);
            QBrush b2(pixmap);
            QPalette pal;
            pal.setBrush(QPalette::Window,b2);
            setPalette(pal);
}

void MyWidget::paintEvent( QPaintEvent * event){
    QPainter painter(this);

//The brush is used in this example on all platforms.

//    QBrush brush;
//    brush.setTexture(pixmap);
//    brush.setStyle(Qt::TexturePattern);
//    QBrush b2(pixmap);
//    painter.setBrush(b2);
//    painter.drawRoundedRect(0,0,100,100,5,5);
//    painter.drawText(20,20,"Qt");
 }

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    MyWidget *myWin = new MyWidget();
    myWin->show();
    return app.exec();
}