#include <QtGui>

class Widget : public QWidget
{
    Q_OBJECT

public slots:
    void print(QPrinter *);

public:
    Widget(QWidget *parent = 0);

private:
    QPrintPreviewDialog *dialog;
    QPrinter *printer;
    QToolButton *button;
};

Widget::Widget(QWidget *parent) : QWidget(parent)
{
    button = new QToolButton(this);
    button->setText("Rendering of this tool button causes the print preview widget to resize.");

    printer = new QPrinter(QPrinter::ScreenResolution);
    // when the parent is not set to the widget, it doesn't get resized either
    dialog = new QPrintPreviewDialog(printer, this);

    connect(dialog, SIGNAL(paintRequested(QPrinter*)), this, SLOT(print(QPrinter*)));
    connect(button, SIGNAL(pressed()), dialog, SLOT(exec()));
}

void Widget::print(QPrinter *printer)
{
    QPixmap pixmap;
    // uncomment the following line to see the resizing
    button->render(&pixmap);

    QPainter p(printer);
    p.drawEllipse(0, 0, 400, 600);
    p.end();
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    Widget widget;
    widget.show();
    return a.exec();
}

#include "main.moc"