Prevent window size change when font size changes

I have set a dial that changes the overall font size. When I set the dial very big, the window resizes, surpassing the screen limits. Also, if I then move the size back to what it was, the window size stays at its maximum size, with contents outside the screen.

How can I prevent the window size from changing OR how can I make it shrink when I move the dial back to its original position?

Would forcing the window to fit at each resize event work? Calling a function like this:

Code:

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static bool adjustToScreen(QRect& rRect)
{
    QDesktopWidget* desktop = QApplication::desktop();
    QRect rcDesktop = desktop->frameGeometry();
 
    // if the original rect is not completly inside the desktop rectangle, it must be adjusted
    if(!rcDesktop.contains(rRect))
    {
        rRect.setLeft(qMax(rcDesktop.left(), rRect.left()));
        rRect.setTop(qMax(rcDesktop.top(), rRect.top()));
        rRect.setRight(qMin(rcDesktop.right(), rRect.right()));
        rRect.setBottom(qMin(rcDesktop.bottom(), rRect.bottom()));
        return true;
    }
    return false;
}

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