Adjusts the font used for the title based on the current with and \
        display name.

def adjustTitleFont(self):
        """
        Adjusts the font used for the title based on the current with and \
        display name.
        """
        left, top, right, bottom = self.contentsMargins()
        r = self.roundingRadius()
        
        # include text padding
        left += 5 + r / 2
        top += 5 + r / 2
        right += 5 + r / 2
        bottom += 5 + r / 2
        
        r = self.rect()
        rect_l = r.left() + left
        rect_r = r.right() - right
        rect_t = r.top() + top
        rect_b = r.bottom() - bottom
        
        # ensure we have a valid rect
        rect = QRect(rect_l, rect_t, rect_r - rect_l, rect_b - rect_t)
        if rect.width() < 10:
            return
        
        font = XFont(QApplication.font())
        font.adaptSize(self.displayName(), rect, wordWrap=self.wordWrap())
        
        self._titleFont = font