Sets whether or not to display rich text for this button.
        
        :param      state | <bool>

def setShowRichText(self, state):
        """
        Sets whether or not to display rich text for this button.
        
        :param      state | <bool>
        """
        self._showRichText = state
        text = self.text()
        
        if state:
            label = self.richTextLabel()
            label.setText(text)
            label.show()
            super(XPushButton, self).setText('')
        else:
            if self._richTextLabel:
                self._richTextLabel.hide()
            
            super(XPushButton, self).setText(text)