Sets the on pixmap that will be used for this button to the given
        pixmap.  THis can be a QPixmap instance, or a string for where to load
        the pixmap from.
        
        :param      pixmap | <QtGui.QPixmap> || <str>

def setOnPixmap(self, pixmap):
        """
        Sets the on pixmap that will be used for this button to the given
        pixmap.  THis can be a QPixmap instance, or a string for where to load
        the pixmap from.
        
        :param      pixmap | <QtGui.QPixmap> || <str>
        """
        pmap = QtGui.QPixmap(pixmap)
        self._onPixmap = pmap.scaled(self.width(), self.height(),
                                     QtCore.Qt.KeepAspectRatio,
                                     QtCore.Qt.SmoothTransformation)