Clears the current action for this widget.
        
        :param      event | <QEvent>

def leaveEvent(self, event):
        """
        Clears the current action for this widget.
        
        :param      event | <QEvent>
        """
        super(XDockToolbar, self).leaveEvent(event)
        
        if not self.actionHeld():
            self.setCurrentAction(None)