Returns the action that is currently checked in the system.
        
        :return     <QAction> || None

def currentAction( self ):
        """
        Returns the action that is currently checked in the system.
        
        :return     <QAction> || None
        """
        if ( not self._actionGroup ):
            return None
            
        for act in self._actionGroup.actions():
            if ( act.isChecked() ):
                return act
        return None