Hi Kvak,
First I need to say thanks for your help! I think is a little bit misunderstanding about the concept, here's the example picture: The indicator will still work it original function, but only display Buy arrow when MA is uptrend (delete Sell arrow) ; only display Sell arrow when MA is downtrend (delete Buy arrow) , it is like don't against the trend and only trade with the trend, like trend following strategy .
So the user can choose what type of MA he want to use, and what is the MA period to determine the uptrend and downtrend.