for loop forward and backward

How to make the loop below count increasingly (1,2,3,…) when I press the mouse button and count decreasingly (4,3,2,…) when if press a keyboard button?

    for i = 1:10
        disp( num2str( i ) );
        w = waitforbuttonpress;
    end

[John Chilleri]

This can be done with buttons created in a GUI, would that be adequate?

[Rightia Rollmann]

I want the simplest soloution where no GUI is needed

Answer 1

[Luke M]

I'm not sure if it can be done in a for loop, but in a while loop:

i = 1;
while i >= 1 && i <= 10
    disp( num2str( i ) );
    if waitforbuttonpress
        i = i - 1;
    else
        i = i + 1;
    end
end