Size of a QPaintDevice

I've got some nice looking round buttons happening
problem is....their whole area is still clickable....so my re-implamented RoundButton::MouseClickEvent is triggered even when some ambiguous area between 2 buttons is clicked....
how do I redefine the clickable area?

I can't just reduce the size to a v.small bounding rectangle and hope they don't get confused because I occasionally have to draw lines which connect some of my buttons and so the QPainter painter(this) has to return an area big enough to draw 1/2 the line from each button

thanks
=)

it would also maybe work to get some way of making the size of the widget a tight bounding rectangle to stop erroneous clicks, but then somehow get the painter to draw outside of its boundaries, but i don't know how to do this either