http://bunzaga.com/ludum/Buttons.html

You ‘press and drag’ on a button, then move the mouse off of the button and release, it begins its cooldown timer.

You can ‘click’ a button, and it will perform a different callback (no callbacks implemented yet).

You can ‘pre-drag’ on a button while it is in cooldown, and then release it when it is off cooldown, and it will act as expected.

If you drag a button and then decide not to release, but instead bring the mouse cursor back to the buttons original position, it will not begin the cooldown timer.

Quite complex for such a Minimalistic UI. 😀