Double "clicking" on something is pretty uncommon so we don't have an example 🙂 But it should be easy to implement - Inherit from Button and create your own handleClickEvent() handler that registers itself as a timer-widget to receive ticks. Then just keep track of the threshhold that you want to use to register a "double click". Search this forum on how to use time aware widgets. I just something similar in another post.
Search for "registerTimerWidget".
/Martin
