Inverse button press?

Hello. For my iOS game, I want to have a system where the player taps a button to highlight an object. If they then tap the same button (not a double tap…they do not have to do it quickly), one function is invoked, and if the player touches anywhere else on screen, another function is invoked (If memory serves me correctly, old pc adventure games used this). How can I detect this? Thanks

I would use the GUI.Toggle() button, then check when clicking elsewhere if this is toggled, if so do your function. You could tighten it somewhat by defining Rect() to be clicked to execute your outside function if need be too.