https://doc.red-lang.org/en/view.html
over
mouse
Mouse cursor passing over a face. This event is produced once when the mouse enters the face and once when it exits. If flags facet contains all‑over flag, then all intermediary events are produced too.
There is no symetric event ? How do I know mouse is not over anymore ?
In rebol there was http://www.rebol.com/how-to/feel.html but this syntax doesn't exist anymore in Red or I am mistaken ?
view layout [
box "A Box" forest feel [
over: func [face act pos] [print [act pos]]
]
]