how can I know user back from desktop ?

Solar2D General Questions/Discussion
#1

if a user play my game, then he press HOME key to do something in desktop.
and then, he press my app icon, and back to my game, how can I know that he is back from desktop ?
(I want to do a countdown then continue)

thanks. [import]uid: 21680 topic_id: 10616 reply_id: 310616[/import]

#2

no way for this ? [import]uid: 21680 topic_id: 10616 reply_id: 38811[/import]