As we know, system action: wait could hang the execution until time-out. For example:
+ start of layout
[ul]
[li]append text to "1"[/li]
[li]wait 1 sec[/li]
[li]append text to "2"
It might be useful to add another kind of wait action, to hang the execution until notified by other event. For example:
+ start of layout
[ul]
[li]append text to "1"[/li]
[li]system: wait "enter" signal[/li]
[li]append text to "2"[/li]
[/ul]
+ keyboard: on "enter" press
[ul]
[li]system: emit "enter" signal
The execution at '+ start of layout' will be hanged by '- system: wait "enter" signal', until '- system: emit "enter" signal' executed under '+ keyboard: on "enter" press' event.
I know this feature could be implemented by splitting actions into many parts, controlled by fsm under '+ keyboard: on "enter" press'. But a wait signal could help designer describe actions sequence more straightforward and readable.