Action generated when a key is pressed or released. If the key is pressed and held several calls will occur. It is called after the callback K_ANY is processed.
int function(Ihandle *ih, int c, int press); [in C] ih:keypress_cb(c, press: number) -> (ret: number) [in Lua]
identifier of the element that activated the event.
c: identifier of typed key. Please refer to the Keyboard Codes table for a list of possible values.
press: 1 is the user pressed the key or 0 otherwise.
Returns: If IUP_IGNORE is returned the key is ignored by the system. IUP_CLOSE will be processed.