KEYPRESS_CB
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.
Callback
int function(Ihandle *ih, int c, int press);ih: 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.