The predicate procedure and its associated arguments are:
Bool (*predicate)(display, event, arg)
Display *display;
XEvent *event;
XPointer arg;
display | Specifies the connection to the X server. |
event | Specifies the XEvent structure. |
arg | Specifies the argument passed in from the XIfEvent(), XCheckIfEvent(), or XPeekIfEvent() function. |
The predicate procedure is called once for each event in the queue until it finds a match. After finding a match, the predicate procedure must return True. If it did not find a match, it must return False.
To check the event queue for a matching event and, if found, remove the event from the queue, use XIfEvent().
To check the event queue for a matching event without blocking, use XCheckIfEvent().
To check the event queue for a matching event without removing the event from the queue, use XPeekIfEvent().