Bool XCheckIfEvent(display, event_return, predicate, arg)
      Display *display;
      XEvent *event_return;
      Bool (*predicate)();
      XPointer arg;


display Specifies the connection to the X server.
event_return Returns a copy of the matched event's associated structure.
predicate Specifies the procedure that is to be called to determine if the next event in the queue matches what you want.
arg Specifies the user-supplied argument that will be passed to the predicate procedure.


When the predicate procedure finds a match, XCheckIfEvent() copies the matched event into the client-supplied XEvent structure and returns True. (This event is removed from the queue.) If the predicate procedure finds no match, XCheckIfEvent() returns False, and the output buffer will have been flushed. All earlier events stored in the queue are not discarded.

See also

XIfEvent(), XNextEvent(), XPeekIfEvent(), XPutBackEvent(), XSendEvent(), "Selecting Events Using a Predicate Procedure".
Christophe Tronche, [email protected]