XPeekIfEvent() XPeekIfEvent()
Name
XPeekIfEvent - get an event matched by predicate procedure without removing it from the queue.
Synopsis
XPeekIfEvent(display, event_return, predicate, arg)
Display *display;
XEvent *event_return;
Bool (*predicate)();
XPointer arg;
Arguments
display Specifies a connection to an X server; returned from XOpenDisplay().
event_return
Returns a copy of the matched event.
predicate Specifies the procedure to be called to determine if each event that arrives in the queue is the desired one.
arg Specifies the user-specified argument that will be passed to the predicate procedure.
Description
XPeekIfEvent() returns an event only when the specified predicate procedure returns True for the event. The event is copied into
event_return but not removed from the queue. The specified predicate is called each time an event is added to the queue, with the argu-
ments display, event_return, and arg.
XPeekIfEvent() flushes the request buffer if no matching events could be found on the queue, and then waits for the next matching event.
For more information, see Volume One, Chapter 8, Events.
See Also
XQLength(), XAllowEvents(), XCheckIfEvent(), XCheckMaskEvent(), XCheckTypedEvent(), XCheckTypedWindowEvent(), XCheckWindowEvent(),
XEventsQueued(), XGetInputFocus(), XGetMotionEvents(), XIfEvent(), XMaskEvent(), XNextEvent(), XPeekEvent(), XPending(), XPutBackEvent(),
XSelectInput(), XSendEvent(), XSetInputFocus(), XSynchronize(), XWindowEvent().
Xlib - Input Handling XPeekIfEvent()
