XCheckWindowEvent() XCheckWindowEvent()
Name
XCheckWindowEvent - remove the next event matching both passed window and passed mask; don't wait.
Synopsis
Bool XCheckWindowEvent(display, w, event_mask, event_return)
Display *display;
Window w;
long event_mask;
XEvent *event_return;
Arguments
display Specifies a connection to an X server; returned from XOpenDisplay().
w Specifies the window ID. The event must match both the passed window and the passed event mask.
event_mask
Specifies the event mask. See XSelectInput() for a list of mask elements.
event_return
Returns the XEvent structure.
Returns
True if a matching event is found, else False.
Description
XCheckWindowEvent() removes the next event in the queue that matches both the passed window and the passed mask. If such an event exists,
it is copied into an XEvent supplied by the caller. Other events earlier in the queue are not discarded.
If a matching event is found, XCheckWindowEvent() returns True. If no such event has been queued, it flushes the request buffer and
returns False, without waiting.
XCheckWindowEvent() cannot return ClientMessage, MappingNotify, SelectionClear, SelectionNotify, or SelectionRequest events because these
event types are by definition unmaskable.
For more information, see Volume One, Chapter 8, Events.
See Also
XQLength(), XAllowEvents(), XCheckIfEvent(), XCheckMaskEvent(), XCheckTypedEvent(), XCheckTypedWindowEvent(), XEventsQueued(), XGetInputFo-
cus(), XGetMotionEvents(), XIfEvent(), XMaskEvent(), XNextEvent(), XPeekEvent(), XPeekIfEvent(), XPending(), XPutBackEvent(), XSelectIn-
put(), XSendEvent(), XSetInputFocus(), XSynchronize(), XWindowEvent().
Xlib - Input Handling XCheckWindowEvent()
