XCheckWindowEvent()XCheckWindowEvent()NameXCheckWindowEvent – 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.
DescriptionXCheckWindowEvent() 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 ear‐
lier 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, Selec‐
tionClear, SelectionNotify, or SelectionRequest events because these
event types are by definition unmaskable.
For more information, see Volume One, Chapter 8, Events.
See AlsoXQLength(), XAllowEvents(), XCheckIfEvent(), XCheckMaskEvent(), XCheck‐
TypedEvent(), XCheckTypedWindowEvent(), XEventsQueued(), XGetInputFo‐
cus(), XGetMotionEvents(), XIfEvent(), XMaskEvent(), XNextEvent(),
XPeekEvent(), XPeekIfEvent(), XPending(), XPutBackEvent(), XSelectIn‐
put(), XSendEvent(), XSetInputFocus(), XSynchronize(), XWindowEvent().
Xlib - Input Handling XCheckWindowEvent()