XIfEvent(3X11) X11R5 XIfEvent(3X11)NAME
XIfEvent, XCheckIfEvent, XPeekIfEvent - check the event queue with a
predicate procedure
SYNTAX
XIfEvent(display, event_return, predicate, arg)
Display *display;
XEvent *event_return;
Bool (*predicate)();
XPointer arg;
Bool XCheckIfEvent(display, event_return, predicate, arg)
Display *display;
XEvent *event_return;
Bool (*predicate)();
XPointer arg;
XPeekIfEvent(display, event_return, predicate, arg)
Display *display;
XEvent *event_return;
Bool (*predicate)();
XPointer arg;
ARGUMENTS
arg Specifies the user-supplied argument that will be passed to
the predicate procedure.
display Specifies the connection to the X server.
event_return
Returns either a copy of or 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.
DESCRIPTION
The function completes only when the specified predicate procedure
returns for an event, which indicates an event in the queue matches.
flushes the output buffer if it blocks waiting for additional events.
removes the matching event from the queue and copies the structure into
the client-supplied structure.
When the predicate procedure finds a match, copies the matched event
into the client-supplied structure and returns (This event is removed
from the queue.) If the predicate procedure finds no match, returns
and the output buffer will have been flushed. All earlier events
stored in the queue are not discarded.
The function returns only when the specified predicate procedure
returns for an event. After the predicate procedure finds a match,
copies the matched event into the client-supplied structure without
removing the event from the queue. flushes the output buffer if it
blocks waiting for additional events.
SEE ALSOXAnyEvent(3X11), XNextEvent(3X11), XPutBackEvent(3X11)XSendEvent(3X11)
Xlib - C Language X Interface
XIfEvent(3X11)
