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.ds xT X Toolkit Intrinsics \- C Language Interface
.ds xW Athena X Widgets \- C Language X Toolkit Interface
.ds xL Xlib \- C Language X Interface
.ds xC Inter-Client Communication Conventions Manual
.TH XNextEvent 3 "libX11 1.8.7" "X Version 11" "XLIB FUNCTIONS"
.SH NAME
XNextEvent, XPeekEvent, XWindowEvent, XCheckWindowEvent, XMaskEvent, XCheckMaskEvent, XCheckTypedEvent, XCheckTypedWindowEvent \- select events by type
.SH SYNTAX
.HP
int XNextEvent\^(\^Display *\fIdisplay\fP\^, XEvent *\fIevent_return\fP\^);
.HP
int XPeekEvent\^(\^Display *\fIdisplay\fP\^, XEvent *\fIevent_return\fP\^);
.HP
int XWindowEvent\^(\^Display *\fIdisplay\fP\^, Window \fIw\fP\^, long
\fIevent_mask\fP\^, XEvent *\fIevent_return\fP\^);
.HP
Bool XCheckWindowEvent\^(\^Display *\fIdisplay\fP\^, Window \fIw\fP\^, long
\fIevent_mask\fP\^, XEvent *\fIevent_return\fP\^);
.HP
int XMaskEvent\^(\^Display *\fIdisplay\fP\^, long \fIevent_mask\fP\^, XEvent
*\fIevent_return\fP\^);
.HP
Bool XCheckMaskEvent\^(\^Display *\fIdisplay\fP\^, long \fIevent_mask\fP\^,
XEvent *\fIevent_return\fP\^);
.HP
Bool XCheckTypedEvent\^(\^Display *\fIdisplay\fP\^, int \fIevent_type\fP\^,
XEvent *\fIevent_return\fP\^);
.HP
Bool XCheckTypedWindowEvent\^(\^Display *\fIdisplay\fP\^, Window \fIw\fP\^,
int \fIevent_type\fP\^, XEvent *\fIevent_return\fP\^);
.SH ARGUMENTS
.IP \fIdisplay\fP 1i
Specifies the connection to the X server.
.IP \fIevent_mask\fP 1i
Specifies the event mask.
.IP \fIevent_return\fP 1i
Returns the matched event's associated structure.
.IP \fIevent_return\fP 1i
Returns the next event in the queue.
.IP \fIevent_return\fP 1i
Returns a copy of the matched event's associated structure.
.IP \fIevent_type\fP 1i
Specifies the event type to be compared.
.IP \fIw\fP 1i
Specifies the window whose event you are interested in.
.SH DESCRIPTION
The
.B XNextEvent
function copies the first event from the event queue into the specified
.B XEvent
structure and then removes it from the queue.
If the event queue is empty,
.B XNextEvent
flushes the output buffer and blocks until an event is received.
.LP
The
.B XPeekEvent
function returns the first event from the event queue,
but it does not remove the event from the queue.
If the queue is empty,
.B XPeekEvent
flushes the output buffer and blocks until an event is received.
It then copies the event into the client-supplied
.B XEvent
structure without removing it from the event queue.
.LP
The
.B XWindowEvent
function searches the event queue for an event that matches both the specified
window and event mask.
When it finds a match,
.B XWindowEvent
removes that event from the queue and copies it into the specified
.B XEvent
structure.
The other events stored in the queue are not discarded.
If a matching event is not in the queue,
.B XWindowEvent
flushes the output buffer and blocks until one is received.
.LP
The
.B XCheckWindowEvent
function searches the event queue and then the events available
on the server connection for the first event that matches the specified window
and event mask.
If it finds a match,
.B XCheckWindowEvent
removes that event, copies it into the specified
.B XEvent
structure, and returns
.BR True .
The other events stored in the queue are not discarded.
If the event you requested is not available,
.B XCheckWindowEvent
returns
.BR False ,
and the output buffer will have been flushed.
.LP
The
.B XMaskEvent
function searches the event queue for the events associated with the
specified mask.
When it finds a match,
.B XMaskEvent
removes that event and copies it into the specified
.B XEvent
structure.
The other events stored in the queue are not discarded.
If the event you requested is not in the queue,
.B XMaskEvent
flushes the output buffer and blocks until one is received.
.LP
The
.B XCheckMaskEvent
function searches the event queue and then any events available on the
server connection for the first event that matches the specified mask.
If it finds a match,
.B XCheckMaskEvent
removes that event, copies it into the specified
.B XEvent
structure, and returns
.BR True .
The other events stored in the queue are not discarded.
If the event you requested is not available,
.B XCheckMaskEvent
returns
.BR False ,
and the output buffer will have been flushed.
.LP
The
.B XCheckTypedEvent
function searches the event queue and then any events available
on the server connection for the first event that matches the specified type.
If it finds a match,
.B XCheckTypedEvent
removes that event, copies it into the specified
.B XEvent
structure, and returns
.BR True .
The other events in the queue are not discarded.
If the event is not available,
.B XCheckTypedEvent
returns
.BR False ,
and the output buffer will have been flushed.
.LP
The
.B XCheckTypedWindowEvent
function searches the event queue and then any events available
on the server connection for the first event that matches the specified
type and window.
If it finds a match,
.B XCheckTypedWindowEvent
removes the event from the queue, copies it into the specified
.B XEvent
structure, and returns
.BR True .
The other events in the queue are not discarded.
If the event is not available,
.B XCheckTypedWindowEvent
returns
.BR False ,
and the output buffer will have been flushed.
.SH "SEE ALSO"
XAnyEvent(3),
XIfEvent(3),
XPutBackEvent(3),
XSendEvent(3)
.br
\fI\*(xL\fP