XNextEvent(3X11) XLIB FUNCTIONS XNextEvent(3X11)NAME
XNextEvent, XPeekEvent, XWindowEvent, XCheckWindowEvent,
XMaskEvent, XCheckMaskEvent, XCheckTypedEvent, XCheckType-
dWindowEvent - select events by type
SYNTAX
XNextEvent(display, event_return)
Display *display;
XEvent *event_return;
XPeekEvent(display, event_return)
Display *display;
XEvent *event_return;
XWindowEvent(display, w, event_mask, event_return)
Display *display;
Window w;
long event_mask;
XEvent *event_return;
Bool XCheckWindowEvent(display, w, event_mask,
event_return)
Display *display;
Window w;
long event_mask;
XEvent *event_return;
XMaskEvent(display, event_mask, event_return)
Display *display;
long event_mask;
XEvent *event_return;
Bool XCheckMaskEvent(display, event_mask, event_return)
Display *display;
long event_mask;
XEvent *event_return;
Bool XCheckTypedEvent(display, event_type, event_return)
Display *display;
int event_type;
XEvent *event_return;
Bool XCheckTypedWindowEvent(display, w, event_type,
event_return)
Display *display;
Window w;
int event_type;
XEvent *event_return;
ARGUMENTS
display Specifies the connection to the X server.
event_mask
Specifies the event mask.
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XNextEvent(3X11) XLIB FUNCTIONS XNextEvent(3X11)
event_return
Returns the matched event's associated struc-
ture.
event_return
Returns the next event in the queue.
event_return
Returns a copy of the matched event's associated
structure.
event_type
Specifies the event type to be compared.
w Specifies the window whose event uou are inter-
ested in.
DESCRIPTION
The XNextEvent function copies the first event from the
event queue into the specified XEvent structure and then
removes it from the queue. If the event queue is empty,
XNextEvent flushes the output buffer and blocks until an
event is received.
The 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, XPeekEvent flushes the out-
put buffer and blocks until an event is received. It then
copies the event into the client-supplied XEvent structure
without removing it from the event queue.
The XWindowEvent function searches the event queue for an
event that matches both the specified window and event
mask. When it finds a match, XWindowEvent removes that
event from the queue and copies it into the specified
XEvent structure. The other events stored in the queue
are not discarded. If a matching event is not in the
queue, XWindowEvent flushes the output buffer and blocks
until one is received.
The 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, XCheckWindowEvent
removes that event, copies it into the specified XEvent
structure, and returns True. The other events stored in
the queue are not discarded. If the event you requested
is not available, XCheckWindowEvent returns False, and the
output buffer will have been flushed.
The XMaskEvent function searches the event queue for the
events associated with the specified mask. When it finds
a match, XMaskEvent removes that event and copies it into
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XNextEvent(3X11) XLIB FUNCTIONS XNextEvent(3X11)
the specified XEvent structure. The other events stored
in the queue are not discarded. If the event you
requested is not in the queue, XMaskEvent flushes the out-
put buffer and blocks until one is received.
The 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, XCheckMaskEvent removes that event, copies it
into the specified XEvent structure, and returns True.
The other events stored in the queue are not discarded.
If the event you requested is not available, XCheck-
MaskEvent returns False, and the output buffer will have
been flushed.
The 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, XCheckTypedEvent removes that event, copies it
into the specified XEvent structure, and returns True.
The other events in the queue are not discarded. If the
event is not available, XCheckTypedEvent returns False,
and the output buffer will have been flushed.
The XCheckTypedWindowEvent function searches the event
queue and then any events available on the server connec-
tion for the first event that matches the specified type
and window. If it finds a match, XCheckTypedWindowEvent
removes the event from the queue, copies it into the spec-
ified XEvent structure, and returns True. The other
events in the queue are not discarded. If the event is
not available, XCheckTypedWindowEvent returns False, and
the output buffer will have been flushed.
SEE ALSOXAnyEvent(3X11), XIfEvent(3X11), XPutBackEvent(3X11),
XSendEvent(3X11)
Xlib - C Language X Interface
X Version 11 Release 6.4 3