XNextEvent(3X11) XLIB FUNCTIONS XNextEvent(3X11)
NAME
XNextEvent, XPeekEvent, XWindowEvent, XCheckWindowEvent,
XMaskEvent, XCheckMaskEvent, XCheckTypedEvent, XCheck-
TypedWindowEvent - select events by type
SYNTAX
int XNextEvent(Display *display, XEvent *event_return);
int XPeekEvent(Display *display, XEvent *event_return);
int XWindowEvent(Display *display, Window w, long
event_mask, XEvent *event_return);
Bool XCheckWindowEvent(Display *display, Window w, long
event_mask, XEvent *event_return);
int XMaskEvent(Display *display, long event_mask, XEvent
*event_return);
Bool XCheckMaskEvent(Display *display, long event_mask,
XEvent *event_return);
Bool XCheckTypedEvent(Display *display, int event_type,
XEvent *event_return);
Bool XCheckTypedWindowEvent(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.
event_return
Returns the matched event's associated structure.
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
interested in.
XFree86 Version 4.5.0 1
XNextEvent(3X11) XLIB FUNCTIONS XNextEvent(3X11)
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 output
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 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 output 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, XCheckMaskEvent 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
XFree86 Version 4.5.0 2
XNextEvent(3X11) XLIB FUNCTIONS XNextEvent(3X11)
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 connection 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 specified XEvent
structure, and returns True. The other events in the queue
are not discarded. If the event is not available, XCheck-
TypedWindowEvent returns False, and the output buffer will
have been flushed.
SEE ALSO
XAnyEvent(3X11), XIfEvent(3X11), XPutBackEvent(3X11),
XSendEvent(3X11)
Xlib - C Language X Interface
XFree86 Version 4.5.0 3