NAME
XNextEvent, XPeekEvent, XWindowEvent, XCheckWindowEvent, XMaskEvent,
XCheckMaskEvent, XCheckTypedEvent, XCheckTypedWindowEvent - 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.
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 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,
XCheckTypedWindowEvent
returns
False, and the output buffer will have been flushed.
SEE ALSO
XAnyEvent(3), XIfEvent(3), XPutBackEvent(3), XSendEvent(3)
Xlib - C Language X Interface