XNextEvent(3X) XNextEvent(3X)
NAME
NextEvent, XPeekEvent, XWindowEvent, XCheckWindowEvent,
XMaskEvent, XCheckMaskEvent, XCheckTypedEvent,
XCheckTypedWindowEvent - select events by type
SYNOPSIS
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.
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XNextEvent(3X) XNextEvent(3X)
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
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XNextEvent(3X) XNextEvent(3X)
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
XIfEvent(3X11), XPutBackEvent(3X11), XSendEvent(3X11)
Xlib Programming Manual
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