XNextEvent(XS)    X Version 11 (Release 5) 6 January 1993     XNextEvent(XS)


 Name

    XNextEvent - 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.

    eventmask     Specifies the event mask.

    eventreturn   Returns the matched event's associated structure.

    eventreturn   Returns the next event in the queue.

    eventreturn   Returns a copy of the matched event's associated struc-
                   ture.

    eventtype     Specifies the event type to be compared.

    w              Specifies the window whose event you 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, XCheckWin-
    dowEvent returns False, and the output buffer will have been flushed.

    The XMaskEvent function searches the event queue for the events associ-
    ated 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, XCheck-
    TypedWindowEvent 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, XCheckTypedWin-
    dowEvent returns False, and the output buffer will have been flushed.

 See also

    XAnyEvent(XS), XIfEvent(XS), XPutBackEvent(XS), XSendEvent(XS)
    Xlib - C Language X Interface