XtAddEventHandler(3Xt)               BSD                XtAddEventHandler(3Xt)



NAME
     XtAddEventHandler, XtAddRawEventHandler, XtRemoveEventHandler
     XtRemoveRawEventHandler - add and remove event handlers

SYNTAX
     void XtAddEventHandler(w, event_mask, nonmaskable, proc, client_data)
           Widget w;
           EventMask event_mask;
           Boolean nonmaskable;
           XtEventHandler proc;
           caddr_t client_data;

     void XtAddRawEventHandler(w, event_mask, nonmaskable, proc, client_data)
           Widget w;
           EventMask event_mask;
           Boolean nonmaskable;
           XtEventHandler proc;
           caddr_t client_data;

     void XtRemoveEventHandler(w, event_mask, nonmaskable, proc, client_data)
           Widget w;
           EventMask event_mask;
           Boolean nonmaskable;
           XtEventHandler proc;
           caddr_t client_data;

     void XtRemoveRawEventHandler(w, event_mask, nonmaskable, proc,
     client_data)
           Widget w;
           EventMask event_mask;
           Boolean nonmaskable;
           XtEventHandler proc;
           caddr_t client_data;

ARGUMENTS
     client_data
               Specifies additional data to be passed to the client's event
               handler.

     event_mask
               Specifies the event mask for which to call or unregister this
               procedure.

     nonmaskable
               Specifies a Boolean value that indicates whether this procedure
               should be called or removed on the nonmaskable events
               (GraphicsExpose, NoExpose, SelectionClear, SelectionRequest,
               SelectionNotify, ClientMessage, and MappingNotify).

     proc      Specifies the procedure that is to be added or removed.

     w         Specifies the widget for which this event handler is being
               registered.

DESCRIPTION
     The XtAddEventHandler function registers a procedure with the dispatch
     mechanism that is to be called when an event that matches the mask occurs
     on the specified widget.  If the procedure is already registered with the
     same client_data, the specified mask is ORed into the existing mask.  If
     the widget is realized, XtAddEventHandler calls XSelectInput, if
     necessary.

     The XtAddRawEventHandler function is similar to XtAddEventHandler except
     that it does not affect the widget's mask and never causes an
     XSelectInput for its events.  Note that the widget might already have
     those mask bits set because of other nonraw event handlers registered on
     it.

     The XtAddRawEventHandler function is similar to XtAddEventHandler except
     that it does not affect the widget's mask and never causes an
     XSelectInput for its events.  Note that the widget might already have
     those mask bits set because of other nonraw event handlers registered on
     it.

     The XtRemoveRawEventHandler function stops the specified procedure from
     receiving the specified events.  Because the procedure is a raw event
     handler, this does not affect the widget's mask and never causes a call
     on XSelectInput.

SEE ALSO
     XtAppNextEvent(3Xt), XtBuildEventMask(3Xt)
     X Toolkit Intrinsics - C Language Interface
     Xlib - C Language X Interface