hpux man page for xtinserteventhandler

XtInsertEventHandler()													    XtInsertEventHandler()

Name
  XtInsertEventHandler - register an event handler procedure that receives events before or after all previously registered event handlers.

Synopsis
void XtInsertEventHandler(w, event_mask, nonmaskable, proc, client_data, position)
	 Widget w;
	 EventMask event_mask;
	 Boolean nonmaskable;
	 XtEventHandler proc;
	 XtPointer client_data;
	 XtListPosition position;

Inputs
  w	    Specifies the widget for which this event handler is being registered.  Must be of class core or any subclass thereof.

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

  nonmaskable
	    Specifies whether this procedure should be called on nonmaskable events

  proc	    Specifies the procedure that is to be called.

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

  position  Specifies when the event handler is to be called relative to other previously registered handlers.

Availability
  Release 4 and later.

Description
  XtInsertEventHandler()  registers  the  procedure  proc  and the data client_data with the Intrinsics event dispatching mechanism.  When an
  event of one of the types set in event_mask occurs on the window of the widget w, proc will be invoked and client_data passed as one of its
  arguments.

  The argument position specifies where in the list of event handlers proc should be inserted.	If it is XtListHead, proc will be inserted at
  the beginning of the list and will be called before all previously registered handlers.  If it is XtListTail, proc will be inserted at  the
  end of the list and will be called after all previously registered handlers.

  If the procedure is already registered with the same client_data, the specified event_mask augments the existing mask, and the procedure is
  repositioned in the list according to position.

  XtInsertEventHandler() is identical to XtAddEventHandler() with the additional position argument.  See XtAddEventHandler() for more  infor-
  mation.

  See XtEventHandler(2) for an explanation of how to write an event handler procedure.

Usage
  Neither applications nor widgets often need to use event handlers.  Using action procedures and translation tables provides a more flexible
  way to respond to input events.

Structures
  The XtListPosition type is as follows.

     typedef enum {
	 XtListHead,
	 XtListTail
     } XtListPosition;

  See XtAddEventHandler() for a list of bits that can be set in the event_mask argument.

See Also
  XtAddEventHandler(1), XtAddRawEventHandler(1), XtInsertRawEventHandler(1), XtRemoveEventHandler(1), XtRemoveRawEventHandler(1).

Xt - Event Handling													    XtInsertEventHandler()