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.
position
Specifies when the event handler is to be called relative to other
previously registered handlers.
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
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.
XtInsertEventHandler
is identical to
XtAddEventHandler
with the additional position argument. if position is
XtListHead,
the event handler is registered to that it will be called before
any event handlers that were previously registered for the same widget.
If position is
XtListTail,
the event handler is registered to be called after any previously
registered event handlers. If the procedure is already registered with
the same client_data value, the specified mask augments the
existing mask and the procedure is repositioned in the list.
XtInsertRawEventHandler
is similar to
XtInsertEventHandler
except that it does not modify the widget's event mask and never causes an
XSelectInput
for the specified events. If the procedure is already registered with the
same client_data value, the specified mask augments the existing
mask and the procedure is repositioned in the list.