XtAddEventHandler(3XX)Version 11 (Release 6XtAddEventHandler(3Xt)
NAME
XtAddEventHandler, XtAddRawEventHandler,
XtRemoveEventHandler, XtRemoveRawEventHandler,
XtInsertEventHandler, XtInsertRawEventHandler - add and
remove event handlers
SYNTAX
void XtAddEventHandler(w, event_mask, nonmaskable, proc,
client_data)
Widget w;
EventMask event_mask;
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
void XtAddRawEventHandler(w, event_mask, nonmaskable, proc,
client_data)
Widget w;
EventMask event_mask;
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
void XtRemoveEventHandler(w, event_mask, nonmaskable, proc,
client_data)
Widget w;
EventMask event_mask;
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
void XtRemoveRawEventHandler(w, event_mask, nonmaskable,
proc, client_data)
Widget w;
EventMask event_mask;
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
void XtInsertEventHandler(w, event_mask, nonmaskable, proc,
client_data, position)
Widget w;
EventMask event_mask;
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
XtListPosition position;
void XtInsertRawEventHandler(w, event_mask, nonmaskable,
proc, client_data, position)
Widget w;
EventMask event_mask;
Page 1 (printed 7/20/06)
XtAddEventHandler(3XX)Version 11 (Release 6XtAddEventHandler(3Xt)
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
XtListPosition position;
typedef enum { XtListHead, XtListTail } XtListPosition;
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.
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.
Page 2 (printed 7/20/06)
XtAddEventHandler(3XX)Version 11 (Release 6XtAddEventHandler(3Xt)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.
SEE ALSO
XtAppNextEvent(3Xt), XtBuildEventMask(3Xt)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
Page 3 (printed 7/20/06)
