XtAddEventHandler(3Xt) XT FUNCTIONS XtAddEventHandler(3Xt)NAME
XtAddEventHandler, XtAddRawEventHandler, XtRemoveEvent-
Handler, 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;
Boolean nonmaskable;
XtEventHandler proc;
XtPointer client_data;
X Version 11 Release 6.4 1
XtAddEventHandler(3Xt) XT FUNCTIONS XtAddEventHandler(3Xt)
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 han-
dler is being registered.
position Specifies when the event handler is to be called
relative to other previously registered han-
dlers.
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 XtAdd-
EventHandler 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
X Version 11 Release 6.4 2
XtAddEventHandler(3Xt) XT FUNCTIONS XtAddEventHandler(3Xt)
XtListHead, the event handler is registered to that it
will be called before any event handlers that were previ-
ously 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 exist-
ing mask and the procedure is repositioned in the list.
SEE ALSOXtAppNextEvent(3Xt), XtBuildEventMask(3Xt)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
X Version 11 Release 6.4 3