NAME
XtAddEventHandler, XtAddRawEventHandler, XtRemoveEventHandler,
XtRemoveRawEventHandler, XtInsertEventHandler, XtInsertRawEventHandler - add
and remove event handlers
SYNTAX
void
XtAddEventHandler(Widget w, EventMask event_mask, Boolean
nonmaskable, XtEventHandler proc, XtPointer
client_data);
void
XtAddRawEventHandler(Widget w, EventMask event_mask, Boolean
nonmaskable, XtEventHandler proc, XtPointer
client_data);
void
XtRemoveEventHandler(Widget w, EventMask event_mask, Boolean
nonmaskable, XtEventHandler proc, XtPointer
client_data);
void
XtRemoveRawEventHandler(Widget w, EventMask event_mask, Boolean
nonmaskable, XtEventHandler proc, XtPointer
client_data);
void
XtInsertEventHandler(Widget w, EventMask event_mask, Boolean
nonmaskable, XtEventHandler proc, XtPointer client_data,
XtListPosition position);
void
XtInsertRawEventHandler(Widget w, EventMask event_mask, 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.
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(3), XtBuildEventMask(3)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface