XtAddEventHandler(3) XT FUNCTIONS XtAddEventHandler(3)
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 InterfaceX Version 11 libXt 1.1.5 XtAddEventHandler(3)
