XtAddGrab(3Xt) X11R5 XtAddGrab(3Xt)NAME
XtAddGrab, XtRemoveGrab - redirect user input to a modal widget
SYNTAX
void XtAddGrab(w, exclusive, spring_loaded)
Widget w;
Boolean exclusive;
Boolean spring_loaded;
void XtRemoveGrab(w)
Widget w;
ARGUMENTS
exclusive Specifies whether user events should be dispatched exclu‐
sively to this widget or also to previous widgets in the cas‐
cade.
spring_loaded
Specifies whether this widget was popped up because the user
pressed a pointer button.
w Specifies the widget to add to or remove from the modal cas‐
cade.
DESCRIPTION
The function appends the widget (and associated parameters) to the
modal cascade and checks that exclusive is if spring_loaded is If these
are not generates an error.
The modal cascade is used by when it tries to dispatch a user event.
When at least one modal widget is in the widget cascade, first deter‐
mines if the event should be delivered. It starts at the most recent
cascade entry and follows the cascade up to and including the most
recent cascade entry added with the exclusive parameter
This subset of the modal cascade along with all descendants of these
widgets comprise the active subset. User events that occur outside the
widgets in this subset are ignored or remapped. Modal menus with sub‐
menus generally add a submenu widget to the cascade with exclusive
Modal dialog boxes that need to restrict user input to the most deeply
nested dialog box add a subdialog widget to the cascade with exclusive
User events that occur within the active subset are delivered to the
appropriate widget, which is usually a child or further descendant of
the modal widget.
Regardless of where on the screen they occur, remap events are always
delivered to the most recent widget in the active subset of the cascade
that has spring_loaded if any such widget exists.
The function removes widgets from the modal cascade starting at the
most recent widget up to and including the specified widget. It issues
an error if the specified widget is not on the modal cascade.
SEE ALSO
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface
XtAddGrab(3Xt)