Constraint get_values_hook() Constraint get_values_hook()
Name
Constraint get_values_hook - Constraint class method for obtaining values of constraint resources that do not appear in the Constraint
resource list.
Synopsis
typedef void (*XtArgsProc)(Widget, ArgList, Cardinal *);
Widget w;
ArgList args;
Cardinal *num_args;
Inputs
w Specifies the widget or object that is having its resources queried.
args Specifies the argument list that was passed to XtGetValues().
num_args Specifies the number of arguments in the argument list.
Availability
Release 4 and later.
Description
The Constraint get_values_hook() method is registered on the get_values_hook field of a ConstraintClassExtensionRec with record_type NUL-
LQUARK, which is itself registered on the extension field of the Constraint class part structure. If such an extension exists, then this
method is called when XtGetValues() is called for a child of the constraint widget, and gives the constraint widget the opportunity to set
values for resources that do not appear in the Constraint resource list, or to modify any of the resource values that are to be returned.
The Constraint get_values_hook() method is chained in superclass-to-subclass order, and cannot be inherited. Classes that do not need a
get_value_hook() method can set NULL in the Constraint extension record, or can simply omit the extension record.
See XtGetValues(1) for more information on when this method is invoked.
Usage
The usage of this method is similar to the normal get_values_hook() method: the widget can use XtGetSubvalues() or XtGetValues() to obtain
the values of constraint resources that do not appear on its Constraint resource list, so that it can export them as if they did appear on
that list. This method can also be used to modify the returned values in any way, by making a copy of string resource values, for example.
See get_values_hook(4) for more information.
None of the Intrinsics widgets nor any of the Xaw widgets define a Constraint get_values_hook() method.
See Also
XtGetSubvalues(1), XtGetValues(1),
Core(3),
get_values_hook(4).
Xt - Intrinsics Methods Constraint get_values_hook()
