Gtvalhk.cst(3X) — DeltaWindows 1.3.3 Release 4 Version 4.3

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

wSpecifies the widget or object that is having its resources queried.

argsSpecifies the argument list that was passed to XtGetValues().

num_argsSpecifies 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 NULLQUARK, 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.