XtIsSubclass()XtIsSubclass()NameXtIsSubclass - determine whether a widget is a subclass of a class.
Synopsis
Boolean XtIsSubclass(object, object_class)
Widget object;
WidgetClass object_class;
Inputs
object Specifies the object instance whose class is to be checked;
may be of class Object or any subclass thereof.
object_class
Specifies the widget class to test against; may be object‐
Class or any subclass.
Returns
True if object is of class object_class or any subclass of it; False
otherwise.
DescriptionXtIsSubclass() returns True if the specified object is of the specified
class, or is a subclass (any number of classes removed) of it. Other‐
wise it returns False.
Usage
Composite widgets that restrict the type of widgets they will accept as
children can use XtIsSubclass() to find out whether a widget belongs to
the desired widget class.
Public routines that require a widget of a particular class can use
XtIsSubclass() to verify that the object they are passed is of the cor‐
rect type. XtCheckSubclass() does the same thing, but is a macro that
is only compiled when the symbol DEBUG is defined by the compiler.
To test whether a given widget is a subclass of an Intrinsics-defined
class, the Intrinsics define convenience functions equivalent to XtIs‐
Subclass() for each of the built-in classes. These functions are shown
in the table below:
XtIsObject()XtIsOverrideShell()XtIsRectObj()XtIsWMShell()XtIsWidget()XtIsVendorShell()XtIsComposite()XtIsTransientShell()XtIsConstraint()XtIsTopLevelShell()XtIsShell()XtIsApplicationShell()
These functions may be defined as macros, and may be faster than call‐
ing XtIsSubclass() directly for the built-in classes.
See AlsoXtCheckSubclass(1), XtClass(1), XtIs*(1), XtSuperclass(1).
Xt - Object Information XtIsSubclass()
