XtIsSubclass() XtIsSubclass()
Name
XtIsSubclass - 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 objectClass or any subclass.
Returns
True if object is of class object_class or any subclass of it; False otherwise.
Description
XtIsSubclass() returns True if the specified object is of the specified class, or is a subclass (any number of classes removed) of it.
Otherwise 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
XtIsSubclass() 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 calling XtIsSubclass() directly for the built-in classes.
See Also
XtCheckSubclass(1), XtClass(1), XtIs*(1), XtSuperclass(1).
Xt - Object Information XtIsSubclass()
