XtCheckSubclass(3X)						   XT FUNCTIONS 					       XtCheckSubclass(3X)

NAME

       XtCheckSubclass - obtain and verify a widget's class

SYNTAX

       void XtCheckSubclass(w, widget_class, message)
	     Widget w;
	     WidgetClass widget_class;
	     String message;

ARGUMENTS

       w	 Specifies the widget.

       widget_class
		 Specifies the widget class.

       message	 Specifies the message that is to be used.

DESCRIPTION

       The XtCheckSubclass macro determines if the class of the specified widget is equal to or is a subclass of the specified widget class.  The
       widget can be any number of subclasses down the chain and need not be an immediate subclass of the specified widget class.  If the speci-
       fied widget is not a subclass, XtCheckSubclass constructs an error message from the supplied message, the widget's actual class, and the
       expected class and calls XtErrorMsg.  XtCheckSubclass should be used at the entry point of exported routines to ensure that the client has
       passed in a valid widget class for the exported operation.

       XtCheckSubclass is only executed when the widget has been compiled with the compiler symbol DEBUG defined; otherwise, it is defined as the
       empty string and generates no code.

SEE ALSO

       XtClass(3X), XtSuperclass(3X), XtIsSubclass(3X), XtIsObject(3X), XtIsRectObj(3X), XtIsWidget(3X), XtIsComposite(3X), XtIsConstraint(3X),
       XtIsShell(3X), XtIsOverrideShell(3X), XtIsWMShell(3X), XtIsVendorShell(3X), XtIsTransientShell(3X), XtIsTopLevelShell(3X), XtIsApplication-
       Shell(3X), XtIsSessionShell(3X)

X Version 11							     Release 6						       XtCheckSubclass(3X)