xtissubclass(3x) [hpux man page]

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()

XtClass(3)							   XT FUNCTIONS 							XtClass(3)

NAME

       XtClass, XtSuperclass, XtIsSubclass, XtCheckSubclass, XtIsObject, XtIsRectObj, XtIsWidget, XtIsComposite, XtIsConstraint, XtIsShell, XtIs-
       OverrideShell, XtIsWMShell, XtIsVendorShell, XtIsTransientShell, XtIsTopLevelShell, XtIsApplicationShell, XtIsSessionShell - obtain and
       verify a widget's class

SYNTAX

       WidgetClass XtClass(Widget w);

       WidgetClass XtSuperclass(Widget w);

       Boolean XtIsSubclass(Widget w, WidgetClass widget_class);

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

       Boolean XtIsObject(Widget w);

       Boolean XtIsRectObj(Widget w);

       Boolean XtIsWidget(Widget w);

       Boolean XtIsComposite(Widget w);

       Boolean XtIsConstraint(Widget w,

       Boolean XtIsShell(Widget w);

       Boolean XtIsOverrideShell(Widget w);

       Boolean XtIsWMShell(Widget w);

       Boolean XtIsVendorShell(Widget w);

       Boolean XtIsTransientShell(Widget w);

       Boolean XtIsTopLevelShell(Widget w);

       Boolean XtIsApplicationShell(Widget w);

       Boolean XtIsSessionShell(Widget w);

ARGUMENTS

       w	 Specifies the widget.

       widget_class
		 Specifies the widget class.

       message	 Specifies the message that is to be used.

DESCRIPTION

       The XtClass function returns a pointer to the widget's class structure.

       The XtSuperclass function returns a pointer to the widget's superclass class structure.

       The XtIsSubclass function returns True if the class of the specified widget is equal to or is a subclass of the specified class. The wid-
       get's class can be any number of subclasses down the chain and need not be an immediate subclass of the specified class. Composite widgets
       that need to restrict the class of the items they contain can use XtIsSubclass to find out if a widget belongs to the desired class of
       objects.

       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.

       To test if a given widget belongs to a subclass of an Intrinsics-defined class, the Intrinsics defines macros or functions equivalent to
       XtIsSubclass for each of the built-in classes. These procedures are XtIsObject, XtIsRectObj, XtIsWidget, XtIsComposite, XtIsConstraint,
       XtIsShell, XtIsOverrideShell, XtIsWMShell, XtIsVendorShell, XtIsTransientShell, XtIsTopLevelShell, XtIsApplicationShell, and XtIsSession-
       Shell.

       The

SEE ALSO

       XtAppErrorMsg(3), XtDisplay(3)
       X Toolkit Intrinsics - C Language Interface
       Xlib - C Language X Interface

X Version 11							    libXt 1.1.3 							XtClass(3)