XtClass(3Xt)

NAME
XtClass, XtSuperClass, XtIsSubclass, XtCheckSubclass, XtIsComposite, XtIsManaged - obtain and verify a widget's class

SYNTAX
WidgetClass XtClass(w)
      Widget w;

WidgetClass XtSuperclass(w)
      Widget w;

Boolean XtIsSubclass(w, widget_class)
      Widget w;
      WidgetClass widget_class;

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

Boolean XtIsComposite(w)
      Widget w;

Boolean XtIsManaged(w)
       Widget w;

ARGUMENTS

w   Specifies the widget.

widget_class
    Specifies the widget class.

message
    Specifies the message that is to be used.

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

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

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

The 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 specified widget is not a subclass, constructs an error message from the supplied message, the widget's actual class, and the expected class and calls 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.

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.

The function is a convenience function that is equivalent to with specified.

The macro (for widget programmers) or function (for application programmers) returns if the specified child widget is managed or if it is not.

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