XtIsSubclass(3)

1XtClass(3)                       XT FUNCTIONS                       XtClass(3)
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3
4

NAME

6       XtClass, XtSuperclass, XtIsSubclass, XtCheckSubclass, XtIsObject, XtIs‐
7       RectObj, XtIsWidget, XtIsComposite, XtIsConstraint, XtIsShell, XtIs‐
8       OverrideShell, XtIsWMShell, XtIsVendorShell, XtIsTransientShell, XtIs‐
9       TopLevelShell, XtIsApplicationShell, XtIsSessionShell - obtain and ver‐
10       ify a widget's class
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SYNTAX

13       WidgetClass XtClass(Widget w);
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15       WidgetClass XtSuperclass(Widget w);
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17       Boolean XtIsSubclass(Widget w, WidgetClass widget_class);
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19       void XtCheckSubclass(Widget widget, WidgetClass widget_class, String
20              message);
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22       Boolean XtIsObject(Widget w);
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24       Boolean XtIsRectObj(Widget w);
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26       Boolean XtIsWidget(Widget w);
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28       Boolean XtIsComposite(Widget w);
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30       Boolean XtIsConstraint(Widget w,
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32       Boolean XtIsShell(Widget w);
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34       Boolean XtIsOverrideShell(Widget w);
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36       Boolean XtIsWMShell(Widget w);
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38       Boolean XtIsVendorShell(Widget w);
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40       Boolean XtIsTransientShell(Widget w);
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42       Boolean XtIsTopLevelShell(Widget w);
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44       Boolean XtIsApplicationShell(Widget w);
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46       Boolean XtIsSessionShell(Widget w);
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ARGUMENTS

49       w         Specifies the widget.
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51       widget_class
52                 Specifies the widget class.
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54       message   Specifies the message that is to be used.
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DESCRIPTION

57       The XtClass function returns a pointer to the widget's class structure.
58
59       The XtSuperclass function returns a pointer to the widget's superclass
60       class structure.
61
62       The XtIsSubclass function returns True if the class of the specified
63       widget is equal to or is a subclass of the specified class. The wid‐
64       get's class can be any number of subclasses down the chain and need not
65       be an immediate subclass of the specified class. Composite widgets that
66       need to restrict the class of the items they contain can use XtIsSub‐
67       class to find out if a widget belongs to the desired class of objects.
68
69       The XtCheckSubclass macro determines if the class of the specified wid‐
70       get is equal to or is a subclass of the specified widget class.  The
71       widget can be any number of subclasses down the chain and need not be
72       an immediate subclass of the specified widget class.  If the specified
73       widget is not a subclass, XtCheckSubclass constructs an error message
74       from the supplied message, the widget's actual class, and the expected
75       class and calls XtErrorMsg.  XtCheckSubclass should be used at the
76       entry point of exported routines to ensure that the client has passed
77       in a valid widget class for the exported operation.
78
79       XtCheckSubclass is only executed when the widget has been compiled with
80       the compiler symbol DEBUG defined; otherwise, it is defined as the
81       empty string and generates no code.
82
83       To test if a given widget belongs to a subclass of an Intrinsics-
84       defined class, the Intrinsics defines macros or functions equivalent to
85       XtIsSubclass for each of the built-in classes. These procedures are
86       XtIsObject, XtIsRectObj, XtIsWidget, XtIsComposite, XtIsConstraint,
87       XtIsShell, XtIsOverrideShell, XtIsWMShell, XtIsVendorShell, XtIs‐
88       TransientShell, XtIsTopLevelShell, XtIsApplicationShell, and XtIsSes‐
89       sionShell.
90
91       The
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NAME

SYNTAX

ARGUMENTS

DESCRIPTION

SEE ALSO