1XtClass(3x) XT FUNCTIONS XtClass(3x)
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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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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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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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57 The XtClass function returns a pointer to the widget's class structure.
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59 The XtSuperclass function returns a pointer to the widget's superclass
60 class structure.
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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.
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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.
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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.
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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.
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91 The
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94 XtAppErrorMsg(3Xt), XtDisplay(3Xt)
95 X Toolkit Intrinsics - C Language Interface
96 Xlib - C Language X Interface
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100X Version 11 libXt 1.0.4 XtClass(3x)