XtIsComposite(3)

1XtClass(3)                       XT FUNCTIONS                       XtClass(3)
2
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
11

SYNTAX

13       #include <X11/Intrinsic.h>
14
15       WidgetClass XtClass(Widget w);
16
17       WidgetClass XtSuperclass(Widget w);
18
19       Boolean XtIsSubclass(Widget w, WidgetClass widget_class);
20
21       void XtCheckSubclass(Widget widget, WidgetClass widget_class, String
22              message);
23
24       Boolean XtIsObject(Widget w);
25
26       Boolean XtIsRectObj(Widget w);
27
28       Boolean XtIsWidget(Widget w);
29
30       Boolean XtIsComposite(Widget w);
31
32       Boolean XtIsConstraint(Widget w);
33
34       Boolean XtIsShell(Widget w);
35
36       Boolean XtIsOverrideShell(Widget w);
37
38       Boolean XtIsWMShell(Widget w);
39
40       Boolean XtIsVendorShell(Widget w);
41
42       Boolean XtIsTransientShell(Widget w);
43
44       Boolean XtIsTopLevelShell(Widget w);
45
46       Boolean XtIsApplicationShell(Widget w);
47
48       Boolean XtIsSessionShell(Widget w);
49

ARGUMENTS

51       w         Specifies the widget.
52
53       widget_class
54                 Specifies the widget class.
55
56       message   Specifies the message that is to be used.
57

DESCRIPTION

59       The XtClass function returns a pointer to the widget's class structure.
60
61       The XtSuperclass function returns a pointer to the widget's superclass
62       class structure.
63
64       The XtIsSubclass function returns True if the class of the specified
65       widget is equal to or is a subclass of the specified class.  The wid‐
66       get's class can be any number of subclasses down the chain and need not
67       be an immediate subclass of the specified class.  Composite widgets
68       that need to restrict the class of the items they contain can use XtIs‐
69       Subclass to find out if a widget belongs to the desired class of ob‐
70       jects.
71
72       The XtCheckSubclass macro determines if the class of the specified wid‐
73       get is equal to or is a subclass of the specified widget class.  The
74       widget can be any number of subclasses down the chain and need not be
75       an immediate subclass of the specified widget class.  If the specified
76       widget is not a subclass, XtCheckSubclass constructs an error message
77       from the supplied message, the widget's actual class, and the expected
78       class and calls XtErrorMsg.  XtCheckSubclass should be used at the en‐
79       try point of exported routines to ensure that the client has passed in
80       a valid widget class for the exported operation.
81
82       XtCheckSubclass is only executed when the widget has been compiled with
83       the compiler symbol DEBUG defined; otherwise, it is defined as the
84       empty string and generates no code.
85
86       To test if a given widget belongs to a subclass of an Intrinsics-de‐
87       fined class, the Intrinsics defines macros or functions equivalent to
88       XtIsSubclass for each of the built-in classes.  These procedures are
89       XtIsObject, XtIsRectObj, XtIsWidget, XtIsComposite, XtIsConstraint,
90       XtIsShell, XtIsOverrideShell, XtIsWMShell, XtIsVendorShell, XtIs‐
91       TransientShell, XtIsTopLevelShell, XtIsApplicationShell, and XtIsSes‐
92       sionShell.
93
94       The
95

NAME

SYNTAX

ARGUMENTS

DESCRIPTION

SEE ALSO