XtOffset (3)

Leading comments

Copyright (c) 1993, 1994  X Consortium

Permission is hereby granted, free of charge, to any person obtaining a
copy of this software and associated documentation files (the "Software"),
to deal in the Software without restriction, including without limitation
the rights to use, copy, modify, merge, publish, distribute, sublicense,
and/or sell copies of the Software, and to permit persons to whom the
Software furnished to do so, subject to the following conditions:

The above copyright notice...

(The comments found at the beginning of the groff file "man3/XtOffset.3".)

NAME

XtOffset, XtOffsetOf, XtNumber - determine the byte offset or number of array elements

SYNTAX

Cardinal XtOffset(Type pointer_type, Field field_name);

Cardinal XtOffsetOf(Type structure_type, Field field_name);

Cardinal XtNumber(ArrayVariable array);

ARGUMENTS

array

Specifies a fixed-size array.

field_name

Specifies the name of the field for which to calculate the byte offset.

pointer_type

Specifies a type that is declared as a pointer to the structure.

structure_type

Specifies a type that is declared as a structure.

DESCRIPTION

The XtOffset macro is usually used to determine the offset of various resource fields from the beginning of a widget and can be used at compile time in static initializations.

The XtOffsetOf macro expands to a constant expression that gives the offset in bytes to the specified structure member from the beginning of the structure. It is normally used to statically initialize resource lists and is more portable than XtOffset, which serves the same function.

The XtNumber macro returns the number of elements in the specified argument lists, resources lists, and other counted arrays.

SEE ALSO

XtGetResourceList(3), XtSetArg(3)
X Toolkit Intrinsics - C Language Interface
Xlib - C Language X Interface