xtvacreateargslist(3) [x11r4 man page]

XtVaCreateArgsList(3)						   XT FUNCTIONS 					     XtVaCreateArgsList(3)

NAME

       XtVaCreateArgsList - dynamically allocate a varargs list

SYNTAX

       XtVarArgsList XtVaCreateArgsList(XtPointer unused, ...);

ARGUMENTS

       unused	 Must be specified as NULL.

       ...	 Specifies a variable parameter list of resource name and value pairs.

DESCRIPTION

       The XtVaCreateArgsList function allocates memory and copies its arguments into a single list pointer, which may be used with XtVaNest-
       edList.	The end of both lists is identified by a name entry containing NULL. Any entries of type XtVaTypedArg are copied as specified
       without applying conversions. Data passed by reference (including Strings) are not copied, only the pointers themselves; the caller must
       ensure that the data remain valid for the lifetime of the created varargs list. The list should be freed using XtFree when no longer
       needed.

SEE ALSO

       X Toolkit Intrinsics - C Language Interface
       Xlib - C Language X Interface

X Version 11							    libXt 1.0.5 					     XtVaCreateArgsList(3)

XtVaSetValues() 														   XtVaSetValues()

Name
  XtVaSetValues - set resource values for a widget, using varargs argument style.

Synopsis
  void XtVaSetValues(object, ..., NULL)
	   Widget object;

Inputs
  object    Specifies the object whose resources are to be modified; may be of class Object or any subclass thereof.

  ..., NULL A NULL-terminated variable-length list of resource name/value pairs to override any other resource specifications.

Availability
  Release 4 and later.

Description
  XtVaSetValues()  sets  the  resources of object named in the variable-length argument list to the values specified in the same list.	It is
  identical to XtSetValues() except that the args array of resource names and values and the num_args argument of that function are  replaced
  with a NULL-terminated variable-length argument list.

  The "Background" section below explains how to specify resource names and values in a variable-length argument list.	See XtSetValues() for
  more information on setting widget resources.

Usage
  Using variable-length argument lists is usually much more convenient than passing an ArgList which must be declared and initialized.	 Note
  that	the  varargs interface is less efficient than the ArgList interface, because each varargs function converts its argument list into an
  ArgList and calls the corresponding ArgList function.  Unless you are setting or querying resources repeatedly, however, this  overhead  is
  not generally significant.

  Variable-length  argument  lists  cannot be type-checked by the compiler, and so using XtVaSetValues() and other varargs functions can be a
  source of bugs.  Be sure to end all of your argument lists with NULL, and be sure that the type of each argument is as  expected.   If  you
  specify  only  a  single  name/value	pair  per line, it will be easy to delete or comment out resources, and to insert new resources at an
  acceptable place.

Example
  You can use XtVaSetValues() as in the following example:

     XtVaSetValues(w,
		   XtNlabel, "Enter a value:",
		   XtNjustify, XtJustifyRight,
		   XtVaTypedArg, XtNforeground, XtRString, "red", 4,
		   NULL);

Background
  This function and the other XtVa functions have resource names and values specified in a  NULL-terminated  variable-length  argument	list,
  rather  than an ArgList array.  Generally, the argument list to these functions will consist of resource names (of type String) followed by
  resource values (these are of type XtArgVal, but because varargs lists cannot be type-checked, you do not have to cast your values).	There
  are  two  special symbols which can be used in place of a resource name, however.  Each symbol modifies the interpretation of the following
  arguments.

  XtVaNestedList
    If you specify a resource name of XtVaNestedList, the following argument will be interpreted as an XtVarArgsList value,  as  returned  by
    XtVaCreateArgsList().  The resource names and values on this nested list will be treated exactly as if they were specified at the current
    point in the original list.  Nested lists may contain other nested lists, to any depth of nesting.

  XtVaTypedArg
    If you specify a resource name of XtVaTypedArg, then the following four arguments will be interpreted specially as instructions to invoke
    a  resource converter and set a resource to the result of the conversion.  The first following argument is the name of the resource to be
    set, and must be of type String.  The second following argument is also a String, the resource type of the following value.   This	type,
    plus  the  type  of  the named resource identify the resource converter to be invoked.  This argument is usually XtRString, or one of the
    other XtR types predefined by the Intrinsics.  The third following argument is the value to be converted.  It is of the type specified by
    the  previous  argument, usually a String.	If the type is not XtRString, then if the value fits in an XtArgVal, it is passed directly in
    the argument list, otherwise a pointer to the value is passed.  Finally, the forth following argument is the size in bytes of  the	type.
    If the type is XtRString, however, then type should be the length of the string plus one, not sizeof(String).

  The example above show a use of the XtVaTypedArg value.  See XtVaCreateArgsList() for an example of XtVaNestedList.

See Also
  XtSetValues(1), XtVaCreateArgsList(1).

Xt - Resource Management													   XtVaSetValues()