.ds Vv 1.2.14
.TH VistaIOSetAttr 3 "24 April 1993" "VistaIO Version \*(Vv"
.SH NAME
VistaIOSetAttr \- set an attribute's value
.SH SYNOPSIS
.nf
.ft B
void VistaIOSetAttr (\fIlist\fP, \fIname\fP, \fIdict\fP, \fIrepn\fP, \fIvalue\fP)
.RS
VistaIOAttrList \fIlist\fP;
VistaIOStringConst \fItype\fP;
VistaIODictEntry *\fIdict\fP;
VistaIORepnKind \fIrepn\fP;
\fItype value\fP;
.RE
.PP
.ft B
void VistaIOSetAttrValue (\fIposn\fP, \fIdict\fP, \fIrepn\fP, \fIvalue\fP)
.RS
VistaIOAttrListPosn \fIposn\fP;
VistaIODictEntry *\fIdict\fP;
VistaIORepnKind \fIrepn\fP;
\fItype value\fP;
.RE
.PP
.fi
where \fItype\fP, according to \fIrepn\fP, is \fBVistaIOBit\fP, \fBVistaIOUByte\fP,
\fBVistaIOSByte\fP, \fBVistaIOShort\fP, \fBVistaIOLong\fP, \fBVistaIOFloat\fP, \fBVistaIODouble\fP,
\fBVistaIOAttrList\fP, \fBVistaIOBoolean\fP, \fBVistaIOBundle\fP, \fBVistaIOList\fP,
\fBVistaIOPointer\fP, \fBVistaIOString\fP, \fBVistaIOEdges\fP, \fBVistaIOImage\fP, etc.
.SH ARGUMENTS
.IP \fIlist\fP 10n
Specifies and returns the attribute list in which an attribute
is to be set.
.IP \fIname\fP
Specifies by name of the attribute to be set.
.IP \fIposn\fP
Specifies by position the attribute to be set.
.IP \fIdict\fP
May specify a dictionary to be used in translating the value supplied
to a keyword that should be stored as the attribute's value, or it may be
.SB NULL\c
.
.IP \fIrepn\fP
Specifies the representation of the new attribute value.
.IP \fIvalue\fP
Specifies the new attribute value.
.SH DESCRIPTION
These routines both set an attribute's value, but they differ in how the 
attribute is identified:
.RS 2n
.IP \(bu 2n
\fBVistaIOSetAttr\fP sets the value of an attribute named \fIname\fP in the 
attribute list \fIlist\fP. If \fIlist\fP does not already contain an 
attribute named \fIname\fP then a new attribute with that name is appended 
to it. Otherwise, only the first attribute named \fIname\fP is located and 
changed.
.IP \(bu
\fBVistaIOSetAttrValue\fP sets the value of the attribute whose position within 
an attribute list is \fIposn\fP.
.RE
.PP
With the \fIdict\fP argument you can provide a dictionary for mapping 
\fIvalue\fP to a keyword that will be stored as the attribute's value (see 
\fBVistaIOdictionary\fP(3)). For example, if you pass an attribute value of 1 
and a dictionary that associates the value 1 with the keyword \fBubyte\fP 
(as the dictionary\fBVistaIORepnDict\fP does), then the string \fBubyte\fP will 
be stored as the attribute's value. Dictionaries may be used to map both 
numeric values and strings to keywords. If you supply a dictionary but 
\fIvalue\fP is not mentioned in that dictionary, then \fIvalue\fP itself 
will be stored with the attribute. 
.PP
If \fIvalue\fP is a number or character string, the routine makes its own
copy of the value as a character string for storing in the attribute. If,
on the other hand, \fIvalue\fP is an attribute list, pointer, image, edge
set, etc., then the routine stores a pointer in the attribute but it does
not make a copy of the object pointed to.
.SH "RETURN VALUES"
As a side effect, these routines modify the attribute list referred to by
\fIlist\fP or \fIposn\fP.
.SH EXAMPLES
The following code fragment sets an image's name:
.PP
.nf
.RS
.B VistaIOImage image;
.PP
.ft B
VistaIOSetAttr (VistaIOImageAttrList (image), VistaIONameAttr, NULL,
.RS
VistaIOStringRepn, "Mona Lisa");
.RE
.RE
.fi
.SH "SEE ALSO"
.na
.nh
.BR VistaIOGetAttr (3),
.BR VistaIOGetAttrValue (3),
.br
.BR VistaIOattribute (3),
.BR VistaIOdictionary (3),

.ad
.hy
.SH AUTHOR
Art Pope <pope@cs.ubc.ca>

Adaption to vistaio: Gert Wollny <gw.fossdev@gmail.com>