SECTION 8.6
695
Interactive Forms
The
Opt
array specifies the list of options in the choice field, each of which is rep-
resented by a text string to be displayed on the screen. Each element of the
Opt
array contains either this text string by itself or a two-element array, whose sec-
ond element is the text string and whose first element is a text string representing
the export value to be used when exporting interactive form field data from the
document.
The field dictionary’s
V
(value) entry (see Table 8.69 on page 675) identifies the
item or items currently selected in the choice field. If the field does not allow mul-
tiple selection—that is, if the MultiSelect flag
(PDF 1.4)
is not set—or if multiple
selection is supported but only one item is currently selected,
V
is a text string
representing the name of the selected item, as given in the field dictionary’s
Opt
array. If multiple items are selected,
V
is an array of such strings. (For items repre-
sented in the
Opt
array by a two-element array, the name string is the second of
the two array elements.) The default value of
V
is
null
, indicating that no item is
currently selected.
Example 8.19
<< /FT /Ch
/Ff …
/T ( Body Color )
/V ( Blue )
/Opt [ ( Red )
( My favorite color )
( Blue )
]
>>
Signature Fields
A
signature field (PDF 1.3)
is a form field that contains a digital signature (see
field may contain the additional entries listed in Table 8.81, as well as the stan-
dard entries described in Table 8.69. The field type (
FT
) is
Sig
, and the field value
(
V
) is a
signature dictionary
containing the signature and specifying various at-
tributes of the signature field (see Table 8.102).