CHAPTER 4
378
Graphics
KEY
TYPE
VALUE
RBGroups
array
(Optional)
An array consisting of one or more arrays, each of which repre-
sents a collection of optional content groups whose states are intended to fol-
low a radio button paradigm. That is, the state of at most one optional
content group in each array should be
ON
at a time. If one group is turned
ON
, all others must be turned
OFF
. However, turning a group from
ON
to
OFF
does not force any other group to be turned
ON
.
An empty array
[]
explicitly indicates that no such collections exist.
In the default configuration dictionary, the default value is an empty array;
in other configuration dictionaries, the default is the
RBGroups
value from
the default configuration dictionary.
Locked
array
(Optional; PDF 1.6)
An array of optional content groups that should be
locked when this configuration is applied. The state of a locked group cannot
be changed through the user interface of a viewer application. Producers can
use this entry to prevent the visibility of content that depends on these
groups from being changed by users.
Default value: an empty array.
Note:
This entry does not prevent the states of optional content groups from be-
ing changed by means other than the user interface, such as JavaScript or items
in the
AS
entry of a configuration dictionary.
Examples 4.37 and 4.38 illustrates the use of the
Order
entry to control the display
of groups in a user interface.
Example 4.37
Given the following PDF objects:
1 0 obj <</Type /OCG /Name (Skin)>> endobj
2 0 obj <</Type /OCG /Name (Bones)>> endobj
3 0 obj <</Type /OCG /Name (Bark)>> endobj
4 0 obj <</Type /OCG /Name (Wood)>> endobj
% Optional content groups
5 0 obj
% Configuration dictionary
<< /Order [[(Frog Anatomy) 1 0 R 2 0 R] [(Tree Anatomy) 3 0 R 4 0 R] ] >>