CHAPTER 10
886
Document Interchange
The first form is used to identify a generic artifact; the second is used for those
that have an associated property list. Table 10.17 shows the properties that can be
included in such a property list.
Note:
To aid in text reflow, it is recommended that artifacts be defined with proper-
ty lists whenever possible. Artifacts lacking a specified bounding box are likely to be
discarded during reflow.
TABLE 10.17 Property list entries for artifacts
KEY
TYPE
VALUE
Type
name
rectangle
(Optional)
The type of artifact that this property list describes; if present, must
be one of the names
Pagination
,
Layout
,
Page
, or (PDF
1.7)
Background
.
(Optional; required for background artifacts)
An array of four numbers in default
user space units giving the coordinates of the left, bottom, right, and top edges,
respectively, of the artifact’s bounding box (the rectangle that completely enclos-
es its visible extent).
(Optional; pagination and full-page background artifacts only)
An array of name
objects containing one to four of the names
Top
,
Bottom
,
Left
, and
Right
, specify-
ing the edges of the page, if any, to which the artifact is logically attached. Page
edges are defined by the page’s crop box (see Section 10.10.1, “Page Bound-
Left
and
Right
or both
Top
and
Bottom
indicates a full-width or full-height arti-
fact, respectively.
Use of this entry for background artifacts is limited to full-page artifacts. Back-
ground artifacts that are not full-page take their dimensions from their parent
structural element. An example of such a background artifact is a colored back-
ground for a sidebar.
BBox
Attached
array
Subtype
name
(Optional;
PDF 1.7)
The subtype of the artifact. This entry applies only when the
Type
entry has a value of
Pagination
. Valid values are
Header
,
Footer
, and
Watermark
. Additional values can be defined for this entry, provided they com-
ply with the naming conventions described in Appendix E.
The following types of artifacts can be specified by the
Type
entry:
•
Pagination artifacts.
Ancillary page features such as running heads and folios
(page numbers).
•
Layout artifacts.
Purely cosmetic typographical or design elements such as
footnote rules or background screens.