pdf-association
Add document level & page level annotations
Currently all annotations are tied to a specific bounding area of a specific page - this precludes the ability to have an annotation that is connected to a page w/o a specific area of the page, or the entire document.
Recommend that we extend the existing annotation data structures (and potentially processor requirements) to provide for this.
Another possible thing is "shared annotations", where it's visible from two or more pages but maybe with different offsets from page origin.
What is the use case, @crlf0710?
On Fri, May 23, 2025 at 10:59 PM Charles Lew @.***> wrote:
crlf0710 left a comment (pdf-association/pdf-issues#547) https://github.com/pdf-association/pdf-issues/issues/547#issuecomment-2906330667
Another possible thing is "shared annotations", where it's visible from two or more pages but maybe with different offsets from page origin.
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Another possible thing is "shared annotations", where it's visible from two or more pages but maybe with different offsets from page origin.
That an annotation may be referenced from only one page is an important property some PDF processors both rely upon, and strive to maintain (for example, when duplicating pages). It should be possible, and would be best, to implement this feature request without breaking that property.
What is the use case, @crlf0710? …
I had the "paging seals" example on my mind when i mentioned this, but this might not appear motivative enough.
Just thinking if an annotation is not tied to any page but to the document level, i think it (and its appearance) might be considered shared between all pages (the whole page tree) of the document.
It should be possible, and would be best, to implement this feature request without breaking that property.
Yes, for instance just assigning the shared annotation an "owning page" and make other pages the "observing pages" will make things backward compatible.
If some entity has visualizations on multiple pages, one could model that in a way similar to how it's done for form fields where you have form field objects which references a collection of widget annotations, the individual visualization annotations of the form field.
In my thinking, these new types of annotations do not have any appearances - because they don't exist in coordinate space.
Just out of curiosity, if they don't have any appearances, what's the difference between them and, say, DocPart or XMP Metadata?