[poppler] Annotation interoperability

[Adam Reichold]

Hello,

This is not exactly Poppler only but more interoperability between
programs using Poppler, specifically Okular and qpdfview. It concerns
the correct usage of the annotation API. Sorry for being vaguely off-topic.

Currently, to add a text annotation, I basically do something like:

Poppler::TextAnnotation* annotation = new
Poppler::TextAnnotation(Poppler::TextAnnotation::Linked);

annotation->setBoundary(boundary);
annotation->setContents(contents);

page->addAnnotation(annotation);

This seems to work fine with qpdfview and Adobe's acroread. But opened
in Okular, it just displays an inert annotation icon with no way of
accessing its contents.

So my two questions are: What is the mandatory contents for a valid text
annotation? (Does it need a popup? Or a window? acroread seems to like
it but then acroread has its own ideas about the PDF standard anyway.)
What does Okular need to make the contents of a text annotation accessible?

Thanks for your help! Best regards, Adam.

P.S.: I tried to have a look at the Okular source code, specifically the
Poppler generator. But I suppose this has something to do with the
assumption on text annotations in the UI part of it. So any hints for
where to search there would be appreciated as well.