Ah, I see. Essentially, you're stuck in the case where the IF is loaded
from XML in which case the user agent hasn't received the structure tree,
yet. So, to visualize this:

Direct Rendering:
- Reduced FO tree is built using XSLT and set on the user agent
- DocumentHandler.startPageSequence is called (structure tree is

IF Case:
- IFParser encounters starting page-sequence tag and calls
DocumentHandler.startPageSequence but the FO tree is inside the
page-sequence tag and therefore not available at this point.

IFParser is also still missing the parse code for the structure tree. I
guess I would defer the call to startPageSequence in the IFParser, then
parse the reduced FO tree using a ContentHandler delegate, set that on
the user agent and then call startPageSequence when the first page tag
is encountered. I wouldn't do the deferring in the document handler as
the problem only happens in the IF case.


On 24.09.2009 13:07:11 Vincent Hennebert wrote:
> Jeremias Maerki wrote:
> > Not just like that (if at all). The content items being produced inside
> > the page-sequence have to be linked into the structure tree. There are
> > links (MCIDs) back and forth between the structure tree and the content
> > streams. You have to have the structure tree available while you create
> > the page contents to build up the links. You could probably move the
> > generation to endPageSequence but you'd end up duplicating some of the
> > data structures for establishing the links in the process which you'd
> > then have to map to the PDF library in the end. Not sure if that's what
> > you want. I don't have this stuff present as much as back when I helped
> > Jost, so I may be missing something.
> Ok, then there’s the following problem: when creating the PDF document
> out of an IF XML file, the structure tree is not yet available at the
> time PDFDocumentHandler.startPageSequence is called. Indeed in the IF
> the structure tree is stored as a child of the page-sequence element.
> Any idea of how to handle this, other than putting an ugly boolean at
> the beginning of PDFDocumentHandler.startPage, “if structure tree not
> yet built, then build structure tree”?
> > On 23.09.2009 13:44:11 Vincent Hennebert wrote:
> >> To those PDF specialists around here: am I right that the structure tree
> >> could as well be converted into PDF at the end of a page sequence, as at
> >> the beginning?
> >>
> >> In other words: could the piece of code dealing with the structure tree
> >> be moved from PDFDocumentHandler.startPageSequence to
> >> PDFDocumentHandler.endPageSequence?
> >>
> >> Thanks,
> >> Vincent
> > 
> > 
> > 
> > 
> > Jeremias Maerki
> Thanks,
> Vincent

Jeremias Maerki

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