Here is what I understand, others may have more to add: I see two ways to interpret your question: (1) what happens in the code that makes page-sequence be the lowest granularity we have, and (2) why we do it that way.
1) When the page-sequence's children (layout-master-set, declarations?, flow) have been finished processing, endElement() in our SAXHandler FOTreeBuilder is called.  That method calls end() of the PageSequenceObject , which in turn calls endPageSequence()  of the FOInputHandler object, which is either FOTreeHandler for PDF/PS, etc. or MIFHandler or RTFHandler. It is endPageSequence() which calls formatPageSequence(pageSequence, areaTree)--which starts the formatting process.  http://cvs.apache.org/viewcvs.cgi/xml-fop/src/java/org/apache/fop/fo/FOTreeBuilder.java?annotate=1.35#197  http://cvs.apache.org/viewcvs.cgi/xml-fop/src/java/org/apache/fop/fo/pagination/PageSequence.java?annotate=1.27#170  http://cvs.apache.org/viewcvs.cgi/xml-fop/src/java/org/apache/fop/fo/FOTreeHandler.java?annotate=1.25#199 2) Our processing is directly on top of SAX--we react at the start and end of XML elements as they come in. Unlike FAD we don't cache into any intermediate data structures, so I don't see how we could do a lower granularity. We could stop at the end of fo:flow, but that is only one element away from fo:page-sequence's object endElement() being called from above, so nothing measurable would be gained. I guess the answer to your question in (2) is (a) that our process is driven by fo:objects, not the areas that they generate, and there is no fo:object that corresponds to "1 page", etc.--that's determined by fo:flow as it is formatted and (b) there are some programmatic conveniences to stopping at the page-sequence level, as the layout-master-set can be read in one time and is valid for all the pages generated. Glen --- "Peter B. West" <[EMAIL PROTECTED]> wrote: > Fop-devs, > > It occurs to me that some of the implications of the > FAD approach have > not been successfully communicated. Part of this > may well be because of > my own inadequate understanding of the FOP process. > Before I continuing > with this discussion, I had better ensure that my > understanding of one > important point is correct. Why does FOP process in > minimum units of a > page-sequence? > > Peter > -- > Peter B. West > <http://www.powerup.com.au/~pbwest/resume.html> >