Hi Keiron, I'm pretty sure all the various details are not quite correct, but I agree that the best way to find out is to try to actually use it and then we'll figure out what to change. I've started to think about the character level, but I'm short on time for the next week. Also mulling over the Property/Trait handling.
Concerning your question, it's one I've already thought about. I think that yes, it should be possible to run the FO tree building and the layout process in parallel. That's one of the reasons the layout is designed to run in a thread. I think it can wait on the flow tree events via the iterator over the children (in generateAreas). The iterator can wait to see if there is a new child available. When an FO node is completed its "end()" method gets invoked by the FOTreeBuilder. It can then be marked as complete so the iterator will know when it's not worth waiting for any more children to be added. I think using that scheme, we can start layout as soon as the flow has some block level child, even if that child is not yet finished. Of course, some kinds of FO need to have more children before doing layout. For example, it makes no sense to start laying out a table until at least all the columns have been seen to calculate column widths. Regards, Karen Keiron Liddle wrote: > > Hi Karen, > > Thanks for the contributions. > I have had a look and I think it is along the right track. It is a bit hard > to know if all the various details are correct. The only way to determine > if it will eventually work is to gradually build it up and see that it is > working for us. > > One question I think we should consider and tackle if possible at this > stage is: > Is it possible to layout blocks as soon as possible and generate a page > once blocks have filled a page. > That is, the driving events are the starting and ending of elements in the > sax events. When a block level object is finished directly under the flow > level then can we add this block to the current page. Once the page is full > (or page break) then we finish the layout of the page then send it on to > the render. Then the completed fo elements that made up the page can be > discarded. > Rather than always waiting for a page sequence to end, which is easier but > not better. > > Regards, > Keiron. > > On 2001.11.10 00:05 Karen Lease wrote: > > Hi all, > > An initial version of the Layout Manager classes (package > > org.apache.fop.layoutmgr) is now in CVS, plus some related changes in > > Area (up for discussion; this is just past the pseudocode point, but at > > least it builds :-) and in the fo/pagination classes. > > Needless to say, it does nothing useful whatsoever yet. > > > > Regards, > > Karen > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, email: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, email: [EMAIL PROTECTED]
