On May 19, 2008, at 17:08, Vincent Hennebert wrote:
Hi
bonekrusher wrote:
Hi,
Since FOP 0.94 and 0.95 Beta do not have support for Table
Continuation
Labels, I would like to see if I can possible work on this for the
project.
To implement this feature, 4 steps basically need to be performed:
- implement support for fo:retrieve-table-marker in the FO tree;
I believe this stage is more or less complete
Indeed. I added this recently. The only thing currently incomplete is
support for retrieve-table-markers as substitutes for the header/
footer. (It seems like the Recommendation offers the possibility of
putting the entire fo:table-header element in a fo:marker... Adrian
pointed this out after I committed. As Vincent points out: read /and/
re-read ;-))
<snip />
I can’t help you much regarding how other markers are currently
handled,
since I haven’t looked at this part of the code yet.
The key point here is PageSequenceLayoutManager.resolveRetrieveMarker
() which is called from AbstractLayoutManager.createChildLMs() (for
the subclass StaticContentLayoutManager).
<snip />
However,
org.apache.fop.fo.flow.AbstractRetrieveMarker seems like a good
starting
point.
This contains the basic code for cloning the marker. Normally, this
should not need any changes (apart from cleaning up some unrelated
TODOs...)
While it may be of educational value to browse through, it does not
contain anything specific wrt the actual marker-resolution. It only
contains the mechanism for the marker-duplication: cloning the
subtree, evaluating property expressions in the proper context,
triggering white-space-handling.
This is all done because one fo:marker may be retrieved multiple
times into different contexts, so it's important to separate the
retrieved copy from the original.
The main challenge in the layoutengine, as I see it is that, for
marker-retrieval to work (on page-level), the cells in the table-body
have to have 'added' their markers (see
AbstractLayoutManager.addMarkersToPage(), which is called from
addAreas()).
In normal flow-layout, the marker-retrieval is triggered by the
StaticContentLayoutManager.createChildLMs(), which is activated /
after/ the areas for the Flow have been added to the body-region for
the current page-viewport.
Just my 2 cents...
Cheers
Andreas
