Andreas L Delmelle a écrit : > On Feb 12, 2007, at 20:02, Andreas L Delmelle wrote: > >> On Feb 12, 2007, at 18:00, Vincent Hennebert wrote: >>> So my question is: is there a possibility of creating a tree of FObj >>> instances from a corresponding FO fragment, and use it to feed objects >>> from the layout engine in order to unit test them? It doesn't seem to be >>> the case currently, but how difficult would it be to extract that from >>> the current codebase? >> >> The code that constructs a tree of FObjs is located in >> fop.fo.FOTreeBuilder: catching SAX startElement() events and >> constructing FONodes + trigger the creation of PropertyLists from the >> Attributes. >> Unfortunately, FOTreeBuilder currently only accommodates construction >> of a complete FOTree, starting with the root. >> >> Once a sufficient part of the FOTree is available, the LayoutManagers >> are created from the FO subtrees in the main loops of the >> getNextKnuthElements() methods (getChildLM() -> getNextChildLMs()), >> ultimately triggered by AreaTreeHandler.endPageSequence(). > > To elaborate a bit on ideas on how to extract/implement it: > If all you need is > a) a way to test simple documents (build a complete FOTree of them), and > b) only need to control the instantiation of the LMs > > then I guess you could create your own subclass of FOEventHandler, and > catch the FO events as they occur. You could write a FOEventHandler that > only handles table-related FOs in a document, and ignores all the > others. They will still be created, by the FOTreeBuilder, though... > Advantage is that the default AreaTreeHandler can quite easily be > overridden/replaced by a custom one. (The RTFHandler is an example) > > If you also need control over the FOTree creation, then you'll need a > special FOSubTreeBuilder as well.
Many thanks Andreas, that was enough to get me started! I've just committed a first test case for tables. This is still very rough, there's no testsuite, that won't be called by ant, but as long as I can run the tests from Eclipse from time to time I'm happy. Of course I'm open to any comments or suggestions. Cheers, Vincent
