Hi Mark, On Thu, Jul 23, 2009 at 02:11:47PM -0700, Mark Polesky wrote: > > Does a grob-type always have the same set of parent-types?
No, I don't think so. [see below] > For example, does an Accidental grob always have X-parent > AccidentalPlacement and Y-parent NoteHead? Yes, this appears to be true. > If so, could this > information be incororated into the IR? It took me a while > before I was able to figure this sort of thing out: > > ________________System__________________ > | | | | | > | | | | | > | | NonMusicalPaperColumn | > | | \ \ | > | | \ VerticalAlignment > \ \ \ / > PaperColumn VerticalAxisGroup > / \ / / > / X / > / / \ / > / / NoteColumn > \ / / \ > AccidentalPlacement | | > \ \ / > \ NoteHead > \ / > Accidental > > > And that's the ancestry for just one grob! This is *very* cool. Thanks for posting it. > I assume that a comprehensive visual "parent-web" demonstrating > all such relationships would be too convoluted to have any > practical value, and too difficult to generate to even justify > trying such a thing (although I've seen some impressive examples, > like http://www.visualthesaurus.com/). But, I imagine it should be > (at the very least) possible to have something like this near the > top of each node within IR 3.1 All layout objects: > > X and Y parents: AccidentalPlacement and NoteHead. > > But I don't know if the parents can change in different contexts. Depending on the situation, grobs may change parents. For example, consider Script_interface::calc_positioning_done. This function first checks to see if the grob (me) has an X parent. If so, then the grob may change parents if the other two conditional tests pass. Instead of documenting this in the IR, maybe it would be better to write a section in the CG about how to find a grob's parent, the parent's parent, etc. with GDB? Plus, I can't think of a good way of automatically documenting the parents (or the different possibilities for parents) of grobs. -Patrick _______________________________________________ lilypond-devel mailing list lilypond-devel@gnu.org http://lists.gnu.org/mailman/listinfo/lilypond-devel
