Re: add general_alignment (issue 2613) (issue 6308093)

[Keith OHara]

On Fri, 22 Jun 2012 08:21:02 -0700, Janek Warchoł <address@hidden> wrote:

> > The new property X-alignment will be awkward to use, because it is a
> > complex structure of unnamed conceptually-distinct objects.
>
> Unnamed?  What do you mean?

If you change things as you have the patch now, when someone asks, over the 
telephone,
"Why doesn't \once\override self-alignment-X work anymore ?"
you have to say "If you are using on lyrics, don't use self-alignment-X; instead 
copy X-alignment from the define-grobs.scm and change the car of the second element in 
the list to what you used to use for self-alignment-X".  I think I might have gotten 
something wrong in that.

> I hope these examples are explained clear enough.
Yes. It takes some imagination to visualize an implementation of solutions, 
though.

I see how it makes sense to have LyricsText determine its 'core' and then let 
self-alignment-X (or, rather, the appropriate element in X-alignment) refer to 
that core.

It is hard for me to predict if a "core extent" can be determined by 
straightforward code for the various parent objects.   It worked as a description for 
what you want in the cases you described.

The relationship between parent and child is asymmetric, though, so you might 
not want the symmetric concept of parent and child each having a core.  Tou 
might think of the child having a core extent and the parent having a choice of 
alignment points (including its reference point which is our choice today).  It 
depends on what you can reasonably extract from the parent objects.