Staff group barlineStyle

[rpatters1]

I was thinking implementing barlineStyle would be straightforward and I would knock it out this evening, but I am immediately hit with a conundrum. While I understand the intended difference between individual and instrument, I do not think it is a useful distinction given how staff groups work. On the contrary, I think it introduces ambiguity, brittleness, and complexity.

Staff groups are nested and hierarchical. To create a bracket on a typical piano grand staff, the only way is to create a layout with a staff group and set the barlineStyle to (usually) unified. You could set it to instrument but that would be visually no different than unified. Plus you are mixing part/instrument concerns with layout concerns by making the distinction. Right now you could have that piano part in multiple different layouts with or without staff groups, so honoring instrument in an importer is a crap shoot.

Now go out a level. The next level out contains all the instruments (hypothetically). The choice now is really just mensurstrich or unified or noOverride. And every level out from there. If we ever add deskBracket shapes (which I don't understand why we haven't already), we could get 3-4 levels deep.

To me the only bracket styles at any given level are

• unified: overrides all lower groups & staves with a unified barline
• mensurtrich: overrides all lower groups & staves with mensurstrich barlines
• noOverride: which does not override the barline styles of the next level down. At the lowest level it is individual staff barlines.

The instrument option is somehow trying to override from the bottom up, and I don't think one can reliably implement it.

[adrianholovaty]

Perhaps it's best to think about the barlineStyle from the outside inward? In a score with lots of instruments, I'd recommend setting barlineStyle on the outermost layout, then just leaving it undefined for all inner layouts. Wouldn't that work for most cases? Let me know what I'm missing.

[rpatters1]

One does have to think about it from outward inward. The outwardmost override wins. I had the idea this morning, instead of barlineStyle (which conflicts semantically with barline-type in global measure), why not call it barlineOverride. Then the options would be:

• none (default: the next level inward determines the barlines)
• unified
• mensurstrich