fix #9020: Select correct brace symbol for each system independently

[Nick-Mazuk]

Resolves: #9020

MuseScore uses different brace symbols depending on the number of staves the brace covers. Currently, this is is calculated once for the entire piece. This PR allows the brace size to be calculated on a system-by-system basis, such that staves hidden in a particular system don't affect the size of the brace.

[Jojo-Schmitz]

vtest error might be expected, but certainly not this one?

[Jojo-Schmitz]

If you prefix the commit title with "Fix #322436:" that issue would (also) get auto-closed on merging this PR

[Jojo-Schmitz]

Before:

after:

[Nick-Mazuk]

vtest error might be expected, but certainly not this one?

It looks like the test failed when creating the reference images, not even during the actual tests. I'm not too knowledgable about the test suite, but I don't know why this change would cause the image creation to fail.

If you prefix the commit title with "Fix #322436:" that issue would (also) get auto-closed on merging this PR

Good to know. Typically, GitHub auto-closes issues even if it's referenced in the PR message as "resolved" or "fixed". But if adding it to the commit message that way is the preferred way to do things here, I'll do that in the future.

[Jojo-Schmitz]

Reg. vtest:
The vtest error is something that happens at times, nothing to worry about.
Except it'd be interesting to see whether there's a 'real' vtest a) testing these braces and b) failing on this (rightfully in this case, alöbeit a failure we'd have to accept).
But checking the vtests of my backport of this to 3.x show no such test nor failure (but a lot of unrelated others).

Reg. commit title:
It is for issues on the muescore.org tracker

[Nick-Mazuk]

Reg. vtest:
The vtest error is something that happens at times, nothing to worry about.
Except it'd be interesting to see whether there's a 'real' vtest a) testing these braces and b) failing on this (rightfully in this case, alöbeit a failure we'd have to accept).
But checking the vtests of my backport of this to 3.x show no such test nor failure (but a lot of unrelated others).

Reg. commit title:
It is for issues on the muescore.org tracker

I see, thanks for the explanations!

[DmitryArefiev]

Hi @Nick-Mazuk can you help with testing this. I don't see a difference between latest master (Win) and old build 20-days old.

And one more thing.. The brace size is different depending on what staves are hidden (in the middle of system or starting from the edge):

[Jojo-Schmitz]

That's what the PR is all about. The brace size is picked based on the number of visible staves in any given system

[Nick-Mazuk]

@DmitryArefiev The desired behavior is the one where the brace is smaller when you hide Flute 2, 3, 4. When you hide the middle two staves, the brace size should also become smaller (which it isn't, so that's a bug). I think I know what's going on and will submit a new PR with a fix hopefully today.