Moving pianoroll changes into new PR.

[blackears]

Resolves: (direct link to the issue)

(short description of the changes and the motivation to make the changes)

• I signed CLA
• I made sure the code in the PR follows the coding rules
• I made sure the code compiles on my machine
• I made sure there are no unnecessary changes in the code
• I made sure the title of the PR reflects the core meaning of the issue you are solving
• I made sure the commit message(s) contain a description and answer the question "Why do those changes fix that particular issue?" or "Why are those changes really necessary as improvements?"
• I made sure the commit message title starts with "fix #424242:" if there is a related issue
• I created the test (mtest, vtest, script test) to verify the changes I made

[blackears]

This replaces #9033 which has gotten unmanageable.

[wizofaus]

how will this work if the user removes or inserts a time range (measure etc.) into the music - will all existing vertices be adjusted accordingly?
All ticks can just be integers no? (even _value might be better as a float or qreal, I haven't seen a lot of doubles being used so far)

[blackears]

I was planning for the vertices to be stored in a list sorted by _ticks. _ticks could be an integer or something else, but if it is an integer then we will need to determine what unit one tick is. We could use the 1/480 of a whole note MS3 used - is that unit still relevant?

[wizofaus]

Yeah I assumed that's what it was meant to be!
But what I meant is that if you had, say, vertices defined for ticks 480 to 4800 then the user removed the first (4/4) measure entirely, would that modify all extract vertices in all staffs to subtract 480 from the "tick" values?
What if the user removed measures at the end of the piece that meant the vertex tick value was
now beyond the end of the piece? (I would think you couldn't just delete the vertex if it was defining a slope...)

[blackears]

If a measure is deleted, I would presume any coresponding vertices would be deleted too and it would be up to the user to fix things if it caused a problem. Probably something to ask Martin about, though.

[RobFog]

A rebase is needed.

[blackears]

Looks like Github just upgraded its security. I need to change all my keys first.

[Jojo-Schmitz]

One unit test failed, see https://github.com/musescore/MuseScore/runs/5579586289?check_suite_focus=true#step:8:1231

I believe the reason is #9109 (comment)

[scorster]

Just adding a link to Piano Roll Editor bug reports and requests located in the MuseScore discussion area.

https://github.com/orgs/musescore/discussions/16925