[MU4 Issue] If note or rest selected, key signature from palette is applied only to selected staff

[cbjeukendrup]

Describe the bug
If a note or rest is selected, or when you are in note input mode, and you click a key signature in the Palettes, it is applied only to the selected staff.

To Reproduce
Steps to reproduce the behavior:

1. Select a note or rest, or enter note input mode
2. Click a key signature in the Palettes
3. It is applied only to the staff containing the selected note or rest, or containing the note input cursor.

Expected behavior
It should be applied to all staves. Only when using the Ctrl/Cmd modifier, it should be applied to a single staff.

Platform information

• OS: reported on macOS

Additional context
If a full measure is selected, or when dragging a key signature instead of just clicking it, it works as expected.
It does not apply to time signatures, only to key signatures.

[MarcSabatella]

You probably noticed this, but it's true for MuseScore 3 as well. While it was originally by design, it's one that nearly everyone agrees was a mistake. It stemmed from the desire to allow mid-measure key changes, and in that case - if the selected note/rest is not at the start of a measure - it could arguably make sense to make it per-staff. After all, there is no guarantee the selected segment makes sense on any other staff (it might be in the middle of a whole note). Or we could just disallow this, and I doubt many would complain.

But anyhow, indeed, clearly, with the first note/rest of a measure selected, the key signature should be applied normally, not as one of these special mid-measure single-staff key signatures.

[wizofaus]

So what is the supported way in v3 to add a key signature part way through a measure so that it applies to all staves? (even if it would require splitting/padding rests etc.)

[MarcSabatella]

Either add it one staff at a time, or - usually a much saner choice if you really need a mid-measure key change - split the measure then add normally to the second half. Both methods continue to work in MU4.

Hmm, actually, maybe the smart thing to do if a single note mid-measure is selected when you add the key signature is just go ahead and do the split there, only adding the single-staff mid-measure key signature if you hold Ctrl.

[wizofaus]

Mid-measure key changes aren't that uncommon! Having to split measures before adding one (then rejoining afterward) seems more than a bit clunky. Then again, apparently it's pretty clunky in Finale too, not sure about other packages.
It had been asked about previously here too: https://musescore.org/en/node/305729 (and yes, you gave the same answer!)

[MarcSabatella]

I didn't say anything about rejoining - not sure that was ever supported. You can hide the barline if you want to create the illusion of a single measure.

Splitting measures has always been the supported way of doing pretty much anything mid-measure that normally only happens at measure boundaries - system breaks, repeats/voltas/segno/fine/coda, etc.

[wizofaus]

It would never even occur to me that it was an illusion - there are plenty of times it makes sense to change key signature mid-measure. The other examples you give there are good reasons why it's problematic to have mid-measure.

[Tantacrul]

@oktophonie - feels like this one could potentially be for you? Not sure the solution you'd prefer.

I'm bumping to 4.x. For the moment, since it is already an issue with V3.

[mike-spa]

Resolved in #17237