Don't reset xfader when auto DJ is disabled

[daschuer]

This fixes #10683

[ronso0]

As I stated in the original bug lp:1965298 I disagree with the rationale of the PR which introduced this behaviour #313 (I just never noticed since I don't use AutoDJ)

TLDR;
Let's remove the crossfader auto-centering completely.

Using automation when turning AutoDJ OFF to work around forgetting to check a central, obvious DJ control is not appropriate IMO. If that was about some rather inaccessible effect toggle or something, okay, but it's the crossfader :| And it's even more obvious since it's been moved by AutoDJ all the time.

we should remove such magic and leave the crossfader where it is, no matter if it's the last queued song or if AutoDJ is stopped manually.

You're right about not introducing changes for unaffected users in a stable release, that should be avoided if possible. However, I'd appreciate a consistent fix. Though, making the crossfader behaviour depend on the selected xfader mode is confusing IMO.

[daschuer]

I agree for 2.4 to remove the behaviour completely.

When you think we can effort to break the existing reset feature in the stable release has well, I will change this PR accordingly. For now I think this PR is the least controversial version.

What do you think?

[ronso0]

When you think we can effort to break the existing reset feature in the stable release has well

If we want to fix the volume bug and agree that consistent, predictable behaviour is crucial there is no other choice than removing auto-centering now.

Also, I think for AutoDJ users it doesn't matter if we change the behaviour in a minor or in a major update. Let's keep in mind that Mixxx is primarily designed for manual DJing and AutoDJ is a supplementary feature. Even though there are appearantly many AutoDJ-only users, I doubt they mix its crossfader mixing with manual volume fader mixing, and if so resetting the crossfader is just a right-click away.

[ronso0]

What do other @mixxxdj/developers think?

When AutoDJ runs out (auto-off after fading to last queued track) should we

• center the crossfader only with crossfader's mixing mode to avoid the volume reduction
• remove auto-centering entirely

?

[Swiftb0y]

Also, I think for AutoDJ users it doesn't matter if we change the behaviour in a minor or in a major update. Let's keep in mind that Mixxx is primarily designed for manual DJing and AutoDJ is a supplementary feature. Even though there are appearantly many AutoDJ-only users, I doubt they mix its crossfader mixing with manual volume fader mixing, and if so resetting the crossfader is just a right-click away.

see https://www.hyrumslaw.com/. I still think we should change the behavior, but we need to make it clear enough in the changelog.

remove auto-centering entirely

I favor this. AutoDJ is already full of magic, making it seemingly unpredictable (and thus the reason I still don't trust it in live situations), so removing one more undocumented behavior is a good idea!

[daschuer]

OK, I have removed the xfader reset unconditionally.

[ronso0]

Thank you, LGTM

[ronso0]

I also did a manual test of this one-line change. Works as intended : )