Bar line palette drops only affect some bar line properties

Seems related to #25251: Unable to create barline after undo

As far as I see it, a bar line can have up to four properties:

1) span: from which line of which staff to which line of which (other) staff it runs; the two flavours of 'tick' and of 'short' fall in this category; span also includes the Mensurstrich case, which requires a rather peculiar management;
2) line style: continuous, dashed, dotted;
3) bar style: single, double (thin-thin), end (thin-thick);
4) function: none, start repeat, end repeat, end-start repeat.

Additionally, it makes quite a difference if a bar line property is dropped on a individual bar or on a measure:

A) if dropped on an individual bar, the code assumes that individual bar line has to be customized from the default situation.

B) if dropped on the whole measure, the code assumes that:
B1) for spans, the user wants to modify the bar lines of the whole staff: the most common situation is to have bar lining span consistent over the whole staff or staves => generalize in horizontal sense;
B2) for line/bar styles, the user wants to modify the bar lines of the whole measure: the most common case is to have double or end bar lines consistent across all the parts of a measure => generalize in vertical sense.

(Aside: The last property, function, is the only structural one and it should not be possible to assign a function to a single bar line of a measure, as it would make no sense that a part repeats while the other go on or vice versa).

@Bertalan Fodor:

You may think this to be over-engineered; I would say it is flexible. Also, the current situation -- with a single exception, not related with this issue -- is working correctly (and I would say predictably) for the great majority of users, who just need 'common' bar lines and do not care about peculiar bar line spans or styles.

If you need the 'tick' bar line, you are probably in the niche of users with specialized needs, as I feel I am myself by quite often needing the Mensurstrich bar lining. We could go on indefinitely arguing which approach is better, without reaching an agreement: your approach (a palette drop should affect all the bar line properties) may well be more suited to your specialized needs, my approach (a palette drop should affect only the property it conveys) to my specialized needs and still another approach to someone else's specialized needs. If by chance we could arrive at some agreement, it would concern only a rather tiny minority of MuseScore users, so I tend to rate the primary issue you describe as rather minor.

In summary, as far as this issue is concerned, I can only say that, so far, it is "by design".

Does the above means that everything is perfect? Far from it! There are still things which do not work and/or could be improved:

*) Undoing a bar line property change is unpredictable (this is the exception I was referring to above) and is covered by #25251: Unable to create barline after undo.
*) The Inspector part related to bar lines is mostly unreliable.
*) The bar line palette could probably be re-organized.
*) Labels for bar lines palette items could be improved.

and probably many other as well. Creating specific issues in the tracker covering the individual details as they are noticed would help: step by step, I hope we will fix them.

Thanks,

Maurizio