musescore
Fix editing Hairpin text style (and probably others) in EditStyle
Resolves: #12336 Resolves: #13420
The problem (also existed in MU3, by the way):
A "TextStyle" was defined as a set of 14 (*) pairs of a style ID and a property ID. In EditStyle, we assumed that the property IDs are always the same. This is not true: for example, some text styles work with Pid::FONT_FACE, others with Pid::BEGIN_FONT_FACE. So for styles with the latter, loading or editing them doesn't work.
The solution is to introduce a dedicated TextStylePropertyType enum, that can always be used to identify properties of a text style. That fixes the problem for now, with not too big refactoring.
However, there's a lot more to be done with text styles. It is bad that the Pids are stored as part of the TextStyle; they should depend on the EngravingItem in question, rather than the TextStyle, since a text style is not necessarily bound to a certain kind of EngravingItem. The result of the current situation is that if you apply the "hairpin" style to a regular text element, we try to modify Pid::BEGIN_FONT_FACE, but that has no effect on the text element, because the text element listens to Pid::FONT_FACE. This is not fixed in this PR, and would be slightly less urgent and more risky. If someone from the community would like to volunteer, you're welcome!
I'm considering the idea to do a huge refactor of TextStyles in 4.x. They could be much more powerful; for example, it would be very useful if styles could be based on others, so that if you want to chance the font family for the whole score, you only need to change it for the base style, instead of for every individual style. Anyway, that's for the future...
(*) For one or more TextStyles, it turns out that some values are missing, because some style IDs do not exist! That does not cause serious problems though (but this is the reason that we need TextStylePropertyType::Undefined, because if the std::array constructor contains not enough elements, the remaining ones will be zero-initialized.)
