Creating new tracks & changing instrument/sound programatically

[zopieux]

Hi,

I'm trying to programmatically create new parts (this works) and change their instrument (not working) directly in this C++ function.

    // Added in .h
    INJECT(notation::IInstrumentsRepository, instrumentsRepository)

    // Added in .c ConverterController::fileConvert
    mu::notation::IMasterNotationPtr master = notationProject->masterNotation();
    mu::notation::INotationPtr notation = notationProject->masterNotation()->notation();
    mu::engraving::MasterScore *score = notationProject->masterNotation()->masterScore();
    mu::notation::INotationPartsPtr notationParts = notation->parts();

    PartInstrumentList partList;
    IDList originalIDs;
    size_t idx = 0;
    for (const auto *p : notationParts->partList())
    {
        originalIDs.emplace_back(p->id());
        partList.append(PartInstrument{
            .partId = p->id(),
            .instrumentTemplate = instrumentsRepository()->instrumentTemplate(p->instrumentId().toStdString()),
            .isExistingPart = true,  // exisiting
            .isSoloist = p->soloist(),
        });
        partList.append(PartInstrument{
            .partId = notationParts->partList().size() + (idx++),
            .instrumentTemplate = instrumentsRepository()->instrumentTemplate(p->instrumentId().toStdString()),
            .isExistingPart = false,  // new
            .isSoloist = p->soloist(),
        });
    }
    master->parts()->setParts(partList, master->parts()->scoreOrder());
    score->doLayout();

While this correctly creates new parts for each existing part, it seems like the instrumentRepository is not working as intended. The instrument template is the dummy empty one, and when doing playback, there is no instrument found.

1. Is this the correct approach to create a new empty part for each existing expart?
2. How can I fix the above code to assign the same instrument & SoundFont to the newly created parts? It looks like the instrumentRepository is not correctly initialized because I'm not using it appropriately. But I don't know how to otherwise fill in the instrumentTemplate field.

Thanks.

[sammik]

To change instrument, there is part.setInstrument(instrument)

MuseScore/src/engraving/dom/part.h

Line 143 in eff81f3

void setInstrument(Instrument*, Fraction = { -1, 1 }); // transfer ownership

isnt it?

[zopieux]

Thanks, most likely, yes but it seems like the instrument repository is not initialized so it's empty. I can't wrap my head around the dependency injection stuff. Can't I just instantiate one manually?

[cbjeukendrup]

The instance of IInstrumentsRepository is instantiated here:

MuseScore/src/notation/notationmodule.cpp

Lines 106 to 110 in a13d8b4

	m_instrumentsRepository = std::make_shared<InstrumentsRepository>();
	ioc()->registerExport<INotationConfiguration>(moduleName(), m_configuration);
	ioc()->registerExport<INotationCreator>(moduleName(), new NotationCreator());
	ioc()->registerExport<IInstrumentsRepository>(moduleName(), m_instrumentsRepository);

It is initialised here:

MuseScore/src/notation/notationmodule.cpp

Line 229 in a13d8b4

m_instrumentsRepository->init();

This is the instance that is retrieved using dependency injection.

[cbjeukendrup]

If the repository is indeed still empty, you're most likely running a non-installed build: you're using the executable from the build folder instead of the one from the install folder specified using CMAKE_INSTALL_PREFIX.

[zopieux]

@cbjeukendrup Thanks for bearing with me. Indeed I'm running the binary straight out of ninja since I'm iterating on my code patch. I'll try to "install" properly or hack around search paths.

As for dependency injection, what's unclear to me is whether the convertcontroller context in which I'm running this code has access to the correctly initialized instance, or if more boilerplate code is necessary. My guess is that module initialization (including notationmodule) is done early in the main binary and so I don't need to take extra precautions. It's just not working because it can't find the instruments (wrong run location per your previous comment).

[cbjeukendrup]

Yes, those module initialisation methods are called in App::run (app.cpp), which is basically the only interesting content of the main function. So as long as you're just working on the MuseScore app, initialisation should not be a problem. Only if you're writing a new unit tests suite or creating your own app using some code from MuseScore, you need to be careful (and also when working in onInit of some other module, of course).

[zopieux]

Thanks, it was indeed an issue with the repository not finding the instrument files in its configured prefix.