Questions about custom editors

[segevfiner]

The documentation around custom editors seems to be lacking, so I have a few questions:

1. How does VS really use logical views? When will it request anything other than the primary logical view? When does it use MapLogicalView vs the registry/config entries? (And there are also both ProvideLogicalEditorView and ProvideView attributes...)
2. What interfaces the doc data and doc view classes created by CreateEditorInstance need, can, or should support?
3. Can you create the core editor via CreateInstance or that no longer works and you have to use the factory class from MEF?, either the adapters or the new editor itself I assume.
4. I assume document data can also be the core editor text buffer implementation if what I'm editing is at its core a text file? What's the right way to instantiate that?
5. How do you support having View Code/View designer options like the vsixmanifest editor has?
6. There doesn't seem to be support for sub file extensions in VS, e.g. .something.json. I wonder if it is possible to make my editor by the default for some core file extension but defer to the other default editor if it's not really from my secondary extension so it opens automatically without messing up editing other files with that extension.

P.S. Is there any example project for how to target multiple VS versions using the community toolkit? It's not clear what's the best way to do so from the VSSDK docs... And whether it is possible to release a vsix for multiple versions and what version of the community toolkit it needs to depend on.

Also, is there any documentation or wizard for the VSPackage.resx resources file that VS looks for in your package for resources outside the examples? It took me some time to figure it out until I found out how to set it up from the examples.

[segevfiner]

Ugh. Trying around stuff based on other samples and docs. I tried using IVsEditorAdaptersFactoryService but an editor created using it from a custom EditorFactory doesn't load any of the default customization of it from other packages, so e.g. no syntax highlighting. And annoyingly it will let you "open with" a different editor when using an IVsTextBuffer as document data, which will also result in such a crippled editor even if your factory is creating a custom component. I'm not sure how to get this to work well...

I think this is related to the ServiceProvider passed to the EditorFactory? But I'm not sure... As the customizations to the editor that are missing are mef components rather then COM services...

[segevfiner]

Ugh. It was due to VSConstants.VsTextBufferUserDataGuid.VsBufferDetectLangSID_guid not the service provider. It seems the language auto detection for whatever language I extended doesn't work and seems to override even the initially set content type for the IVsTextBuffer... Weird and poorly documented, if at all...