Rework access to preferences

[ruspl-afed]

Currently preferences are located in org.eclipse.cdt.lsp.clangd UI part, while some of them could be

• required from general headless part to decide if we need to launch LSP at all.
• required from clangd headless part to decide how we should launch (see Support changing language server parameters from third party plugins #81 )

So , the preferences should be:

• split to have general and 'clangd' items
• reworked from UI to headless manner

[ghentschke]

I would like to introduce a requirement for the enable preference:
As a vendor I would like to have the possibility to hide the "Prefer C/C++ Editor (LSP)" check box in the preferences and on project level, since I have my own enable logic.

Not sure if this is part of this issue. It may be helpful to keep in mind while working on this issue here.

[ruspl-afed]

to hide the "Prefer C/C++ Editor (LSP)" check box in the preferences and on project level, since I have my own enable logic

Implementing "hide" and "own enable logic" are different aspects, and I can see two paths here:

1. We can say that generis "Prefer LSP" is a prerequisite for all the further logic provided by vendor, in this case we don't need to hide this generic UI.
2. We can try to make both UI and logic fully replaceable, this will need a bit more effort.

WDYT?

[ghentschke]

We can say that generis "Prefer LSP" is a prerequisite for all the further logic provided by vendor, in this case we don't need to hide this generic UI.

I don't like a general switch here, because as a vendor I don't want to give the user the possibility to disable LS based editor for some projects types.

We can try to make both UI and logic fully replaceable, this will need a bit more effort.

That would be great and makes the whole thing more flexible.

[ddscharfe]

@ruspl-afed, @ghentschke, is any of you already working on this? I'd like to implement #81 which depends on this issue.

My quick attempt was to create my own ICLanguageServerProvider which derives from CdtCLanguageServerProvider and set its priority higher than the default one. However when the providers are created in the CLanguageServerRegistry, my provider gets created first and therefore sets the preferenceStore defaults, the default provider is created second and overwrites the preferenceStore defaults.

[ruspl-afed]

, is any of you already working on this?

not yet, I was busy on Mylyn and on paid tasks

and set its priority higher than the default one

The idea of "priority" is questionable for me, especially in the form of enum - one can just declare highest and this is the end of the game for others.

my provider gets created first and therefore sets the preferenceStore defaults, the default provider is created second and overwrites the preferenceStore defaults.

yes, this is the one of key points to rework. As discussed above, there is no preferences to share between LS providers, every LS provider should configure itself.

[ghentschke]

, is any of you already working on this?

me neither.

The idea of "priority" is questionable for me, especially in the form of enum - one can just declare highest and this is the end of the game for others.

That's the reason why I designed it this way. As a vendor I want to overwrite everybody else.

yes, this is the one of key points to rework. #83 (comment), there is no preferences to share between LS providers, every LS provider should configure itself.

I agree.

[ghentschke]

@ruspl-afed could you provide a PR for this issue? If not I can do this, when I am done with #87

[ruspl-afed]

That's the reason why I designed it this way. As a vendor I want to overwrite everybody else.

I see. If you need to restrict some functionality please consider Eclipse Passage, it was designed to solve this kind of problems.

@ruspl-afed could you provide a PR for this issue?

I plan to work on it in the coming days

[ghentschke]

my provider gets created first and therefore sets the preferenceStore defaults, the default provider is created second and overwrites the preferenceStore defaults.

yes, this is the one of key points to rework. #83 (comment), there is no preferences to share between LS providers, every LS provider should configure itself.

That's why vendors should extend org.eclipse.cdt.lsp.server.DefaultCLanguageServerProvider. I should move this to the clangd plugin as well, since it is only applicable for clangd and rename it to DefaultClangdServerProvider. CdtCLanguageServerProvider should be tagged as final, since it should not be extended by vendors.

[ruspl-afed]

If the type is for extension, can we consider to make it abstract and start its name from Base... instead of Default...?