Add breadcrumb on headerline

[ericdallo]

• Add breadcrumb on headerline via lsp-headerline-breadcrumb-mode:
  
• Support for deprecated symbols:
  
• Add missing documentation to modeline code actions and breadcrumb.

Full screenshot:

In a next PR, the idea is to add mouse support to breadcrumb.

[yyoncho]

Looks good.

[yyoncho]

when tested manually, when I move outside of an element with one char it still stays the same, so probably something here is off by one.

[ericdallo]

I didn't get this problem with lsp-dart, could you provide more details? Maybe the dart or other server is sending different ranges?

[yyoncho]

I tested it, seems like the issue is lack of refresh mentioned bellow.

[ericdallo]

I see, so I guess it's fixed now after adding (force-modeline-update)

[yyoncho]

Can you merge it in plists branch as well?

Few things that can be addressed in the future:

1. Breadcrumb functionality - I like the way it works in vscode, clicking symbol shows the stuff on the same level.
2. It contains also the path to the file in the project.
3. Allowing clicking with avy, similar to what we do with lsp-avy-lens. I think this will be very powerfull way to navigate, with no equivalent in emacs world. That would allow jumping in anything containing the current file. As an alternative to avy we may have a shortcut open Nth symbol from the breadcrumb.
4. Review the whole document symbol story. Those patches we did for imenu are really ugly.

[ericdallo]

Can you merge it in plists branch as well?

Few things that can be addressed in the future:

1. Breadcrumb functionality - I like the way it works in vscode, clicking symbol shows the stuff on the same level.
2. It contains also the path to the file in the project.
3. Allowing clicking with avy, similar to what we do with lsp-avy-lens. I think this will be very powerfull way to navigate, with no equivalent in emacs world. That would allow jumping in anything containing the current file. As an alternative to avy we may have a shortcut open Nth symbol from the breadcrumb.
4. Review the whole document symbol story. Those patches we did for imenu are really ugly.

1. we can start using completing-read when user clicks on it.
2. I thought about that, but don't you think that can be too much stuff on headerline? what about just the file name?
3. Agree, we can think in implement that.

[yyoncho]

2. I thought about that, but don't you think that can be too much stuff on headerline? what about just the file name?

I think that it looks fine in vscode. We could limit the length and use some kind of strategy to shorten the path(e. g. replace with the first letter of the directory). Anyways, it won't be a feature for everyone.

Just to make sure we are on the same page, the proposal is to you the file name relative to project root.