Lsp: Report progress

[hunger]

!!! Sits on top of #1922 !!!

I want to abuse this to notify the Properties View (and potentially others) about files getting processed by the LSP.

Currently we have this flow of information:

sequenceDiagram
    participant Editor
    participant PropertiesView
    participant LSP

    Editor->>PropertiesView: Something changed
    PropertiesView->>LSP: PropertyData?
    LSP->>PropertiesView: No or outdated data
    Editor->>LSP: Something changed
    loop Parse change
        LSP->>LSP: Do magic
    end
    
    Editor->>PropertiesView: Cursor Change
    PropertiesView->>LSP: PropertyData?
    LSP->>PropertiesView: Current PropertiesData!

    PropertiesView->>LSP: change property X
    LSP->>Editor: change property X

    Editor->>LSP: Changed!
    LSP->>PropertiesView: property X changed
    Editor->>LSP: After changing X, my contents is now...

I hope I can abuse the progress report to do this instead:

sequenceDiagram
    participant Editor
    participant PropertiesView
    participant LSP

    LSP->>PropertiesView: No or outdated data
    Editor->>LSP: Something changed
    LSP->>PropertiesView: Invalidate data when progress starts
    loop Parse change
        LSP->>LSP: Do magic
    end
    LSP->>PropertiesView: Progress done: My data is valid again!
    PropertiesView->>LSP: PropertyData?
    LSP->>PropertiesView: Current PropertiesData!

    PropertiesView->>LSP: change property X
    LSP->>Editor: change property X
    Editor->>LSP: Changed!
    LSP->>PropertiesView: property X changed

    Editor->>LSP: After changing X, my contents is now...
    LSP->>PropertiesView: Invalidate data when progress starts
    loop Parse change
        LSP->>LSP: Do magic
    end
    LSP->>PropertiesView: Progress done: My data is valid again!
    PropertiesView->>LSP: PropertyData?
    LSP->>PropertiesView: Current PropertiesData!    

[ogoffart]

What is this magic things here that the loop does?
The loading and reloading of document is totally synchronous on the non-browser version. (and you did not implement the thing for the browser version)

[hunger]

It parses the files, which takes a moment. Think of those boxes as "some time passes".

The problem is that the Editor drives synchronization at this time and that has no idea what state the data in the LSP is in. I want to change it such that the the PropertiesView only gets position changes from the Editor and all the data synchronization happens via the LSP.

[ogoffart]

Does it means we'll see popup all the time in vscode?

[hunger]

I see that our LSP sent progress information to VSCode in the traces, but I did not see VSCode report them anywhere. So I think it won't pop up messages:-)

[ogoffart]

Ok, then it seems like a good idea.