Extension: Text Decoration API

[bryphe]

An API that Onivim currently doesn't support is VSCode's text decoration API: https://code.visualstudio.com/api/references/vscode-api#DecorationRenderOptions

This is needed to support several extensions, including:

• wallaby.js
• Bracket pair colorizer 2 (#2491 , #2863 )
• GitLens

The work required will be:

• Implement msg handlers / types for the decoration API: https://github.com/onivim/vscode-exthost/blob/0d6b39803352369daaa97a444ff76352d8452be2/src/vs/workbench/api/common/extHost.protocol.ts#L283
• Integrate the decoration info into our Editor model
• Implement the rendering log for decorations

It seems that some of the extensions require SVG rendering in the text decoration API (at least, bracket pair colorizer does - I suspect wallaby may as well) - so it may require building out the remaining primitives in Revery: https://github.com/revery-ui/revery/blob/18eb60e6d5b99adebcf5912d05c447e83a0f7e0b/src/SVG/Revery_SVG.re

[yunti]

I do love those coloured brackets 😀 can’t seem to live without them these days.

[jgr]

Gitlens is how I get by without fugitive's :Gblame when I'm in VSCode, I'd love to see it supported.

[manaskarekar]

This would also enable one of my favorite features that most editors seem to miss, a highlight plugin that let's you highlight different words/sequences with different colors, persistently.

The best example of this was for jedit http://plugins.jedit.org/plugins/?Highlight