feat(core): Add highlighting callback for custom inline highlighting

[jettptacek]

Adds an onHighlight callback to CodeRenderable that allows post-processing of syntax highlights before they're rendered. This enables custom inline highlighting

Changes

• Added onHighlight option to CodeRenderable that receives tree-sitter highlights and can modify them
• Added HighlightContext interface providing access to content, filetype, and syntaxStyle

Usage

const codeDisplay = new CodeRenderable(renderer, {
  content: code,
  filetype: "typescript",
  syntaxStyle,
  onHighlight: (highlights, ctx) => {
    highlights.push([startPos, endPos, "(registered style) i.e color.FF0000", {}])
    return highlights
  },
})

Solves

I have an open pr in opencode anomalyco/opencode#9016 to close anomalyco/opencode#2586 but my pr monkey patches treeSitterClient.highlightOnce to get that feature working and this onHighlight callback change would allow a cleaner implementation of anomalyco/opencode#2586 and/or other custom highlight features

Examples

I made 2 examples using this feature that I can add to the pull request as well. If it's wanted.

SearchHighlightingExample.mp4

ColorCodeExample.mp4

[pkg-pr-new]

@opentui/core

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core@568

@opentui/react

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/react@568

@opentui/solid

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/solid@568

@opentui/core-darwin-arm64

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core-darwin-arm64@568

@opentui/core-darwin-x64

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core-darwin-x64@568

@opentui/core-linux-arm64

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core-linux-arm64@568

@opentui/core-linux-x64

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core-linux-x64@568

@opentui/core-win32-arm64

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core-win32-arm64@568

@opentui/core-win32-x64

npm i https://pkg.pr.new/anomalyco/opentui/@opentui/core-win32-x64@568

commit: 80e8b9b

[kommander]

Just as a tip, I'd try to avoid re-creating syntax styles in the callback itself where possible. It will not actually re-create the style or use more memory, but it has to do an FFI call with checks every time. Just something to keep in mind for repeated re-highlighting.

[kommander]

Oh and I'd try to get the basics test covered to catch regressions early.

[jettptacek]

Ah yes thank you, there's no reason I should be registering styles inside the callback. I was doing that in my examples.

I did add some tests and please let know if I need to be more thorough. Thanks!

[kommander]

Github is not picking up the core build and test job somehow 🙄 Looks fine though. I'll try again in a bit.