Decorations

SweetEditor uses decoration providers to supply non-text editing overlays and semantic information.

What You Can Decorate

• syntax highlight
• semantic highlight
• inlay hints
• phantom text
• diagnostics
• gutter icons
• indent / bracket / flow / separator guides
• fold regions

Registering A Decoration Provider

val provider = object : DecorationProvider {
    override val id: String = "demo.decorations"
    override val capabilities: Set<DecorationType> = setOf(
        DecorationType.InlayHint,
        DecorationType.Diagnostic,
        DecorationType.PhantomText,
    )

    override suspend fun provide(context: DecorationProviderContext): DecorationUpdate {
        return DecorationUpdate(
            decorations = DecorationSet(
                inlayHints = mapOf(
                    0 to listOf(
                        InlayHint(
                            type = InlayType.Text,
                            column = 3,
                            text = "value: "
                        )
                    )
                )
            ),
            applyMode = DecorationApplyMode.ReplaceRange,
            lineRange = context.requestedLineRange,
        )
    }
}

controller.addDecorationProvider(provider)

Important Merge Rule

For viewport-scoped, line-based decorations, prefer:

• DecorationApplyMode.ReplaceRange

This avoids duplicate decorations during scroll and refresh.

Related APIs

• DecorationProvider
• DecorationProviderContext
• DecorationSet
• DecorationUpdate
• DecorationApplyMode