Spans

enum class EditorSpanLayer { SYNTAX, SEMANTIC, OVERLAY }

object EditorFontStyle {
    const val NORMAL = 0
    const val BOLD = 1
    const val ITALIC = 2
    const val STRIKETHROUGH = 4
}

data class StyleSpan(val column: Int, val length: Int, val styleId: Int)
data class EditorTextStyle(
    val color: Int,
    val backgroundColor: Int = 0,
    val fontStyle: Int = EditorFontStyle.NORMAL,
)

fontStyle bits can be OR-ed (BOLD or ITALIC).

Controller

fun registerTextStyle(styleId: Int, color: Int, backgroundColor: Int = 0, fontStyle: Int = 0)
fun registerBatchTextStyles(styles: Map<Int, EditorTextStyle>)
fun setLineSpans(line: Int, layer: EditorSpanLayer, spans: List<StyleSpan>)
fun setBatchLineSpans(layer: EditorSpanLayer, spansByLine: Map<Int, List<StyleSpan>>)
fun clearLineSpans(line: Int, layer: EditorSpanLayer)
fun clearHighlights()
fun clearHighlights(layer: EditorSpanLayer)

Register a styleId before using it in a span. Re-registering the same id updates the look.

clearHighlights() without a layer clears SYNTAX, SEMANTIC, and OVERLAY.

See Syntax highlights for a walkthrough.