SAX-style RTF reader/writer emitting sealed event streams and styled-text models, with streaming I/O adapters, Markdown↔RTF and AnnotatedString converters, robust charset and Unicode handling.
An idiomatic Kotlin Multiplatform RTF reader and writer.
RtfParserKmp is a port of RTFParserKit by Jon Iles
(Apache 2.0) — its proven, SAX-style Standard parser, re-homed into commonMain so it runs on the JVM,
JS, WebAssembly, and every Kotlin/Native target with no platform code in the hot path. The parsing
engine and the entire command dictionary are faithful translations of the original; the public API is
reshaped to be idiomatic Kotlin (sealed event types, listener interfaces with default methods, a
dependency-free byte source).
Acknowledgement. This library is a derivative work of RTFParserKit, © 2013 Jon Iles, used under the Apache License 2.0. See
NOTICE. New code is © 2026 The RtfParserKmp contributors.
Each module publishes as its own Maven artifact under the group com.darkrockstudios, so you
depend only on what you use.
A non-published sample-cli (Kotlin/Native) demonstrates the stack end to end. rtf-compose targets the
Compose-supported subset (JVM, Android, wasmJs, iOS, macOS); the other modules cover the full matrix.
dependencies {
implementation("com.darkrockstudios:rtf-reader:0.1.0")
implementation("com.darkrockstudios:rtf-writer:0.1.0") // optional, for export
implementation("com.darkrockstudios:rtf-io-kotlinx:0.1.0") // optional, for streaming I/O
}
JVM · Android · JS (IR, browser + node) · wasmJs · wasmWasi · iOS (x64/arm64/simulatorArm64) · macOS (x64/arm64) · tvOS · watchOS · Linux (x64/arm64) · Windows (mingwX64).
Core parsing — including \uN Unicode, all single-byte codepages (Windows-125x, CP437/850/874,
Mac Roman and friends), and UTF-8 — runs identically on every target with zero platform code.
Full API reference and per-module recipe guides: darkrock-studios.github.io/RtfParserKmp.
import com.darkrockstudios.libs.rtfparserkmp.parser.parseRtf
import com.darkrockstudios.libs.rtfparserkmp.converter.extractPlainText
import com.darkrockstudios.libs.rtfparserkmp.converter.convertToMarkdown
val bytes: ByteArray = /* your .rtf */
val text: String = extractPlainText(bytes)
val markdown: String = convertToMarkdown(bytes)
// Or drive the event stream yourself:
for (event in parseRtf(bytes)) { /* RtfEvent.Text, .Command, GroupStart, ... */ }
Implement RtfListener (every method has a no-op default) for streaming, or when over the sealed
RtfEvent from parseRtf.
import com.darkrockstudios.libs.rtfparserkmp.writer.convertMarkdownToRtf
import com.darkrockstudios.libs.rtfparserkmp.writer.writeRtf
import com.darkrockstudios.libs.rtfparserkmp.model.*
val rtf: String = convertMarkdownToRtf("This is **bold** and _italic_.")
// Or from the styled-text model directly:
val doc = StyledDocument(listOf(Paragraph(listOf(TextRun("Hello", CharacterStyle(bold = true))))))
val rtf2: String = writeRtf(doc)
The writer emits 7-bit ASCII (non-ASCII as \uN), so it has no charset dependency and round-trips
cleanly with the reader.
For authoring rich documents — fonts, colors, headings, page breaks, hyperlinks, bookmarks, and
paragraph layout — build an RtfDocument and serialize it with RtfDocumentWriter. See the
Writing rich RTF guide.
import com.darkrockstudios.libs.rtfparserkmp.io.asRtfSource // kotlinx-io or okio
import com.darkrockstudios.libs.rtfparserkmp.parser.StandardRtfParser
StandardRtfParser().parse(source.asRtfSource(), myListener) // source: kotlinx-io Source / okio BufferedSource
import com.darkrockstudios.libs.rtfparserkmp.compose.rtfToAnnotatedString
import androidx.compose.foundation.text.BasicText
val styled: AnnotatedString = rtfToAnnotatedString(bytes) // bold/italic/underline -> SpanStyle
// BasicText(styled)
val rtf: String = annotatedStringToRtf(styled) // and back the other way
rtfcli <input> [--text | --markdown | --rtf] [-o <out>]
.rtf input → --text (default) or --markdown; .md input → --rtf.
The 22 real-world .rtf fixtures from upstream (Word, LibreOffice, Pages, encodings, \upr, negative
Unicode, …) are embedded and compared byte-for-byte against their expected event dumps — green on JVM,
and on every target for the single-byte/UTF-8 subset. CI runs the suite across Linux, macOS, and
Windows runners.
\'xx) decodes on JVM, Android, JS, wasmJs,
and all Apple targets (web via TextDecoder, Apple via CFString). Only the remaining native
targets — Linux, Windows (mingw), and wasmWasi — throw for those legacy bytes. \uN Unicode (what
modern Word/LibreOffice/Pages emit) and all single-byte codepages work on every target.| Artifact | Purpose | Runtime deps |
|---|
rtf-core | Shared model: Command/CommandType, RtfEvent, RtfListener, RtfSource/ByteArrayRtfSource, styled-text model | none |
rtf-reader | StandardRtfParser, parseRtf, charset decoding, RtfTextExtractor, RtfToMarkdown | rtf-core |
rtf-writer | RtfWriter (styled model → RTF), MarkdownToRtf | rtf-core |
rtf-io-kotlinx | RtfSource over a kotlinx-io Source | rtf-core, kotlinx-io |
rtf-io-okio | RtfSource over an Okio BufferedSource | rtf-core, Okio |
rtf-compose | RTF ↔ Compose AnnotatedString (rtfToAnnotatedString / annotatedStringToRtf) | rtf-core, rtf-reader, rtf-writer, Compose ui-text |
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