Hyphen

A WYSIWYG Markdown editor for Compose Multiplatform.
Type in Markdown, see formatting live. Copy as Markdown. Works on Android, Desktop, and Web.

→ Try the live web demo

Features

✍️ Live Markdown Input

Type Markdown syntax directly and watch it convert as you write — no mode switching, no preview pane required.

Syntax	Style
`text`	Bold
`text`	Italic
`__text__`	Underline
`[text](url)`	Link
`text`	`Inline code`
`~~text~~`	~~Strikethrough~~
`==text==`	Highlight
`#` at line start	Heading 1
`##` at line start	Heading 2
`###` at line start	Heading 3
`####` at line start	Heading 4
`#####` at line start	Heading 5
`######` at line start	Heading 6
`-` at line start	Bullet list
`1.` at line start	Ordered list
`>` at line start	Blockquote
`- [ ]` at line start	Checkbox (unchecked)
`- [x]` at line start	Checkbox (checked)

📋 Markdown Clipboard

Cut, copy, and paste all work across Android, Desktop, and Web. Copying a selection serializes it to Markdown automatically, paste into any Markdown-aware editor and all formatting travels with it.

⌨️ Keyboard Shortcuts

Full hardware keyboard support on Desktop and Web:

Shortcut	Action
`Ctrl / Cmd + B`	Toggle bold
`Ctrl / Cmd + I`	Toggle italic
`Ctrl / Cmd + U`	Toggle underline
`Ctrl / Cmd + Shift + S`	Toggle strikethrough
`Ctrl / Cmd + Shift + X`	Toggle strikethrough
`Ctrl / Cmd + Alt + X`	Toggle strikethrough
`Ctrl / Cmd + Shift + H`	Toggle highlight
`Ctrl / Cmd + Space`	Clear all styles on selection
`Ctrl / Cmd + 1`	Toggle Heading 1
`Ctrl / Cmd + 2`	Toggle Heading 2
`Ctrl / Cmd + 3`	Toggle Heading 3
`Ctrl / Cmd + 4`	Toggle Heading 4
`Ctrl / Cmd + 5`	Toggle Heading 5
`Ctrl / Cmd + 6`	Toggle Heading 6
`Ctrl / Cmd + Enter`	Toggle checkbox on current line
`Ctrl / Cmd + K`	Toggle link on selection
`Ctrl / Cmd + Z`	Undo
`Ctrl / Cmd + Y`	Redo
`Ctrl / Cmd + Shift + Z`	Redo

↩️ Undo / Redo History

Granular history with snapshots saved at word boundaries, pastes, and Markdown conversions. The redo stack is maintained correctly across all operations, including toolbar toggles and programmatic edits.

🌍 Compose Multiplatform

Single shared implementation targeting Android, Desktop (JVM), and Web (WasmJS / JS).

Installation

Using `libs.versions.toml` (recommended)

Add the version and library entry to your version catalog:

gradle/libs.versions.toml

[versions]
hyphen = "0.4.0-alpha01"

[libraries]
hyphen = { group = "io.github.densermeerkat", name = "hyphen", version.ref = "hyphen" }

Then reference it in your shared module:

shared/build.gradle.kts

kotlin {
    sourceSets {
        commonMain.dependencies {
            implementation(libs.hyphen)
        }
    }
}

commonMain is the source set that compiles for every target at once — Android, Desktop, and Web. Declaring Hyphen there means you write the dependency once and all platforms pick it up automatically.

Using string notation

// shared/build.gradle.kts
kotlin {
    sourceSets {
        commonMain.dependencies {
            implementation("io.github.densermeerkat:hyphen:0.4.0-alpha01")
        }
    }
}

Quick Start

val state = rememberHyphenTextState(
    initialText = "**Hello**, *Hyphen*!"
)

HyphenTextField(
    state = state,
    label = { Text("Notes") },
)

// Read the result at any time
val markdown = state.toMarkdown()

Choosing an Editor Component

Hyphen ships two editor composables. Use whichever fits your design:

`HyphenBasicTextEditor`

A thin wrapper around BasicTextField with no decoration. Use this when you control the layout yourself or want full design freedom.

HyphenBasicTextEditor(
    state = state,
    modifier = Modifier
        .fillMaxWidth()
        .padding(16.dp),
    textStyle = TextStyle(
        fontSize = 16.sp,
        color = MaterialTheme.colorScheme.onSurface,
    ),
    cursorBrush = SolidColor(MaterialTheme.colorScheme.primary),
    onMarkdownChange = { markdown -> /* sync to ViewModel */ },
)

`HyphenTextField` (Material 3)

Wraps HyphenBasicTextEditor inside a standard Material3 filled text field decorator — labels, placeholder, leading/trailing icons, supporting text, and error state all work out of the box.

HyphenTextField(
    state = state,
    label = { Text("Notes") },
    placeholder = { Text("Start typing…") },
    trailingIcon = { Icon(Icons.Default.Edit, contentDescription = null) },
    supportingText = { Text("Markdown supported") },
    modifier = Modifier.fillMaxWidth(),
)

Both composables accept the same styleConfig, onTextChange, onMarkdownChange, and clipboardLabel parameters. The Material3 variant additionally accepts colors, shape, labelPosition, contentPadding, and all standard decoration slots.

Usage

Toolbar buttons — keeping focus on Desktop & Web

On Desktop and Web, clicking a button moves keyboard focus away from the editor. This causes the text selection to be lost before the style toggle runs. Fix this by adding focusProperties { canFocus = false } to every toolbar button so focus never leaves the editor when a button is tapped:

IconToggleButton(
    checked = state.hasStyle(MarkupStyle.Bold),
    onCheckedChange = { state.toggleStyle(MarkupStyle.Bold) },
    modifier = Modifier.focusProperties { canFocus = false }, // ← required on Desktop & Web
) {
    Icon(Icons.Default.FormatBold, contentDescription = "Bold")
}

This applies to any clickable element in your toolbar — IconButton, Button, IconToggleButton, etc.

Custom style config

HyphenBasicTextEditor(
    state = state,
    styleConfig = HyphenStyleConfig(
        boldStyle = SpanStyle(
            fontWeight = FontWeight.ExtraBold,
            color = Color(0xFF1A73E8),
        ),
        highlightStyle = SpanStyle(
            background = Color(0xFFFFF176),
        ),
        inlineCodeStyle = SpanStyle(
            background = Color(0xFFF1F3F4),
            fontFamily = FontFamily.Monospace,
            color = Color(0xFFD93025),
        ),
    ),
)

Programmatic control

// Load new Markdown content (resets undo history)
state.setMarkdown("# New content\n\nHello!")

// Toggle formatting from a custom button
Button(onClick = { state.toggleStyle(MarkupStyle.Bold) }) { Text("B") }

// Remove all inline formatting from the current selection
Button(onClick = { state.clearAllStyles() }) { Text("Clear") }

// Undo / redo
state.undo()
state.redo()

Reactive observation

// Callback — fires on every text or formatting change
HyphenBasicTextEditor(
    state = state,
    onMarkdownChange = { markdown -> viewModel.onContentChanged(markdown) },
)

// Flow — collect anywhere, debounce freely
viewModelScope.launch {
    state.markdownFlow
        .debounce(500)
        .collect { markdown -> repository.save(markdown) }
}

API Reference

`HyphenBasicTextEditor`

Parameter	Type	Default	Description
`state`	`HyphenTextState`	Required	Holds text content, spans, selection, and undo/redo history.
`modifier`	`Modifier`	`Modifier`	Applied to the underlying `BasicTextField`.
`enabled`	`Boolean`	`true`	When `false`, the field is neither editable nor focusable.
`readOnly`	`Boolean`	`false`	When `true`, the field cannot be modified but can be focused and copied.
`textStyle`	`TextStyle`	`TextStyle(fontSize = 16.sp)`	Typographic style applied to the visible text.
`styleConfig`	`HyphenStyleConfig`	`HyphenStyleConfig()`	Visual appearance of each `MarkupStyle`.
`linkConfig`	`HyphenLinkConfig`	`HyphenLinkConfig()`	Interaction configuration for link spans (menus, dialogs, opening URLs).
`keyboardOptions`	`KeyboardOptions`	Sentences, no autocorrect	Software keyboard options.
`lineLimits`	`TextFieldLineLimits`	`TextFieldLineLimits.Default`	Single-line or multi-line behaviour.
`scrollState`	`ScrollState`	`rememberScrollState()`	Controls vertical or horizontal scroll of the field content.
`interactionSource`	`MutableInteractionSource?`	`null`	Hoist to observe focus, hover, and press interactions externally.
`cursorBrush`	`Brush`	`SolidColor(Color.Black)`	Brush used to paint the cursor.
`decorator`	`TextFieldDecorator?`	`null`	Optional decorator for external visual styling.
`onTextLayout`	`(Density.(...) -> Unit)?`	`null`	Callback invoked on every text layout recalculation.
`clipboardLabel`	`String`	`"Markdown Text"`	Label attached to clipboard entries on copy/cut.
`onTextChange`	`((String) -> Unit)?`	`null`	Callback invoked whenever the plain text changes.
`onMarkdownChange`	`((String) -> Unit)?`	`null`	Callback invoked whenever text or formatting changes, providing the serialized Markdown string.

`HyphenTextState`

Property / Method	Type / Return	Description
`textFieldState`	`TextFieldState`	The underlying Compose foundation state driving the editor.
`text`	`String`	Plain text with all Markdown syntax stripped.
`selection`	`TextRange`	Current cursor position or selected range.
`spans`	`List<MarkupStyleRange>`	Snapshot-observable list of active formatting spans.
`pendingOverrides`	`Map<MarkupStyle, Boolean>`	Transient style intent applied to the next typed characters.
`canUndo` / `canRedo`	`Boolean`	`true` if undo/redo actions are available in the history stack.
`activeLinkForEditing`	`MarkupStyleRange?`	The link span currently being edited via the built-in dialog.
`isFocused`	`Boolean`	Whether the text field currently has input focus.
`toggleStyle(style)`	`Unit`	Toggles an inline or block style on the current selection.
`toggleCheckbox(index?)`	`Unit`	Toggles the checked/unchecked state of checkboxes in the selection or at a specific index.
`clearAllStyles()`	`Unit`	Removes all inline formatting from the selection; suppresses at cursor.
`toggleLink()`	`Unit`	Wraps selection in a link, or opens an existing link at the cursor for editing.
`updateLink(span, text, url)`	`Unit`	Updates an existing link's display text and URL.
`hasStyle(style)`	`Boolean`	`true` if the style is active at the current selection or cursor.
`isStyleAt(index, style)`	`Boolean`	Point query against the span list (ignores selection / overrides).
`clearPendingOverrides()`	`Unit`	Resets transient typing intent.
`undo()` / `redo()`	`Unit`	Navigates the undo / redo history stack.
`toMarkdown(start?, end?)`	`String`	Serializes content (or a substring range) to a Markdown formatted string.
`setMarkdown(markdown)`	`Unit`	Replaces all content programmatically, parses it, and resets history.
`markdownFlow`	`Flow<String>`	Emits the serialized Markdown string on every text or formatting change.

`HyphenStyleConfig`

Property	Default Value
`boldStyle`	`SpanStyle(fontWeight = FontWeight.Bold)`
`italicStyle`	`SpanStyle(fontStyle = FontStyle.Italic)`
`underlineStyle`	`SpanStyle(textDecoration = TextDecoration.Underline)`
`strikethroughStyle`	`SpanStyle(textDecoration = TextDecoration.LineThrough)`
`highlightStyle`	`SpanStyle(background = Color(0xFFFFEB3B).copy(alpha = 0.4f))`
`inlineCodeStyle`	`SpanStyle(background = Color.Gray.copy(alpha = 0.15f), fontFamily = FontFamily.Monospace)`
`blockquoteSpanStyle`	`SpanStyle(fontStyle = FontStyle.Italic, color = Color.Gray, background = Color.Gray.copy(0.05f))`
`bulletListStyle`	`ListItemStyle()`
`orderedListStyle`	`ListItemStyle()`
`checkboxCheckedStyle`	`SpanStyle(textDecoration = TextDecoration.LineThrough)`
`checkboxUncheckedStyle`	`null`
`h1Style`	`SpanStyle(fontSize = 24.sp, fontWeight = FontWeight.Bold)`
`h2Style`	`SpanStyle(fontSize = 22.sp, fontWeight = FontWeight.Bold)`
`h3Style`	`SpanStyle(fontSize = 20.sp, fontWeight = FontWeight.Bold)`
`h4Style`	`SpanStyle(fontSize = 18.sp, fontWeight = FontWeight.Bold)`
`h5Style`	`SpanStyle(fontSize = 17.sp, fontWeight = FontWeight.Bold)`
`h6Style`	`SpanStyle(fontSize = 16.sp, fontWeight = FontWeight.Bold)`
`linkStyle`	`SpanStyle(color = Color.Blue, textDecoration = TextDecoration.Underline)`

`MarkupStyle`

// Inline styles
MarkupStyle.Bold
MarkupStyle.Italic
MarkupStyle.Underline
MarkupStyle.Strikethrough
MarkupStyle.InlineCode
MarkupStyle.Highlight

// Heading styles
MarkupStyle.H1
MarkupStyle.H2
MarkupStyle.H3
MarkupStyle.H4
MarkupStyle.H5
MarkupStyle.H6

// Block styles
MarkupStyle.BulletList
MarkupStyle.OrderedList
MarkupStyle.Blockquote
MarkupStyle.CheckboxUnchecked
MarkupStyle.CheckboxChecked

`ListItemStyle`

Controls the prefix marker and content text of a list item independently. Used by bulletListStyle and orderedListStyle on HyphenStyleConfig.

Note

Checklist items (- [ ], - [x]) do not use ListItemStyle. They use an overlay widget and can be styled via checkboxCheckedStyle and checkboxUncheckedStyle (which take a SpanStyle?).

Property	Type	Default	Description
`prefixStyle`	`SpanStyle?`	`null`	Applied to the marker (`-`, `1.`, `- [ ]`, `- [x]`).
`contentStyle`	`SpanStyle?`	`null`	Applied to the text after the marker.

Checklist Styling

Checkboxes in Hyphen are rendered as native Material3 widgets overlaid on the editor. This ensures they always match your theme and remain perfectly aligned regardless of font size. Use checkboxCheckedStyle and checkboxUncheckedStyle to style the label text of the checklist items:

HyphenBasicTextEditor(
    state = state,
    styleConfig = HyphenStyleConfig(
        checkboxCheckedStyle = SpanStyle(
            textDecoration = TextDecoration.LineThrough,
            color = Color.Gray,
        ),
    ),
)

Supported Platforms

Platform	Status
Android	✅
Desktop (JVM)	✅
Web (WasmJS)	✅
Web (JS / IR)	✅
iOS	🚧 Planned

Name		Name	Last commit message	Last commit date
Latest commit History 33 Commits
assets/images		assets/images
docs		docs
gradle		gradle
hyphen		hyphen
kotlin-js-store		kotlin-js-store
sample		sample
.gitignore		.gitignore
CHANGELOG.md		CHANGELOG.md
LICENSE		LICENSE
README.md		README.md
build.gradle.kts		build.gradle.kts
gradle.properties		gradle.properties
gradlew		gradlew
gradlew.bat		gradlew.bat
settings.gradle.kts		settings.gradle.kts

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Repository files navigation

Hyphen

Features

✍️ Live Markdown Input

📋 Markdown Clipboard

⌨️ Keyboard Shortcuts

↩️ Undo / Redo History

🌍 Compose Multiplatform

Installation

Using `libs.versions.toml` (recommended)

Using string notation

Quick Start

Choosing an Editor Component

`HyphenBasicTextEditor`

`HyphenTextField` (Material 3)

Usage

Toolbar buttons — keeping focus on Desktop & Web

Custom style config

Programmatic control

Reactive observation

API Reference

`HyphenBasicTextEditor`

`HyphenTextState`

`HyphenStyleConfig`

`MarkupStyle`

`ListItemStyle`

Checklist Styling

Supported Platforms

About

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Releases 4

Contributors

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Languages

Folders and files

Latest commit

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Repository files navigation

Hyphen

Features

✍️ Live Markdown Input

📋 Markdown Clipboard

⌨️ Keyboard Shortcuts

↩️ Undo / Redo History

🌍 Compose Multiplatform

Installation

Using libs.versions.toml (recommended)

Using string notation

Quick Start

Choosing an Editor Component

HyphenBasicTextEditor

HyphenTextField (Material 3)

Usage

Toolbar buttons — keeping focus on Desktop & Web

Custom style config

Programmatic control

Reactive observation

API Reference

HyphenBasicTextEditor

HyphenTextState

HyphenStyleConfig

MarkupStyle

ListItemStyle

Checklist Styling

Supported Platforms

About

Topics

Resources

License

Uh oh!

Stars

Watchers

Forks

Releases 4

Contributors

Uh oh!

Languages

Using `libs.versions.toml` (recommended)

`HyphenBasicTextEditor`

`HyphenTextField` (Material 3)

`HyphenBasicTextEditor`

`HyphenTextState`

`HyphenStyleConfig`

`MarkupStyle`

`ListItemStyle`