Custom design systems in Compose

While Material is our recommended design system and Jetpack Compose ships an implementation of Material, you are not forced to use it. Material is built entirely on public APIs, so it’s possible to create your own design system in the same manner.

There are several approaches you might take:

You may also wish to continue using Material components with a custom design system. It’s possible to do this but there are things to keep in mind to suit the approach you’ve taken.

To learn more about the lower-level constructs and APIs used by MaterialTheme and custom design systems, check out the Anatomy of a theme in Compose guide.

Extending Material Theming

Compose Material closely models Material Theming to make it simple and type-safe to follow the Material guidelines. However, it’s possible to extend the color, typography, and shape sets with additional values.

The simplest approach is to add extension properties:

// Use with MaterialTheme.colors.snackbarAction
val Colors.snackbarAction: Color
    get() = if (isLight) Red300 else Red700

// Use with MaterialTheme.typography.textFieldInput
val Typography.textFieldInput: TextStyle
    get() = TextStyle(/* ... */)

// Use with MaterialTheme.shapes.card
val Shapes.card: Shape
    get() = RoundedCornerShape(size = 20.dp)
CustomDesignSystem.kt

This provides consistency with MaterialTheme usage APIs. An example of this defined by Compose itself is primarySurface, which acts as a proxy between primary and surface depending on Colors.isLight.

Another approach is to define an extended theme that “wraps” MaterialTheme and its values.

Suppose you wish to add two additional colors — tertiary and onTertiary — whilst keeping the existing Material colors:

@Immutable
data class ExtendedColors(
    val tertiary: Color,
    val onTertiary: Color
)

val LocalExtendedColors = staticCompositionLocalOf {
    ExtendedColors(
        tertiary = Color.Unspecified,
        onTertiary = Color.Unspecified
    )
}

@Composable
fun ExtendedTheme(
    /* ... */
    content: @Composable () -> Unit
) {
    val extendedColors = ExtendedColors(
        tertiary = Color(0xFFA8EFF0),
        onTertiary = Color(0xFF002021)
    )
    CompositionLocalProvider(LocalExtendedColors provides extendedColors) {
        MaterialTheme(
            /* colors = ..., typography = ..., shapes = ... */
            content = content
        )
    }
}

// Use with eg. ExtendedTheme.colors.tertiary
object ExtendedTheme {
    val colors: ExtendedColors
        @Composable
        get() = LocalExtendedColors.current
}
CustomDesignSystem.kt

This is similar to MaterialTheme usage APIs. It also supports multiple themes as you can nest ExtendedThemes in the same way as MaterialTheme.

Using Material components

When extending Material Theming, existing MaterialTheme values are maintained and Material components still have reasonable defaults.

If you wish to use extended values in components, wrap them in your own composable functions, directly setting the values you wish to alter, and exposing others as parameters to the containing composable:

@Composable
fun ExtendedButton(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit
) {
    Button(
        colors = ButtonDefaults.buttonColors(
            containerColor = ExtendedTheme.colors.tertiary,
            contentColor = ExtendedTheme.colors.onTertiary
            /* Other colors use values from MaterialTheme */
        ),
        onClick = onClick,
        modifier = modifier,
        content = content
    )
}
CustomDesignSystem.kt

You would then replace usages of Button with ExtendedButton where appropriate.

@Composable
fun ExtendedApp() {
    ExtendedTheme {
        /*...*/
        ExtendedButton(onClick = { /* ... */ }) {
            /* ... */
        }
    }
}
CustomDesignSystem.kt

Replacing Material systems

Instead of extending Material Theming, you may wish to replace one or more systems — Colors, Typography, or Shapes — with a custom implementation, while maintaining the others.

Suppose you wish to replace the type and shape systems while keeping the color system:

@Immutable
data class ReplacementTypography(
    val body: TextStyle,
    val title: TextStyle
)

@Immutable
data class ReplacementShapes(
    val component: Shape,
    val surface: Shape
)

val LocalReplacementTypography = staticCompositionLocalOf {
    ReplacementTypography(
        body = TextStyle.Default,
        title = TextStyle.Default
    )
}
val LocalReplacementShapes = staticCompositionLocalOf {
    ReplacementShapes(
        component = RoundedCornerShape(ZeroCornerSize),
        surface = RoundedCornerShape(ZeroCornerSize)
    )
}

@Composable
fun ReplacementTheme(
    /* ... */
    content: @Composable () -> Unit
) {
    val replacementTypography = ReplacementTypography(
        body = TextStyle(fontSize = 16.sp),
        title = TextStyle(fontSize = 32.sp)
    )
    val replacementShapes = ReplacementShapes(
        component = RoundedCornerShape(percent = 50),
        surface = RoundedCornerShape(size = 40.dp)
    )
    CompositionLocalProvider(
        LocalReplacementTypography provides replacementTypography,
        LocalReplacementShapes provides replacementShapes
    ) {
        MaterialTheme(
            /* colors = ... */
            content = content
        )
    }
}

// Use with eg. ReplacementTheme.typography.body
object ReplacementTheme {
    val typography: ReplacementTypography
        @Composable
        get() = LocalReplacementTypography.current
    val shapes: ReplacementShapes
        @Composable
        get() = LocalReplacementShapes.current
}
CustomDesignSystem.kt

Using Material components

When one or more systems of MaterialTheme have been replaced, using Material components as-is may result in unwanted Material color, type, or shape values.

If you wish to use replacement values in components, wrap them in your own composable functions, directly setting the values for the relevant system, and exposing others as parameters to the containing composable.

@Composable
fun ReplacementButton(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit
) {
    Button(
        shape = ReplacementTheme.shapes.component,
        onClick = onClick,
        modifier = modifier,
        content = {
            ProvideTextStyle(
                value = ReplacementTheme.typography.body
            ) {
                content()
            }
        }
    )
}
CustomDesignSystem.kt

You would then replace usages of Button with ReplacementButton where appropriate.

@Composable
fun ReplacementApp() {
    ReplacementTheme {
        /*...*/
        ReplacementButton(onClick = { /* ... */ }) {
            /* ... */
        }
    }
}
CustomDesignSystem.kt

Implementing a fully-custom design system

You may wish to replace Material Theming with a fully-custom design system. Consider that MaterialTheme provides the following systems:

  • Colors, Typography, and Shapes: Material Theming systems
  • ContentAlpha: Opacity levels to convey emphasis in Text and Icon
  • TextSelectionColors: Colors used for text selection by Text and TextField
  • Ripple and RippleTheme: Material implementation of Indication

If you want to continue using Material components, you'll need to replace some of these systems in your custom theme or themes, or handle the systems in your components, to avoid unwanted behavior.

However, design systems are not limited to the concepts Material relies on. You can modify existing systems and introduce entirely new ones — with new classes and types — to make other concepts compatible with themes.

In the following code, we model a custom color system that includes gradients (List<Color>), include a type system, introduce a new elevation system, and exclude other systems provided by MaterialTheme:

@Immutable
data class CustomColors(
    val content: Color,
    val component: Color,
    val background: List<Color>
)

@Immutable
data class CustomTypography(
    val body: TextStyle,
    val title: TextStyle
)

@Immutable
data class CustomElevation(
    val default: Dp,
    val pressed: Dp
)

val LocalCustomColors = staticCompositionLocalOf {
    CustomColors(
        content = Color.Unspecified,
        component = Color.Unspecified,
        background = emptyList()
    )
}
val LocalCustomTypography = staticCompositionLocalOf {
    CustomTypography(
        body = TextStyle.Default,
        title = TextStyle.Default
    )
}
val LocalCustomElevation = staticCompositionLocalOf {
    CustomElevation(
        default = Dp.Unspecified,
        pressed = Dp.Unspecified
    )
}

@Composable
fun CustomTheme(
    /* ... */
    content: @Composable () -> Unit
) {
    val customColors = CustomColors(
        content = Color(0xFFDD0D3C),
        component = Color(0xFFC20029),
        background = listOf(Color.White, Color(0xFFF8BBD0))
    )
    val customTypography = CustomTypography(
        body = TextStyle(fontSize = 16.sp),
        title = TextStyle(fontSize = 32.sp)
    )
    val customElevation = CustomElevation(
        default = 4.dp,
        pressed = 8.dp
    )
    CompositionLocalProvider(
        LocalCustomColors provides customColors,
        LocalCustomTypography provides customTypography,
        LocalCustomElevation provides customElevation,
        content = content
    )
}

// Use with eg. CustomTheme.elevation.small
object CustomTheme {
    val colors: CustomColors
        @Composable
        get() = LocalCustomColors.current
    val typography: CustomTypography
        @Composable
        get() = LocalCustomTypography.current
    val elevation: CustomElevation
        @Composable
        get() = LocalCustomElevation.current
}
CustomDesignSystem.kt

Using Material components

When no MaterialTheme is present, using Material components as-is will result in unwanted Material color, type, and shape values and indication behavior.

If you wish to use custom values in components, wrap them in your own composable functions, directly setting the values for the relevant system, and exposing others as parameters to the containing composable.

We recommend you access values you set from your custom theme. Alternatively, if your theme doesn’t provide Color, TextStyle, Shape, or other systems, you can hardcode them.

@Composable
fun CustomButton(
    onClick: () -> Unit,
    modifier: Modifier = Modifier,
    content: @Composable RowScope.() -> Unit
) {
    Button(
        colors = ButtonDefaults.buttonColors(
            containerColor = CustomTheme.colors.component,
            contentColor = CustomTheme.colors.content,
            disabledContainerColor = CustomTheme.colors.content
                .copy(alpha = 0.12f)
                .compositeOver(CustomTheme.colors.component),
            disabledContentColor = CustomTheme.colors.content
                .copy(alpha = ContentAlpha.disabled)
        ),
        shape = ButtonShape,
        elevation = ButtonDefaults.elevatedButtonElevation(
            defaultElevation = CustomTheme.elevation.default,
            pressedElevation = CustomTheme.elevation.pressed
            /* disabledElevation = 0.dp */
        ),
        onClick = onClick,
        modifier = modifier,
        content = {
            ProvideTextStyle(
                value = CustomTheme.typography.body
            ) {
                content()
            }
        }
    )
}

val ButtonShape = RoundedCornerShape(percent = 50)
CustomDesignSystem.kt

If you’ve introduced new class types — such as List<Color> to represent gradients — then it may be better to implement components from scratch instead of wrapping them. For an example, take a look at JetsnackButton from the Jetsnack sample.