androidx.compose.ui.text.font

fun Font(
    familyName: DeviceFontFamilyName,
    weight: FontWeight = FontWeight.Normal,
    style: FontStyle = FontStyle.Normal,
    variationSettings: FontVariation.Settings = FontVariation.Settings()
): Font

Describes a system-installed font that may be present on some Android devices.

You should assume this will not resolve on some devices and provide an appropriate fallback font.

Family name lookup is device and platform-specific, and different OEMs may install different fonts. All fonts described this way are considered FontLoadingStrategy.OptionalLocal and will continue to the next font in the chain if they are not present on a device.

Use this method to prefer locally pre-loaded system fonts when they are available. System fonts are always more efficient to load than reading a font file, or downloadable fonts.

A system installed font resolution will never trigger text reflow.

This descriptor will trust the weight and style parameters as accurate. However, it is not required that the loaded fonts actually support the requested weight and style and this may trigger platform level font-synthesis of fake bold or fake italic during font resolution.

This Font can not describe the system-installed Typeface.DEFAULT. All other system-installed fonts are allowed.

Note: When setting variationSettings any unset axis may be reset to the font default, ignoring any axis restrictions in fonts.xml or font_customizations.xml. This may have surprising side-effects when named fonts differ only by the default axis settings in XML. When setting variation axis for device fonts, ensure you set all possible settings for the font.

@RequiresApi(value = 26)
fun Font(
    fileDescriptor: ParcelFileDescriptor,
    weight: FontWeight = FontWeight.Normal,
    style: FontStyle = FontStyle.Normal,
    variationSettings: FontVariation.Settings = FontVariation.Settings(weight, style)
): Font

Create a Font declaration from a ParcelFileDescriptor. The content of the ParcelFileDescriptor is read during construction.

fun Font(
    file: File,
    weight: FontWeight = FontWeight.Normal,
    style: FontStyle = FontStyle.Normal,
    variationSettings: FontVariation.Settings = FontVariation.Settings(weight, style)
): Font

Create a Font declaration from a file. The content of the File is read during construction.

fun Font(
    resId: Int,
    weight: FontWeight = FontWeight.Normal,
    style: FontStyle = FontStyle.Normal,
    loadingStrategy: FontLoadingStrategy = FontLoadingStrategy.Blocking
): Font

Creates a Font with using resource ID.

Allows control over FontLoadingStrategy strategy. You may supply FontLoadingStrategy.Blocking, or FontLoadingStrategy.OptionalLocal for fonts that are expected on the first frame.

FontLoadingStrategy.Async, will load the font in the background and cause text reflow when loading completes. Fonts loaded from a remote source via resources should use FontLoadingStrategy.Async.

fun Font(
    path: String,
    assetManager: AssetManager,
    weight: FontWeight = FontWeight.Normal,
    style: FontStyle = FontStyle.Normal,
    variationSettings: FontVariation.Settings = FontVariation.Settings(weight, style)
): Font

Create a Font declaration from a file in the assets directory. The content of the File is read during construction.

fun FontFamily(vararg fonts: Font): FontFamily

Construct a font family that contains list of custom font files.

fun FontFamily(fonts: List<Font>): FontFamily

Construct a font family that contains list of custom font files.

fun FontFamily(typeface: Typeface): FontFamily

Creates a FontFamily from Android Typeface.

fun FontFamily(typeface: Typeface): FontFamily

Construct a font family that contains loaded font family: Typeface.

fun Typeface(typeface: Typeface): Typeface

Returns a Compose androidx.compose.ui.text.font.Typeface from Android Typeface.

fun Typeface(
    context: Context,
    fontFamily: FontFamily,
    styles: List<Pair<FontWeight, FontStyle>>? = null
): Typeface

Build an Android specific Typeface from FontFamily.

You can pass styles for loading only specific styles.

This function caches the internal native Typeface but always create the new Typeface object. Caller should cache if necessary.

fun createFontFamilyResolver(context: Context): FontFamily.Resolver

Create a new fontFamilyResolver for use outside of composition context

Example usages:

• Application.onCreate to preload fonts

• Creating Paragraph objects on background thread

Usages inside of Composition should use LocalFontFamilyResolver.current

All instances of FontFamily.Resolver created by createFontFamilyResolver share the same typeface caches.

fun createFontFamilyResolver(
    context: Context,
    coroutineContext: CoroutineContext
): FontFamily.Resolver

Create a new fontFamilyResolver for use outside of composition context with a coroutine context.

Example usages:

• Application.onCreate to preload fonts

• Creating Paragraph objects on background thread

• Configuring LocalFontFamilyResolver with a different CoroutineScope

Usages inside of Composition should use LocalFontFamilyResolver.current

Any kotlinx.coroutines.CoroutineExceptionHandler provided will be called with exceptions related to fallback font loading. These exceptions are not fatal, and indicate that font fallback continued to the next font load.

If no kotlinx.coroutines.CoroutineExceptionHandler is provided, a default implementation will be added that ignores all exceptions.

All instances of FontFamily.Resolver created by createFontFamilyResolver share the same typeface caches.

fun createFontFamilyResolver(
    fontResourceLoader: Font.ResourceLoader,
    context: Context
): FontFamily.Resolver

Bridge between subclasses of Font.ResourceLoader and the new FontFamily.Resolver API.

To use add as a CompositionLocal replacing the default FontFamily.Resolver:

LocalFontFamilyResolver provides createFontFamilyResolver(myFontResourceLoader, context)

This FontFamily.Resolver is capable of loading all fonts that the default FontFamily.Resolver is. In addition, it will delegate all resource fonts to the provided Font.ResourceLoader, preserving the behavior of Compose 1.0.

This method will be removed by Compose 2.0, and callers should migrate to using AndroidFont to implement the same behavior using font fallback chains.

A FontFamily.Resolver created this way will not share caches with other FontFamily.Resolvers.

fun lerp(start: FontWeight, stop: FontWeight, fraction: Float): FontWeight

Linearly interpolate between two font weights.

The fraction argument represents position on the timeline, with 0.0 meaning that the interpolation has not started, returning start (or something equivalent to start), 1.0 meaning that the interpolation has finished, returning stop (or something equivalent to stop), and values in between meaning that the interpolation is at the relevant point on the timeline between start and stop. The interpolation can be extrapolated beyond 0.0 and 1.0, so negative values and values greater than 1.0 are valid (and can easily be generated by curves).

Values for fraction are usually obtained from an Animation, such as an AnimationController.

fun FontFamily.Resolver.resolveAsTypeface(
    fontFamily: FontFamily? = null,
    fontWeight: FontWeight = FontWeight.Normal,
    fontStyle: FontStyle = FontStyle.Normal,
    fontSynthesis: FontSynthesis = FontSynthesis.All
): State<Typeface>

Resolve a font to an Android Typeface

On Android, font resolution always produces an android.graphics.Typeface.

This convenience method converts State to State to avoid casting the result.

fun Font.toFontFamily(): FontFamily

Create a FontFamily from this single Font.