Preview

@Retention(value = AnnotationRetention.BINARY)
@Target(allowedTargets = [AnnotationTarget.ANNOTATION_CLASS, AnnotationTarget.FUNCTION])
@Repeatable
@MustBeDocumented
public annotation Preview

The annotation that marks Tile preview components that should have a visual preview in the Android Studio preview panel. Tile preview components are methods that take an optional Context parameter and return a TilePreviewData. Methods annotated with Preview must be top level declarations or in a top level class with a default constructor.

For example:

@Preview
fun myTilePreview(): TilePreviewData {
    return TilePreviewData { request -> myTile(request) }
}

or:

@Preview
fun myTilePreview(context: Context): TilePreviewData {
    return TilePreviewData { request -> myTile(request, context) }
}

Because of the way previews are rendered within Android Studio, they are lightweight and don't require the whole Android framework to render them. However, this comes with the following limitations:

• No network access

• No file access

• Some Context APIs may not be fully available, such as launching activities or retrieving services

For more information, see https://developer.android.com/jetpack/compose/tooling/previews#preview-limitations

The annotation contains a number of parameters that allow to define the way the Tile will be rendered within the preview. The passed parameters are only read by Studio when rendering the preview.

Summary

public Preview(
    @NonNull String name,
    @NonNull String group,
    @NonNull String locale,
    @NonNull String device,
    @FloatRange(from = 0.01) float fontScale
)

public final @NonNull String getDevice()

public final float getFontScale()

public final @NonNull String getGroup()

public final @NonNull String getLocale()

public final @NonNull String getName()