compose-slot-api-pattern

To make a Jetpack Compose component reusable, replace primitive content parameters with flexible slot-based content using @Composable () -> Unit parameters like headlineContent or leadingContent to delegate visuals to callers.

Slot APIs in Jetpack Compose are parameters defined as @Composable () -> Unit that let a component describe structure while delegating content to callers, used when a UI composite must adapt across multiple layouts without changing its API.

To omit optional content in a Compose slot API without breaking layout, define slots as nullable parameters like @Composable (() -> Unit)? so callers can pass null, allowing the component to skip space and padding when content is absent.

Yes, you can provide scope receivers in Compose slot APIs by defining slots as @Composable RowScope.() -> Unit, unlocking layout helpers like weight to let callers control how their supplied content blocks render inside the specific layout.

The best way to centralize defaults for a Material3 Compose component is using a shared XxxDefaults object, ensuring consistent theming and spacing across all call sites when applying slot-based content parameters.

Refactoring a Compose component to replace primitive parameters with slots ensures the component remains layout-focused, enabling flexible reuse across different visual shapes and layouts without requiring API changes at the call sites.