Wrapping still is a pain, and losing type info from Screen.withEnvironment is too.

[rjrjr]

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From a long discussion w/ @RBusarow

How about this:

sealed interface Screen

@WorkflowUiExperimentalApi
interface Screen_2 : Screen

@WorkflowUiExperimentalApi
class EnvironmentScreen<V : Screen_2> @PublishedApi internal constructor(
  public val screen: V,
  public val viewEnvironment: ViewEnvironment = ViewEnvironment.EMPTY
) : Compatible, Screen {
  /* ... */
}

or this:

sealed interface Screen {
  val environment : ViewEnvironment get() = EMPTY

  interface LeafScreen : Screen

  abstract class <S> ContainerScreen<S, C: ContainerScreen<S, C>>(
    val children: List<S>,
  ): Screen {
    abstract val environment: ViewEnvironment
    abstract fun withEnvironment(e: Environment): C
  }
}

class EnvironmentScreen<S: Screen>(
  val wrapped: S,
  override  val environment: ViewEnvironment
) : ContainerScreen<S, EnvironmentScreen<S>>(listOf(wrapped), environment) {
  override fun withEnvironment(e: Environment): EnvironmentScreen<S> {
    return ...
  }
}

fun <S: Screen> S.withEnvironment(e: ViewEnvironment): EnvironmentScreen<S>

[rjrjr]

VisualFactory to be introduced with #874 should address this.

[rjrjr]

• VisualFactory was abandoned, long live #1146
• Most of this pain has been addressed by the Container and Wrapper types.