Use inner types for RenderContext to reduce type boilerplate.

Renamed `RenderContext` to `BaseRenderContext`, and gave both `StatelessWorkflow`
and `StatefulWorkflow` their own verions of `RenderContext`. These are inner classes,
so they can use the workflow's type parameters. This removes the type parameters from
the `RenderContext` reference in the `render` parameter list. Both types implement
`BaseWorkflowContext` however, so code that doesn't know about a particular workflow
instance can use this base type and convert it to a specific `RenderContext` later,
given a `Stateful/StatelessWorkflow` instance.

Author: zach-klippenstein

samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemListWorkflow.kt

@@ -16,7 +16,6 @@
 package com.squareup.sample.poetryapp
 
 import com.squareup.sample.poetry.model.Poem
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.StatelessWorkflow
 import com.squareup.workflow1.makeEventSink
 
@@ -27,7 +26,7 @@ object PoemListWorkflow : StatelessWorkflow<List<Poem>, Int, PoemListRendering>(
 
   override fun render(
     props: List<Poem>,
-    context: RenderContext<List<Poem>, Nothing, Int>
+    context: RenderContext
   ): PoemListRendering {
     // A sink that emits the given index as the result of this workflow.
     val sink = context.makeEventSink { index: Int -> setOutput(index) }

samples/containers/app-poetry/src/main/java/com/squareup/sample/poetryapp/PoemsBrowserWorkflow.kt

@@ -18,7 +18,6 @@ package com.squareup.sample.poetryapp
 import com.squareup.sample.container.overviewdetail.OverviewDetailScreen
 import com.squareup.sample.poetry.PoemWorkflow
 import com.squareup.sample.poetry.model.Poem
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -42,7 +41,7 @@ object PoemsBrowserWorkflow :
   override fun render(
     props: List<Poem>,
     state: SelectedPoem,
-    context: RenderContext<List<Poem>, SelectedPoem, Nothing>
+    context: RenderContext
   ): OverviewDetailScreen {
     val poems: OverviewDetailScreen =
       context.renderChild(PoemListWorkflow, props) { selected -> choosePoem(selected) }

samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/AreYouSureWorkflow.kt

@@ -21,7 +21,6 @@ import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.Finished
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.State
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.State.Quitting
 import com.squareup.sample.hellobackbutton.AreYouSureWorkflow.State.Running
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction.Companion.noAction
@@ -59,7 +58,7 @@ object AreYouSureWorkflow : StatefulWorkflow<Unit, State, Finished, AlertContain
   override fun render(
     props: Unit,
     state: State,
-    context: RenderContext<Unit, State, Finished>
+    context: RenderContext
   ): AlertContainerScreen<*> {
     val ableBakerCharlie = context.renderChild(HelloBackButtonWorkflow, Unit) { noAction() }
 

samples/containers/hello-back-button/src/main/java/com/squareup/sample/hellobackbutton/HelloBackButtonWorkflow.kt

@@ -21,7 +21,6 @@ import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State
 import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State.Able
 import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State.Baker
 import com.squareup.sample.hellobackbutton.HelloBackButtonWorkflow.State.Charlie
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -51,7 +50,7 @@ object HelloBackButtonWorkflow : StatefulWorkflow<Unit, State, Nothing, Renderin
   override fun render(
     props: Unit,
     state: State,
-    context: RenderContext<Unit, State, Nothing>
+    context: RenderContext
   ): Rendering {
     return Rendering(
         message = "$state",

samples/containers/poetry/src/main/java/com/squareup/sample/poetry/PoemWorkflow.kt

@@ -58,7 +58,7 @@ object PoemWorkflow : StatefulWorkflow<Poem, Int, ClosePoem, OverviewDetailScree
   override fun render(
     props: Poem,
     state: Int,
-    context: RenderContext<Poem, Int, ClosePoem>
+    context: RenderContext
   ): OverviewDetailScreen {
     val previousStanzas: List<StanzaRendering> =
       if (state == -1) emptyList()

samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaListWorkflow.kt

@@ -29,7 +29,7 @@ object StanzaListWorkflow : StatelessWorkflow<Poem, Int, StanzaListRendering>()
 
   override fun render(
     props: Poem,
-    context: RenderContext<Poem, Nothing, Int>
+    context: RenderContext
   ): StanzaListRendering {
     // A sink that emits the given index as the result of this workflow.
     val sink = context.makeEventSink { index: Int -> setOutput(index) }

samples/containers/poetry/src/main/java/com/squareup/sample/poetry/StanzaWorkflow.kt

@@ -42,7 +42,7 @@ object StanzaWorkflow : StatelessWorkflow<Props, Output, StanzaRendering>() {
 
   override fun render(
     props: Props,
-    context: RenderContext<Props, Nothing, Output>
+    context: RenderContext
   ): StanzaRendering {
     with(props) {
       val sink: Sink<Output> = context.makeEventSink { setOutput(it) }

samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/DungeonAppWorkflow.kt

@@ -21,7 +21,6 @@ import com.squareup.sample.dungeon.DungeonAppWorkflow.State.ChoosingBoard
 import com.squareup.sample.dungeon.DungeonAppWorkflow.State.LoadingBoardList
 import com.squareup.sample.dungeon.DungeonAppWorkflow.State.PlayingGame
 import com.squareup.sample.dungeon.board.Board
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -57,7 +56,7 @@ class DungeonAppWorkflow(
   override fun render(
     props: Props,
     state: State,
-    context: RenderContext<Props, State, Nothing>
+    context: RenderContext
   ): AlertContainerScreen<Any> = when (state) {
 
     LoadingBoardList -> {

samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/GameSessionWorkflow.kt

@@ -24,7 +24,6 @@ import com.squareup.sample.dungeon.GameSessionWorkflow.State.Running
 import com.squareup.sample.dungeon.GameWorkflow.Output.PlayerWasEaten
 import com.squareup.sample.dungeon.GameWorkflow.Output.Vibrate
 import com.squareup.sample.dungeon.board.Board
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
@@ -68,7 +67,7 @@ class GameSessionWorkflow(
   override fun render(
     props: Props,
     state: State,
-    context: RenderContext<Props, State, Nothing>
+    context: RenderContext
   ): AlertContainerScreen<Any> = when (state) {
 
     Loading -> {

samples/dungeon/app/src/main/java/com/squareup/sample/dungeon/TimeMachineAppWorkflow.kt

@@ -21,7 +21,6 @@ import com.squareup.sample.timemachine.TimeMachineWorkflow
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineRendering
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow.PropsFactory
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.StatelessWorkflow
 import com.squareup.workflow1.renderChild
 import kotlin.time.ExperimentalTime
@@ -43,7 +42,7 @@ class TimeMachineAppWorkflow(
 
   override fun render(
     props: BoardPath,
-    context: RenderContext<BoardPath, Nothing, Nothing>
+    context: RenderContext
   ): ShakeableTimeMachineRendering {
     val propsFactory = PropsFactory { recording ->
       Props(paused = !recording)

samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/AiWorkflow.kt

@@ -23,7 +23,6 @@ import com.squareup.sample.dungeon.Direction.LEFT
 import com.squareup.sample.dungeon.Direction.RIGHT
 import com.squareup.sample.dungeon.Direction.UP
 import com.squareup.sample.dungeon.board.BoardCell
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.Worker
@@ -68,7 +67,7 @@ class AiWorkflow(
   override fun render(
     props: ActorProps,
     state: State,
-    context: RenderContext<ActorProps, State, Nothing>
+    context: RenderContext
   ): ActorRendering {
     context.runningWorker(state.directionTicker) { updateDirection }
 

samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/GameWorkflow.kt

@@ -106,7 +106,7 @@ class GameWorkflow(
   override fun render(
     props: Props,
     state: State,
-    context: RenderContext<Props, State, Output>
+    context: RenderContext
   ): GameRendering {
     val running = !props.paused && !state.game.isPlayerEaten
     // Stop actors from ticking if the game is paused or finished.

samples/dungeon/common/src/main/java/com/squareup/sample/dungeon/PlayerWorkflow.kt

@@ -64,7 +64,7 @@ class PlayerWorkflow(
   override fun render(
     props: ActorProps,
     state: Movement,
-    context: RenderContext<ActorProps, Movement, Nothing>
+    context: RenderContext
   ): Rendering = Rendering(
       actorRendering = ActorRendering(avatar = avatar, movement = state),
       onStartMoving = { context.actionSink.send(StartMoving(it)) },

samples/dungeon/timemachine-shakeable/src/main/java/com/squareup/sample/timemachine/shakeable/ShakeableTimeMachineWorkflow.kt

@@ -22,7 +22,6 @@ import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow.Pr
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow.State
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow.State.PlayingBack
 import com.squareup.sample.timemachine.shakeable.ShakeableTimeMachineWorkflow.State.Recording
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
@@ -70,7 +69,7 @@ class ShakeableTimeMachineWorkflow<in P, O : Any, out R : Any>(
   override fun render(
     props: PropsFactory<P>,
     state: State,
-    context: RenderContext<PropsFactory<P>, State, O>
+    context: RenderContext
   ): ShakeableTimeMachineRendering {
     // Only listen to shakes when recording.
     if (state === Recording) context.runningWorker(shakeWorker) { onShake }

samples/dungeon/timemachine/src/main/java/com/squareup/sample/timemachine/RecorderWorkflow.kt

@@ -19,7 +19,6 @@ import com.squareup.sample.timemachine.RecorderWorkflow.RecorderProps
 import com.squareup.sample.timemachine.RecorderWorkflow.RecorderProps.PlaybackAt
 import com.squareup.sample.timemachine.RecorderWorkflow.RecorderProps.RecordValue
 import com.squareup.sample.timemachine.RecorderWorkflow.Recording
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import kotlin.time.Duration
@@ -92,7 +91,7 @@ internal class RecorderWorkflow<T>(
   override fun render(
     props: RecorderProps<T>,
     state: Recording<T>,
-    context: RenderContext<RecorderProps<T>, Recording<T>, Nothing>
+    context: RenderContext
   ): TimeMachineRendering<T> {
     val value = when (props) {
       is RecordValue -> props.value

samples/dungeon/timemachine/src/main/java/com/squareup/sample/timemachine/TimeMachineWorkflow.kt

@@ -84,7 +84,7 @@ class TimeMachineWorkflow<P, O : Any, out R>(
 
   override fun render(
     props: TimeMachineProps<P>,
-    context: RenderContext<TimeMachineProps<P>, Nothing, O>
+    context: RenderContext
   ): TimeMachineRendering<R> {
     // Always render the delegate, even if in playback mode, to keep it alive.
     val delegateRendering =

samples/hello-terminal/hello-terminal-app/src/main/java/com/squareup/sample/helloterminal/BlinkingCursorWorkflow.kt

@@ -15,7 +15,6 @@
  */
 package com.squareup.sample.helloterminal
 
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.Worker
@@ -51,7 +50,7 @@ class BlinkingCursorWorkflow(
   override fun render(
     props: Unit,
     state: Boolean,
-    context: RenderContext<Unit, Boolean, Nothing>
+    context: RenderContext
   ): String {
     context.runningWorker(intervalWorker) { setCursorShowing(it) }
     return if (state) cursorString else ""

samples/hello-terminal/hello-terminal-app/src/main/java/com/squareup/sample/helloterminal/HelloTerminalWorkflow.kt

@@ -23,7 +23,6 @@ import com.squareup.sample.helloterminal.terminalworkflow.TerminalProps
 import com.squareup.sample.helloterminal.terminalworkflow.TerminalRendering
 import com.squareup.sample.helloterminal.terminalworkflow.TerminalRendering.Color.GREEN
 import com.squareup.sample.helloterminal.terminalworkflow.TerminalWorkflow
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
@@ -53,7 +52,7 @@ class HelloTerminalWorkflow : TerminalWorkflow,
   override fun render(
     props: TerminalProps,
     state: State,
-    context: RenderContext<TerminalProps, State, ExitCode>
+    context: RenderContext
   ): TerminalRendering {
     val (rows, columns) = props.size
     val header = """

samples/hello-terminal/todo-terminal-app/src/main/java/com/squareup/sample/hellotodo/EditTextWorkflow.kt

@@ -8,7 +8,6 @@ import com.squareup.sample.helloterminal.terminalworkflow.KeyStroke.KeyType.Char
 import com.squareup.sample.helloterminal.terminalworkflow.TerminalProps
 import com.squareup.sample.hellotodo.EditTextWorkflow.EditTextProps
 import com.squareup.sample.hellotodo.EditTextWorkflow.EditTextState
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -48,7 +47,7 @@ class EditTextWorkflow : StatefulWorkflow<EditTextProps, EditTextState, String,
   override fun render(
     props: EditTextProps,
     state: EditTextState,
-    context: RenderContext<EditTextProps, EditTextState, String>
+    context: RenderContext
   ): String {
     context.runningWorker(props.terminalProps.keyStrokes) { key -> onKeystroke(props, key) }
 

samples/hello-terminal/todo-terminal-app/src/main/java/com/squareup/sample/hellotodo/TodoWorkflow.kt

@@ -26,7 +26,7 @@ import com.squareup.sample.helloterminal.terminalworkflow.TerminalWorkflow
 import com.squareup.sample.hellotodo.EditTextWorkflow.EditTextProps
 import com.squareup.sample.hellotodo.TodoWorkflow.TodoList
 import com.squareup.sample.hellotodo.TodoWorkflow.TodoList.Companion.TITLE_FIELD_INDEX
-import com.squareup.workflow1.RenderContext
+import com.squareup.workflow1.BaseRenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
@@ -76,14 +76,14 @@ class TodoWorkflow : TerminalWorkflow,
   override fun render(
     props: TerminalProps,
     state: TodoList,
-    context: RenderContext<TerminalProps, TodoList, ExitCode>
+    context: RenderContext
   ): TerminalRendering {
 
     context.runningWorker(props.keyStrokes) { onKeystroke(it) }
 
     return TerminalRendering(buildString {
       @Suppress("UNCHECKED_CAST")
-      appendln(state.renderTitle(props, context as RenderContext<TerminalProps, TodoList, Nothing>))
+      appendln(state.renderTitle(props, context))
       appendln(renderSelection(state.titleSeparator, false))
       appendln(state.renderItems(props, context))
     })
@@ -118,7 +118,7 @@ private fun setLabel(
 
 private fun TodoList.renderTitle(
   props: TerminalProps,
-  context: RenderContext<TerminalProps, TodoList, Nothing>
+  context: BaseRenderContext<TerminalProps, TodoList, *>
 ): String {
   val isSelected = focusedField == TITLE_FIELD_INDEX
   val titleString = if (isSelected) {
@@ -137,7 +137,7 @@ private val TodoList.titleSeparator get() = "–".repeat(title.length + 1)
 
 private fun TodoList.renderItems(
   props: TerminalProps,
-  context: RenderContext<TerminalProps, TodoList, Nothing>
+  context: BaseRenderContext<TerminalProps, TodoList, *>
 ): String =
   items
       .mapIndexed { index, item ->

samples/hello-workflow-fragment/src/main/java/com/squareup/sample/helloworkflowfragment/HelloWorkflow.kt

@@ -19,7 +19,6 @@ import com.squareup.sample.helloworkflowfragment.HelloWorkflow.Rendering
 import com.squareup.sample.helloworkflowfragment.HelloWorkflow.State
 import com.squareup.sample.helloworkflowfragment.HelloWorkflow.State.Goodbye
 import com.squareup.sample.helloworkflowfragment.HelloWorkflow.State.Hello
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -45,7 +44,7 @@ object HelloWorkflow : StatefulWorkflow<Unit, State, Nothing, Rendering>() {
   override fun render(
     props: Unit,
     state: State,
-    context: RenderContext<Unit, State, Nothing>
+    context: RenderContext
   ): Rendering {
     return Rendering(
         message = state.name,

samples/hello-workflow/src/main/java/com/squareup/sample/helloworkflow/HelloWorkflow.kt

@@ -19,7 +19,6 @@ import com.squareup.sample.helloworkflow.HelloWorkflow.Rendering
 import com.squareup.sample.helloworkflow.HelloWorkflow.State
 import com.squareup.sample.helloworkflow.HelloWorkflow.State.Goodbye
 import com.squareup.sample.helloworkflow.HelloWorkflow.State.Hello
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -45,7 +44,7 @@ object HelloWorkflow : StatefulWorkflow<Unit, State, Nothing, Rendering>() {
   override fun render(
     props: Unit,
     state: State,
-    context: RenderContext<Unit, State, Nothing>
+    context: RenderContext
   ): Rendering {
     return Rendering(
         message = state.name,

samples/recyclerview/src/main/java/com/squareup/sample/recyclerview/AppWorkflow.kt

@@ -28,7 +28,6 @@ import com.squareup.sample.recyclerview.inputrows.DropdownInputRow
 import com.squareup.sample.recyclerview.inputrows.InputRow
 import com.squareup.sample.recyclerview.inputrows.SwitchInputRow
 import com.squareup.sample.recyclerview.inputrows.TextInputRow
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.WorkflowAction
@@ -96,7 +95,7 @@ object AppWorkflow : StatefulWorkflow<Unit, State, Nothing, Rendering>() {
   override fun render(
     props: Unit,
     state: State,
-    context: RenderContext<Unit, State, Nothing>
+    context: RenderContext
   ): Rendering {
     val listRendering = context.renderChild(EditableListWorkflow, Props(state.rows))
     val baseScreen = BaseScreen(

samples/recyclerview/src/main/java/com/squareup/sample/recyclerview/editablelistworkflow/EditableListWorkflow.kt

@@ -19,7 +19,6 @@ import com.squareup.sample.recyclerview.editablelistworkflow.EditableListWorkflo
 import com.squareup.sample.recyclerview.editablelistworkflow.EditableListWorkflow.Rendering
 import com.squareup.sample.recyclerview.editablelistworkflow.EditableListWorkflow.State
 import com.squareup.sample.recyclerview.inputrows.InputRow
-import com.squareup.workflow1.RenderContext
 import com.squareup.workflow1.Snapshot
 import com.squareup.workflow1.StatefulWorkflow
 import com.squareup.workflow1.action
@@ -61,7 +60,7 @@ object EditableListWorkflow : StatefulWorkflow<Props, State, Nothing, Rendering>
   override fun render(
     props: Props,
     state: State,
-    context: RenderContext<Props, State, Nothing>
+    context: RenderContext
   ): Rendering {
     return Rendering(
         rowValues = state.rowValues,

samples/tictactoe/common/src/main/java/com/squareup/sample/authworkflow/AuthWorkflow.kt

@@ -150,7 +150,7 @@ class RealAuthWorkflow(private val authService: AuthService) : AuthWorkflow,
   override fun render(
     props: Unit,
     state: AuthState,
-    context: RenderContext<Unit, AuthState, AuthResult>
+    context: RenderContext
   ): BackStackScreen<Any> = when (state) {
     is LoginPrompt -> {
       BackStackScreen(