wip

Author: zach-klippenstein

samples/containers/thingy/src/main/java/com/squareup/sample/thingy/BackStackWorkflow.kt

@@ -8,6 +8,7 @@ import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.flowOf
+import kotlin.experimental.ExperimentalTypeInference
 
 /**
  * Creates a [BackStackWorkflow]. See the docs on [BackStackWorkflow.runBackStack] for more
@@ -164,11 +165,17 @@ public sealed interface BackStackNestedScope<OutputT, R> : BackStackScope<Output
   suspend fun goBack(): Nothing
 }
 
+@OptIn(ExperimentalTypeInference::class)
 public suspend inline fun <OutputT, ChildOutputT, R> BackStackScope<OutputT>.showWorkflow(
   workflow: Workflow<Unit, ChildOutputT, Screen>,
-  noinline onOutput: suspend BackStackNestedScope<OutputT, R>.(output: ChildOutputT) -> Unit
+  @BuilderInference noinline onOutput: suspend BackStackNestedScope<OutputT, R>.(output: ChildOutputT) -> Unit
 ): R = showWorkflow(workflow, props = flowOf(Unit), onOutput)
 
+// public suspend inline fun <OutputT, ChildOutputT> BackStackScope<OutputT>.showWorkflow(
+//   workflow: Workflow<Unit, ChildOutputT, Screen>,
+//   noinline onOutput: suspend BackStackNestedScope<OutputT, Unit>.(output: ChildOutputT) -> Unit
+// ): Unit = showWorkflow(workflow, props = flowOf(Unit), onOutput)
+
 public suspend inline fun <ChildPropsT> BackStackScope<*>.showWorkflow(
   workflow: Workflow<ChildPropsT, Nothing, Screen>,
   props: Flow<ChildPropsT>,

samples/containers/thingy/src/main/java/com/squareup/sample/thingy/MyWorkflow.kt

@@ -3,6 +3,7 @@ package com.squareup.sample.thingy
 import com.squareup.workflow1.Workflow
 import com.squareup.workflow1.ui.Screen
 import kotlinx.coroutines.delay
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.flowOf
 import kotlinx.coroutines.launch
 import kotlin.time.Duration.Companion.seconds
@@ -12,41 +13,44 @@ enum class MyOutputs {
   Done,
 }
 
-fun MyWorkflow(
-  child1: Workflow<Unit, String, Screen>,
-  child2: Workflow<Unit, String, Screen>,
-  child3: Workflow<String, Nothing, Screen>,
-  networkCall: suspend (String) -> String
-) = backStackWorkflow<String, MyOutputs> {
+class MyWorkflow(
+  private val child1: Workflow<Unit, String, Screen>,
+  private val child2: Workflow<Unit, String, Screen>,
+  private val child3: Workflow<String, Nothing, Screen>,
+  private val networkCall: suspend (String) -> String
+) : BackStackWorkflow<String, MyOutputs>() {
 
-  // Step 1
-  showWorkflow(child1) { output ->
-    when (output) {
-      "back" -> emitOutput(MyOutputs.Back)
-      "next" -> {
-        // Step 2
-        val childResult = showWorkflow(child2) { output ->
-          if (output == "back") {
-            // Removes child2 from the stack, cancels the output handler from step 1, and just
-            // leaves child1 rendering.
-            goBack()
-          } else {
-            finishWith(output)
+  override suspend fun BackStackScope<MyOutputs>.runBackStack(props: StateFlow<String>) {
+    // Step 1
+    // TODO clean this up
+    val ignored: Unit = showWorkflow(child1) { output ->
+      when (output) {
+        "back" -> emitOutput(MyOutputs.Back)
+        "next" -> {
+          // Step 2
+          val childResult = showWorkflow(child2) { output ->
+            if (output == "back") {
+              // Removes child2 from the stack, cancels the output handler from step 1, and just
+              // leaves child1 rendering.
+              goBack()
+            } else {
+              finishWith(output)
+            }
           }
-        }
 
-        // TODO: Show a loading screen automatically.
-        val networkResult = networkCall(childResult)
+          // TODO: Show a loading screen automatically.
+          val networkResult = networkCall(childResult)
 
-        // Step 3: Show a workflow for 3 seconds then finish.
-        launch {
-          delay(3.seconds)
-          emitOutput(MyOutputs.Done)
+          // Step 3: Show a workflow for 3 seconds then finish.
+          launch {
+            delay(3.seconds)
+            emitOutput(MyOutputs.Done)
+          }
+          showWorkflow(child3, flowOf(networkResult))
         }
-        showWorkflow(child3, flowOf(networkResult))
-      }
 
-      else -> {}
+        else -> {}
+      }
     }
   }
 }