WIP: Exploring Compose Runtime Integration

Is it as simple as key()?

Author: steve-the-edwards

build.gradle.kts

@@ -10,6 +10,7 @@ buildscript {
     classpath(libs.kotlin.serialization.gradle.plugin)
     classpath(libs.kotlinx.binaryCompatibility.gradle.plugin)
     classpath(libs.kotlin.gradle.plugin)
+    classpath(libs.molecule.gradle.plugin)
     classpath(libs.google.ksp)
     classpath(libs.ktlint.gradle)
     classpath(libs.vanniktech.publish)
@@ -19,6 +20,9 @@ buildscript {
     mavenCentral()
     gradlePluginPortal()
     google()
+    maven {
+      url = uri("https://oss.sonatype.org/content/repositories/snapshots/")
+    }
     // For binary compatibility validator.
     maven { url = uri("https://kotlin.bintray.com/kotlinx") }
   }

buildSrc/build.gradle.kts

@@ -7,6 +7,8 @@ plugins {
 repositories {
   mavenCentral()
   google()
+  // For molecule SNAPSHOT
+  maven { url = uri("https://oss.sonatype.org/content/repositories/snapshots/")}
 }
 
 dependencies {

gradle/libs.versions.toml

@@ -9,8 +9,8 @@ targetSdk = "30"
 androidx-activity = "1.3.0"
 androidx-appcompat = "1.3.1"
 androidx-benchmark = "1.1.0-rc03"
-androidx-compose = "1.1.0-rc01"
-androidx-compose-compiler = "1.1.0-rc02"
+compose = "1.1.0"
+compose-compiler = "1.1.0"
 androidx-constraintlayout = "2.1.2"
 androidx-core = "1.6.0"
 androidx-fragment = "1.3.6"
@@ -49,8 +49,8 @@ kotest = "5.1.0"
 kotlin = "1.6.10"
 
 kotlinx-binary-compatibility = "0.6.0"
-kotlinx-coroutines = "1.5.1"
-# The 1.5.1 test artifact is jvm-only. The commonTest module should use 1.6.1.
+kotlinx-coroutines = "1.5.2"
+# The 1.5.2 test artifact is jvm-only. The commonTest module should use 1.6.1.
 kotlinx-coroutines-test-common = "1.6.1"
 kotlinx-serialization-json = "1.3.2"
 kotlinx-benchmark = "0.4.2"
@@ -64,6 +64,9 @@ mockito-core = "3.3.3"
 mockito-kotlin = "3.2.0"
 
 mockk = "1.11.0"
+
+molecule = "0.3.0-SNAPSHOT"
+
 robolectric = "4.6.1"
 
 rxjava2-android = "2.1.1"
@@ -100,8 +103,12 @@ kotlinx-benchmark = { id = "org.jetbrains.kotlinx.benchmark", version.ref = "kot
 ktlint = { id = "org.jlleitschuh.gradle.ktlint", version.ref = "ktlint" }
 mavenPublish = { id = "com.vanniktech.maven.publish", version.ref = "vanniktech-publish" }
 
+molecule = { id = "app.cash.molecule", version.ref = "molecule"}
+
 [libraries]
 
+molecule-gradle-plugin = { module = "app.cash.molecule:molecule-gradle-plugin", version.ref = "molecule"}
+
 android-gradle-plugin = { module = "com.android.tools.build:gradle", version.ref = "androidTools" }
 
 androidx-activity-compose = { module = "androidx.activity:activity-compose", version.ref = "androidx-activity" }
@@ -112,13 +119,16 @@ androidx-appcompat = { module = "androidx.appcompat:appcompat", version.ref = "a
 
 androidx-macro-benchmark = { module = "androidx.benchmark:benchmark-macro-junit4", version.ref = "androidx-benchmark" }
 
-androidx-compose-foundation = { module = "androidx.compose.foundation:foundation", version.ref = "androidx-compose" }
+androidx-compose-foundation = { module = "androidx.compose.foundation:foundation", version.ref = "compose" }
+
+androidx-compose-material = { module = "androidx.compose.material:material", version.ref = "compose" }
 
-androidx-compose-material = { module = "androidx.compose.material:material", version.ref = "androidx-compose" }
+androidx-compose-ui = { module = "androidx.compose.ui:ui", version.ref = "compose" }
+androidx-compose-ui-test-junit4 = { module = "androidx.compose.ui:ui-test-junit4", version.ref = "compose" }
+androidx-compose-ui-tooling = { module = "androidx.compose.ui:ui-tooling", version.ref = "compose" }
 
-androidx-compose-ui = { module = "androidx.compose.ui:ui", version.ref = "androidx-compose" }
-androidx-compose-ui-test-junit4 = { module = "androidx.compose.ui:ui-test-junit4", version.ref = "androidx-compose" }
-androidx-compose-ui-tooling = { module = "androidx.compose.ui:ui-tooling", version.ref = "androidx-compose" }
+compose-runtime = { module = "org.jetbrains.compose.runtime:runtime", version.ref = "compose"}
+compose-compiler = { module = "org.jetbrains.compose.compiler:compiler", version.ref = "compose"}
 
 androidx-constraintlayout = { module = "androidx.constraintlayout:constraintlayout", version.ref = "androidx-constraintlayout" }
 
@@ -203,6 +213,8 @@ mockito-kotlin = { module = "org.mockito.kotlin:mockito-kotlin", version.ref = "
 
 mockk = { module = "io.mockk:mockk", version.ref = "mockk" }
 
+molecule-runtime = { module = "app.cash.molecule:molecule-runtime", version.ref = "molecule"}
+
 robolectric = { module = "org.robolectric:robolectric", version.ref = "robolectric" }
 
 rxjava2-rxandroid = { module = "io.reactivex.rxjava2:rxandroid", version.ref = "rxjava2-android" }

samples/compose-samples/build.gradle.kts

@@ -14,7 +14,7 @@ android {
     compose = true
   }
   composeOptions {
-    kotlinCompilerExtensionVersion = libs.versions.androidx.compose.compiler.get()
+    kotlinCompilerExtensionVersion = libs.versions.compose.compiler.get()
   }
 }
 

settings.gradle.kts

@@ -9,6 +9,8 @@ pluginManagement {
     google()
     // For binary compatibility validator.
     maven { url = uri("https://kotlin.bintray.com/kotlinx") }
+    // For molecule SNAPSHOT
+    maven { url = uri("https://oss.sonatype.org/content/repositories/snapshots/")}
   }
 }
 
@@ -29,6 +31,8 @@ dependencyResolutionManagement {
   repositories {
     mavenCentral()
     google()
+    // For molecule SNAPSHOT
+    maven { url = uri("https://oss.sonatype.org/content/repositories/snapshots/")}
     // See androidx.dev (can use this for Snapshot builds of AndroidX)
     // maven { url = java.net.URI.create("https://androidx.dev/snapshots/builds/8224905/artifacts/repository") }
   }

workflow-core/build.gradle.kts

@@ -7,7 +7,7 @@ apply(from = rootProject.file(".buildscript/configure-maven-publish.gradle"))
 
 kotlin {
   jvm { withJava() }
-  ios()
+  // ios()
 
   sourceSets {
     all {
@@ -19,6 +19,7 @@ kotlin {
       dependencies {
         api(libs.kotlin.jdk6)
         api(libs.kotlinx.coroutines.core)
+        api(libs.compose.runtime)
         // For Snapshot.
         api(libs.squareup.okio)
       }
@@ -28,6 +29,7 @@ kotlin {
         implementation(libs.kotlinx.atomicfu)
         implementation(libs.kotlinx.coroutines.test.common)
         implementation(libs.kotlin.test.jdk)
+        implementation(libs.molecule.runtime)
       }
     }
   }

workflow-core/src/commonMain/kotlin/com/squareup/workflow1/BaseRenderContext.kt

@@ -4,6 +4,7 @@
 
 package com.squareup.workflow1
 
+import androidx.compose.runtime.Composable
 import com.squareup.workflow1.WorkflowAction.Companion.noAction
 import kotlinx.coroutines.CoroutineScope
 import kotlin.jvm.JvmMultifileClass
@@ -71,6 +72,7 @@ public interface BaseRenderContext<out PropsT, StateT, in OutputT> {
    * @param key An optional string key that is used to distinguish between workflows of the same
    * type.
    */
+  @Composable
   public fun <ChildPropsT, ChildOutputT, ChildRenderingT> renderChild(
     child: Workflow<ChildPropsT, ChildOutputT, ChildRenderingT>,
     props: ChildPropsT,
@@ -217,6 +219,7 @@ public interface BaseRenderContext<out PropsT, StateT, in OutputT> {
 /**
  * Convenience alias of [BaseRenderContext.renderChild] for workflows that don't take props.
  */
+@Composable
 public fun <PropsT, StateT, OutputT, ChildOutputT, ChildRenderingT>
 BaseRenderContext<PropsT, StateT, OutputT>.renderChild(
   child: Workflow<Unit, ChildOutputT, ChildRenderingT>,
@@ -226,6 +229,7 @@ BaseRenderContext<PropsT, StateT, OutputT>.renderChild(
 /**
  * Convenience alias of [BaseRenderContext.renderChild] for workflows that don't emit output.
  */
+@Composable
 public fun <PropsT, ChildPropsT, StateT, OutputT, ChildRenderingT>
 BaseRenderContext<PropsT, StateT, OutputT>.renderChild(
   child: Workflow<ChildPropsT, Nothing, ChildRenderingT>,
@@ -236,6 +240,7 @@ BaseRenderContext<PropsT, StateT, OutputT>.renderChild(
  * Convenience alias of [BaseRenderContext.renderChild] for children that don't take props or emit
  * output.
  */
+@Composable
 public fun <PropsT, StateT, OutputT, ChildRenderingT>
 BaseRenderContext<PropsT, StateT, OutputT>.renderChild(
   child: Workflow<Unit, Nothing, ChildRenderingT>,

workflow-core/src/commonMain/kotlin/com/squareup/workflow1/StatefulWorkflow.kt

@@ -4,6 +4,7 @@
 
 package com.squareup.workflow1
 
+import androidx.compose.runtime.Composable
 import com.squareup.workflow1.StatefulWorkflow.RenderContext
 import com.squareup.workflow1.WorkflowAction.Companion.toString
 import kotlin.jvm.JvmMultifileClass
@@ -123,6 +124,7 @@ public abstract class StatefulWorkflow<
    * _† This method is guaranteed to be called *at least* once for every state, but may be called
    * multiple times. Allowing this method to be invoked multiple times makes the internals simpler._
    */
+  @Composable
   public abstract fun render(
     renderProps: PropsT,
     renderState: StateT,
@@ -191,6 +193,7 @@ public inline fun <PropsT, StateT, OutputT, RenderingT> Workflow.Companion.state
       state: StateT
     ): StateT = onPropsChanged(old, new, state)
 
+    @Composable
     override fun render(
       renderProps: PropsT,
       renderState: StateT,

workflow-core/src/commonMain/kotlin/com/squareup/workflow1/StatelessWorkflow.kt

@@ -3,6 +3,7 @@
 
 package com.squareup.workflow1
 
+import androidx.compose.runtime.Composable
 import kotlin.jvm.JvmMultifileClass
 import kotlin.jvm.JvmName
 
@@ -52,6 +53,7 @@ public abstract class StatelessWorkflow<in PropsT, out OutputT, out RenderingT>
    * blocks the current thread. It may be called multiple times for the same state. It must do all its
    * work by calling methods on [context].
    */
+  @Composable
   public abstract fun render(
     renderProps: PropsT,
     context: RenderContext
@@ -90,6 +92,7 @@ public inline fun <PropsT, OutputT, RenderingT> Workflow.Companion.stateless(
   crossinline render: BaseRenderContext<PropsT, Nothing, OutputT>.(props: PropsT) -> RenderingT
 ): Workflow<PropsT, OutputT, RenderingT> =
   object : StatelessWorkflow<PropsT, OutputT, RenderingT>() {
+    @Composable
     override fun render(
       renderProps: PropsT,
       context: RenderContext

workflow-core/src/commonMain/kotlin/com/squareup/workflow1/WorkerWorkflow.kt

@@ -3,6 +3,7 @@
 
 package com.squareup.workflow1
 
+import androidx.compose.runtime.Composable
 import kotlinx.coroutines.CoroutineName
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.withContext
@@ -48,6 +49,7 @@ internal class WorkerWorkflow<OutputT>(
     state: Int
   ): Int = if (!old.doesSameWorkAs(new)) state + 1 else state
 
+  @Composable
   override fun render(
     renderProps: Worker<OutputT>,
     renderState: Int,