Remove Compose Dependency from Android Runtime

.github/workflows/kotlin.yml

@@ -179,10 +179,10 @@ jobs:
           write-cache-key: main-build-artifacts
 
   check:
-    name: Check
+    name: Unit Tests
     runs-on: macos-latest
     needs: build-all
-    timeout-minutes: 20
+    timeout-minutes: 40
     steps:
       - name: Checkout
         uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4.1.1

samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposebinding/HelloBindingActivity.kt

@@ -6,6 +6,7 @@ import android.os.Bundle
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.material.MaterialTheme
+import androidx.compose.ui.platform.AndroidUiDispatcher
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
@@ -21,6 +22,7 @@ import com.squareup.workflow1.ui.plus
 import com.squareup.workflow1.ui.withEnvironment
 import com.squareup.workflow1.ui.workflowContentView
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.plus
 
 private val viewEnvironment =
   (ViewEnvironment.EMPTY + ViewRegistry(HelloBinding))
@@ -47,7 +49,7 @@ class HelloBindingActivity : AppCompatActivity() {
     val renderings: StateFlow<Screen> by lazy {
       renderWorkflowIn(
         workflow = HelloWorkflow.mapRendering { it.withEnvironment(viewEnvironment) },
-        scope = viewModelScope,
+        scope = viewModelScope + AndroidUiDispatcher.Main,
         savedStateHandle = savedState,
         runtimeConfig = AndroidRuntimeConfigTools.getAppWorkflowRuntimeConfig()
       )

samples/compose-samples/src/main/java/com/squareup/sample/compose/hellocomposeworkflow/HelloComposeWorkflowActivity.kt

@@ -5,6 +5,7 @@ package com.squareup.sample.compose.hellocomposeworkflow
 import android.os.Bundle
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
+import androidx.compose.ui.platform.AndroidUiDispatcher
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
@@ -18,6 +19,7 @@ import com.squareup.workflow1.ui.compose.withComposeInteropSupport
 import com.squareup.workflow1.ui.withEnvironment
 import com.squareup.workflow1.ui.workflowContentView
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.plus
 
 class HelloComposeWorkflowActivity : AppCompatActivity() {
   override fun onCreate(savedInstanceState: Bundle?) {
@@ -32,7 +34,7 @@ class HelloComposeWorkflowActivity : AppCompatActivity() {
         workflow = HelloWorkflow.mapRendering {
           it.withEnvironment(ViewEnvironment.EMPTY.withComposeInteropSupport())
         },
-        scope = viewModelScope,
+        scope = viewModelScope + AndroidUiDispatcher.Main,
         savedStateHandle = savedState,
         runtimeConfig = AndroidRuntimeConfigTools.getAppWorkflowRuntimeConfig()
       )

samples/compose-samples/src/main/java/com/squareup/sample/compose/inlinerendering/InlineRenderingActivity.kt

@@ -5,6 +5,7 @@ package com.squareup.sample.compose.inlinerendering
 import android.os.Bundle
 import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
+import androidx.compose.ui.platform.AndroidUiDispatcher
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
@@ -18,6 +19,7 @@ import com.squareup.workflow1.ui.compose.withComposeInteropSupport
 import com.squareup.workflow1.ui.withEnvironment
 import com.squareup.workflow1.ui.workflowContentView
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.plus
 
 /**
  * A workflow that returns an anonymous
@@ -37,7 +39,7 @@ class InlineRenderingActivity : AppCompatActivity() {
         workflow = InlineRenderingWorkflow.mapRendering {
           it.withEnvironment(ViewEnvironment.EMPTY.withComposeInteropSupport())
         },
-        scope = viewModelScope,
+        scope = viewModelScope + AndroidUiDispatcher.Main,
         savedStateHandle = savedState,
         runtimeConfig = AndroidRuntimeConfigTools.getAppWorkflowRuntimeConfig()
       )

samples/compose-samples/src/main/java/com/squareup/sample/compose/nestedrenderings/NestedRenderingsActivity.kt

@@ -7,6 +7,7 @@ import androidx.activity.viewModels
 import androidx.appcompat.app.AppCompatActivity
 import androidx.compose.runtime.CompositionLocalProvider
 import androidx.compose.ui.graphics.Color
+import androidx.compose.ui.platform.AndroidUiDispatcher
 import androidx.lifecycle.SavedStateHandle
 import androidx.lifecycle.ViewModel
 import androidx.lifecycle.viewModelScope
@@ -22,6 +23,7 @@ import com.squareup.workflow1.ui.plus
 import com.squareup.workflow1.ui.withEnvironment
 import com.squareup.workflow1.ui.workflowContentView
 import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.plus
 
 private val viewRegistry = ViewRegistry(RecursiveComposableFactory)
 
@@ -45,7 +47,7 @@ class NestedRenderingsActivity : AppCompatActivity() {
     val renderings: StateFlow<Screen> by lazy {
       renderWorkflowIn(
         workflow = RecursiveWorkflow.mapRendering { it.withEnvironment(viewEnvironment) },
-        scope = viewModelScope,
+        scope = viewModelScope + AndroidUiDispatcher.Main,
         savedStateHandle = savedState,
         runtimeConfig = AndroidRuntimeConfigTools.getAppWorkflowRuntimeConfig()
       )

workflow-runtime-android/build.gradle.kts

@@ -16,12 +16,12 @@ dependencies {
   val composeBom = platform(libs.androidx.compose.bom)
 
   api(project(":workflow-runtime"))
-  api(libs.androidx.compose.ui.android)
   api(libs.androidx.lifecycle.viewmodel.savedstate)
 
-  implementation(composeBom)
   implementation(project(":workflow-core"))
 
+  androidTestImplementation(libs.androidx.compose.ui.android)
+  androidTestImplementation(composeBom)
   androidTestImplementation(libs.androidx.activity.ktx)
   androidTestImplementation(libs.androidx.lifecycle.viewmodel.ktx)
   androidTestImplementation(libs.androidx.test.core)

workflow-runtime-android/dependencies/releaseRuntimeClasspath.txt

@@ -1,57 +1,24 @@
-androidx.activity:activity-ktx:1.7.0
-androidx.activity:activity:1.7.0
-androidx.annotation:annotation-experimental:1.4.1
 androidx.annotation:annotation-jvm:1.8.1
 androidx.annotation:annotation:1.8.1
 androidx.arch.core:core-common:2.2.0
 androidx.arch.core:core-runtime:2.2.0
-androidx.autofill:autofill:1.0.0
-androidx.collection:collection-jvm:1.4.4
-androidx.collection:collection-ktx:1.4.4
-androidx.collection:collection:1.4.4
-androidx.compose.runtime:runtime-android:1.7.2
-androidx.compose.runtime:runtime-saveable-android:1.7.2
-androidx.compose.runtime:runtime-saveable:1.7.2
-androidx.compose.runtime:runtime:1.7.2
-androidx.compose.ui:ui-android:1.7.2
-androidx.compose.ui:ui-geometry-android:1.7.2
-androidx.compose.ui:ui-geometry:1.7.2
-androidx.compose.ui:ui-graphics-android:1.7.2
-androidx.compose.ui:ui-graphics:1.7.2
-androidx.compose.ui:ui-text-android:1.7.2
-androidx.compose.ui:ui-text:1.7.2
-androidx.compose.ui:ui-unit-android:1.7.2
-androidx.compose.ui:ui-unit:1.7.2
-androidx.compose.ui:ui-util-android:1.7.2
-androidx.compose.ui:ui-util:1.7.2
-androidx.compose:compose-bom:2024.09.02
+androidx.collection:collection:1.0.0
 androidx.concurrent:concurrent-futures:1.1.0
-androidx.core:core-ktx:1.12.0
-androidx.core:core:1.12.0
-androidx.customview:customview-poolingcontainer:1.0.0
-androidx.emoji2:emoji2:1.2.0
-androidx.graphics:graphics-path:1.0.1
-androidx.interpolator:interpolator:1.0.0
+androidx.core:core-ktx:1.2.0
+androidx.core:core:1.2.0
 androidx.lifecycle:lifecycle-common-jvm:2.8.7
 androidx.lifecycle:lifecycle-common:2.8.7
 androidx.lifecycle:lifecycle-livedata-core:2.8.7
-androidx.lifecycle:lifecycle-process:2.8.7
 androidx.lifecycle:lifecycle-runtime-android:2.8.7
-androidx.lifecycle:lifecycle-runtime-compose-android:2.8.7
-androidx.lifecycle:lifecycle-runtime-compose:2.8.7
-androidx.lifecycle:lifecycle-runtime-ktx-android:2.8.7
-androidx.lifecycle:lifecycle-runtime-ktx:2.8.7
 androidx.lifecycle:lifecycle-runtime:2.8.7
 androidx.lifecycle:lifecycle-viewmodel-android:2.8.7
-androidx.lifecycle:lifecycle-viewmodel-ktx:2.8.7
 androidx.lifecycle:lifecycle-viewmodel-savedstate:2.8.7
 androidx.lifecycle:lifecycle-viewmodel:2.8.7
 androidx.profileinstaller:profileinstaller:1.3.1
-androidx.savedstate:savedstate-ktx:1.2.1
 androidx.savedstate:savedstate:1.2.1
 androidx.startup:startup-runtime:1.1.1
 androidx.tracing:tracing:1.0.0
-androidx.versionedparcelable:versionedparcelable:1.1.1
+androidx.versionedparcelable:versionedparcelable:1.1.0
 com.google.guava:listenablefuture:1.0
 com.squareup.okio:okio-jvm:3.3.0
 com.squareup.okio:okio:3.3.0

workflow-runtime-android/src/main/java/com/squareup/workflow1/android/AndroidRenderWorkflow.kt

@@ -3,23 +3,20 @@
 package com.squareup.workflow1.android
 
 import androidx.annotation.VisibleForTesting
-import androidx.compose.ui.platform.AndroidUiDispatcher
 import androidx.lifecycle.SavedStateHandle
 import com.squareup.workflow1.RuntimeConfig
 import com.squareup.workflow1.RuntimeConfigOptions
 import com.squareup.workflow1.Workflow
 import com.squareup.workflow1.WorkflowInterceptor
 import com.squareup.workflow1.WorkflowTracer
 import com.squareup.workflow1.renderWorkflowIn
-import kotlinx.coroutines.CoroutineDispatcher
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.flow.MutableStateFlow
 import kotlinx.coroutines.flow.SharingStarted.Companion.Eagerly
 import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.map
 import kotlinx.coroutines.flow.onEach
 import kotlinx.coroutines.flow.stateIn
-import kotlinx.coroutines.plus
 
 /**
  * An Android `ViewModel`-friendly wrapper for [com.squareup.workflow1.renderWorkflowIn],
@@ -58,10 +55,12 @@ import kotlinx.coroutines.plus
  * in any workflows, after the initial render pass, will be handled by this scope, and cancelling
  * this scope will cancel the workflow runtime and any running workers. Note that any dispatcher
  * in this scope will _not_ be used to execute the very first render pass (which happens
- * synchronously).
- * Also note that if there is no [CoroutineDispatcher] in this scope then Compose UI's
- * [AndroidUiDispatcher.Main] will be used as this is the most performant Android UI dispatcher
- * for Workflow.
+ * synchronously). We recommend using a `CoroutineDispatcher` in this scope's `CoroutineContext`
+ * that will ensure that all dispatched coroutines are run before the next Choreographer frame.
+ * Compose UI's `AndroidUiDispatcher.Main` provides this behavior in a performant way!
+ * Another way to achieve that is to use an immediate (or Unconfined) dispatcher like
+ * Dispatchers.Main.immediate. However, that dispatcher cannot take advantage of some runtime
+ * optimizations. E.G., see [RuntimeConfigOptions.DRAIN_EXCLUSIVE_ACTIONS].
  *
  * @param savedStateHandle
  * Used to restore workflow state in a new process. Typically this is the
@@ -141,10 +140,12 @@ public fun <OutputT, RenderingT> renderWorkflowIn(
  * in any workflows, after the initial render pass, will be handled by this scope, and cancelling
  * this scope will cancel the workflow runtime and any running workers. Note that any dispatcher
  * in this scope will _not_ be used to execute the very first render pass (which happens
- * synchronously).
- * Also note that if there is no [CoroutineDispatcher] in this scope then Compose UI's
- * [AndroidUiDispatcher.Main] will be used as this is the most performant Android UI dispatcher
- * for Workflow.
+ * synchronously). We recommend using a `CoroutineDispatcher` in this scope's `CoroutineContext`
+ * that will ensure that all dispatched coroutines are run before the next Choreographer frame.
+ * Compose UI's `AndroidUiDispatcher.Main` provides this behavior in a performant way!
+ * Another way to achieve that is to use an immediate (or Unconfined) dispatcher like
+ * Dispatchers.Main.immediate. However, that dispatcher cannot take advantage of some runtime
+ * optimizations. E.G., see [RuntimeConfigOptions.DRAIN_EXCLUSIVE_ACTIONS].
  *
  * @param prop
  * Specifies the sole [PropsT] value to use to render the root workflow. To allow updates,
@@ -243,10 +244,12 @@ public fun <PropsT, OutputT, RenderingT> renderWorkflowIn(
  * in any workflows, after the initial render pass, will be handled by this scope, and cancelling
  * this scope will cancel the workflow runtime and any running workers. Note that any dispatcher
  * in this scope will _not_ be used to execute the very first render pass (which happens
- * synchronously).
- * Also note that if there is no [CoroutineDispatcher] in this scope then Compose UI's
- * [AndroidUiDispatcher.Main] will be used as this is the most performant Android UI dispatcher
- * for Workflow.
+ * synchronously). We recommend using a `CoroutineDispatcher` in this scope's `CoroutineContext`
+ * that will ensure that all dispatched coroutines are run before the next Choreographer frame.
+ * Compose UI's `AndroidUiDispatcher.Main` provides this behavior in a performant way!
+ * Another way to achieve that is to use an immediate (or Unconfined) dispatcher like
+ * Dispatchers.Main.immediate. However, that dispatcher cannot take advantage of some runtime
+ * optimizations. E.G., see [RuntimeConfigOptions.DRAIN_EXCLUSIVE_ACTIONS].
  *
  * @param props
  * Specifies the initial [PropsT] to use to render the root workflow, and will cause a re-render
@@ -278,7 +281,6 @@ public fun <PropsT, OutputT, RenderingT> renderWorkflowIn(
  * A [StateFlow] of [RenderingT]s that will emit any time the root workflow creates a new
  * rendering.
  */
-@OptIn(ExperimentalStdlibApi::class)
 public fun <PropsT, OutputT, RenderingT> renderWorkflowIn(
   workflow: Workflow<PropsT, OutputT, RenderingT>,
   scope: CoroutineScope,
@@ -291,16 +293,9 @@ public fun <PropsT, OutputT, RenderingT> renderWorkflowIn(
 ): StateFlow<RenderingT> {
   val restoredSnap = savedStateHandle?.get<PickledTreesnapshot>(KEY)?.snapshot
 
-  // Add in Compose's AndroidUiDispatcher.Main by default if none is specified.
-  val updatedContext = if (scope.coroutineContext[CoroutineDispatcher.Key] == null) {
-    scope.coroutineContext + AndroidUiDispatcher.Main
-  } else {
-    scope.coroutineContext
-  }
-
   val renderingsAndSnapshots = renderWorkflowIn(
     workflow,
-    scope + updatedContext,
+    scope,
     props,
     restoredSnap,
     interceptors,

workflow-runtime/src/commonMain/kotlin/com/squareup/workflow1/RenderWorkflow.kt

@@ -51,16 +51,22 @@ import kotlinx.coroutines.plus
  * available actions and do another render pass.
  * 1. Pass the updated rendering into the [StateFlow] returned from this method.
  *
- * Note that if this is run on the main thread we must `suspend` in order to release the thread and
- * let any actions that can be processed queue up. How that happens will depend on the
- * [CoroutineDispatcher] used in [scope].
+ * When there is UI involved, we recommend using a `CoroutineDispatcher` in [scope]'s
+ * `CoroutineContext` that runs the above runtime loop until it is stable before the next 'frame',
+ * whatever frame means on your platform. Specifically, ensure that all dispatched coroutines are
+ * run before the next 'frame', so that the Workflow runtime has done all the work it can.
  *
- * If an "immediate" dispatcher is used, then after 1 only 1 action will ever be available since
- * as soon as it is available it will resume and start processing the rest of the loop immediately.
+ * One way to achieve that guarantee is with an "immediate" dispatcher on the main thread - like,
+ * `Dispatchers.Main.immediate` - since it will continue to run until the runtime is stable before
+ * it lets any frame get updated by the main thread.
+ * However, if an "immediate" dispatcher is used, then only 1 action will ever be available
+ * since as soon as it is available it will resume (step #1 above) and start processing the rest of
+ * the loop immediately.
+ * This means that [DRAIN_EXCLUSIVE_ACTIONS] and [CONFLATE_STALE_RENDERINGS] will have no effect.
  *
- * There is no need to try the [DRAIN_EXCLUSIVE_ACTIONS] loop after each render pass in
- * [CONFLATE_STALE_RENDERINGS] because they all happen synchronously so no new exclusive actions
- * could have been queued.
+ * A preferred way to achieve that is to have your dispatcher drain coroutines for each frame
+ * explicitly. On Android, for example, that can be done with Compose UI's
+ * `AndroidUiDispatcher.Main`.
  *
  * ## Scoping
  *

workflow-ui/core-android/dependencies/releaseRuntimeClasspath.txt

@@ -1,61 +1,33 @@
-androidx.activity:activity-ktx:1.8.2
 androidx.activity:activity:1.8.2
-androidx.annotation:annotation-experimental:1.4.1
+androidx.annotation:annotation-experimental:1.4.0
 androidx.annotation:annotation-jvm:1.8.1
 androidx.annotation:annotation:1.8.1
 androidx.arch.core:core-common:2.2.0
 androidx.arch.core:core-runtime:2.2.0
-androidx.autofill:autofill:1.0.0
-androidx.collection:collection-jvm:1.4.4
-androidx.collection:collection-ktx:1.4.4
-androidx.collection:collection:1.4.4
-androidx.compose.runtime:runtime-android:1.7.2
-androidx.compose.runtime:runtime-saveable-android:1.7.2
-androidx.compose.runtime:runtime-saveable:1.7.2
-androidx.compose.runtime:runtime:1.7.2
-androidx.compose.ui:ui-android:1.7.2
-androidx.compose.ui:ui-geometry-android:1.7.2
-androidx.compose.ui:ui-geometry:1.7.2
-androidx.compose.ui:ui-graphics-android:1.7.2
-androidx.compose.ui:ui-graphics:1.7.2
-androidx.compose.ui:ui-text-android:1.7.2
-androidx.compose.ui:ui-text:1.7.2
-androidx.compose.ui:ui-unit-android:1.7.2
-androidx.compose.ui:ui-unit:1.7.2
-androidx.compose.ui:ui-util-android:1.7.2
-androidx.compose.ui:ui-util:1.7.2
-androidx.compose:compose-bom:2024.09.02
+androidx.collection:collection:1.1.0
 androidx.concurrent:concurrent-futures:1.1.0
 androidx.core:core-ktx:1.13.1
 androidx.core:core:1.13.1
-androidx.customview:customview-poolingcontainer:1.0.0
 androidx.documentfile:documentfile:1.0.0
 androidx.dynamicanimation:dynamicanimation:1.0.0
-androidx.emoji2:emoji2:1.2.0
-androidx.graphics:graphics-path:1.0.1
 androidx.interpolator:interpolator:1.0.0
 androidx.legacy:legacy-support-core-utils:1.0.0
 androidx.lifecycle:lifecycle-common-jvm:2.8.7
 androidx.lifecycle:lifecycle-common:2.8.7
 androidx.lifecycle:lifecycle-livedata-core-ktx:2.8.7
 androidx.lifecycle:lifecycle-livedata-core:2.8.7
 androidx.lifecycle:lifecycle-livedata:2.8.7
-androidx.lifecycle:lifecycle-process:2.8.7
 androidx.lifecycle:lifecycle-runtime-android:2.8.7
-androidx.lifecycle:lifecycle-runtime-compose-android:2.8.7
-androidx.lifecycle:lifecycle-runtime-compose:2.8.7
 androidx.lifecycle:lifecycle-runtime-ktx-android:2.8.7
 androidx.lifecycle:lifecycle-runtime-ktx:2.8.7
 androidx.lifecycle:lifecycle-runtime:2.8.7
 androidx.lifecycle:lifecycle-viewmodel-android:2.8.7
-androidx.lifecycle:lifecycle-viewmodel-ktx:2.8.7
 androidx.lifecycle:lifecycle-viewmodel-savedstate:2.8.7
 androidx.lifecycle:lifecycle-viewmodel:2.8.7
 androidx.loader:loader:1.0.0
 androidx.localbroadcastmanager:localbroadcastmanager:1.0.0
 androidx.print:print:1.0.0
 androidx.profileinstaller:profileinstaller:1.3.1
-androidx.savedstate:savedstate-ktx:1.2.1
 androidx.savedstate:savedstate:1.2.1
 androidx.startup:startup-runtime:1.1.1
 androidx.tracing:tracing:1.0.0