Delete flatMapWorkflow.

`WorkflowRunnerViewModel` now uses `WorkflowHost` directly.

kotlin/settings.gradle

@@ -25,7 +25,6 @@ include ':samples:tictactoe:common'
 include ':workflow-core'
 include ':workflow-runtime'
 include ':workflow-rx2'
-include ':workflow-rx2-runtime'
 include ':workflow-testing'
 include ':workflow-ui-core'
 include ':workflow-ui-android'

kotlin/workflow-ui-android/build.gradle

@@ -37,7 +37,7 @@ dependencies {
   api deps.rxjava2.rxjava2
   api deps.transition
 
-  implementation project(':workflow-rx2-runtime')
+  implementation project(':workflow-runtime')
   implementation deps.appcompatv7
   implementation deps.kotlin.coroutines.android
   implementation deps.kotlin.coroutines.core

kotlin/workflow-rx2-runtime/build.gradle → kotlin/workflow-ui-android/src/main/java/com/squareup/workflow/ui/FlowOperators.kt

@@ -1,38 +1,38 @@
 /*
  * Copyright 2019 Square Inc.
- *
+ *  
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
- *
+ *  
  *     http://www.apache.org/licenses/LICENSE-2.0
- *
+ *  
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-apply plugin: 'java-library'
-apply plugin: 'kotlin'
-apply plugin: 'com.vanniktech.maven.publish'
-apply plugin: 'org.jetbrains.dokka'
-
-sourceCompatibility = JavaVersion.VERSION_1_7
-targetCompatibility = JavaVersion.VERSION_1_7
-
-dokka rootProject.ext.defaultDokkaConfig
+package com.squareup.workflow.ui
 
-dependencies {
-  compileOnly deps.annotations.intellij
+import io.reactivex.Flowable
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.ObsoleteCoroutinesApi
+import kotlinx.coroutines.channels.consumeEach
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.reactive.openSubscription
 
-  api project(':workflow-runtime')
-  api deps.kotlin.stdLib.jdk6
-  api deps.kotlin.coroutines.core
-  api deps.rxjava2.rxjava2
-
-  implementation deps.kotlin.coroutines.rx2
-
-  testImplementation project(':workflow-testing')
-  testImplementation deps.kotlin.test.jdk
+/**
+ * TODO kdoc
+ *
+ * TODO unit tests
+ */
+@FlowPreview
+@UseExperimental(ObsoleteCoroutinesApi::class)
+@Suppress("NOTHING_TO_INLINE")
+internal inline fun <T> Flowable<out T>.asFlow(): Flow<T> = flow {
+  openSubscription().consumeEach {
+    emit(it)
+  }
 }

kotlin/workflow-ui-android/src/main/java/com/squareup/workflow/ui/WorkflowRunner.kt

@@ -24,6 +24,9 @@ import com.squareup.workflow.Workflow
 import io.reactivex.BackpressureStrategy.LATEST
 import io.reactivex.Flowable
 import io.reactivex.Observable
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.flowOf
 
 /**
  * Uses a [Workflow] and a [ViewRegistry] to drive a [WorkflowLayout].
@@ -43,7 +46,7 @@ interface WorkflowRunner<out OutputT> {
    * A stream of the [output][OutputT] values emitted by the running
    * [Workflow][com.squareup.workflow.Workflow].
    */
-  val output: Observable<out OutputT>
+  val output: Flowable<out OutputT>
 
   val renderings: Observable<out Any>
 
@@ -57,11 +60,12 @@ interface WorkflowRunner<out OutputT> {
      * It's probably more convenient to use [FragmentActivity.setContentWorkflow]
      * rather than calling this method directly.
      */
+    @FlowPreview
     fun <InputT, OutputT : Any> of(
       activity: FragmentActivity,
       viewRegistry: ViewRegistry,
       workflow: Workflow<InputT, OutputT, Any>,
-      inputs: Flowable<InputT>,
+      inputs: Flow<InputT>,
       savedInstanceState: Bundle?
     ): WorkflowRunner<OutputT> {
       val factory =
@@ -71,6 +75,24 @@ interface WorkflowRunner<out OutputT> {
           as WorkflowRunner<OutputT>
     }
 
+    /**
+     * Returns a [ViewModel][android.arch.lifecycle.ViewModel] implementation of
+     * [WorkflowRunner], tied to the given [activity].
+     *
+     * It's probably more convenient to use [FragmentActivity.setContentWorkflow]
+     * rather than calling this method directly.
+     */
+    @UseExperimental(FlowPreview::class)
+    fun <InputT, OutputT : Any> of(
+      activity: FragmentActivity,
+      viewRegistry: ViewRegistry,
+      workflow: Workflow<InputT, OutputT, Any>,
+      inputs: Flowable<InputT>,
+      savedInstanceState: Bundle?
+    ): WorkflowRunner<OutputT> {
+      return of(activity, viewRegistry, workflow, inputs.asFlow(), savedInstanceState)
+    }
+
     /**
      * Convenience overload for workflows unconcerned with back-pressure of their inputs.
      */
@@ -87,14 +109,15 @@ interface WorkflowRunner<out OutputT> {
     /**
      * Convenience overload for workflows that take one input value rather than a stream.
      */
+    @UseExperimental(FlowPreview::class)
     fun <InputT, OutputT : Any> of(
       activity: FragmentActivity,
       viewRegistry: ViewRegistry,
       workflow: Workflow<InputT, OutputT, Any>,
       input: InputT,
       savedInstanceState: Bundle?
     ): WorkflowRunner<OutputT> {
-      return of(activity, viewRegistry, workflow, Observable.just(input), savedInstanceState)
+      return of(activity, viewRegistry, workflow, flowOf(input), savedInstanceState)
     }
 
     /**
@@ -116,11 +139,12 @@ interface WorkflowRunner<out OutputT> {
      * It's probably more convenient to subclass [WorkflowFragment] rather than calling
      * this method directly.
      */
+    @FlowPreview
     fun <InputT, OutputT : Any> of(
       fragment: Fragment,
       viewRegistry: ViewRegistry,
       workflow: Workflow<InputT, OutputT, Any>,
-      inputs: Flowable<InputT>,
+      inputs: Flow<InputT>,
       savedInstanceState: Bundle?
     ): WorkflowRunner<OutputT> {
       val factory =
@@ -130,6 +154,24 @@ interface WorkflowRunner<out OutputT> {
           as WorkflowRunner<OutputT>
     }
 
+    /**
+     * Returns a [ViewModel][android.arch.lifecycle.ViewModel] implementation of
+     * [WorkflowRunner], tied to the given [fragment].
+     *
+     * It's probably more convenient to subclass [WorkflowFragment] rather than calling
+     * this method directly.
+     */
+    @UseExperimental(FlowPreview::class)
+    fun <InputT, OutputT : Any> of(
+      fragment: Fragment,
+      viewRegistry: ViewRegistry,
+      workflow: Workflow<InputT, OutputT, Any>,
+      inputs: Flowable<InputT>,
+      savedInstanceState: Bundle?
+    ): WorkflowRunner<OutputT> {
+      return of(fragment, viewRegistry, workflow, inputs.asFlow(), savedInstanceState)
+    }
+
     /**
      * Convenience overload for workflows unconcerned with back-pressure of their inputs.
      */
@@ -146,14 +188,15 @@ interface WorkflowRunner<out OutputT> {
     /**
      * Convenience overload for workflows that take one input value rather than a stream.
      */
+    @UseExperimental(FlowPreview::class)
     fun <InputT, OutputT : Any> of(
       fragment: Fragment,
       viewRegistry: ViewRegistry,
       workflow: Workflow<InputT, OutputT, Any>,
       input: InputT,
       savedInstanceState: Bundle?
     ): WorkflowRunner<OutputT> {
-      return of(fragment, viewRegistry, workflow, Flowable.just(input), savedInstanceState)
+      return of(fragment, viewRegistry, workflow, flowOf(input), savedInstanceState)
     }
 
     /**