├── .gitignore ├── .idea ├── .gitignore ├── .name ├── compiler.xml ├── gradle.xml ├── misc.xml └── vcs.xml ├── README.md ├── app ├── .gitignore ├── build.gradle ├── proguard-rules.pro └── src │ ├── main │ ├── AndroidManifest.xml │ ├── java │ │ └── com │ │ │ └── example │ │ │ └── statereducerflow │ │ │ ├── StateReducerFlow.kt │ │ │ ├── data │ │ │ ├── Movie.kt │ │ │ └── MoviesJson.kt │ │ │ ├── logic │ │ │ └── FetchMovies.kt │ │ │ └── ui │ │ │ ├── MoviesListActivity.kt │ │ │ ├── MoviesListEvent.kt │ │ │ ├── MoviesListState.kt │ │ │ └── MoviesListViewModel.kt │ └── res │ │ ├── drawable-v24 │ │ └── ic_launcher_foreground.xml │ │ ├── drawable │ │ ├── ic_launcher_background.xml │ │ ├── ic_shuffle.xml │ │ ├── ic_star.xml │ │ └── ic_star_outline.xml │ │ ├── mipmap-anydpi-v26 │ │ ├── ic_launcher.xml │ │ └── ic_launcher_round.xml │ │ ├── mipmap-hdpi │ │ ├── ic_launcher.webp │ │ └── ic_launcher_round.webp │ │ ├── mipmap-mdpi │ │ ├── ic_launcher.webp │ │ └── ic_launcher_round.webp │ │ ├── mipmap-xhdpi │ │ ├── ic_launcher.webp │ │ └── ic_launcher_round.webp │ │ ├── mipmap-xxhdpi │ │ ├── ic_launcher.webp │ │ └── ic_launcher_round.webp │ │ ├── mipmap-xxxhdpi │ │ ├── ic_launcher.webp │ │ └── ic_launcher_round.webp │ │ └── values │ │ ├── colors.xml │ │ ├── strings.xml │ │ └── themes.xml │ └── test │ └── java │ └── com │ └── example │ └── statereducerflow │ ├── MoviesListViewModelTest.kt │ └── TestCoroutineRule.kt ├── build.gradle ├── demo.gif ├── gradle.properties ├── gradle └── wrapper │ ├── gradle-wrapper.jar │ └── gradle-wrapper.properties ├── gradlew ├── gradlew.bat └── settings.gradle /.gitignore: -------------------------------------------------------------------------------- 1 | *.iml 2 | .gradle 3 | /local.properties 4 | /.idea/caches 5 | /.idea/libraries 6 | /.idea/modules.xml 7 | /.idea/workspace.xml 8 | /.idea/navEditor.xml 9 | /.idea/assetWizardSettings.xml 10 | .DS_Store 11 | /build 12 | /captures 13 | .externalNativeBuild 14 | .cxx 15 | local.properties 16 | -------------------------------------------------------------------------------- /.idea/.gitignore: -------------------------------------------------------------------------------- 1 | # Default ignored files 2 | /shelf/ 3 | /workspace.xml 4 | -------------------------------------------------------------------------------- /.idea/.name: -------------------------------------------------------------------------------- 1 | StateReducerFlow -------------------------------------------------------------------------------- /.idea/compiler.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | -------------------------------------------------------------------------------- /.idea/gradle.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 19 | 20 | -------------------------------------------------------------------------------- /.idea/misc.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 11 | 12 | 13 | 14 | 15 | 16 | 18 | -------------------------------------------------------------------------------- /.idea/vcs.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 6 | -------------------------------------------------------------------------------- /README.md: -------------------------------------------------------------------------------- 1 | # All you need for MVI is Kotlin. How to reduce without a reducer? 2 | 3 | ## :scroll: Description 4 | 5 | This repository contains [the article](https://maciej-sady.medium.com/all-you-need-for-mvi-is-kotlin-how-to-reduce-without-reducer-5e986856610f) describing my attempt to implement a simple state reducer based on [Kotlin Flow](https://kotlinlang.org/docs/flow.html) and an example app that uses it. 6 | 7 | ## :bulb: Motivation and Context 8 | 9 | Like any Android developer following the latest trends, I like MVI architecture and the unidirectional 10 | data flow concept. It solves many issues out of the box making our code even more bulletproof. 11 | 12 | ![Alt Text](https://media4.giphy.com/media/ZGuCTJqQxefrq/giphy.gif) 13 | 14 | In this article, I won't go into detail about what MVI is, but you can find many great write-ups about it, e.g. 15 | - [Modern Android Architecture with MVI design pattern](https://amsterdamstandard.com/en/post/modern-android-architecture-with-mvi-design-pattern), 16 | - [MVI beyond state reducers](https://medium.com/bumble-tech/a-modern-kotlin-based-mvi-architecture-9924e08efab1). 17 | 18 | Playing with libraries like [MVICore](https://github.com/badoo/MVICore), [Mobius](https://github.com/spotify/mobius), or [Orbit](https://github.com/orbit-mvi/orbit-mvi) inspired me to experiment and try to implement a flow that can perform state reduction. 19 | 20 | That's how [StateReducerFlow](https://github.com/linean/StateReducerFlow/blob/main/app/src/main/java/com/example/statereducerflow/StateReducerFlow.kt) was born. Let me explain how I've built it, how it works, and how you can use it. 21 | 22 | ## :man_student: Thinking process 23 | 24 | _Please keep in mind that the following examples are simplified._ 25 | 26 | Let's start with a simple counter. It has one state that can be changed with two events: decrement and increment. 27 | 28 | ``` 29 | sealed class Event { 30 | object Increment : Event() 31 | object Decrement : Event() 32 | } 33 | 34 | data class State( 35 | val counter: Int = 0 36 | ) 37 | 38 | class ViewModel { 39 | val state = MutableStateFlow(State()) 40 | 41 | fun handleEvent(event: Event) { 42 | when (event) { 43 | is Increment -> state.update { it.copy(counter = it.counter + 1) } 44 | is Decrement -> state.update { it.copy(counter = it.counter - 1) } 45 | } 46 | } 47 | } 48 | ``` 49 | 50 | Using the above approach, we can structure our logic in the following way: 51 | ``` 52 | Event -> ViewModel -> State 53 | ``` 54 | 55 | One issue, though, is that `handleEvent` can be called from any thread. 56 | Having unstructured state updates can lead to tricky bugs and race conditions. 57 | Luckily, [state.update()](https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/update.html) is already thread-safe, but still, any other logic can be affected. 58 | 59 | To solve that we can introduce a channel that will allow us to process events sequentially, no matter from which thread they come. 60 | 61 | ``` 62 | class ViewModel { 63 | 64 | private val events = Channel() 65 | 66 | val state = MutableStateFlow(State()) 67 | 68 | init { 69 | events.receiveAsFlow() 70 | .onEach(::updateState) 71 | .launchIn(viewModelScope) 72 | } 73 | 74 | fun handleEvent(event: Event) { 75 | events.trySend(event) 76 | } 77 | 78 | private fun updateState(event: Event) { 79 | when (event) { 80 | is Increment -> state.update { it.copy(counter = it.counter + 1) } 81 | is Decrement -> state.update { it.copy(counter = it.counter - 1) } 82 | } 83 | } 84 | } 85 | ``` 86 | 87 | Much better. Now we process all events sequentially but state updates are still possible outside of the `updateState` method. 88 | Ideally, state updates should be only allowed during event processing. 89 | 90 | To achieve that we can implement a simple reducer using [runningFold](https://kotlinlang.org/api/latest/jvm/stdlib/kotlin.collections/running-fold.html). 91 | 92 | ``` 93 | class ViewModel { 94 | 95 | private val events = Channel() 96 | 97 | val state = events.receiveAsFlow() 98 | .runningFold(State(), ::reduceState) 99 | .stateIn(viewModelScope, Eagerly, State()) 100 | 101 | fun handleEvent(event: Event) { 102 | events.trySend(event) 103 | } 104 | 105 | private fun reduceState(currentState: State, event: Event): State { 106 | return when (event) { 107 | is Increment -> currentState.copy(counter = currentState.counter + 1) 108 | is Decrement -> currentState.copy(counter = currentState.counter - 1) 109 | } 110 | } 111 | } 112 | ``` 113 | 114 | Now only the `reduceState` method can perform state transformations. 115 | 116 | ![Alt Text](https://media3.giphy.com/media/3oEjHYibHwRL7mrNyo/giphy.gif) 117 | 118 | When you look at this example ViewModel you may notice that only the `reduceState` method contains important logic. 119 | Everything else is just boilerplate that needs to be repeated for every new ViewModel. 120 | 121 | As we all like to stay [DRY](https://en.wikipedia.org/wiki/Don%27t_repeat_yourself), I needed to extract the generic logic from the ViewModel. 122 | 123 | That's how StateReducerFlow was born. 124 | 125 | ## :rocket: StateReducerFlow 126 | 127 | I wanted [StateReducerFlow](https://github.com/linean/StateReducerFlow/blob/main/app/src/main/java/com/example/statereducerflow/StateReducerFlow.kt) to be a [StateFlow](https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/-state-flow) that can handle generic events. I started with this definition: 128 | ``` 129 | interface StateReducerFlow : StateFlow { 130 | fun handleEvent(event: EVENT) 131 | } 132 | ``` 133 | 134 | Moving forward I extracted my ViewModel logic to the new flow implementation: 135 | 136 | ``` 137 | private class StateReducerFlowImpl( 138 | initialState: STATE, 139 | reduceState: (STATE, EVENT) -> STATE, 140 | scope: CoroutineScope 141 | ) : StateReducerFlow { 142 | 143 | private val events = Channel() 144 | 145 | private val stateFlow = events 146 | .receiveAsFlow() 147 | .runningFold(initialState, reduceState) 148 | .stateIn(scope, Eagerly, initialState) 149 | 150 | override val replayCache get() = stateFlow.replayCache 151 | 152 | override val value get() = stateFlow.value 153 | 154 | override suspend fun collect(collector: FlowCollector): Nothing { 155 | stateFlow.collect(collector) 156 | } 157 | 158 | override fun handleEvent(event: EVENT) { 159 | events.trySend(event) 160 | } 161 | } 162 | ``` 163 | 164 | As you can see, the only new things are a few overrides from [StateFlow](https://kotlin.github.io/kotlinx.coroutines/kotlinx-coroutines-core/kotlinx.coroutines.flow/-state-flow). 165 | To construct the flow you provide the initial state, the function that can reduce it, and the coroutine scope in which the state can be shared. 166 | 167 | The last missing part is a factory function that can create our new flow. I've decided to go with ViewModel extension to access [viewModelScope](https://developer.android.com/topic/libraries/architecture/coroutines#viewmodelscope). 168 | 169 | ``` 170 | fun ViewModel.StateReducerFlow( 171 | initialState: STATE, 172 | reduceState: (STATE, EVENT) -> STATE, 173 | ): StateReducerFlow = StateReducerFlowImpl(initialState, reduceState, viewModelScope) 174 | ``` 175 | 176 | Now we can migrate our ViewModel to the new [StateReducerFlow](https://github.com/linean/StateReducerFlow/blob/main/app/src/main/java/com/example/statereducerflow/StateReducerFlow.kt). 177 | 178 | ``` 179 | class ViewModel { 180 | 181 | val state = StateReducerFlow( 182 | initialState = State(), 183 | reduceState = ::reduceState 184 | ) 185 | 186 | private fun reduceState(currentState: State, event: Event): State { 187 | return when (event) { 188 | is Increment -> currentState.copy(counter = currentState.counter + 1) 189 | is Decrement -> currentState.copy(counter = currentState.counter - 1) 190 | } 191 | } 192 | } 193 | ``` 194 | 195 | Voilà! The boilerplate is gone. 196 | 197 | ![Alt Text](https://media2.giphy.com/media/5xaOcLHoUh2pQODngZ2/giphy.gif) 198 | 199 | Now anyone who has access to [StateReducerFlow](https://github.com/linean/StateReducerFlow/blob/main/app/src/main/java/com/example/statereducerflow/StateReducerFlow.kt) can send events to it, e.g. 200 | 201 | ``` 202 | class ExampleActivity : Activity() { 203 | 204 | private val viewModel = ViewModel() 205 | 206 | override fun onCreate(savedInstanceState: Bundle?) { 207 | super.onCreate(savedInstanceState) 208 | viewModel.state.handleEvent(ExampleEvent) 209 | } 210 | } 211 | ``` 212 | 213 | That's it! Are you interested in how it works in a real app or how it can be tested? 214 | See my example project: https://github.com/linean/StateReducerFlow/tree/main/app/src 215 | 216 | 217 | 218 | 219 | 220 | Stay inspired! 221 | -------------------------------------------------------------------------------- /app/.gitignore: -------------------------------------------------------------------------------- 1 | /build -------------------------------------------------------------------------------- /app/build.gradle: -------------------------------------------------------------------------------- 1 | plugins { 2 | id 'com.android.application' 3 | id 'org.jetbrains.kotlin.android' 4 | id 'org.jetbrains.kotlin.plugin.serialization' 5 | } 6 | 7 | android { 8 | compileSdk 32 9 | 10 | defaultConfig { 11 | applicationId "com.example.statereducerflow" 12 | minSdk 26 13 | targetSdk 32 14 | versionCode 1 15 | versionName "1.0" 16 | 17 | testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner" 18 | vectorDrawables { 19 | useSupportLibrary true 20 | } 21 | } 22 | 23 | buildTypes { 24 | release { 25 | minifyEnabled false 26 | proguardFiles getDefaultProguardFile('proguard-android-optimize.txt'), 'proguard-rules.pro' 27 | } 28 | } 29 | compileOptions { 30 | sourceCompatibility JavaVersion.VERSION_1_8 31 | targetCompatibility JavaVersion.VERSION_1_8 32 | } 33 | kotlinOptions { 34 | jvmTarget = '1.8' 35 | } 36 | buildFeatures { 37 | compose true 38 | } 39 | composeOptions { 40 | kotlinCompilerExtensionVersion compose_version 41 | } 42 | packagingOptions { 43 | resources { 44 | excludes += '/META-INF/{AL2.0,LGPL2.1}' 45 | } 46 | } 47 | } 48 | 49 | dependencies { 50 | 51 | implementation 'androidx.core:core-ktx:1.7.0' 52 | implementation "androidx.compose.ui:ui:$compose_version" 53 | implementation "androidx.compose.material:material:$compose_version" 54 | implementation "androidx.compose.ui:ui-tooling-preview:$compose_version" 55 | implementation 'androidx.lifecycle:lifecycle-runtime-ktx:2.4.1' 56 | implementation 'androidx.activity:activity-compose:1.4.0' 57 | implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-core:1.6.0' 58 | implementation 'org.jetbrains.kotlinx:kotlinx-coroutines-android:1.6.0' 59 | implementation 'com.google.accompanist:accompanist-swiperefresh:0.23.1' 60 | implementation 'org.jetbrains.kotlinx:kotlinx-serialization-json:1.3.2' 61 | implementation "io.coil-kt:coil-compose:2.0.0-rc02" 62 | 63 | testImplementation 'junit:junit:4.13.2' 64 | testImplementation "io.mockk:mockk:1.12.3" 65 | testImplementation "org.jetbrains.kotlinx:kotlinx-coroutines-test:1.6.0" 66 | } -------------------------------------------------------------------------------- /app/proguard-rules.pro: -------------------------------------------------------------------------------- 1 | # Add project specific ProGuard rules here. 2 | # You can control the set of applied configuration files using the 3 | # proguardFiles setting in build.gradle. 4 | # 5 | # For more details, see 6 | # http://developer.android.com/guide/developing/tools/proguard.html 7 | 8 | # If your project uses WebView with JS, uncomment the following 9 | # and specify the fully qualified class name to the JavaScript interface 10 | # class: 11 | #-keepclassmembers class fqcn.of.javascript.interface.for.webview { 12 | # public *; 13 | #} 14 | 15 | # Uncomment this to preserve the line number information for 16 | # debugging stack traces. 17 | #-keepattributes SourceFile,LineNumberTable 18 | 19 | # If you keep the line number information, uncomment this to 20 | # hide the original source file name. 21 | #-renamesourcefileattribute SourceFile -------------------------------------------------------------------------------- /app/src/main/AndroidManifest.xml: -------------------------------------------------------------------------------- 1 | 2 | 4 | 5 | 6 | 7 | 14 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/StateReducerFlow.kt: -------------------------------------------------------------------------------- 1 | @file:Suppress("FunctionName") 2 | 3 | package com.example.statereducerflow 4 | 5 | import androidx.lifecycle.ViewModel 6 | import androidx.lifecycle.viewModelScope 7 | import kotlinx.coroutines.CoroutineScope 8 | import kotlinx.coroutines.channels.Channel 9 | import kotlinx.coroutines.channels.Channel.Factory.BUFFERED 10 | import kotlinx.coroutines.flow.* 11 | import kotlinx.coroutines.flow.SharingStarted.Companion.Eagerly 12 | 13 | interface StateReducerFlow : StateFlow { 14 | fun handleEvent(event: EVENT) 15 | } 16 | 17 | fun ViewModel.StateReducerFlow( 18 | initialState: STATE, 19 | reduceState: (STATE, EVENT) -> STATE, 20 | ): StateReducerFlow = StateReducerFlow(initialState, reduceState, viewModelScope) 21 | 22 | fun StateReducerFlow( 23 | initialState: STATE, 24 | reduceState: (STATE, EVENT) -> STATE, 25 | scope: CoroutineScope 26 | ): StateReducerFlow = StateReducerFlowImpl(initialState, reduceState, scope) 27 | 28 | private class StateReducerFlowImpl( 29 | initialState: STATE, 30 | reduceState: (STATE, EVENT) -> STATE, 31 | scope: CoroutineScope 32 | ) : StateReducerFlow { 33 | 34 | private val events = Channel(BUFFERED) 35 | 36 | private val stateFlow = events 37 | .receiveAsFlow() 38 | .runningFold(initialState, reduceState) 39 | .stateIn(scope, Eagerly, initialState) 40 | 41 | override val replayCache get() = stateFlow.replayCache 42 | 43 | override val value get() = stateFlow.value 44 | 45 | override suspend fun collect(collector: FlowCollector): Nothing { 46 | stateFlow.collect(collector) 47 | } 48 | 49 | override fun handleEvent(event: EVENT) { 50 | val delivered = events.trySend(event).isSuccess 51 | if (!delivered) { 52 | error("Missed event $event! You are doing something wrong during state transformation.") 53 | } 54 | } 55 | } 56 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/data/Movie.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.data 2 | 3 | import kotlinx.serialization.Serializable 4 | 5 | @Serializable 6 | data class Movie( 7 | val id: Int, 8 | val name: String, 9 | val imageUrl: String, 10 | val isSelected: Boolean = false 11 | ) 12 | 13 | fun List.copySelectionFrom(movies: List): List { 14 | val selectedIds = movies.filter { it.isSelected }.map { it.id }.toSet() 15 | return map { movie -> movie.copy(isSelected = selectedIds.contains(movie.id)) } 16 | } 17 | 18 | fun List.toggleSelection(movieId: Int) = map { movie -> 19 | if (movie.id == movieId) movie.copy(isSelected = !movie.isSelected) 20 | else movie 21 | } 22 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/data/MoviesJson.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.data 2 | 3 | val moviesJson 4 | get() = """[ 5 | { 6 | "id": 1, 7 | "name": "The Shawshank Redemption", 8 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BMDFkYTc0MGEtZmNhMC00ZDIzLWFmNTEtODM1ZmRlYWMwMWFmXkEyXkFqcGdeQXVyMTMxODk2OTU@._V1_UY67_CR0,0,45,67_AL_.jpg" 9 | }, 10 | { 11 | "id": 2, 12 | "name": "The Godfather", 13 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BM2MyNjYxNmUtYTAwNi00MTYxLWJmNWYtYzZlODY3ZTk3OTFlXkEyXkFqcGdeQXVyNzkwMjQ5NzM@._V1_UY67_CR1,0,45,67_AL_.jpg" 14 | }, 15 | { 16 | "id": 3, 17 | "name": "The Dark Knight", 18 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BMTMxNTMwODM0NF5BMl5BanBnXkFtZTcwODAyMTk2Mw@@._V1_UY67_CR0,0,45,67_AL_.jpg" 19 | }, 20 | { 21 | "id": 4, 22 | "name": "The Godfather: Part II", 23 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BMWMwMGQzZTItY2JlNC00OWZiLWIyMDctNDk2ZDQ2YjRjMWQ0XkEyXkFqcGdeQXVyNzkwMjQ5NzM@._V1_UY67_CR1,0,45,67_AL_.jpg" 24 | }, 25 | { 26 | "id": 5, 27 | "name": "12 Angry Men", 28 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BMWU4N2FjNzYtNTVkNC00NzQ0LTg0MjAtYTJlMjFhNGUxZDFmXkEyXkFqcGdeQXVyNjc1NTYyMjg@._V1_UX45_CR0,0,45,67_AL_.jpg" 29 | }, 30 | { 31 | "id": 6, 32 | "name": "Schindler's List", 33 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BNDE4OTMxMTctNmRhYy00NWE2LTg3YzItYTk3M2UwOTU5Njg4XkEyXkFqcGdeQXVyNjU0OTQ0OTY@._V1_UX45_CR0,0,45,67_AL_.jpg" 34 | }, 35 | { 36 | "id": 7, 37 | "name": "The Lord of the Rings: The Return of the King", 38 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BNzA5ZDNlZWMtM2NhNS00NDJjLTk4NDItYTRmY2EwMWZlMTY3XkEyXkFqcGdeQXVyNzkwMjQ5NzM@._V1_UY67_CR0,0,45,67_AL_.jpg" 39 | }, 40 | { 41 | "id": 8, 42 | "name": "Pulp Fiction", 43 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BNGNhMDIzZTUtNTBlZi00MTRlLWFjM2ItYzViMjE3YzI5MjljXkEyXkFqcGdeQXVyNzkwMjQ5NzM@._V1_UY67_CR0,0,45,67_AL_.jpg" 44 | }, 45 | { 46 | "id": 9, 47 | "name": "The Lord of the Rings: The Fellowship of the Ring", 48 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BN2EyZjM3NzUtNWUzMi00MTgxLWI0NTctMzY4M2VlOTdjZWRiXkEyXkFqcGdeQXVyNDUzOTQ5MjY@._V1_UY67_CR0,0,45,67_AL_.jpg" 49 | }, 50 | { 51 | "id": 10, 52 | "name": "The Good, the Bad and the Ugly", 53 | "imageUrl": "https://m.media-amazon.com/images/M/MV5BNjJlYmNkZGItM2NhYy00MjlmLTk5NmQtNjg1NmM2ODU4OTMwXkEyXkFqcGdeQXVyMjUzOTY1NTc@._V1_UX45_CR0,0,45,67_AL_.jpg" 54 | } 55 | ] 56 | """ 57 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/logic/FetchMovies.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.logic 2 | 3 | import com.example.statereducerflow.data.Movie 4 | import com.example.statereducerflow.data.moviesJson 5 | import kotlinx.coroutines.Dispatchers 6 | import kotlinx.coroutines.delay 7 | import kotlinx.coroutines.withContext 8 | import kotlinx.serialization.decodeFromString 9 | import kotlinx.serialization.json.Json 10 | import kotlin.random.Random 11 | 12 | class FetchMovies { 13 | 14 | suspend operator fun invoke(): List = withContext(Dispatchers.IO) { 15 | delay(Random.nextLong(300, 2000)) 16 | Json.decodeFromString(moviesJson) 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/ui/MoviesListActivity.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.ui 2 | 3 | import android.os.Bundle 4 | import androidx.activity.ComponentActivity 5 | import androidx.activity.compose.setContent 6 | import androidx.activity.viewModels 7 | import androidx.compose.foundation.ExperimentalFoundationApi 8 | import androidx.compose.foundation.background 9 | import androidx.compose.foundation.clickable 10 | import androidx.compose.foundation.layout.* 11 | import androidx.compose.foundation.lazy.LazyColumn 12 | import androidx.compose.foundation.lazy.items 13 | import androidx.compose.foundation.shape.CircleShape 14 | import androidx.compose.material.Icon 15 | import androidx.compose.material.MaterialTheme 16 | import androidx.compose.material.Text 17 | import androidx.compose.runtime.Composable 18 | import androidx.compose.runtime.collectAsState 19 | import androidx.compose.runtime.getValue 20 | import androidx.compose.ui.Alignment 21 | import androidx.compose.ui.Alignment.Companion.BottomEnd 22 | import androidx.compose.ui.Modifier 23 | import androidx.compose.ui.draw.clip 24 | import androidx.compose.ui.draw.shadow 25 | import androidx.compose.ui.graphics.Color 26 | import androidx.compose.ui.layout.ContentScale 27 | import androidx.compose.ui.res.painterResource 28 | import androidx.compose.ui.unit.dp 29 | import coil.compose.AsyncImage 30 | import com.example.statereducerflow.R 31 | import com.example.statereducerflow.data.Movie 32 | import com.example.statereducerflow.ui.MoviesListEvent.* 33 | import com.google.accompanist.swiperefresh.SwipeRefresh 34 | import com.google.accompanist.swiperefresh.rememberSwipeRefreshState 35 | 36 | class MoviesListActivity : ComponentActivity() { 37 | 38 | private val viewModel: MoviesListViewModel by viewModels() 39 | 40 | override fun onCreate(savedInstanceState: Bundle?) { 41 | super.onCreate(savedInstanceState) 42 | setContent { 43 | val state by viewModel.state.collectAsState() 44 | MoviesListScreen(state, viewModel.state::handleEvent) 45 | } 46 | } 47 | 48 | override fun onStart() { 49 | super.onStart() 50 | viewModel.state.handleEvent(ScreenStarted) 51 | } 52 | } 53 | 54 | @Composable 55 | private fun MoviesListScreen( 56 | state: MoviesListState, 57 | handleEvent: (MoviesListEvent) -> Unit 58 | ) = MaterialTheme { 59 | Box(modifier = Modifier.fillMaxSize()) { 60 | MoviesList( 61 | title = state.title, 62 | movies = state.movies, 63 | isLoading = state.isLoading, 64 | handleEvent = handleEvent 65 | ) 66 | 67 | ShuffleButton( 68 | handleEvent = handleEvent, 69 | modifier = Modifier.align(BottomEnd) 70 | ) 71 | } 72 | } 73 | 74 | @OptIn(ExperimentalFoundationApi::class) 75 | @Composable 76 | private fun MoviesList( 77 | title: String, 78 | movies: List, 79 | isLoading: Boolean, 80 | handleEvent: (MoviesListEvent) -> Unit 81 | ) { 82 | SwipeRefresh( 83 | state = rememberSwipeRefreshState(isRefreshing = isLoading), 84 | onRefresh = { handleEvent(RefreshClicked) } 85 | ) { 86 | LazyColumn( 87 | modifier = Modifier.fillMaxSize(), 88 | contentPadding = PaddingValues(bottom = 78.dp) 89 | ) { 90 | item { 91 | MoviesHeader(title) 92 | } 93 | 94 | items( 95 | items = movies, 96 | key = Movie::id 97 | ) { movie -> 98 | Movie( 99 | movie = movie, 100 | handleEvent = handleEvent, 101 | modifier = Modifier.animateItemPlacement() 102 | ) 103 | } 104 | } 105 | } 106 | } 107 | 108 | @Composable 109 | private fun MoviesHeader(title: String) { 110 | Text( 111 | text = title, 112 | style = MaterialTheme.typography.h3, 113 | modifier = Modifier.padding(16.dp) 114 | ) 115 | } 116 | 117 | @Composable 118 | private fun Movie( 119 | movie: Movie, 120 | handleEvent: (MoviesListEvent) -> Unit, 121 | modifier: Modifier = Modifier 122 | ) { 123 | Row( 124 | verticalAlignment = Alignment.CenterVertically, 125 | modifier = modifier 126 | .fillMaxWidth() 127 | .clickable { handleEvent(MovieClicked(movie)) } 128 | .padding(horizontal = 16.dp, vertical = 4.dp) 129 | ) { 130 | AsyncImage( 131 | model = movie.imageUrl, 132 | contentDescription = null, 133 | contentScale = ContentScale.Crop, 134 | modifier = Modifier 135 | .size(40.dp, 64.dp) 136 | .background(MaterialTheme.colors.onSurface.copy(alpha = 0.2F)) 137 | ) 138 | 139 | Text( 140 | text = movie.name, 141 | style = MaterialTheme.typography.subtitle1, 142 | modifier = Modifier 143 | .weight(1f) 144 | .padding(start = 8.dp) 145 | ) 146 | 147 | val imageResource = when (movie.isSelected) { 148 | true -> R.drawable.ic_star 149 | false -> R.drawable.ic_star_outline 150 | } 151 | 152 | Icon( 153 | painter = painterResource(imageResource), 154 | contentDescription = null, 155 | tint = Color(0xFFFFC107), 156 | modifier = Modifier.size(32.dp) 157 | ) 158 | } 159 | } 160 | 161 | @Composable 162 | private fun ShuffleButton( 163 | handleEvent: (MoviesListEvent) -> Unit, 164 | modifier: Modifier = Modifier, 165 | ) { 166 | Icon( 167 | painter = painterResource(id = R.drawable.ic_shuffle), 168 | contentDescription = null, 169 | tint = Color.White, 170 | modifier = modifier 171 | .padding(16.dp) 172 | .size(56.dp) 173 | .shadow(4.dp, CircleShape) 174 | .background(MaterialTheme.colors.secondary) 175 | .clip(CircleShape) 176 | .clickable { handleEvent(ShuffleClicked) } 177 | .padding(12.dp) 178 | ) 179 | } 180 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/ui/MoviesListEvent.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.ui 2 | 3 | import com.example.statereducerflow.data.Movie 4 | 5 | sealed class MoviesListEvent { 6 | object ScreenStarted : MoviesListEvent() 7 | object RefreshClicked : MoviesListEvent() 8 | object ShuffleClicked : MoviesListEvent() 9 | data class MoviesLoaded(val movies: List) : MoviesListEvent() 10 | data class MovieClicked(val movie: Movie) : MoviesListEvent() 11 | } 12 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/ui/MoviesListState.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.ui 2 | 3 | import com.example.statereducerflow.data.Movie 4 | 5 | data class MoviesListState( 6 | val isLoading: Boolean, 7 | val title: String, 8 | val movies: List 9 | ) { 10 | 11 | companion object { 12 | val initial = MoviesListState( 13 | isLoading = false, 14 | title = "IMDb\nTop 10 Movies", 15 | movies = emptyList() 16 | ) 17 | } 18 | } 19 | -------------------------------------------------------------------------------- /app/src/main/java/com/example/statereducerflow/ui/MoviesListViewModel.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow.ui 2 | 3 | import androidx.lifecycle.ViewModel 4 | import androidx.lifecycle.viewModelScope 5 | import com.example.statereducerflow.StateReducerFlow 6 | import com.example.statereducerflow.data.copySelectionFrom 7 | import com.example.statereducerflow.data.toggleSelection 8 | import com.example.statereducerflow.logic.FetchMovies 9 | import com.example.statereducerflow.ui.MoviesListEvent.* 10 | import kotlinx.coroutines.launch 11 | 12 | class MoviesListViewModel( 13 | val fetchMovies: FetchMovies = FetchMovies() 14 | ) : ViewModel() { 15 | 16 | val state = StateReducerFlow( 17 | initialState = MoviesListState.initial, 18 | reduceState = ::reduceState, 19 | ) 20 | 21 | private fun reduceState( 22 | currentState: MoviesListState, 23 | event: MoviesListEvent 24 | ): MoviesListState = when (event) { 25 | is ScreenStarted, 26 | is RefreshClicked -> { 27 | refreshMovies() 28 | currentState.copy(isLoading = true) 29 | } 30 | 31 | is MovieClicked -> { 32 | val clickedId = event.movie.id 33 | val updatedMovies = currentState.movies.toggleSelection(clickedId) 34 | currentState.copy(movies = updatedMovies) 35 | } 36 | 37 | is ShuffleClicked -> { 38 | val shuffledMovies = currentState.movies.shuffled() 39 | currentState.copy(movies = shuffledMovies) 40 | } 41 | 42 | is MoviesLoaded -> { 43 | val newMovies = event.movies 44 | val currentMovies = currentState.movies 45 | val updatedMovies = newMovies.copySelectionFrom(currentMovies) 46 | currentState.copy(isLoading = false, movies = updatedMovies) 47 | } 48 | } 49 | 50 | private fun refreshMovies() = viewModelScope.launch { 51 | val movies = fetchMovies() 52 | state.handleEvent(MoviesLoaded(movies)) 53 | } 54 | } 55 | -------------------------------------------------------------------------------- /app/src/main/res/drawable-v24/ic_launcher_foreground.xml: -------------------------------------------------------------------------------- 1 | 7 | 8 | 9 | 15 | 18 | 21 | 22 | 23 | 24 | 30 | -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_launcher_background.xml: -------------------------------------------------------------------------------- 1 | 2 | 7 | 10 | 15 | 20 | 25 | 30 | 35 | 40 | 45 | 50 | 55 | 60 | 65 | 70 | 75 | 80 | 85 | 90 | 95 | 100 | 105 | 110 | 115 | 120 | 125 | 130 | 135 | 140 | 145 | 150 | 155 | 160 | 165 | 170 | 171 | -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_shuffle.xml: -------------------------------------------------------------------------------- 1 | 6 | 9 | 10 | -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_star.xml: -------------------------------------------------------------------------------- 1 | 6 | 9 | 10 | -------------------------------------------------------------------------------- /app/src/main/res/drawable/ic_star_outline.xml: -------------------------------------------------------------------------------- 1 | 6 | 9 | 10 | -------------------------------------------------------------------------------- /app/src/main/res/mipmap-anydpi-v26/ic_launcher.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 5 | 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https://raw.githubusercontent.com/linean/StateReducerFlow/742e624e9bef955124094956de394c9eb458d54e/app/src/main/res/mipmap-xxxhdpi/ic_launcher_round.webp -------------------------------------------------------------------------------- /app/src/main/res/values/colors.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | #FFBB86FC 4 | #FF6200EE 5 | #FF3700B3 6 | #FF03DAC5 7 | #FF018786 8 | #FF000000 9 | #FFFFFFFF 10 | -------------------------------------------------------------------------------- /app/src/main/res/values/strings.xml: -------------------------------------------------------------------------------- 1 | 2 | StateReducerFlow 3 | -------------------------------------------------------------------------------- /app/src/main/res/values/themes.xml: -------------------------------------------------------------------------------- 1 | 2 | 3 | 4 | 7 | -------------------------------------------------------------------------------- /app/src/test/java/com/example/statereducerflow/MoviesListViewModelTest.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow 2 | 3 | import com.example.statereducerflow.data.Movie 4 | import com.example.statereducerflow.logic.FetchMovies 5 | import com.example.statereducerflow.ui.MoviesListEvent 6 | import com.example.statereducerflow.ui.MoviesListEvent.* 7 | import com.example.statereducerflow.ui.MoviesListState 8 | import com.example.statereducerflow.ui.MoviesListViewModel 9 | import io.mockk.coVerify 10 | import io.mockk.mockk 11 | import junit.framework.TestCase.assertEquals 12 | import junit.framework.TestCase.assertNotSame 13 | import org.junit.Before 14 | import org.junit.Rule 15 | import org.junit.Test 16 | 17 | private fun Movie(id: Int = 1) = Movie(id, "name", "image") 18 | 19 | class MoviesListViewModelTest { 20 | 21 | @get:Rule 22 | val testCoroutineRule = TestCoroutineRule() 23 | 24 | private val fetchMovies = mockk() 25 | private lateinit var state: StateReducerFlow 26 | 27 | @Before 28 | fun setUp() { 29 | val viewModel = MoviesListViewModel(fetchMovies) 30 | state = viewModel.state 31 | } 32 | 33 | @Test 34 | fun `fetches movies after screen is started`() { 35 | state.handleEvent(ScreenStarted) 36 | 37 | coVerify { fetchMovies() } 38 | assertEquals(true, state.value.isLoading) 39 | } 40 | 41 | @Test 42 | fun `fetches movies after refresh clicked`() { 43 | state.handleEvent(RefreshClicked) 44 | 45 | coVerify { fetchMovies() } 46 | assertEquals(true, state.value.isLoading) 47 | } 48 | 49 | @Test 50 | fun `displays movies after loaded`() { 51 | val testMovies = (0..2).map(::Movie) 52 | state.handleEvent(MoviesLoaded(testMovies)) 53 | 54 | assertEquals(false, state.value.isLoading) 55 | assertEquals(testMovies, state.value.movies) 56 | } 57 | 58 | @Test 59 | fun `toggles selection after movie clicked`() { 60 | fun isSelected() = state.value.movies.first().isSelected 61 | val testMovie = Movie() 62 | 63 | state.handleEvent(MoviesLoaded(listOf(testMovie))) 64 | assertEquals(false, isSelected()) 65 | 66 | state.handleEvent(MovieClicked(testMovie)) 67 | assertEquals(true, isSelected()) 68 | 69 | state.handleEvent(MovieClicked(testMovie)) 70 | assertEquals(false, isSelected()) 71 | } 72 | 73 | @Test 74 | fun `persist selection across updates`() { 75 | fun isSelected() = state.value.movies.first().isSelected 76 | val testMovie = Movie() 77 | 78 | state.handleEvent(MoviesLoaded(listOf(testMovie))) 79 | assertEquals(false, isSelected()) 80 | 81 | state.handleEvent(MovieClicked(testMovie)) 82 | assertEquals(true, isSelected()) 83 | 84 | state.handleEvent(MoviesLoaded(listOf(testMovie))) 85 | assertEquals(true, isSelected()) 86 | } 87 | 88 | @Test 89 | fun `shuffles movies after shuffle clicked`() { 90 | val movies = (0..50).map(::Movie) 91 | state.handleEvent(MoviesLoaded(movies)) 92 | assertEquals(movies, state.value.movies) 93 | 94 | state.handleEvent(ShuffleClicked) 95 | 96 | assertEquals(movies.size, state.value.movies.size) 97 | assertNotSame(movies, state.value.movies) 98 | } 99 | } 100 | -------------------------------------------------------------------------------- /app/src/test/java/com/example/statereducerflow/TestCoroutineRule.kt: -------------------------------------------------------------------------------- 1 | package com.example.statereducerflow 2 | 3 | import kotlinx.coroutines.Dispatchers 4 | import kotlinx.coroutines.ExperimentalCoroutinesApi 5 | import kotlinx.coroutines.test.UnconfinedTestDispatcher 6 | import kotlinx.coroutines.test.resetMain 7 | import kotlinx.coroutines.test.setMain 8 | import org.junit.rules.TestWatcher 9 | import org.junit.runner.Description 10 | 11 | @OptIn(ExperimentalCoroutinesApi::class) 12 | class TestCoroutineRule : TestWatcher() { 13 | 14 | val dispatcher = UnconfinedTestDispatcher(name = "TestCoroutineRuleDispatcher") 15 | 16 | override fun starting(description: Description?) { 17 | super.starting(description) 18 | Dispatchers.setMain(dispatcher) 19 | } 20 | 21 | override fun finished(description: Description?) { 22 | super.finished(description) 23 | Dispatchers.resetMain() 24 | } 25 | } 26 | -------------------------------------------------------------------------------- /build.gradle: -------------------------------------------------------------------------------- 1 | buildscript { 2 | ext { 3 | compose_version = '1.1.1' 4 | kotlin_version = '1.6.10' 5 | } 6 | }// Top-level build file where you can add configuration options common to all sub-projects/modules. 7 | plugins { 8 | id 'com.android.application' version '7.1.2' apply false 9 | id 'com.android.library' version '7.1.2' apply false 10 | id 'org.jetbrains.kotlin.android' version "$kotlin_version" apply false 11 | id 'org.jetbrains.kotlin.plugin.serialization' version "$kotlin_version" apply false 12 | } 13 | 14 | task clean(type: Delete) { 15 | delete rootProject.buildDir 16 | } -------------------------------------------------------------------------------- /demo.gif: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/linean/StateReducerFlow/742e624e9bef955124094956de394c9eb458d54e/demo.gif -------------------------------------------------------------------------------- /gradle.properties: -------------------------------------------------------------------------------- 1 | # Project-wide Gradle settings. 2 | # IDE (e.g. Android Studio) users: 3 | # Gradle settings configured through the IDE *will override* 4 | # any settings specified in this file. 5 | # For more details on how to configure your build environment visit 6 | # http://www.gradle.org/docs/current/userguide/build_environment.html 7 | # Specifies the JVM arguments used for the daemon process. 8 | # The setting is particularly useful for tweaking memory settings. 9 | org.gradle.jvmargs=-Xmx2048m -Dfile.encoding=UTF-8 10 | # When configured, Gradle will run in incubating parallel mode. 11 | # This option should only be used with decoupled projects. More details, visit 12 | # http://www.gradle.org/docs/current/userguide/multi_project_builds.html#sec:decoupled_projects 13 | # org.gradle.parallel=true 14 | # AndroidX package structure to make it clearer which packages are bundled with the 15 | # Android operating system, and which are packaged with your app"s APK 16 | # https://developer.android.com/topic/libraries/support-library/androidx-rn 17 | android.useAndroidX=true 18 | # Kotlin code style for this project: "official" or "obsolete": 19 | kotlin.code.style=official 20 | # Enables namespacing of each library's R class so that its R class includes only the 21 | # resources declared in the library itself and none from the library's dependencies, 22 | # thereby reducing the size of the R class for that library 23 | android.nonTransitiveRClass=true -------------------------------------------------------------------------------- /gradle/wrapper/gradle-wrapper.jar: -------------------------------------------------------------------------------- https://raw.githubusercontent.com/linean/StateReducerFlow/742e624e9bef955124094956de394c9eb458d54e/gradle/wrapper/gradle-wrapper.jar -------------------------------------------------------------------------------- /gradle/wrapper/gradle-wrapper.properties: -------------------------------------------------------------------------------- 1 | #Thu Mar 31 11:25:16 CEST 2022 2 | distributionBase=GRADLE_USER_HOME 3 | distributionUrl=https\://services.gradle.org/distributions/gradle-7.2-bin.zip 4 | distributionPath=wrapper/dists 5 | zipStorePath=wrapper/dists 6 | zipStoreBase=GRADLE_USER_HOME 7 | -------------------------------------------------------------------------------- /gradlew: -------------------------------------------------------------------------------- 1 | #!/usr/bin/env sh 2 | 3 | # 4 | # Copyright 2015 the original author or authors. 5 | # 6 | # Licensed under the Apache License, Version 2.0 (the "License"); 7 | # you may not use this file except in compliance with the License. 8 | # You may obtain a copy of the License at 9 | # 10 | # https://www.apache.org/licenses/LICENSE-2.0 11 | # 12 | # Unless required by applicable law or agreed to in writing, software 13 | # distributed under the License is distributed on an "AS IS" BASIS, 14 | # WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 15 | # See the License for the specific language governing permissions and 16 | # limitations under the License. 17 | # 18 | 19 | ############################################################################## 20 | ## 21 | ## Gradle start up script for UN*X 22 | ## 23 | ############################################################################## 24 | 25 | # Attempt to set APP_HOME 26 | # Resolve links: $0 may be a link 27 | PRG="$0" 28 | # Need this for relative symlinks. 29 | while [ -h "$PRG" ] ; do 30 | ls=`ls -ld "$PRG"` 31 | link=`expr "$ls" : '.*-> \(.*\)$'` 32 | if expr "$link" : '/.*' > /dev/null; then 33 | PRG="$link" 34 | else 35 | PRG=`dirname "$PRG"`"/$link" 36 | fi 37 | done 38 | SAVED="`pwd`" 39 | cd "`dirname \"$PRG\"`/" >/dev/null 40 | APP_HOME="`pwd -P`" 41 | cd "$SAVED" >/dev/null 42 | 43 | APP_NAME="Gradle" 44 | APP_BASE_NAME=`basename "$0"` 45 | 46 | # Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. 47 | DEFAULT_JVM_OPTS='"-Xmx64m" "-Xms64m"' 48 | 49 | # Use the maximum available, or set MAX_FD != -1 to use that value. 50 | MAX_FD="maximum" 51 | 52 | warn () { 53 | echo "$*" 54 | } 55 | 56 | die () { 57 | echo 58 | echo "$*" 59 | echo 60 | exit 1 61 | } 62 | 63 | # OS specific support (must be 'true' or 'false'). 64 | cygwin=false 65 | msys=false 66 | darwin=false 67 | nonstop=false 68 | case "`uname`" in 69 | CYGWIN* ) 70 | cygwin=true 71 | ;; 72 | Darwin* ) 73 | darwin=true 74 | ;; 75 | MINGW* ) 76 | msys=true 77 | ;; 78 | NONSTOP* ) 79 | nonstop=true 80 | ;; 81 | esac 82 | 83 | CLASSPATH=$APP_HOME/gradle/wrapper/gradle-wrapper.jar 84 | 85 | 86 | # Determine the Java command to use to start the JVM. 87 | if [ -n "$JAVA_HOME" ] ; then 88 | if [ -x "$JAVA_HOME/jre/sh/java" ] ; then 89 | # IBM's JDK on AIX uses strange locations for the executables 90 | JAVACMD="$JAVA_HOME/jre/sh/java" 91 | else 92 | JAVACMD="$JAVA_HOME/bin/java" 93 | fi 94 | if [ ! -x "$JAVACMD" ] ; then 95 | die "ERROR: JAVA_HOME is set to an invalid directory: $JAVA_HOME 96 | 97 | Please set the JAVA_HOME variable in your environment to match the 98 | location of your Java installation." 99 | fi 100 | else 101 | JAVACMD="java" 102 | which java >/dev/null 2>&1 || die "ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 103 | 104 | Please set the JAVA_HOME variable in your environment to match the 105 | location of your Java installation." 106 | fi 107 | 108 | # Increase the maximum file descriptors if we can. 109 | if [ "$cygwin" = "false" -a "$darwin" = "false" -a "$nonstop" = "false" ] ; then 110 | MAX_FD_LIMIT=`ulimit -H -n` 111 | if [ $? -eq 0 ] ; then 112 | if [ "$MAX_FD" = "maximum" -o "$MAX_FD" = "max" ] ; then 113 | MAX_FD="$MAX_FD_LIMIT" 114 | fi 115 | ulimit -n $MAX_FD 116 | if [ $? -ne 0 ] ; then 117 | warn "Could not set maximum file descriptor limit: $MAX_FD" 118 | fi 119 | else 120 | warn "Could not query maximum file descriptor limit: $MAX_FD_LIMIT" 121 | fi 122 | fi 123 | 124 | # For Darwin, add options to specify how the application appears in the dock 125 | if $darwin; then 126 | GRADLE_OPTS="$GRADLE_OPTS \"-Xdock:name=$APP_NAME\" \"-Xdock:icon=$APP_HOME/media/gradle.icns\"" 127 | fi 128 | 129 | # For Cygwin or MSYS, switch paths to Windows format before running java 130 | if [ "$cygwin" = "true" -o "$msys" = "true" ] ; then 131 | APP_HOME=`cygpath --path --mixed "$APP_HOME"` 132 | CLASSPATH=`cygpath --path --mixed "$CLASSPATH"` 133 | 134 | JAVACMD=`cygpath --unix "$JAVACMD"` 135 | 136 | # We build the pattern for arguments to be converted via cygpath 137 | ROOTDIRSRAW=`find -L / -maxdepth 1 -mindepth 1 -type d 2>/dev/null` 138 | SEP="" 139 | for dir in $ROOTDIRSRAW ; do 140 | ROOTDIRS="$ROOTDIRS$SEP$dir" 141 | SEP="|" 142 | done 143 | OURCYGPATTERN="(^($ROOTDIRS))" 144 | # Add a user-defined pattern to the cygpath arguments 145 | if [ "$GRADLE_CYGPATTERN" != "" ] ; then 146 | OURCYGPATTERN="$OURCYGPATTERN|($GRADLE_CYGPATTERN)" 147 | fi 148 | # Now convert the arguments - kludge to limit ourselves to /bin/sh 149 | i=0 150 | for arg in "$@" ; do 151 | CHECK=`echo "$arg"|egrep -c "$OURCYGPATTERN" -` 152 | CHECK2=`echo "$arg"|egrep -c "^-"` ### Determine if an option 153 | 154 | if [ $CHECK -ne 0 ] && [ $CHECK2 -eq 0 ] ; then ### Added a condition 155 | eval `echo args$i`=`cygpath --path --ignore --mixed "$arg"` 156 | else 157 | eval `echo args$i`="\"$arg\"" 158 | fi 159 | i=`expr $i + 1` 160 | done 161 | case $i in 162 | 0) set -- ;; 163 | 1) set -- "$args0" ;; 164 | 2) set -- "$args0" "$args1" ;; 165 | 3) set -- "$args0" "$args1" "$args2" ;; 166 | 4) set -- "$args0" "$args1" "$args2" "$args3" ;; 167 | 5) set -- "$args0" "$args1" "$args2" "$args3" "$args4" ;; 168 | 6) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" ;; 169 | 7) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" ;; 170 | 8) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" ;; 171 | 9) set -- "$args0" "$args1" "$args2" "$args3" "$args4" "$args5" "$args6" "$args7" "$args8" ;; 172 | esac 173 | fi 174 | 175 | # Escape application args 176 | save () { 177 | for i do printf %s\\n "$i" | sed "s/'/'\\\\''/g;1s/^/'/;\$s/\$/' \\\\/" ; done 178 | echo " " 179 | } 180 | APP_ARGS=`save "$@"` 181 | 182 | # Collect all arguments for the java command, following the shell quoting and substitution rules 183 | eval set -- $DEFAULT_JVM_OPTS $JAVA_OPTS $GRADLE_OPTS "\"-Dorg.gradle.appname=$APP_BASE_NAME\"" -classpath "\"$CLASSPATH\"" org.gradle.wrapper.GradleWrapperMain "$APP_ARGS" 184 | 185 | exec "$JAVACMD" "$@" 186 | -------------------------------------------------------------------------------- /gradlew.bat: -------------------------------------------------------------------------------- 1 | @rem 2 | @rem Copyright 2015 the original author or authors. 3 | @rem 4 | @rem Licensed under the Apache License, Version 2.0 (the "License"); 5 | @rem you may not use this file except in compliance with the License. 6 | @rem You may obtain a copy of the License at 7 | @rem 8 | @rem https://www.apache.org/licenses/LICENSE-2.0 9 | @rem 10 | @rem Unless required by applicable law or agreed to in writing, software 11 | @rem distributed under the License is distributed on an "AS IS" BASIS, 12 | @rem WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 | @rem See the License for the specific language governing permissions and 14 | @rem limitations under the License. 15 | @rem 16 | 17 | @if "%DEBUG%" == "" @echo off 18 | @rem ########################################################################## 19 | @rem 20 | @rem Gradle startup script for Windows 21 | @rem 22 | @rem ########################################################################## 23 | 24 | @rem Set local scope for the variables with windows NT shell 25 | if "%OS%"=="Windows_NT" setlocal 26 | 27 | set DIRNAME=%~dp0 28 | if "%DIRNAME%" == "" set DIRNAME=. 29 | set APP_BASE_NAME=%~n0 30 | set APP_HOME=%DIRNAME% 31 | 32 | @rem Resolve any "." and ".." in APP_HOME to make it shorter. 33 | for %%i in ("%APP_HOME%") do set APP_HOME=%%~fi 34 | 35 | @rem Add default JVM options here. You can also use JAVA_OPTS and GRADLE_OPTS to pass JVM options to this script. 36 | set DEFAULT_JVM_OPTS="-Xmx64m" "-Xms64m" 37 | 38 | @rem Find java.exe 39 | if defined JAVA_HOME goto findJavaFromJavaHome 40 | 41 | set JAVA_EXE=java.exe 42 | %JAVA_EXE% -version >NUL 2>&1 43 | if "%ERRORLEVEL%" == "0" goto execute 44 | 45 | echo. 46 | echo ERROR: JAVA_HOME is not set and no 'java' command could be found in your PATH. 47 | echo. 48 | echo Please set the JAVA_HOME variable in your environment to match the 49 | echo location of your Java installation. 50 | 51 | goto fail 52 | 53 | :findJavaFromJavaHome 54 | set JAVA_HOME=%JAVA_HOME:"=% 55 | set JAVA_EXE=%JAVA_HOME%/bin/java.exe 56 | 57 | if exist "%JAVA_EXE%" goto execute 58 | 59 | echo. 60 | echo ERROR: JAVA_HOME is set to an invalid directory: %JAVA_HOME% 61 | echo. 62 | echo Please set the JAVA_HOME variable in your environment to match the 63 | echo location of your Java installation. 64 | 65 | goto fail 66 | 67 | :execute 68 | @rem Setup the command line 69 | 70 | set CLASSPATH=%APP_HOME%\gradle\wrapper\gradle-wrapper.jar 71 | 72 | 73 | @rem Execute Gradle 74 | "%JAVA_EXE%" %DEFAULT_JVM_OPTS% %JAVA_OPTS% %GRADLE_OPTS% "-Dorg.gradle.appname=%APP_BASE_NAME%" -classpath "%CLASSPATH%" org.gradle.wrapper.GradleWrapperMain %* 75 | 76 | :end 77 | @rem End local scope for the variables with windows NT shell 78 | if "%ERRORLEVEL%"=="0" goto mainEnd 79 | 80 | :fail 81 | rem Set variable GRADLE_EXIT_CONSOLE if you need the _script_ return code instead of 82 | rem the _cmd.exe /c_ return code! 83 | if not "" == "%GRADLE_EXIT_CONSOLE%" exit 1 84 | exit /b 1 85 | 86 | :mainEnd 87 | if "%OS%"=="Windows_NT" endlocal 88 | 89 | :omega 90 | -------------------------------------------------------------------------------- /settings.gradle: -------------------------------------------------------------------------------- 1 | pluginManagement { 2 | repositories { 3 | gradlePluginPortal() 4 | google() 5 | mavenCentral() 6 | } 7 | } 8 | dependencyResolutionManagement { 9 | repositoriesMode.set(RepositoriesMode.FAIL_ON_PROJECT_REPOS) 10 | repositories { 11 | google() 12 | mavenCentral() 13 | } 14 | } 15 | rootProject.name = "StateReducerFlow" 16 | include ':app' 17 | --------------------------------------------------------------------------------