HW Flow | Nuradil

build.gradle

@@ -1,6 +1,6 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 buildscript {
-    ext.kotlin_version = "1.4.32"
+    ext.kotlin_version = "1.6.0"
     repositories {
         google()
         jcenter()

flowcats/build.gradle

@@ -4,13 +4,13 @@ plugins {
 }
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 32
     buildToolsVersion "30.0.3"
 
     defaultConfig {
         applicationId "otus.homework.flowcats"
         minSdkVersion 23
-        targetSdkVersion 30
+        targetSdkVersion 32
         versionCode 1
         versionName "1.0"
 
@@ -46,4 +46,5 @@ dependencies {
     implementation 'androidx.activity:activity-ktx:1.2.3'
     testImplementation 'org.jetbrains.kotlinx:kotlinx-coroutines-test:1.4.3'
     implementation 'androidx.lifecycle:lifecycle-viewmodel-ktx:2.3.1'
+    implementation "androidx.lifecycle:lifecycle-runtime-ktx:2.5.1"
 }

flowcats/src/main/AndroidManifest.xml

@@ -9,8 +9,10 @@
         android:label="@string/app_name"
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
-        android:theme="@style/Theme.Flow" >
-        <activity android:name=".MainActivity">
+        android:theme="@style/Theme.Flow">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

flowcats/src/main/java/otus/homework/flowcats/CatsView.kt

@@ -3,6 +3,7 @@ package otus.homework.flowcats
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.TextView
+import android.widget.Toast
 import androidx.constraintlayout.widget.ConstraintLayout
 
 class CatsView @JvmOverloads constructor(
@@ -14,9 +15,15 @@ class CatsView @JvmOverloads constructor(
     override fun populate(fact: Fact) {
         findViewById<TextView>(R.id.fact_textView).text = fact.text
     }
+
+    override fun showToast(message: String) {
+        Toast.makeText(context, message, Toast.LENGTH_SHORT).show()
+    }
 }
 
 interface ICatsView {
 
     fun populate(fact: Fact)
+
+    fun showToast(message: String)
 }

flowcats/src/main/java/otus/homework/flowcats/CatsViewModel.kt

@@ -1,23 +1,43 @@
 package otus.homework.flowcats
 
-import androidx.lifecycle.*
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.Dispatchers
-import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.launch
 import kotlinx.coroutines.withContext
 
 class CatsViewModel(
     private val catsRepository: CatsRepository
 ) : ViewModel() {
 
-    private val _catsLiveData = MutableLiveData<Fact>()
-    val catsLiveData: LiveData<Fact> = _catsLiveData
+    sealed class Result {
+        class Success<T>(val data: T) : Result()
+        class Error(val throwable: Throwable) : Result()
+    }
+
+    private val _result = MutableStateFlow<Result?>(null)
+    val resultObservable = _result.asStateFlow()
 
     init {
         viewModelScope.launch {
-            withContext(Dispatchers.IO) {
+            try {
                 catsRepository.listenForCatFacts().collect {
-                    _catsLiveData.value = it
+                    withContext(Dispatchers.IO) {
+                        _result.value = Result.Success(it)
+                    }
+                }
+            } catch (throwable: Throwable) {
+                when (throwable) {
+                    is CancellationException -> {
+                        throw throwable
+                    }
+                    else -> {
+                        _result.value = Result.Error(throwable)
+                    }
                 }
             }
         }

flowcats/src/main/java/otus/homework/flowcats/MainActivity.kt

@@ -1,8 +1,12 @@
 package otus.homework.flowcats
 
-import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import androidx.activity.viewModels
+import androidx.appcompat.app.AppCompatActivity
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
+import kotlinx.coroutines.launch
 
 class MainActivity : AppCompatActivity() {
 
@@ -14,8 +18,25 @@ class MainActivity : AppCompatActivity() {
         val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
         setContentView(view)
 
-        catsViewModel.catsLiveData.observe(this){
-            view.populate(it)
+        lifecycleScope.launch {
+            repeatOnLifecycle(Lifecycle.State.STARTED) {
+                catsViewModel.resultObservable.collect { result ->
+                    result?.let {
+                        when (result) {
+                            is CatsViewModel.Result.Success<*> -> {
+                                if (result.data is Fact) {
+                                    view.populate(result.data)
+                                }
+                            }
+                            is CatsViewModel.Result.Error -> {
+                                result.throwable.message?.let {
+                                    view.showToast(it)
+                                }
+                            }
+                        }
+                    }
+                }
+            }
         }
     }
 }

operators/src/main/java/otus/homework/flow/SampleInteractor.kt

@@ -18,7 +18,12 @@ class SampleInteractor(
      * 6) возвращает результат
      */
     fun task1(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .map { it * 5 }
+            .filter { it >= 20 }
+            .filter { it % 2 == 1 }
+            .map { "$it won" }
+            .take(3)
     }
 
     /**
@@ -29,7 +34,21 @@ class SampleInteractor(
      * Если число не делится на 3,5,15 - эмитим само число
      */
     fun task2(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .transform {
+                emit(it.toString())
+                when {
+                    it % 15 == 0 -> {
+                        emit("FizzBuzz")
+                    }
+                    it % 5 == 0 -> {
+                        emit("Buzz")
+                    }
+                    it % 3 == 0 -> {
+                        emit("Fizz")
+                    }
+                }
+            }
     }
 
     /**
@@ -38,7 +57,10 @@ class SampleInteractor(
      * Если айтемы в одно из флоу кончились то результирующий флоу также должен закончится
      */
     fun task3(): Flow<Pair<String, String>> {
-        return flowOf()
+        val colorsFlow = sampleRepository.produceColors()
+        val formsFlow = sampleRepository.produceForms()
+
+        return colorsFlow.zip(formsFlow) { f1, f2 -> Pair(f1, f2) }
     }
 
     /**
@@ -48,6 +70,13 @@ class SampleInteractor(
      * При любом исходе, будь то выброс исключения или успешная отработка функции вызовите метод dotsRepository.completed()
      */
     fun task4(): Flow<Int> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .onCompletion { sampleRepository.completed() }
+            .catch { throwable ->
+                when (throwable) {
+                    is IllegalArgumentException -> emit(-1)
+                    else -> throw throwable
+                }
+            }
     }
 }