Homework

flowcats/build.gradle

@@ -4,15 +4,15 @@ plugins {
 }
 
 android {
-    compileSdkVersion 30
+    compileSdkVersion 33
     buildToolsVersion "30.0.3"
 
     namespace = "otus.homework.flowcats"
 
     defaultConfig {
         applicationId "otus.homework.flowcats"
         minSdkVersion 23
-        targetSdkVersion 30
+        targetSdkVersion 33
         versionCode 1
         versionName "1.0"
 
@@ -48,4 +48,5 @@ 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:2.4.0'
 }

flowcats/src/main/AndroidManifest.xml

@@ -10,7 +10,9 @@
         android:roundIcon="@mipmap/ic_launcher_round"
         android:supportsRtl="true"
         android:theme="@style/Theme.Flow" >
-        <activity android:name=".MainActivity">
+        <activity
+            android:name=".MainActivity"
+            android:exported="true">
             <intent-filter>
                 <action android:name="android.intent.action.MAIN" />
 

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

@@ -1,7 +1,10 @@
 package otus.homework.flowcats
 
+import android.util.Log
+import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.delay
 import kotlinx.coroutines.flow.flow
+import kotlinx.coroutines.flow.flowOn
 
 class CatsRepository(
     private val catsService: CatsService,
@@ -10,9 +13,14 @@ class CatsRepository(
 
     fun listenForCatFacts() = flow {
         while (true) {
-            val latestNews = catsService.getCatFact()
-            emit(latestNews)
+            Log.d("TAGTAG", "listenForCatFacts: ")
+            try {
+                val latestNews = catsService.getCatFact()
+                emit(Result.Success(latestNews))
+            } catch (t: Throwable) {
+                emit(Result.Error(t))
+            }
             delay(refreshIntervalMs)
         }
-    }
+    }.flowOn(Dispatchers.IO)
 }

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(
@@ -11,12 +12,16 @@ class CatsView @JvmOverloads constructor(
     defStyleAttr: Int = 0
 ) : ConstraintLayout(context, attrs, defStyleAttr), ICatsView {
 
-    override fun populate(fact: Fact) {
-        findViewById<TextView>(R.id.fact_textView).text = fact.text
+    override fun populate(text: String) {
+        findViewById<TextView>(R.id.fact_textView).text = text
+    }
+
+    fun showToast(text: String) {
+        Toast.makeText(context, text, Toast.LENGTH_SHORT).show()
     }
 }
 
 interface ICatsView {
 
-    fun populate(fact: Fact)
+    fun populate(text: String)
 }

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

@@ -1,23 +1,28 @@
 package otus.homework.flowcats
 
 import androidx.lifecycle.*
-import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
+import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.collect
 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
+    private val _state: MutableStateFlow<State> = MutableStateFlow(State.Initial)
+    val state: StateFlow<State> = _state.asStateFlow()
 
     init {
         viewModelScope.launch {
-            withContext(Dispatchers.IO) {
-                catsRepository.listenForCatFacts().collect {
-                    _catsLiveData.value = it
+            catsRepository.listenForCatFacts().collect {
+                when (it) {
+                    is Result.Success<*> -> (it.data as? Fact)?.let { fact ->
+                        _state.emit(State.Success(fact.text))
+                    }
+
+                    is Result.Error -> _state.emit(State.Error(it.t.message ?: ""))
                 }
             }
         }
@@ -26,6 +31,6 @@ class CatsViewModel(
 
 class CatsViewModelFactory(private val catsRepository: CatsRepository) :
     ViewModelProvider.NewInstanceFactory() {
-    override fun <T : ViewModel?> create(modelClass: Class<T>): T =
+    override fun <T : ViewModel> create(modelClass: Class<T>): T =
         CatsViewModel(catsRepository) as T
 }

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

@@ -3,6 +3,11 @@ package otus.homework.flowcats
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
 import androidx.activity.viewModels
+import androidx.lifecycle.Lifecycle
+import androidx.lifecycle.lifecycleScope
+import androidx.lifecycle.repeatOnLifecycle
+import kotlinx.coroutines.flow.collect
+import kotlinx.coroutines.launch
 
 class MainActivity : AppCompatActivity() {
 
@@ -13,9 +18,16 @@ class MainActivity : AppCompatActivity() {
         super.onCreate(savedInstanceState)
         val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
         setContentView(view)
-
-        catsViewModel.catsLiveData.observe(this){
-            view.populate(it)
+        lifecycleScope.launch {
+            lifecycle.repeatOnLifecycle(Lifecycle.State.STARTED) {
+                catsViewModel.state.collect {
+                    when (it) {
+                        State.Initial -> Unit
+                        is State.Error -> view.showToast(it.text)
+                        is State.Success -> view.populate(it.text)
+                    }
+                }
+            }
         }
     }
 }

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

@@ -0,0 +1,7 @@
+package otus.homework.flowcats
+
+
+sealed class Result {
+    data class Success<T>(val data: T) : Result()
+    data class Error(val t: Throwable) : Result()
+}

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

@@ -0,0 +1,7 @@
+package otus.homework.flowcats
+
+sealed class State {
+    data object Initial : State()
+    data class Success(val text: String) : State()
+    data class Error(val text: String) : State()
+}

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

@@ -1,6 +1,7 @@
 package otus.homework.flow
 
 import kotlinx.coroutines.ExperimentalCoroutinesApi
+import kotlinx.coroutines.FlowPreview
 import kotlinx.coroutines.flow.*
 
 @ExperimentalCoroutinesApi
@@ -18,7 +19,12 @@ class SampleInteractor(
      * 6) возвращает результат
      */
     fun task1(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .map { it * 5 }
+            .filter { it > 20 }
+            .filter { it % 2 != 0 }
+            .map { "$it won" }
+            .take(3)
     }
 
     /**
@@ -29,7 +35,15 @@ class SampleInteractor(
      * Если число не делится на 3,5,15 - эмитим само число
      */
     fun task2(): Flow<String> {
-        return flowOf()
+        return sampleRepository.produceNumbers()
+            .flatMapConcat {
+                when {
+                    it % 15 == 0 -> flowOf(it.toString(), "FizzBuzz")
+                    it % 3 == 0 -> flowOf(it.toString(), "Fizz")
+                    it % 5 == 0 -> flowOf(it.toString(), "Buzz")
+                    else -> flowOf(it.toString())
+                }
+            }
     }
 
     /**
@@ -38,7 +52,12 @@ class SampleInteractor(
      * Если айтемы в одно из флоу кончились то результирующий флоу также должен закончится
      */
     fun task3(): Flow<Pair<String, String>> {
-        return flowOf()
+        val flow1 = sampleRepository.produceColors()
+        val flow2 = sampleRepository.produceForms()
+
+        return flow1.zip(flow2) { first, second ->
+            Pair(first, second)
+        }
     }
 
     /**
@@ -48,6 +67,14 @@ 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()
+            .catch { e ->
+                if (e is IllegalArgumentException) {
+                    println(e.toString())
+                    emit(-1)
+                } else {
+                    throw e
+                }
+            }.onCompletion { sampleRepository.completed() }
     }
 }