Coroutines Homework

app/build.gradle

@@ -40,5 +40,8 @@ dependencies {
     implementation 'androidx.appcompat:appcompat:1.6.1'
     implementation 'com.google.android.material:material:1.11.0'
     implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
+    implementation "org.jetbrains.kotlinx:kotlinx-coroutines-android:1.9.0"
+    implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:2.8.0"
+    implementation 'androidx.activity:activity-ktx:1.9.0'
     implementation 'com.squareup.picasso:picasso:2.71828'
 }

app/src/main/java/otus/homework/coroutines/CatImage.kt

@@ -0,0 +1,17 @@
+package otus.homework.coroutines
+
+import com.google.gson.annotations.SerializedName
+
+data class CatImage(
+    @field:SerializedName("id")
+    val id: String,
+
+    @field:SerializedName("url")
+    val url: String,
+
+    @field:SerializedName("width")
+    val width: Int,
+
+    @field:SerializedName("height")
+    val height: Int
+)

app/src/main/java/otus/homework/coroutines/CatPresentationModel.kt

@@ -0,0 +1,6 @@
+package otus.homework.coroutines
+
+data class CatPresentationModel(
+    val fact: String,
+    val imageUrl: String
+)

app/src/main/java/otus/homework/coroutines/CatsService.kt

@@ -1,10 +1,13 @@
 package otus.homework.coroutines
 
-import retrofit2.Call
 import retrofit2.http.GET
 
 interface CatsService {
 
     @GET("fact")
-    fun getCatFact() : Call<Fact>
+    suspend fun getCatFact() : Fact
+
+    @GET("v1/images/search")
+    suspend fun getCatImage(): List<CatImage>
+
 }

app/src/main/java/otus/homework/coroutines/CatsView.kt

@@ -3,30 +3,44 @@ package otus.homework.coroutines
 import android.content.Context
 import android.util.AttributeSet
 import android.widget.Button
+import android.widget.ImageView
 import android.widget.TextView
+import android.widget.Toast
 import androidx.constraintlayout.widget.ConstraintLayout
+import com.squareup.picasso.Picasso
 
 class CatsView @JvmOverloads constructor(
     context: Context,
     attrs: AttributeSet? = null,
     defStyleAttr: Int = 0
 ) : ConstraintLayout(context, attrs, defStyleAttr), ICatsView {
 
-    var presenter :CatsPresenter? = null
+    lateinit var factTextView: TextView
+    lateinit var catImageView: ImageView
+    lateinit var button: Button
 
     override fun onFinishInflate() {
         super.onFinishInflate()
-        findViewById<Button>(R.id.button).setOnClickListener {
-            presenter?.onInitComplete()
-        }
+
+        factTextView = findViewById(R.id.fact_textView)
+        catImageView = findViewById(R.id.cat_imageView)
+        button = findViewById(R.id.button)
+    }
+
+    override fun populate(data: CatPresentationModel) {
+        factTextView.text = data.fact
+        Picasso.get()
+            .load(data.imageUrl)
+            .into(catImageView)
     }
 
-    override fun populate(fact: Fact) {
-        findViewById<TextView>(R.id.fact_textView).text = fact.fact
+    override fun showToast(message: String) {
+        Toast.makeText(context, message, Toast.LENGTH_SHORT).show()
     }
 }
 
 interface ICatsView {
 
-    fun populate(fact: Fact)
+    fun populate(data: CatPresentationModel)
+    fun showToast(message: String)
 }

app/src/main/java/otus/homework/coroutines/CatsViewModel.kt

@@ -0,0 +1,52 @@
+package otus.homework.coroutines
+
+import androidx.lifecycle.LiveData
+import androidx.lifecycle.MutableLiveData
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.viewModelScope
+import kotlinx.coroutines.CoroutineExceptionHandler
+import kotlinx.coroutines.Dispatchers
+import kotlinx.coroutines.async
+import kotlinx.coroutines.launch
+import java.net.SocketTimeoutException
+
+class CatsViewModel(
+    private val catsService: CatsService
+) : ViewModel() {
+
+    private val _catsState = MutableLiveData<Result<CatPresentationModel>?>()
+    val catsState: LiveData<Result<CatPresentationModel>?> = _catsState
+
+    private val exceptionHandler = CoroutineExceptionHandler { _, throwable ->
+        CrashMonitor.trackWarning(throwable)
+
+        val errorMessage = when (throwable) {
+            is SocketTimeoutException -> "Не удалось получить ответ от сервера"
+            else -> throwable.message ?: "Произошла ошибка"
+        }
+
+        _catsState.postValue(Result.Error(errorMessage, throwable))
+    }
+
+    fun onInitComplete() {
+        viewModelScope.launch(exceptionHandler) {
+            _catsState.postValue(null)
+
+            val factDeferred = async(Dispatchers.IO) {
+                catsService.getCatFact()
+            }
+            val imageDeferred = async(Dispatchers.IO) {
+                catsService.getCatImage().first()
+            }
+            val fact = factDeferred.await()
+            val image = imageDeferred.await()
+
+            val model = CatPresentationModel(
+                fact = fact.fact,
+                imageUrl = image.url
+            )
+            _catsState.postValue(Result.Success(model))
+        }
+    }
+
+}

app/src/main/java/otus/homework/coroutines/CatsViewModelFactory.kt

@@ -0,0 +1,18 @@
+package otus.homework.coroutines
+
+import androidx.lifecycle.ViewModel
+import androidx.lifecycle.ViewModelProvider
+
+class CatsViewModelFactory(
+    private val catsService: CatsService
+) : ViewModelProvider.Factory {
+
+    @Suppress("UNCHECKED_CAST")
+    override fun <T : ViewModel> create(modelClass: Class<T>): T {
+        if (modelClass.isAssignableFrom(CatsViewModel::class.java)) {
+            return CatsViewModel(catsService) as T
+        }
+        throw IllegalArgumentException("Unknown ViewModel class")
+    }
+
+}

app/src/main/java/otus/homework/coroutines/CrashMonitor.kt

@@ -5,6 +5,7 @@ object CrashMonitor {
     /**
      * Pretend this is Crashlytics/AppCenter
      */
-    fun trackWarning() {
+    fun trackWarning(throwable: Throwable? = null) {
+        throwable?.printStackTrace()
     }
 }

app/src/main/java/otus/homework/coroutines/DiContainer.kt

@@ -5,12 +5,32 @@ import retrofit2.converter.gson.GsonConverterFactory
 
 class DiContainer {
 
-    private val retrofit by lazy {
+    private val catFactRetrofit by lazy {
         Retrofit.Builder()
             .baseUrl("https://catfact.ninja/")
             .addConverterFactory(GsonConverterFactory.create())
             .build()
     }
 
-    val service by lazy { retrofit.create(CatsService::class.java) }
+    private val catImageRetrofit by lazy {
+        Retrofit.Builder()
+            .baseUrl("https://api.thecatapi.com/")
+            .addConverterFactory(GsonConverterFactory.create())
+            .build()
+    }
+
+    val service by lazy {
+        object : CatsService {
+            private val catFactService = catFactRetrofit.create(CatsService::class.java)
+            private val catImageService = catImageRetrofit.create(CatsService::class.java)
+
+            override suspend fun getCatFact(): Fact {
+                return catFactService.getCatFact()
+            }
+
+            override suspend fun getCatImage(): List<CatImage> {
+                return catImageService.getCatImage()
+            }
+        }
+    }
 }

app/src/main/java/otus/homework/coroutines/MainActivity.kt

@@ -2,29 +2,43 @@ package otus.homework.coroutines
 
 import androidx.appcompat.app.AppCompatActivity
 import android.os.Bundle
+import androidx.activity.viewModels
+import androidx.lifecycle.Observer
 
 class MainActivity : AppCompatActivity() {
 
-    lateinit var catsPresenter: CatsPresenter
-
     private val diContainer = DiContainer()
+    private val viewModel: CatsViewModel by viewModels {
+        CatsViewModelFactory(diContainer.service)
+    }
+
+    private lateinit var catsView: CatsView
 
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
 
-        val view = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
-        setContentView(view)
+        catsView = layoutInflater.inflate(R.layout.activity_main, null) as CatsView
+        setContentView(catsView)
 
-        catsPresenter = CatsPresenter(diContainer.service)
-        view.presenter = catsPresenter
-        catsPresenter.attachView(view)
-        catsPresenter.onInitComplete()
-    }
+        catsView.button.setOnClickListener {
+            viewModel.onInitComplete()
+        }
 
-    override fun onStop() {
-        if (isFinishing) {
-            catsPresenter.detachView()
+        viewModel.catsState.observe(this, Observer { result ->
+            when (result) {
+                is Result.Success -> {
+                    catsView.populate(result.data)
+                }
+                is Result.Error -> {
+                    catsView.showToast(result.message)
+                }
+                else -> {}
+            }
+        })
+
+        if (savedInstanceState == null) {
+            viewModel.onInitComplete()
         }
-        super.onStop()
     }
+
 }

app/src/main/java/otus/homework/coroutines/Result.kt

@@ -0,0 +1,6 @@
+package otus.homework.coroutines
+
+sealed class Result<out T> {
+    data class Success<out T>(val data: T) : Result<T>()
+    data class Error(val message: String, val throwable: Throwable? = null) : Result<Nothing>()
+}

app/src/main/res/layout/activity_main.xml

@@ -7,16 +7,26 @@
     android:layout_height="match_parent"
     tools:context=".MainActivity">
 
+    <ImageView
+        android:id="@+id/cat_imageView"
+        android:layout_width="200dp"
+        android:layout_height="200dp"
+        android:scaleType="centerCrop"
+        android:contentDescription="@string/cat_image_description"
+        app:layout_constraintTop_toTopOf="parent"
+        app:layout_constraintStart_toStartOf="parent"
+        app:layout_constraintEnd_toEndOf="parent"
+        app:layout_constraintBottom_toTopOf="@+id/fact_textView" />
+
     <TextView
         android:id="@+id/fact_textView"
         android:textColor="@color/black"
         android:textSize="24sp"
-        android:layout_width="wrap_content"
+        android:layout_width="0dp"
         android:layout_height="wrap_content"
-        app:layout_constraintBottom_toBottomOf="parent"
         app:layout_constraintEnd_toEndOf="parent"
         app:layout_constraintStart_toStartOf="parent"
-        app:layout_constraintTop_toTopOf="parent" />
+        app:layout_constraintTop_toBottomOf="@id/cat_imageView" />
 
     <Button
         android:id="@+id/button"

app/src/main/res/values/strings.xml

@@ -1,4 +1,5 @@
 <resources>
     <string name="app_name">Cat Facts </string>
     <string name="more_facts">More Facts</string>
+    <string name="cat_image_description">Cat Image</string>
 </resources>