Otus-Android#3 Result added

Author: AkashevPavel

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

@@ -13,17 +13,24 @@ import kotlinx.coroutines.flow.filterNotNull
 import kotlinx.coroutines.flow.onStart
 import kotlinx.coroutines.flow.shareIn
 import kotlinx.coroutines.launch
+import java.net.SocketTimeoutException
 
 class CatsViewModel(
     private val catsService: CatsService,
     private val imageService: ImageService
 ) : ViewModel() {
 
     private val exceptionHandler = CoroutineExceptionHandler { _, throwable ->
-        CrashMonitor.trackWarning(throwable)
+        when(throwable) {
+            is SocketTimeoutException -> _uiState.tryEmit(Result.Error(Throwable("Не удалось получить ответ от сервера")))
+            else -> {
+                CrashMonitor.trackWarning(throwable)
+                _uiState.tryEmit(Result.Error(throwable))
+            }
+        }
     }
 
-    private val _uiState = MutableStateFlow<CatsUIState?>(null)
+    private val _uiState = MutableStateFlow<Result?>(null)
     val uiState = _uiState.onStart { load() }
         .filterNotNull()
         .shareIn(
@@ -38,9 +45,11 @@ class CatsViewModel(
             val image = async { imageService.getCatImage() }
 
             _uiState.emit(
-                CatsUIState(
-                    fact = fact.await(),
-                    image = image.await()[0]
+                Result.Success(
+                    CatsUIState(
+                        fact = fact.await(),
+                        image = image.await()[0]
+                    )
                 )
             )
         }

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

@@ -4,11 +4,13 @@ import android.os.Bundle
 import android.widget.Button
 import android.widget.ImageView
 import android.widget.TextView
+import android.widget.Toast
 import androidx.appcompat.app.AppCompatActivity
 import androidx.lifecycle.ViewModelProvider
 import androidx.lifecycle.lifecycleScope
 import com.squareup.picasso.Picasso
 import kotlinx.coroutines.launch
+import otus.homework.coroutines.Result.*
 
 class MainActivity : AppCompatActivity() {
 
@@ -32,7 +34,7 @@ class MainActivity : AppCompatActivity() {
         image = view.findViewById(R.id.catImage)
         loadButton = view.findViewById(R.id.button)
 
-        configureFact()
+        processState()
         setListeners()
     }
 
@@ -42,12 +44,23 @@ class MainActivity : AppCompatActivity() {
         }
     }
 
-    private fun configureFact() {
+    private fun processState() {
         lifecycleScope.launch {
             viewModel.uiState.collect { state ->
-                fact.text = state.fact.fact
-                Picasso.get().load(state.image.url).into(image)
+                when(state) {
+                    is Success<*> -> {
+                        (state.data as CatsUIState).also {
+                            fact.text = it.fact.fact
+                            Picasso.get().load(it.image.url).into(image)
+                        }
+                    }
+                    is Error -> showToast(state.error)
+                }
             }
         }
     }
+
+    private fun showToast(throwable: Throwable, duration: Int = Toast.LENGTH_LONG) {
+        Toast.makeText(this, throwable.message, duration).show()
+    }
 }

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

@@ -0,0 +1,6 @@
+package otus.homework.coroutines
+
+sealed class Result{
+    data class Success<out T>(val data: T) : Result()
+    data class Error(val error: Throwable) : Result()
+}