Otus-Android#1 added try-catch

Author: AkashevPavel

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

@@ -1,28 +1,53 @@
 package otus.homework.coroutines
 
+import kotlinx.coroutines.CancellationException
 import kotlinx.coroutines.CoroutineScope
+import kotlinx.coroutines.Job
 import kotlinx.coroutines.launch
+import java.net.SocketTimeoutException
 
 class CatsPresenter(
     private val catsService: CatsService,
     private val presenterScope: CoroutineScope
 ) {
 
     private var _catsView: ICatsView? = null
+    private var _job: Job? = null
 
     fun onInitComplete() {
-        presenterScope.launch {
-            catsService.getCatFact().also { fact ->
-                _catsView?.populate(fact)
+        _job = presenterScope.launch {
+            try {
+                catsService.getCatFact().also { fact ->
+                    _catsView?.populate(fact)
+                }
+            } catch (e: CancellationException) {
+                throw e
+            } catch (e: SocketTimeoutException) {
+                showToast("Не удалось получить ответ от сервера")
+            } catch (e: Exception) {
+                CrashMonitor.trackWarning(e)
+                e.message?.let(::showToast)
             }
         }
     }
 
+    private fun showToast(message: String) {
+        _catsView?.showToast(message)
+    }
+
     fun attachView(catsView: ICatsView) {
         _catsView = catsView
     }
 
     fun detachView() {
         _catsView = null
     }
+
+    fun cancelCoroutine() {
+        _job?.run {
+            if (isActive) {
+                cancel()
+            }
+        }
+    }
 }

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

@@ -4,10 +4,11 @@ import android.content.Context
 import android.util.AttributeSet
 import android.widget.Button
 import android.widget.TextView
+import android.widget.Toast
 import androidx.constraintlayout.widget.ConstraintLayout
 
 class CatsView @JvmOverloads constructor(
-    context: Context,
+    private val context: Context,
     attrs: AttributeSet? = null,
     defStyleAttr: Int = 0
 ) : ConstraintLayout(context, attrs, defStyleAttr), ICatsView {
@@ -24,9 +25,15 @@ class CatsView @JvmOverloads constructor(
     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 showToast(message: String)
 }

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

@@ -5,6 +5,5 @@ object CrashMonitor {
     /**
      * Pretend this is Crashlytics/AppCenter
      */
-    fun trackWarning() {
-    }
+    fun trackWarning(exception: Exception) {}
 }

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

@@ -23,7 +23,10 @@ class MainActivity : AppCompatActivity() {
 
     override fun onStop() {
         if (isFinishing) {
-            catsPresenter.detachView()
+            catsPresenter.apply {
+                detachView()
+                cancelCoroutine()
+            }
         }
         super.onStop()
     }