Fix crash after returning result for an external call (#104)

app/src/main/java/org/fairscan/app/MainActivity.kt

@@ -78,8 +78,6 @@ import java.io.File
 
 class MainActivity : ComponentActivity() {
 
-    private lateinit var sessionDir: File
-
     override fun onCreate(savedInstanceState: Bundle?) {
         super.onCreate(savedInstanceState)
         initLibraries()
@@ -220,13 +218,6 @@ class MainActivity : ComponentActivity() {
         }
     }
 
-    override fun onDestroy() {
-        super.onDestroy()
-        if (resolveLaunchMode(intent) == LaunchMode.EXTERNAL_SCAN_TO_PDF) {
-            sessionDir.deleteRecursively()
-        }
-    }
-
     private fun resolveLaunchMode(intent: Intent?): LaunchMode {
         return when (intent?.action) {
             "org.fairscan.app.action.SCAN_TO_PDF" -> LaunchMode.EXTERNAL_SCAN_TO_PDF

app/src/main/java/org/fairscan/app/SessionViewModel.kt

@@ -24,7 +24,7 @@ import java.util.UUID
 
 class SessionViewModel(
     app: Application,
-    launchMode: LaunchMode,
+    val launchMode: LaunchMode,
     appContainer: AppContainer
 ) : AndroidViewModel(app) {
 
@@ -43,6 +43,14 @@ class SessionViewModel(
     )
 
     val imageRepository: ImageRepository = sessionContainer.imageRepository
+
+    override fun onCleared() {
+        super.onCleared()
+
+        if (launchMode == LaunchMode.EXTERNAL_SCAN_TO_PDF) {
+            sessionDir.deleteRecursively()
+        }
+    }
 }
 
 class ScanSessionContainer(