Progress displayed

app/src/main/java/de/server47/messageexport/MainActivity.java

@@ -48,6 +48,7 @@ public class MainActivity extends Activity
 
     long messageCount = 0;
 
+    enum EnumResult { success, errorReadingMessages, noMessages, errorWritingFile };
 
     @Override
     protected void onCreate(@Nullable Bundle savedInstanceState)
@@ -92,7 +93,7 @@ public class MainActivity extends Activity
         }
     }
 
-    class AsyncTaskExport extends AsyncTask<Uri, Integer, Boolean>
+    class AsyncTaskExport extends AsyncTask<Uri, Integer, EnumResult>
     {
         String getExportString()
         {
@@ -168,7 +169,7 @@ public class MainActivity extends Activity
         }
 
         @Override
-        protected Boolean doInBackground(Uri... uriTree)
+        protected EnumResult doInBackground(Uri... uriTree)
         {
             int selectedMessageType;
             if(rbRcs.isChecked())
@@ -185,10 +186,11 @@ public class MainActivity extends Activity
             {
                 if (Looper.myLooper() == null)
                     Looper.prepare();
-                Toast.makeText(MainActivity.this, "Error reading messages. Can\'t export.", Toast.LENGTH_SHORT).show();
-            }
 
-            return false;
+                Toast.makeText(MainActivity.this, "Error reading messages. Can\'t export.", Toast.LENGTH_SHORT).show();
+
+                return EnumResult.noMessages;
+            }
         }
 
         @Override
@@ -199,14 +201,25 @@ public class MainActivity extends Activity
         }
 
         @Override
-        protected void onPostExecute(Boolean result)
+        protected void onPostExecute(EnumResult result)
         {
             super.onPostExecute(result);
 
-            if(result)
+            switch(result)
+            {
+                case success:
                     tvStatus.setText(String.format(getResources().getString(R.string.exported), String.valueOf(messageCount)));
-            else
-                tvStatus.setText(getResources().getString(R.string.errorExporting));
+                    break;
+                case errorReadingMessages:
+                    tvStatus.setText(getResources().getString(R.string.errorReadingMessages));
+                    break;
+                case noMessages:
+                    tvStatus.setText(getResources().getString(R.string.noMessages));
+                    break;
+                case errorWritingFile:
+                    tvStatus.setText(getResources().getString(R.string.errorWritingFile));
+                    break;
+            }
         }
     }
 
@@ -220,7 +233,7 @@ public class MainActivity extends Activity
             switch (requestCode)
             {
                 case requestCodeExport:
-                    AsyncTask<Uri,Integer,Boolean> exportTask = new AsyncTaskExport();
+                    AsyncTask<Uri,Integer,EnumResult> exportTask = new AsyncTaskExport();
                     exportTask.execute(data.getData());
                     break;
                 case requestCodePermissionRequest:
@@ -230,7 +243,7 @@ public class MainActivity extends Activity
         }
     }
 
-    boolean exportFiles(Uri uriTree, int messageType, String content)
+    EnumResult exportFiles(Uri uriTree, int messageType, String content)
     {
         String messageTypeString;
         if(messageType == typeRCS)
@@ -269,17 +282,18 @@ public class MainActivity extends Activity
                 OutputStream out = getApplicationContext().getContentResolver().openOutputStream(exportFile.getUri());
                 out.write(content.getBytes());
                 out.close();
-                return true;
+                return EnumResult.success;
             }
             catch (IOException e)
             {
                 e.printStackTrace();
+                return EnumResult.errorWritingFile;
             }
         }
+        else
+            return EnumResult.errorWritingFile;
 //        else
 //            Toast.makeText(MainActivity.this, getResources().getString(R.string.ConfigurationExportError), Toast.LENGTH_LONG).show();
-
-        return false;
     }
 
     List<Map<String,String>> readMessages(int messageType)

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

@@ -13,4 +13,7 @@
     <string name="exporting">Exporting %1$s messages.</string>
     <string name="exported">%1$s messages have been exported.</string>
     <string name="errorExporting">An error occured while exporting your messages.</string>
+    <string name="errorReadingMessages">Error reading messages.</string>
+    <string name="noMessages">There are no messages of the selected type. Nothing exported.</string>
+    <string name="errorWritingFile">File could not be written.</string>
 </resources>