Check for empty cardId in BarcodeSelectorActivity instead

app/src/main/java/protect/card_locker/BarcodeImageWriterTask.java

@@ -90,11 +90,6 @@ class BarcodeImageWriterTask extends AsyncTask<Void, Void, Bitmap>
 
     public Bitmap doInBackground(Void... params)
     {
-        if (cardId.isEmpty())
-        {
-            return null;
-        }
-
         MultiFormatWriter writer = new MultiFormatWriter();
         BitMatrix bitMatrix;
         try

app/src/main/java/protect/card_locker/BarcodeSelectorActivity.java

@@ -177,6 +177,12 @@ public class BarcodeSelectorActivity extends AppCompatActivity
             }
         });
 
+        if (cardId.isEmpty())
+        {
+            image.setVisibility(View.GONE);
+            return;
+        }
+
         if(image.getHeight() == 0)
         {
             // The size of the ImageView is not yet available as it has not