Show sync errors

app/src/main/java/eu/faircode/email/FragmentMessages.java

@@ -1517,8 +1517,13 @@ public class FragmentMessages extends FragmentBase {
                             folders = new ArrayList<>();
 
                         int unseen = 0;
-                        for (TupleFolderEx folder : folders)
+                        boolean errors = false;
+                        for (TupleFolderEx folder : folders) {
                             unseen += folder.unseen;
+                            if (!TextUtils.isEmpty(folder.error))
+                                errors = true;
+                        }
+
                         String name = getString(R.string.title_folder_unified);
                         if (unseen > 0)
                             setSubtitle(getString(R.string.title_unseen_count, name, unseen));
@@ -1537,6 +1542,10 @@ public class FragmentMessages extends FragmentBase {
                             rvMessage.scrollToPosition(0);
                         }
 
+                        if (errors &&
+                                !refreshing && swipeRefresh.isRefreshing())
+                            Snackbar.make(view, R.string.title_sync_errors, Snackbar.LENGTH_LONG).show();
+
                         swipeRefresh.setRefreshing(refreshing);
                     }
                 });
@@ -1569,6 +1578,10 @@ public class FragmentMessages extends FragmentBase {
                             rvMessage.scrollToPosition(0);
                         }
 
+                        if (folder != null && !TextUtils.isEmpty(folder.error) &&
+                                !refreshing && swipeRefresh.isRefreshing())
+                            Snackbar.make(view, folder.error, Snackbar.LENGTH_LONG).show();
+
                         swipeRefresh.setRefreshing(refreshing);
                     }
                 });

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

@@ -258,6 +258,7 @@
     <string name="title_no_uidplus">This provider does not support UIDPLUS</string>
     <string name="title_no_utf8">This provider does not support UTF-8</string>
     <string name="title_no_sync">Synchronization errors since %1$s</string>
+    <string name="title_sync_errors">Synchronizing some folders failed</string>
     <string name="title_drafts_required">A drafts folder is required to send messages</string>
     <string name="title_account_delete">Delete this account permanently?</string>
     <string name="title_identity_delete">Delete this identity permanently?</string>