Fetch more messages for sub folders

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

@@ -637,6 +637,7 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                 submenu.add(Menu.FIRST, R.string.title_synchronize_batch_disable, 3, R.string.title_synchronize_batch_disable);
                 submenu.add(Menu.FIRST, R.string.title_notify_batch_enable, 4, R.string.title_notify_batch_enable);
                 submenu.add(Menu.FIRST, R.string.title_notify_batch_disable, 5, R.string.title_notify_batch_disable);
+                submenu.add(Menu.FIRST, R.string.title_synchronize_more, 6, R.string.title_synchronize_more);
             }
 
             if (folder.account != null && folder.accountProtocol == EntityAccount.TYPE_IMAP)
@@ -669,6 +670,9 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                         } else if (itemId == R.string.title_notify_batch_disable) {
                             onActionEnableNotify(false);
                             return true;
+                        } else if (itemId == R.string.title_synchronize_more) {
+                            onActionSyncMore(true);
+                            return true;
                         }
                         return false;
                     }
@@ -678,7 +682,7 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                         onActionSync(false);
                         return true;
                     } else if (itemId == R.string.title_synchronize_more) {
-                        onActionSyncMore();
+                        onActionSyncMore(false);
                         return true;
                     } else if (itemId == R.string.title_unified_folder || itemId == R.string.title_navigation_folder || itemId == R.string.title_notify_folder || itemId == R.string.title_synchronize_enabled) {
                         onActionProperty(itemId, !item.isChecked());
@@ -892,10 +896,11 @@ public class AdapterFolder extends RecyclerView.Adapter<AdapterFolder.ViewHolder
                     }.execute(context, owner, args, "enable");
                 }
 
-                private void onActionSyncMore() {
+                private void onActionSyncMore(boolean children) {
                     Bundle args = new Bundle();
                     args.putLong("folder", folder.id);
                     args.putString("name", folder.getDisplayName(context));
+                    args.putBoolean("children", children);
 
                     FragmentDialogSync sync = new FragmentDialogSync();
                     sync.setArguments(args);

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

@@ -33,6 +33,7 @@ import androidx.annotation.NonNull;
 import androidx.annotation.Nullable;
 import androidx.appcompat.app.AlertDialog;
 
+import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
@@ -91,6 +92,7 @@ public class FragmentDialogSync extends FragmentDialogBase {
                                 long fid = args.getLong("folder");
                                 String type = args.getString("type");
                                 int months = args.getInt("months", -1);
+                                boolean children = args.getBoolean("children");
 
                                 DB db = DB.getInstance(context);
                                 try {
@@ -103,7 +105,15 @@ public class FragmentDialogSync extends FragmentDialogBase {
                                         EntityFolder folder = db.folder().getFolder(fid);
                                         if (folder == null)
                                             return null;
-                                        folders = Arrays.asList(folder);
+
+                                        folders = new ArrayList<>();
+                                        folders.add(folder);
+
+                                        if (children) {
+                                            List<EntityFolder> sub = db.folder().getChildFolders(folder.id);
+                                            if (sub != null)
+                                                folders.addAll(sub);
+                                        }
                                     }
 
                                     for (EntityFolder folder : folders)