diff -r 0c98d3b249f7 -r 4df9d8cedf7f QTfrontend/model/ThemeFilterProxyModel.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/QTfrontend/model/ThemeFilterProxyModel.cpp	Sun Mar 18 14:38:48 2018 +0100
@@ -0,0 +1,51 @@
+/*
+ * Hedgewars, a free turn based strategy game
+ * Copyright (c) 2004-2018 Andrey Korotaev <unC0Rr@gmail.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+/**
+ * @file
+ * @brief ThemeFilterProxyModel class implementation
+ */
+
+#include "ThemeModel.h"
+#include "ThemeFilterProxyModel.h"
+
+ThemeFilterProxyModel::ThemeFilterProxyModel(QObject *parent)
+    : QSortFilterProxyModel(parent)
+{
+    isFilteringDLC = false;
+}
+
+bool ThemeFilterProxyModel::filterAcceptsRow(int sourceRow, const QModelIndex & sourceParent) const
+{
+    if(isFilteringDLC)
+    {
+        QModelIndex index = sourceModel()->index(sourceRow, 0, sourceParent);
+        bool isDLC = index.data(ThemeModel::IsDlcRole).toBool();
+        return !isDLC;
+    }
+    else
+    {
+        return true;
+    }
+}
+
+void ThemeFilterProxyModel::setFilterDLC(bool enable)
+{
+    isFilteringDLC = enable;
+    invalidateFilter();
+}