Switch to side-by-side view

--- a
+++ b/cfgui/mainwindow.h
@@ -0,0 +1,47 @@
+/* Copyright (C) 2017-2018 J.F.Dockes
+ *   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; either version 2 of the License, or
+ *   (at your option) any later version.
+ *
+ *   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.,
+ *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
+ */
+
+#ifndef _MAINWINDOW_H_INCLUDED_
+#define _MAINWINDOW_H_INCLUDED_
+
+#include <QMainWindow>
+
+namespace confgui {
+class ConfTabsW;
+}
+
+class MainWindow : public QMainWindow {
+    Q_OBJECT;
+
+public:
+    MainWindow(confgui::ConfTabsW *);
+
+protected:
+    void closeEvent(QCloseEvent *event) override;
+
+private slots:
+    bool open();
+    bool save();
+    bool saveAs();
+
+private:
+    bool saveToFile();
+    confgui::ConfTabsW *m_tabs;
+};
+
+
+#endif /* _MAINWINDOW_H_INCLUDED_ */