Split X/26 packet handling into intermediate class

pagex26base holds methods for converting between the enhancements
QList and teletext packets. A future page subclass for POP pages will
re-use those same methods.

pagex26base.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2020 Gavin MacGregor
+ *
+ * This file is part of QTeletextMaker.
+ *
+ * QTeletextMaker 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 3 of the License, or
+ * (at your option) any later version.
+ *
+ * QTeletextMaker 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 QTeletextMaker.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+#ifndef PAGEX26BASE_H
+#define PAGEX26BASE_H
+
+#include <QByteArray>
+#include <QList>
+
+#include "pagebase.h"
+#include "x26triplets.h"
+
+class PageX26Base : public PageBase //: public QObject
+{
+	//Q_OBJECT
+
+protected:
+	QByteArray packetFromEnhancementList(int) const;
+	void setEnhancementListFromPacket(int, QByteArray);
+	bool packetFromEnhancementListNeeded(int n) const { return ((m_enhancements.size()+12) / 13) > n; };
+
+	QList<X26Triplet> m_enhancements;
+	const X26Triplet m_paddingX26Triplet { 41, 0x1e, 0 };
+};
+
+#endif