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.

levelonepage.cpp

@@ -27,18 +27,12 @@
 
 LevelOnePage::LevelOnePage()
 {
-	m_paddingX26Triplet.setAddress(41);
-	m_paddingX26Triplet.setMode(0x1e);
-	m_paddingX26Triplet.setData(0);
 	m_enhancements.reserve(208);
 	clearPage();
 }
 
 LevelOnePage::LevelOnePage(const PageBase &other)
 {
-	m_paddingX26Triplet.setAddress(41);
-	m_paddingX26Triplet.setMode(0x1e);
-	m_paddingX26Triplet.setData(0);
 	m_enhancements.reserve(208);
 	clearPage();
 
@@ -120,38 +114,10 @@ QByteArray LevelOnePage::packet(int packetNumber, int designationCode) const
 	QByteArray result(40, 0x00);
 
 	if (packetNumber == 26) {
-		if (!packetNeeded(26, designationCode))
+		if (!packetFromEnhancementListNeeded(designationCode))
 			return result; // Blank result
 
-		int enhanceListPointer;
+		return packetFromEnhancementList(designationCode);
-		X26Triplet lastTriplet;
-
-		for (int i=0; i<13; i++) {
-			enhanceListPointer = designationCode*13+i;
-
-			if (enhanceListPointer < m_enhancements.size()) {
-				result[i*3+1] = m_enhancements.at(enhanceListPointer).address();
-				result[i*3+2] = m_enhancements.at(enhanceListPointer).mode() | ((m_enhancements.at(enhanceListPointer).data() & 1) << 5);
-				result[i*3+3] = m_enhancements.at(enhanceListPointer).data() >> 1;
-
-				// If this is the last triplet, get a copy to repeat to the end of the packet
-				if (enhanceListPointer == m_enhancements.size()-1) {
-					lastTriplet = m_enhancements.at(enhanceListPointer);
-					// If the last triplet was NOT a Termination Marker, make up one
-					if (lastTriplet.mode() != 0x1f || lastTriplet.address() != 0x3f) {
-						lastTriplet.setAddress(0x3f);
-						lastTriplet.setMode(0x1f);
-						lastTriplet.setData(0x07);
-					}
-				}
-			} else {
-				// We've gone past the end of the triplet list, so repeat the Termination Marker to the end
-				result[i*3+1] = lastTriplet.address();
-				result[i*3+2] = lastTriplet.mode() | ((lastTriplet.data() & 1) << 5);
-				result[i*3+3] = lastTriplet.data() >> 1;
-			}
-		}
-		return result;
 	}
 
 	if (packetNumber == 27 && designationCode == 0) {
@@ -224,28 +190,7 @@ bool LevelOnePage::setPacket(int packetNumber, QByteArray packetContents)
 bool LevelOnePage::setPacket(int packetNumber, int designationCode, QByteArray packetContents)
 {
 	if (packetNumber == 26) {
-		// Preallocate entries in the m_enhancements list to hold our incoming triplets.
+		setEnhancementListFromPacket(designationCode, packetContents);
-		// We write "dummy" reserved 11110 Row Triplets in the allocated entries which then get overwritten by the packet contents.
-		// This is in case of missing packets so we can keep Local Object pointers valid.
-		while (m_enhancements.size() < (designationCode+1)*13)
-			m_enhancements.append(m_paddingX26Triplet);
-
-		int enhanceListPointer;
-		X26Triplet newX26Triplet;
-
-		for (int i=0; i<13; i++) {
-			enhanceListPointer = designationCode*13+i;
-
-			newX26Triplet.setAddress(packetContents.at(i*3+1) & 0x3f);
-			newX26Triplet.setMode(packetContents.at(i*3+2) & 0x1f);
-			newX26Triplet.setData(((packetContents.at(i*3+3) & 0x3f) << 1) | ((packetContents.at(i*3+2) & 0x20) >> 5));
-			m_enhancements[enhanceListPointer] = newX26Triplet;
-		}
-		if (newX26Triplet.mode() == 0x1f && newX26Triplet.address() == 0x3f && newX26Triplet.data() & 0x01)
-			// Last triplet was a Termination Marker (without ..follows) so clean up the repeated ones
-			while (m_enhancements.size()>1 && m_enhancements.at(m_enhancements.size()-2).mode() == 0x1f && m_enhancements.at(m_enhancements.size()-2).address() == 0x3f && m_enhancements.at(m_enhancements.size()-2).data() == newX26Triplet.data())
-				m_enhancements.removeLast();
-
 		return true;
 	}
 
@@ -324,7 +269,7 @@ bool LevelOnePage::packetNeeded(int packetNumber) const
 bool LevelOnePage::packetNeeded(int packetNumber, int designationCode) const
 {
 	if (packetNumber == 26)
-		return ((m_enhancements.size()+12) / 13) > designationCode;
+		return packetFromEnhancementListNeeded(designationCode);
 
 	if (packetNumber == 27 && designationCode == 0) {
 		for (int i=0; i<6; i++)

levelonepage.h

@@ -22,17 +22,15 @@
 
 #include <QByteArray>
 #include <QColor>
-#include <QList>
 #include <QObject>
 #include <QString>
 
-#include "pagebase.h"
+#include "pagex26base.h"
 #include "x26triplets.h"
 
 QColor CLUTtoQColor(int myColour);
 
-// If we inherit from QObject then we can't copy construct, so "make a new subpage that's a copy of this one" wouldn't work
+class LevelOnePage : public PageX26Base //: public QObject
-class LevelOnePage : public PageBase //: public QObject
 {
 	//Q_OBJECT
 
@@ -126,9 +124,6 @@ private:
 		int pageNumber, subPageCodes;
 	} m_composeLink[8];
 
-	QList<X26Triplet> m_enhancements;
-	X26Triplet m_paddingX26Triplet;
-
 	const int m_defaultCLUT[32] = {
 		0x000, 0xf00, 0x0f0, 0xff0, 0x00f, 0xf0f, 0x0ff, 0xfff,
 		0x000, 0x700, 0x070, 0x770, 0x007, 0x707, 0x077, 0x777,

pagex26base.cpp

@@ -0,0 +1,83 @@
+/*
+ * 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/>.
+ */
+
+#include <QByteArray>
+
+#include "pagex26base.h"
+
+QByteArray PageX26Base::packetFromEnhancementList(int packetNumber) const
+{
+	QByteArray result(40, 0x00);
+
+	int enhanceListPointer;
+	X26Triplet lastTriplet;
+
+	for (int i=0; i<13; i++) {
+		enhanceListPointer = packetNumber*13+i;
+
+		if (enhanceListPointer < m_enhancements.size()) {
+			result[i*3+1] = m_enhancements.at(enhanceListPointer).address();
+			result[i*3+2] = m_enhancements.at(enhanceListPointer).mode() | ((m_enhancements.at(enhanceListPointer).data() & 1) << 5);
+			result[i*3+3] = m_enhancements.at(enhanceListPointer).data() >> 1;
+
+			// If this is the last triplet, get a copy to repeat to the end of the packet
+			if (enhanceListPointer == m_enhancements.size()-1) {
+				lastTriplet = m_enhancements.at(enhanceListPointer);
+				// If the last triplet was NOT a Termination Marker, make up one
+				if (lastTriplet.mode() != 0x1f || lastTriplet.address() != 0x3f) {
+					lastTriplet.setAddress(0x3f);
+					lastTriplet.setMode(0x1f);
+					lastTriplet.setData(0x07);
+				}
+			}
+		} else {
+			// We've gone past the end of the triplet list, so repeat the Termination Marker to the end
+			result[i*3+1] = lastTriplet.address();
+			result[i*3+2] = lastTriplet.mode() | ((lastTriplet.data() & 1) << 5);
+			result[i*3+3] = lastTriplet.data() >> 1;
+		}
+	}
+
+	return result;
+}
+
+void PageX26Base::setEnhancementListFromPacket(int packetNumber, QByteArray packetContents)
+{
+	// Preallocate entries in the m_enhancements list to hold our incoming triplets.
+	// We write "dummy" reserved 11110 Row Triplets in the allocated entries which then get overwritten by the packet contents.
+	// This is in case of missing packets so we can keep Local Object pointers valid.
+	while (m_enhancements.size() < (packetNumber+1)*13)
+		m_enhancements.append(m_paddingX26Triplet);
+
+	int enhanceListPointer;
+	X26Triplet newX26Triplet;
+
+	for (int i=0; i<13; i++) {
+		enhanceListPointer = packetNumber*13+i;
+
+		newX26Triplet.setAddress(packetContents.at(i*3+1) & 0x3f);
+		newX26Triplet.setMode(packetContents.at(i*3+2) & 0x1f);
+		newX26Triplet.setData(((packetContents.at(i*3+3) & 0x3f) << 1) | ((packetContents.at(i*3+2) & 0x20) >> 5));
+		m_enhancements[enhanceListPointer] = newX26Triplet;
+	}
+	if (newX26Triplet.mode() == 0x1f && newX26Triplet.address() == 0x3f && newX26Triplet.data() & 0x01)
+		// Last triplet was a Termination Marker (without ..follows) so clean up the repeated ones
+		while (m_enhancements.size()>1 && m_enhancements.at(m_enhancements.size()-2).mode() == 0x1f && m_enhancements.at(m_enhancements.size()-2).address() == 0x3f && m_enhancements.at(m_enhancements.size()-2).data() == newX26Triplet.data())
+			m_enhancements.removeLast();
+}

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

qteletextmaker.pro

@@ -8,6 +8,7 @@ HEADERS       = document.h \
                 mainwidget.h \
                 mainwindow.h \
                 pagebase.h \
+                pagex26base.h \
                 pageenhancementsdockwidget.h \
                 pageoptionsdockwidget.h \
                 palettedockwidget.h \
@@ -24,6 +25,7 @@ SOURCES       = document.cpp \
                 mainwidget.cpp \
                 mainwindow.cpp \
                 pagebase.cpp \
+                pagex26base.cpp \
                 pageenhancementsdockwidget.cpp \
                 pageoptionsdockwidget.cpp \
                 palettedockwidget.cpp \