From f9ce912e79b0a4a38033d47595db4d1f0ca0336e Mon Sep 17 00:00:00 2001
From: "G.K.MacGregor" <gkthemac@gmail.com>
Date: Sun, 6 Dec 2020 17:57:05 +0000
Subject: [PATCH] Get "empty document detection" working

---
 document.cpp     | 10 +++++++++-
 document.h       |  5 ++---
 levelonepage.cpp | 17 +++++++++++++++++
 levelonepage.h   |  2 ++
 pagebase.cpp     | 10 ++++++++++
 pagebase.h       |  2 ++
 6 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/document.cpp b/document.cpp
index a6e5747..f379f8c 100644
--- a/document.cpp
+++ b/document.cpp
@@ -29,7 +29,6 @@ TeletextDocument::TeletextDocument()
 	m_description.clear();
 	m_pageFunction = PFLevelOnePage;
 	m_packetCoding = Coding7bit;
-	m_empty = true;
 	m_subPages.push_back(new LevelOnePage);
 	m_currentSubPageIndex = 0;
 	m_undoStack = new QUndoStack(this);
@@ -44,6 +43,15 @@ TeletextDocument::~TeletextDocument()
 		delete(subPage);
 }
 
+bool TeletextDocument::isEmpty() const
+{
+	for (auto &subPage : m_subPages)
+		if (!subPage->isEmpty())
+			return false;
+
+	return true;
+}
+
 /*
 void TeletextDocument::setPageFunction(PageFunctionEnum newPageFunction)
 {
diff --git a/document.h b/document.h
index 8b8f457..fb1efb1 100644
--- a/document.h
+++ b/document.h
@@ -37,8 +37,8 @@ public:
 
 	TeletextDocument();
 	~TeletextDocument();
-	bool isEmpty() const { return m_empty; }
-	void setModified(bool);
+
+	bool isEmpty() const;
 
 	PageFunctionEnum pageFunction() const { return m_pageFunction; }
 //	void setPageFunction(PageFunctionEnum);
@@ -88,7 +88,6 @@ signals:
 
 private:
 	QString m_description;
-	bool m_empty;
 	int m_pageNumber, m_currentSubPageIndex;
 	PageFunctionEnum m_pageFunction;
 	PacketCodingEnum m_packetCoding;
diff --git a/levelonepage.cpp b/levelonepage.cpp
index c62b83f..7d11f1a 100644
--- a/levelonepage.cpp
+++ b/levelonepage.cpp
@@ -81,6 +81,23 @@ void LevelOnePage::clearPage()
 //	If clearPage() is called outside constructor, we need to implement localEnhance.clear();
 }
 
+bool LevelOnePage::isEmpty() const
+{
+	if (!localEnhance.isEmpty())
+		return false;
+
+	for (int i=0; i<32; i++)
+		if (m_CLUT[i] != defaultCLUT[i])
+			return false;
+
+	for (int r=0; r<25; r++)
+		for (int c=0; c<40; c++)
+			if (m_level1Page[r][c] != 0x20)
+				return false;
+
+	return true;
+}
+
 QByteArray LevelOnePage::packet(int packetNumber, int designationCode) const
 {
 	QByteArray result(40, 0x00);
diff --git a/levelonepage.h b/levelonepage.h
index b1bcf2a..621ba0b 100644
--- a/levelonepage.h
+++ b/levelonepage.h
@@ -42,6 +42,8 @@ public:
 	LevelOnePage();
 	LevelOnePage(const PageBase &);
 
+	bool isEmpty() const override;
+
 	QByteArray packet(int, int=0) const override;
 	bool packetNeeded(int, int=0) const override;
 	bool setPacket(int, QByteArray) override;
diff --git a/pagebase.cpp b/pagebase.cpp
index db84f29..3dd9abf 100644
--- a/pagebase.cpp
+++ b/pagebase.cpp
@@ -47,6 +47,16 @@ PageBase::~PageBase()
 		if (m_packets[i] != nullptr)
 			delete m_packets[i];
 }
+
+bool PageBase::isEmpty() const
+{
+	for (int i=0; i<90; i++)
+		if (m_packets[i] != nullptr)
+			return false;
+
+	return true;
+}
+
 QByteArray PageBase::packet(int packetNumber, int designationCode) const
 {
 	int arrayIndex = packetNumber;
diff --git a/pagebase.h b/pagebase.h
index 96ccac7..b6125df 100644
--- a/pagebase.h
+++ b/pagebase.h
@@ -34,6 +34,8 @@ public:
 	PageBase(const PageBase &);
 	~PageBase();
 
+	virtual bool isEmpty() const;
+
 	virtual QByteArray packet(int, int=0) const;
 	virtual bool packetNeeded(int, int=0) const;
 	virtual bool setPacket(int, QByteArray);