Implement exporting PNG images

mainwidget.cpp

@@ -140,6 +140,16 @@ void TeletextWidget::timerEvent(QTimerEvent *event)
 		QWidget::timerEvent(event);
 }
 
+void TeletextWidget::pauseFlash(bool pauseNow)
+{
+	if (pauseNow && m_flashTiming != 0) {
+		m_flashTimer.stop();
+		m_flashPhase = 0;
+		update();
+	} else if (m_flashTiming != 0)
+		m_flashTimer.start((m_flashTiming == 1) ? 500 : 167, this);
+}
+
 void TeletextWidget::setInsertMode(bool insertMode)
 {
 	m_insertMode = insertMode;
@@ -654,6 +664,24 @@ void LevelOneScene::toggleGrid(bool gridOn)
 			m_sidePanelGridItemGroup[i]->setVisible(gridOn);
 }
 
+void LevelOneScene::hideGUIElements(bool hidden)
+{
+	if (hidden) {
+		m_mainGridItemGroup->setVisible(false);
+		m_cursorRectItem->setVisible(false);
+		m_selectionRectItem->setVisible(false);
+		for (int i=0; i<32; i++)
+			if (m_sidePanelGridNeeded[i])
+				m_sidePanelGridItemGroup[i]->setVisible(false);
+	} else {
+		if (static_cast<TeletextWidget *>(m_levelOneProxyWidget->widget())->document()->selectionActive())
+			m_selectionRectItem->setVisible(true);
+
+		m_cursorRectItem->setVisible(true);
+		toggleGrid(m_grid);
+	}
+}
+
 bool LevelOneScene::eventFilter(QObject *object, QEvent *event)
 {
 	Q_UNUSED(object);

mainwidget.h

@@ -64,6 +64,7 @@ public slots:
 	void toggleReveal(bool);
 	void toggleMix(bool);
 	void updateFlashTimer(int);
+	void pauseFlash(bool);
 	void refreshRow(int);
 
 	void setControlBit(int, bool);
@@ -119,6 +120,7 @@ public slots:
 	void updateCursor();
 	void updateSelection();
 	void toggleGrid(bool);
+	void hideGUIElements(bool);
 	void setFullScreenColour(const QColor &);
 	void setFullRowColour(int, const QColor &);
 

mainwindow.cpp

@@ -20,9 +20,11 @@
 #include <QApplication>
 #include <QDesktopServices>
 #include <QFileDialog>
+#include <QImage>
 #include <QList>
 #include <QMenuBar>
 #include <QMessageBox>
+#include <QPainter>
 #include <QPushButton>
 #include <QRadioButton>
 #include <QSaveFile>
@@ -120,6 +122,56 @@ bool MainWindow::saveAs()
 	return saveFile(fileName);
 }
 
+void MainWindow::exportPNG()
+{
+	QString exportFileName = QFileDialog::getSaveFileName(this, tr("Export PNG"), QString(), "PNG image (*.png)");
+	if (exportFileName.isEmpty())
+		return;
+
+	// Prepare widget image for extraction
+	m_textWidget->pauseFlash(true);
+	m_textScene->hideGUIElements(true);
+	bool reshowCodes = m_textWidget->pageRender()->showCodes();
+	if (reshowCodes)
+		m_textWidget->pageRender()->setShowCodes(false);
+	// Disable exporting in Mix mode as it corrupts the background
+	bool reMix = m_textWidget->pageRender()->mix();
+	if (reMix)
+		m_textWidget->pageRender()->setMix(false);
+
+	// Extract the image from the scene
+	QImage interImage = QImage(m_textScene->sceneRect().size().toSize(), QImage::Format_RGB32);
+//	This ought to make the background transparent in Mix mode, but it doesn't
+//	if (m_textWidget->pageRender()->mix())
+//		interImage.fill(QColor(0, 0, 0, 0));
+	QPainter interPainter(&interImage);
+	m_textScene->render(&interPainter);
+
+	// Now we're extracted the image we can put the GUI things back
+	m_textScene->hideGUIElements(false);
+	if (reshowCodes)
+		m_textWidget->pageRender()->setShowCodes(true);
+	if (reMix)
+		m_textWidget->pageRender()->setMix(true);
+	m_textWidget->pauseFlash(false);
+
+	// Now scale the extracted image to the selected aspect ratio
+	// We do this in two steps so that anti-aliasing only occurs on vertical lines
+
+	// Double the vertical height first
+	const QImage doubleHeightImage = interImage.scaled(interImage.width(), interImage.height()*2, Qt::IgnoreAspectRatio, Qt::FastTransformation);
+
+	// If aspect ratio is Pixel 1:2 we're already at the correct scale
+	if (m_viewAspectRatio != 3) {
+		// Scale it horizontally to the selected aspect ratio
+		const QImage scaledImage = doubleHeightImage.scaled((int)((float)doubleHeightImage.width() * aspectRatioHorizontalScaling[m_viewAspectRatio] * 2), doubleHeightImage.height(), Qt::IgnoreAspectRatio, Qt::SmoothTransformation);
+
+		if (!scaledImage.save(exportFileName, "PNG"))
+			QMessageBox::warning(this, tr("QTeletextMaker"), tr("Cannot export file %1.").arg(QDir::toNativeSeparators(exportFileName)));
+	} else if (!doubleHeightImage.save(exportFileName, "PNG"))
+		QMessageBox::warning(this, tr("QTeletextMaker"), tr("Cannot export file %1.").arg(QDir::toNativeSeparators(exportFileName)));
+}
+
 void MainWindow::exportZXNet()
 {
 	QDesktopServices::openUrl(QUrl("http://zxnet.co.uk/teletext/editor/" + exportHashStringPage(m_textWidget->document()->currentSubPage()) + exportHashStringPackets(m_textWidget->document()->currentSubPage())));
@@ -257,6 +309,10 @@ void MainWindow::createActions()
 
 	setRecentFilesVisible(MainWindow::hasRecentFiles());
 
+	QAction *exportPNGAct = fileMenu->addAction(tr("Export subpage as PNG..."));
+	exportPNGAct->setStatusTip("Export a PNG image of this subpage");
+	connect(exportPNGAct, &QAction::triggered, this, &MainWindow::exportPNG);
+
 	QMenu *exportHashStringSubMenu = fileMenu->addMenu(tr("Export subpage to online editor"));
 
 	QAction *exportZXNetAct = exportHashStringSubMenu->addAction(tr("Open in zxnet.co.uk"));
@@ -555,7 +611,6 @@ void MainWindow::createActions()
 
 void MainWindow::setSceneDimensions()
 {
-	const float aspectRatioHorizontalScaling[4] = { 0.6, 0.6, 0.8, 0.5 };
 	const int topBottomBorders[3] = { 0, 10, 19 };
 	const int pillarBoxSizes[3] = { 672, 720, 854 };
 	const int leftRightBorders[3] = { 0, 24, 77 };

mainwindow.h

@@ -58,6 +58,7 @@ private slots:
 	void open();
 	bool save();
 	bool saveAs();
+	void exportPNG();
 	void exportZXNet();
 	void exportEditTF();
 	void updateRecentFileActions();
@@ -82,6 +83,7 @@ private slots:
 
 private:
 	enum { m_MaxRecentFiles = 10 };
+	const float aspectRatioHorizontalScaling[4] = { 0.6, 0.6, 0.8, 0.5 };
 
 	void init();
 	void createActions();

render.h

@@ -189,6 +189,8 @@ public:
 	void decodePage();
 	void renderPage();
 	void renderPage(int r);
+	bool mix() const { return m_mix; };
+	bool showCodes() const { return m_showCodes; };
 	void setTeletextPage(LevelOnePage *);
 	void updateSidePanels();
 	void buildEnhanceMap(TextLayer *, int=0);