Implement draggable rectangle selection

document.cpp

@@ -38,6 +38,7 @@ TeletextDocument::TeletextDocument()
 	m_undoStack = new QUndoStack(this);
 	m_cursorRow = 1;
 	m_cursorColumn = 0;
+	m_selectionSubPage = nullptr;
 }
 
 TeletextDocument::~TeletextDocument()
@@ -285,6 +286,23 @@ void TeletextDocument::moveCursor(int newCursorRow, int newCursorColumn)
 	emit cursorMoved();
 }
 
+void TeletextDocument::setSelection(int topRow, int leftColumn, int bottomRow, int rightColumn)
+{
+	if (m_selectionTopRow != topRow || m_selectionBottomRow != bottomRow || m_selectionLeftColumn != leftColumn || m_selectionRightColumn != rightColumn) {
+		m_selectionSubPage = currentSubPage();
+		m_selectionTopRow = topRow;
+		m_selectionBottomRow = bottomRow;
+		m_selectionLeftColumn = leftColumn;
+		m_selectionRightColumn = rightColumn;
+		emit selectionMoved();
+	}
+}
+
+void TeletextDocument::cancelSelection()
+{
+	m_selectionSubPage = nullptr;
+}
+
 
 OverwriteCharacterCommand::OverwriteCharacterCommand(TeletextDocument *teletextDocument, unsigned char newCharacter, QUndoCommand *parent) : QUndoCommand(parent)
 {

document.h

@@ -61,9 +61,19 @@ public:
 	void cursorLeft();
 	void cursorRight();
 	void moveCursor(int, int);
+	int selectionTopRow() const { return m_selectionTopRow; }
+	int selectionBottomRow() const { return m_selectionBottomRow; }
+	int selectionLeftColumn() const { return m_selectionLeftColumn; }
+	int selectionRightColumn() const { return m_selectionRightColumn; }
+	int selectionWidth() const { return m_selectionRightColumn - m_selectionLeftColumn + 1; }
+	int selectionHeight() const { return m_selectionBottomRow - m_selectionTopRow + 1; }
+	bool selectionActive() const { return m_selectionSubPage == currentSubPage(); }
+	void setSelection(int, int, int, int);
+	void cancelSelection();
 
 signals:
 	void cursorMoved();
+	void selectionMoved();
 	void colourChanged(int);
 	void contentsChange(int);
 	void aboutToChangeSubPage();
@@ -77,7 +87,8 @@ private:
 	int m_fastTextLink[6];
 	std::vector<LevelOnePage *> m_subPages;
 	QUndoStack *m_undoStack;
-	int m_cursorRow, m_cursorColumn;
+	int m_cursorRow, m_cursorColumn, m_selectionTopRow, m_selectionBottomRow, m_selectionLeftColumn, m_selectionRightColumn;
+	LevelOnePage *m_selectionSubPage;
 };
 
 

mainwidget.cpp

@@ -22,6 +22,7 @@
 #include <QKeyEvent>
 #include <QMenu>
 #include <QPainter>
+#include <QPair>
 #include <QUndoCommand>
 #include <QWidget>
 #include <vector>
@@ -42,6 +43,7 @@ TeletextWidget::TeletextWidget(QFrame *parent) : QFrame(parent)
 	m_levelOnePage = m_teletextDocument->currentSubPage();
 	m_pageRender.setTeletextPage(m_levelOnePage);
 	m_insertMode = false;
+	m_selectionInProgress = false;
 	m_grid = false;
 	setFocusPolicy(Qt::StrongFocus);
 	m_flashTiming = m_flashPhase = 0;
@@ -50,6 +52,7 @@ TeletextWidget::TeletextWidget(QFrame *parent) : QFrame(parent)
 	connect(m_teletextDocument, &TeletextDocument::subPageSelected, this, &TeletextWidget::subPageSelected);
 	connect(m_teletextDocument, &TeletextDocument::contentsChange, this, &TeletextWidget::refreshRow);
 	connect(m_teletextDocument, &TeletextDocument::refreshNeeded, this, &TeletextWidget::refreshPage);
+	connect(m_teletextDocument, &TeletextDocument::selectionMoved, this, QOverload<>::of(&TeletextWidget::update));
 }
 
 TeletextWidget::~TeletextWidget()
@@ -91,6 +94,11 @@ void TeletextWidget::paintEvent(QPaintEvent *event)
 		widgetPainter.drawPixmap(480+m_pageRender.leftSidePanelColumns()*12, 0, *m_pageRender.pagePixmap(m_flashPhase), 480, 0, m_pageRender.rightSidePanelColumns()*12, 250);
 	if (this->hasFocus())
 		widgetPainter.fillRect((m_teletextDocument->cursorColumn()+m_pageRender.leftSidePanelColumns())*12, m_teletextDocument->cursorRow()*10, 12, 10, QColor(128, 128, 128, 192));
+	if (m_teletextDocument->selectionActive()) {
+		widgetPainter.setPen(QPen(QColor(192, 192, 192, 224), 1, Qt::DashLine));
+		widgetPainter.setBrush(QBrush(QColor(255, 255, 255, 64)));
+		widgetPainter.drawRect((m_teletextDocument->selectionLeftColumn()+m_pageRender.leftSidePanelColumns())*12, m_teletextDocument->selectionTopRow()*10, m_teletextDocument->selectionWidth()*12-1, m_teletextDocument->selectionHeight()*10-1);
+	}
 }
 
 void TeletextWidget::updateFlashTimer(int newFlashTimer)
@@ -329,29 +337,64 @@ void TeletextWidget::backspaceEvent()
 	m_teletextDocument->undoStack()->push(backspaceCommand);
 }
 
-void TeletextWidget::cursorToMouse(QPoint mousePosition)
+QPair<int, int> TeletextWidget::mouseToRowAndColumn(const QPoint &mousePosition)
 {
-	int newCursorRow = mousePosition.y() / 10;
-	int newCursorColumn = mousePosition.x() / 12 - m_pageRender.leftSidePanelColumns();
-	if (newCursorRow < 1)
-		newCursorRow = 1;
-	if (newCursorRow > 24)
-		newCursorRow = 24;
-	if (newCursorColumn < 0)
-		newCursorColumn = 0;
-	if (newCursorColumn > 39)
-		newCursorColumn = 39;
-	m_teletextDocument->moveCursor(newCursorRow, newCursorColumn);
+	int row = mousePosition.y() / 10;
+	int column = mousePosition.x() / 12 - m_pageRender.leftSidePanelColumns();
+	if (row < 1)
+		row = 1;
+	if (row > 24)
+		row = 24;
+	if (column < 0)
+		column = 0;
+	if (column > 39)
+		column = 39;
+	return qMakePair(row, column);
 }
 
 void TeletextWidget::mousePressEvent(QMouseEvent *event)
 {
 	if (event->button() == Qt::LeftButton) {
-		cursorToMouse(event->pos());
+		m_teletextDocument->cancelSelection();
+		QPair<int, int> position = mouseToRowAndColumn(event->pos());
+		m_teletextDocument->moveCursor(position.first, position.second);
 		update();
 	}
 }
 
+void TeletextWidget::mouseMoveEvent(QMouseEvent *event)
+{
+	if (event->buttons() & Qt::LeftButton) {
+		QPair<int, int> position = mouseToRowAndColumn(event->pos());
+		if (m_selectionInProgress || position.first != m_teletextDocument->cursorRow() || position.second != m_teletextDocument->cursorColumn()) {
+			int topRow, bottomRow, leftColumn, rightColumn;
+
+			m_selectionInProgress = true;
+			if (m_teletextDocument->cursorRow() < position.first) {
+				topRow = m_teletextDocument->cursorRow();
+				bottomRow = position.first;
+			} else {
+				topRow = position.first;
+				bottomRow = m_teletextDocument->cursorRow();
+			}
+			if (m_teletextDocument->cursorColumn() < position.second) {
+				leftColumn = m_teletextDocument->cursorColumn();
+				rightColumn = position.second;
+			} else {
+				leftColumn = position.second;
+				rightColumn = m_teletextDocument->cursorColumn();
+			}
+			m_teletextDocument->setSelection(topRow, leftColumn, bottomRow, rightColumn);
+		}
+	}
+}
+
+void TeletextWidget::mouseReleaseEvent(QMouseEvent *event)
+{
+	if (event->button() == Qt::LeftButton)
+		m_selectionInProgress = false;
+}
+
 void TeletextWidget::focusInEvent(QFocusEvent *event)
 {
 	QFrame::focusInEvent(event);

mainwidget.h

@@ -22,6 +22,7 @@
 
 #include <QBasicTimer>
 #include <QFrame>
+#include <QPair>
 #include <QTextStream>
 #include <vector>
 
@@ -74,6 +75,8 @@ protected:
 	void paintEvent(QPaintEvent *event) override;
 	void keyPressEvent(QKeyEvent *event) override;
 	void mousePressEvent(QMouseEvent *event) override;
+	void mouseMoveEvent(QMouseEvent *event) override;
+	void mouseReleaseEvent(QMouseEvent *event) override;
 	void focusInEvent(QFocusEvent *event) override;
 	void focusOutEvent(QFocusEvent *event) override;
 
@@ -82,7 +85,7 @@ protected:
 private:
 	TeletextDocument* m_teletextDocument;
 	LevelOnePage* m_levelOnePage;
-	bool m_insertMode, m_grid;
+	bool m_insertMode, m_grid, m_selectionInProgress;
 	QBasicTimer m_flashTimer;
 	int m_flashTiming, m_flashPhase;
 
@@ -90,7 +93,7 @@ private:
 
 	void calculateDimensions();
 
-	void cursorToMouse(QPoint mousePosition);
+	QPair<int, int> mouseToRowAndColumn(const QPoint &);
 };
 
 #endif