Show grid

1 files changed, 77 insertions, 1 deletions

diff --git a/src/diagramdocument.cpp b/src/diagramdocument.cpp
index 71b38db..7ed2418 100644
--- a/src/diagramdocument.cpp
+++ b/src/diagramdocument.cpp
@@ -14,6 +14,7 @@
 // with this program; if not, write to the Free Software Foundation, Inc.,
 // 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 
+#include <cmath>
 #include "diagramdocument.h"
 #include "diagramobject.h"
 #include "diagramconnection.h"
@@ -25,13 +26,88 @@
 #include <QDebug>
 #include <QFile>
 #include <QTextStream>
+#include <QStyle>
+
+using namespace std;
+
+class DiagramDocument::DiagramDocumentPrivate
+{
+public:
+	DiagramDocumentPrivate() :
+		gridSize(10),
+		gridVisible(true),
+		gridPen(QColor(185, 185, 185), 0)
+		{}
+	int gridSize;
+	bool gridVisible;
+	QPen gridPen;
+};
 
 DiagramDocument::DiagramDocument(QObject *parent)
-	: QGraphicsScene(parent), m_mode(DiagramDocument::Select), m_line(NULL)
+	: QGraphicsScene(parent), d(new DiagramDocumentPrivate), m_mode(DiagramDocument::Select), m_line(NULL)
 {
 	m_undoStack = new QUndoStack(this);
 }
 
+int
+DiagramDocument::gridSize() const
+{
+	return d->gridSize;
+}
+
+void
+DiagramDocument::setGridSize(int size)
+{
+	d->gridSize = size;
+	update();
+}
+
+bool
+DiagramDocument::isGridVisible() const
+{
+	return d->gridVisible;
+}
+
+void
+DiagramDocument::setGridVisible(bool visible)
+{
+	d->gridVisible = visible;
+	update();
+}
+
+QColor
+DiagramDocument::gridColor() const
+{
+	return d->gridPen.color();
+}
+
+void
+DiagramDocument::setGridColor(const QColor &color)
+{
+	d->gridPen.setColor(color);
+	update();
+}
+
+void
+DiagramDocument::drawBackground(QPainter *painter, const QRectF &rect)
+{
+	if (d->gridVisible) {
+		qreal gridSize = d->gridSize;
+		qreal x0 = gridSize * floor(rect.left() / gridSize);
+		qreal y0 = gridSize * floor(rect.top() / gridSize);
+		qreal x1 = gridSize * ceil(rect.right() / gridSize);
+		qreal y1 = gridSize * ceil(rect.bottom() / gridSize);
+		painter->save();
+		painter->setPen(d->gridPen);
+		painter->setRenderHint(QPainter::Antialiasing, false);
+		// FIXME do this in one QPainter::drawPoints call
+		for (qreal x = x0; x < x1; x += gridSize)
+			for (qreal y = y0; y < y1; y += gridSize)
+				painter->drawPoint(x, y);
+		painter->restore();
+	}
+}
+
 DiagramDocument::Mode
 DiagramDocument::mode()
 {