Move grid drawing to DiagramView

1 files changed, 56 insertions, 0 deletions

diff --git a/src/diagramview.cpp b/src/diagramview.cpp
index 0c5a45b..e2a5779 100644
--- a/src/diagramview.cpp
+++ b/src/diagramview.cpp
@@ -14,10 +14,14 @@
 // 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 <QMouseEvent>
 #include <QScrollBar>
 #include <QDebug>
 #include "diagramview.h"
+#include "diagramdocument.h"
+
+using namespace std;
 
 DiagramView::DiagramView(QWidget *parent)
 	: QGraphicsView(parent), m_handScrolling(false)
@@ -25,6 +29,13 @@ DiagramView::DiagramView(QWidget *parent)
 	setAlignment(Qt::AlignLeft | Qt::AlignTop);
 	setRenderHint(QPainter::Antialiasing);
 	setDragMode(QGraphicsView::RubberBandDrag);
+	setRubberBandSelectionMode(Qt::ContainsItemBoundingRect);
+}
+
+DiagramDocument *
+DiagramView::document() const
+{
+	return static_cast<DiagramDocument *>(scene());
 }
 
 void
@@ -82,3 +93,48 @@ DiagramView::mouseReleaseEvent(QMouseEvent *event)
 	}
 	QGraphicsView::mouseReleaseEvent(event);
 }
+
+void
+DiagramView::drawBackground(QPainter *painter, const QRectF &rect)
+{
+	DiagramDocument *doc = document();
+	if (doc && doc->isGridVisible()) {
+		drawGrid(painter, rect);
+	}
+}
+
+void
+DiagramView::drawGrid(QPainter *painter, const QRectF &rect)
+{
+	const int pointBufferSize = 5000;
+	static QPoint pointBuffer[pointBufferSize];
+	DiagramDocument *doc = document();
+	int gridSize = doc->gridSize();
+	int x0 = gridSize * floor(rect.left() / gridSize);
+	int y0 = gridSize * floor(rect.top() / gridSize);
+	int x1 = gridSize * ceil(rect.right() / gridSize);
+	int y1 = gridSize * ceil(rect.bottom() / gridSize);
+	painter->save();
+	QPen pen;
+	pen.setColor(doc->gridColor());
+	pen.setWidth(0);
+	painter->setPen(pen);
+	painter->setRenderHint(QPainter::Antialiasing, false);
+	int pointsUsed = 0;
+	for (int x = x0; x < x1; x += gridSize) {
+		for (int y = y0; y < y1; y += gridSize) {
+			pointBuffer[pointsUsed].setX(x);
+			pointBuffer[pointsUsed].setY(y);
+			pointsUsed++;
+			if (pointsUsed == pointBufferSize) {
+				painter->drawPoints(pointBuffer, pointsUsed);
+				pointsUsed = 0;
+			}
+		}
+	}
+	if (pointsUsed > 0) {
+		painter->drawPoints(pointBuffer, pointsUsed);
+		pointsUsed = 0;
+	}
+	painter->restore();
+}