statistics: paint custom grid

With removal of QtCharts' axes, the grid was lost. Readd it.

Signed-off-by: Berthold Stoeger <bstoeger@mail.tuwien.ac.at>

1 files changed, 36 insertions, 0 deletions

diff --git a/stats/statsgrid.cpp b/stats/statsgrid.cpp
new file mode 100644
index 000000000..fe99b1762
--- /dev/null
+++ b/stats/statsgrid.cpp
@@ -0,0 +1,36 @@
+// SPDX-License-Identifier: GPL-2.0
+#include "statsgrid.h"
+#include "statsaxis.h"
+#include "statscolors.h"
+#include "zvalues.h"
+
+#include <QChart>
+#include <QGraphicsLineItem>
+
+static const double gridWidth = 1.0;
+static const Qt::PenStyle gridStyle = Qt::SolidLine;
+
+StatsGrid::StatsGrid(QtCharts::QChart *chart, const StatsAxis &xAxis, const StatsAxis &yAxis)
+	: chart(chart), xAxis(xAxis), yAxis(yAxis)
+{
+}
+
+void StatsGrid::updatePositions()
+{
+	std::vector<double> xtics = xAxis.ticksPositions();
+	std::vector<double> ytics = yAxis.ticksPositions();
+	lines.clear();
+	if (xtics.empty() || ytics.empty())
+		return;
+
+	for (double x: xtics) {
+		lines.emplace_back(new QGraphicsLineItem(x, ytics.front(), x, ytics.back(), chart));
+		lines.back()->setPen(QPen(gridColor, gridWidth, gridStyle));
+		lines.back()->setZValue(ZValues::grid);
+	}
+	for (double y: ytics) {
+		lines.emplace_back(new QGraphicsLineItem(xtics.front(), y, xtics.back(), y, chart));
+		lines.back()->setPen(QPen(gridColor, gridWidth, gridStyle));
+		lines.back()->setZValue(ZValues::grid);
+	}
+}