statistics: implement rectangle selection in scatter plot

Allow the user to select regions of the scatter plot using
a rectangular selection. When shift is pressed, do an
incremental selection.

Unfortunately, the list-selection code is so slow that this
becomes unusable for a large number of selected dives.

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

1 files changed, 19 insertions, 6 deletions

diff --git a/stats/chartitem.h b/stats/chartitem.h
index c700cb421..038054c39 100644
--- a/stats/chartitem.h
+++ b/stats/chartitem.h
@@ -112,23 +112,35 @@ private:
 	double borderWidth;
 };
 
-class ChartLineItem : public HideableChartItem<HideableQSGNode<QSGGeometryNode>> {
+// Common data for line and rect items. Both are represented by two points.
+class ChartLineItemBase : public HideableChartItem<HideableQSGNode<QSGGeometryNode>> {
 public:
-	ChartLineItem(StatsView &v, ChartZValue z, QColor color, double width);
-	~ChartLineItem();
+	ChartLineItemBase(StatsView &v, ChartZValue z, QColor color, double width);
+	~ChartLineItemBase();
 	void setLine(QPointF from, QPointF to);
-	void render() override;		// Only call on render thread!
-private:
+protected:
 	QPointF from, to;
 	QColor color;
 	double width;
-	bool horizontal;
 	bool positionDirty;
 	bool materialDirty;
 	std::unique_ptr<QSGFlatColorMaterial> material;
 	std::unique_ptr<QSGGeometry> geometry;
 };
 
+class ChartLineItem : public ChartLineItemBase {
+public:
+	using ChartLineItemBase::ChartLineItemBase;
+	void render() override;		// Only call on render thread!
+};
+
+// A simple rectangle without fill. Specified by any two opposing vertices.
+class ChartRectLineItem : public ChartLineItemBase {
+public:
+	using ChartLineItemBase::ChartLineItemBase;
+	void render() override;		// Only call on render thread!
+};
+
 // A bar in a bar chart: a rectangle bordered by lines.
 class ChartBarItem : public HideableChartProxyItem<QSGRectangleNode> {
 public:
@@ -185,6 +197,7 @@ public:
 	void render() override;			// Only call on render thread!
 	QRectF getRect() const;
 	bool contains(QPointF point) const;
+	bool inRect(const QRectF &rect) const;
 private:
 	QSGTexture *getTexture() const;
 	QRectF rect;