statistics: highlight selected pie slices

In analogy to the other charts, highlight selected pie slices.
Overlay them with a checkerboard pattern, like in the bar charts.

Since all charts now support highlighting, the divesSelected()
virtual function now doesn't need a default implementation
anymore.

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

stats/chartitem.cpp

@@ -11,6 +11,8 @@
 #include <QSGTexture>
 #include <QSGTextureMaterial>
 
+static int selectionOverlayPixelSize = 2;
+
 static int round_up(double f)
 {
 	return static_cast<int>(ceil(f));
@@ -289,10 +291,26 @@ ChartPieItem::ChartPieItem(StatsView &v, ChartZValue z, double borderWidth) : Ch
 {
 }
 
-void ChartPieItem::drawSegment(double from, double to, QColor fill, QColor border)
+static QBrush makeBrush(QColor fill, bool selected)
+{
+	if (!selected)
+		return QBrush(fill);
+	QImage img(2 * selectionOverlayPixelSize, 2 * selectionOverlayPixelSize, QImage::Format_ARGB32);
+	img.fill(fill);
+	for (int x = 0; x < selectionOverlayPixelSize; ++x) {
+		for (int y = 0; y < selectionOverlayPixelSize; ++y) {
+			img.setPixelColor(x, y, selectionOverlayColor);
+			img.setPixelColor(x + selectionOverlayPixelSize, y + selectionOverlayPixelSize,
+					  selectionOverlayColor);
+		}
+	}
+	return QBrush(img);
+}
+
+void ChartPieItem::drawSegment(double from, double to, QColor fill, QColor border, bool selected)
 {
 	painter->setPen(QPen(border, borderWidth));
-	painter->setBrush(QBrush(fill));
+	painter->setBrush(makeBrush(fill, selected));
 	// For whatever obscure reason, angles of pie pieces are given as 16th of a degree...?
 	// Angles increase CCW, whereas pie charts usually are read CW. Therfore, startAngle
 	// is dervied from "from" and subtracted from the origin angle at 12:00.
@@ -487,13 +505,13 @@ void ChartBarItem::render()
 	}
 
 	if (selected && positionDirty) {
-		// The checkerboard texture is 2x2. By dividing the coordinates by 4, every square is 2x2 pixels on the screen.
+		double pixelFactor = 2.0 * selectionOverlayPixelSize; // The texture image is 2x2 pixels.
 		auto selectionVertices = selectionGeometry->vertexDataAsTexturedPoint2D();
 		selectionNode->markDirty(QSGNode::DirtyGeometry);
 		setPoint(selectionVertices[0], rect.topLeft(), QPointF());
-		setPoint(selectionVertices[1], rect.topRight(), QPointF(rect.width() / 4.0, 0.0));
-		setPoint(selectionVertices[2], rect.bottomRight(), QPointF(rect.width() / 4.0, rect.height() / 4.0));
-		setPoint(selectionVertices[3], rect.bottomLeft(), QPointF(0.0, rect.height() / 4.0));
+		setPoint(selectionVertices[1], rect.topRight(), QPointF(rect.width() / pixelFactor, 0.0));
+		setPoint(selectionVertices[2], rect.bottomRight(), QPointF(rect.width() / pixelFactor, rect.height() / pixelFactor));
+		setPoint(selectionVertices[3], rect.bottomLeft(), QPointF(0.0, rect.height() / pixelFactor));
 	}
 
 	positionDirty = colorDirty = selectedDirty = false;

stats/chartitem.h

@@ -107,7 +107,7 @@ private:
 class ChartPieItem : public ChartPixmapItem {
 public:
 	ChartPieItem(StatsView &v, ChartZValue z, double borderWidth);
-	void drawSegment(double from, double to, QColor fill, QColor border); // from and to are relative (0-1 is full disk).
+	void drawSegment(double from, double to, QColor fill, QColor border, bool selected); // from and to are relative (0-1 is full disk).
 	void resize(QSizeF size);	// As in base class, but clears the canvas
 private:
 	double borderWidth;

stats/pieseries.cpp

@@ -20,7 +20,8 @@ static const double outerLabelRadius = 1.01; // 1.0 = at outer border of pie
 PieSeries::Item::Item(StatsView &view, const QString &name, int from, std::vector<dive *> divesIn, int totalCount,
 		      int bin_nr, int numBins) :
 	name(name),
-	dives(std::move(divesIn))
+	dives(std::move(divesIn)),
+	selected(allDivesSelected(dives))
 {
 	QFont f; // make configurable
 	QLocale loc;
@@ -72,7 +73,7 @@ void PieSeries::Item::highlight(ChartPieItem &item, int bin_nr, bool highlight,
 	QColor border = highlight ? highlightedBorderColor : ::borderColor;
 	if (innerLabel)
 		innerLabel->setColor(highlight ? darkLabelColor : labelColor(bin_nr, numBins), fill);
-	item.drawSegment(angleFrom, angleTo, fill, border);
+	item.drawSegment(angleFrom, angleTo, fill, border, selected);
 }
 
 PieSeries::PieSeries(StatsView &view, StatsAxis *xAxis, StatsAxis *yAxis, const QString &categoryName,
@@ -277,3 +278,16 @@ bool PieSeries::selectItemsUnderMouse(const QPointF &pos, bool)
 	setSelection(dives, dives.empty() ? nullptr : dives.front());
 	return true;
 }
+
+void PieSeries::divesSelected(const QVector<dive *> &)
+{
+	for (Item &segment: items) {
+		bool selected = allDivesSelected(segment.dives);
+		if (segment.selected != selected) {
+			segment.selected = selected;
+
+			int idx = &segment - &items[0];
+			segment.highlight(*item, idx, idx == highlighted, (int)items.size());
+		}
+	}
+}

stats/pieseries.h

@@ -46,6 +46,7 @@ private:
 		double angleFrom, angleTo; // In fraction of total
 		std::vector<dive *> dives;
 		QPointF innerLabelPos, outerLabelPos; // With respect to a (-1, -1)-(1, 1) rectangle.
+		bool selected;
 		Item(StatsView &view, const QString &name, int from, std::vector<dive *> dives, int totalCount,
 		     int bin_nr, int numBins);
 		void updatePositions(const QPointF &center, double radius);
@@ -65,6 +66,7 @@ private:
 	QPointF center; // center of drawing area
 	double radius; // radius of pie
 	int highlighted;
+	void divesSelected(const QVector<dive *> &) override;
 };
 
 #endif

stats/statsseries.cpp

@@ -17,10 +17,6 @@ QPointF StatsSeries::toScreen(QPointF p)
 			      : QPointF(0.0, 0.0);
 }
 
-void StatsSeries::divesSelected(const QVector<dive *> &)
-{
-}
-
 bool StatsSeries::supportsLassoSelection() const
 {
 	return false;

stats/statsseries.h

@@ -24,7 +24,7 @@ public:
 	virtual bool supportsLassoSelection() const;
 	// Needs only be defined if supportsLassoSelection() returns true.
 	virtual void selectItemsInRect(const QRectF &rect, bool shiftPressed, const std::vector<dive *> &oldSelection);
-	virtual void divesSelected(const QVector<dive *> &dives);
+	virtual void divesSelected(const QVector<dive *> &dives) = 0;
 
 protected:
 	StatsView &view;