Returned support of detail dots to linear chart view class.

Telegram/SourceFiles/statistics/chart_widget.cpp

@@ -939,16 +939,12 @@ void ChartWidget::setupChartArea() {
 			}
 		}
 
-		auto detailsPaintContext = DetailsPaintContext{
-			.xIndex = (_details.widget && (detailsAlpha > 0.))
-				? _details.widget->xIndex()
-				: -1,
-		};
 		if (_chartData) {
 			// p.setRenderHint(
 			// 	QPainter::Antialiasing,
 			// 	!_animationController.isFPSSlow()
 			// 		|| !_animationController.animating());
+			PainterHighQualityEnabler hp(p);
 			_linearChartView->paint(
 				p,
 				_chartData,
@@ -956,7 +952,6 @@ void ChartWidget::setupChartArea() {
 				_animationController.currentXLimits(),
 				_animationController.currentHeightLimits(),
 				chartRect,
-				detailsPaintContext,
 				false);
 		}
 
@@ -971,13 +966,16 @@ void ChartWidget::setupChartArea() {
 				QRect(bottom.x(), bottom.y(), bottom.width(), st::lineWidth),
 				st::windowSubTextFg);
 		}
-		for (const auto &dot : detailsPaintContext.dots) {
-			p.setBrush(st::boxBg);
-			p.setPen(QPen(dot.color, st::statisticsChartLineWidth));
-			const auto r = st::statisticsDetailsDotRadius;
+		if (_details.widget && (detailsAlpha > 0.)) {
 			auto hq = PainterHighQualityEnabler(p);
-			auto o = ScopedPainterOpacity(p, dot.alpha * detailsAlpha);
-			p.drawEllipse(dot.point, r, r);
+			auto o = ScopedPainterOpacity(p, detailsAlpha);
+			_linearChartView->paintSelectedXIndex(
+				p,
+				_chartData,
+				_animationController.currentXLimits(),
+				_animationController.currentHeightLimits(),
+				chartRect,
+				_details.widget->xIndex());
 		}
 
 		p.setPen(st::windowSubTextFg);
@@ -1067,7 +1065,6 @@ void ChartWidget::setupFooter() {
 			QPainter &p,
 			const QRect &r) {
 		if (_chartData) {
-			auto detailsPaintContext = DetailsPaintContext{ .xIndex = -1 };
 			p.fillRect(r, st::boxBg);
 			// p.setRenderHint(
 			// 	QPainter::Antialiasing,
@@ -1081,7 +1078,6 @@ void ChartWidget::setupFooter() {
 				fullXLimits,
 				_animationController.currentFooterHeightLimits(),
 				r,
-				detailsPaintContext,
 				true);
 		}
 	});

Telegram/SourceFiles/statistics/linear_chart_view.cpp

@@ -64,7 +64,6 @@ void LinearChartView::paint(
 		const Limits &xPercentageLimits,
 		const Limits &heightLimits,
 		const QRect &rect,
-		DetailsPaintContext &detailsPaintContext,
 		bool footer) {
 
 	const auto cacheToken = LinearChartView::CacheToken(
@@ -128,6 +127,47 @@ void LinearChartView::paint(
 	}
 }
 
+void LinearChartView::paintSelectedXIndex(
+		QPainter &p,
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const Limits &heightLimits,
+		const QRect &rect,
+		int selectedXIndex) {
+	if (selectedXIndex < 0) {
+		return;
+	}
+	p.setBrush(st::boxBg);
+	const auto r = st::statisticsDetailsDotRadius;
+	const auto i = selectedXIndex;
+	const auto isSameToken = (_selectedPoints.lastXIndex == selectedXIndex)
+		&& (_selectedPoints.lastHeightLimits.min == heightLimits.min)
+		&& (_selectedPoints.lastHeightLimits.max == heightLimits.max);
+	for (const auto &line : chartData.lines) {
+		const auto lineAlpha = alpha(line.id);
+		const auto useCache = isSameToken
+			|| (lineAlpha < 1. && !isEnabled(line.id));
+		if (!useCache) {
+			// Calculate.
+			const auto xPoint = rect.width()
+				* ((chartData.xPercentage[i] - xPercentageLimits.min)
+					/ (xPercentageLimits.max - xPercentageLimits.min));
+			const auto yPercentage = (line.y[i] - heightLimits.min)
+				/ float64(heightLimits.max - heightLimits.min);
+			const auto yPoint = (1. - yPercentage) * rect.height();
+			_selectedPoints.points[line.id] = QPointF(xPoint, yPoint)
+				+ rect.topLeft();
+		}
+
+		// Paint.
+		auto o = ScopedPainterOpacity(p, lineAlpha * p.opacity());
+		p.setPen(QPen(line.color, st::statisticsChartLineWidth));
+		p.drawEllipse(_selectedPoints.points[line.id], r, r);
+	}
+	_selectedPoints.lastXIndex = selectedXIndex;
+	_selectedPoints.lastHeightLimits = heightLimits;
+}
+
 void LinearChartView::setEnabled(int id, bool enabled, crl::time now) {
 	const auto it = _entries.find(id);
 	if (it == end(_entries)) {

Telegram/SourceFiles/statistics/linear_chart_view.h

@@ -16,7 +16,6 @@ struct StatisticalChart;
 namespace Statistic {
 
 struct Limits;
-struct DetailsPaintContext;
 
 class LinearChartView {
 public:
@@ -29,9 +28,16 @@ public:
 		const Limits &xPercentageLimits,
 		const Limits &heightLimits,
 		const QRect &rect,
-		DetailsPaintContext &detailsPaintContext,
 		bool footer);
 
+	void paintSelectedXIndex(
+		QPainter &p,
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const Limits &heightLimits,
+		const QRect &rect,
+		int selectedXIndex);
+
 	void setEnabled(int id, bool enabled, crl::time now);
 	[[nodiscard]] bool isEnabled(int id) const;
 	[[nodiscard]] bool isFinished() const;
@@ -82,6 +88,13 @@ private:
 	base::flat_map<int, Cache> _mainCaches;
 	base::flat_map<int, Cache> _footerCaches;
 
+	struct SelectedPoints final {
+		int lastXIndex = -1;
+		Limits lastHeightLimits;
+		base::flat_map<int, QPointF> points;
+	};
+	SelectedPoints _selectedPoints;
+
 	struct Entry final {
 		bool enabled = false;
 		crl::time startedAt = 0;

Telegram/SourceFiles/statistics/statistics_common.h

@@ -14,16 +14,4 @@ struct Limits final {
 	float64 max = 0;
 };
 
-// Dot on line charts.
-struct DetailsPaintContext final {
-	int xIndex = -1;
-
-	struct Dot {
-		QPointF point;
-		QColor color;
-		float64 alpha = 0.;
-	};
-	std::vector<Dot> dots;
-};
-
 } // namespace Statistic