Moved out search of clicked index on chart to chart view.

Telegram/SourceFiles/statistics/chart_widget.cpp

@@ -1183,26 +1183,17 @@ void ChartWidget::setupDetails() {
 		case QEvent::MouseButtonPress:
 		case QEvent::MouseMove: {
 			const auto chartRect = chartAreaRect();
-			const auto pointerRatio = std::clamp(
-				state.point.x() / float64(chartRect.width()),
-				0.,
-				1.);
 			const auto currentXLimits = _animationController.finalXLimits();
-			const auto rawXPercentage = anim::interpolateF(
-				currentXLimits.min,
-				currentXLimits.max,
-				pointerRatio);
-			const auto nearestXPercentageIt = ranges::lower_bound(
-				_chartData.xPercentage,
-				rawXPercentage);
-			const auto nearestXIndex = std::distance(
-				begin(_chartData.xPercentage),
-				nearestXPercentageIt);
+			const auto nearestXIndex = _chartView->findXIndexByPosition(
+				_chartData,
+				currentXLimits,
+				chartRect,
+				state.point.x());
 			const auto currentX = 0
 				+ chartRect.width() * InterpolationRatio(
 					currentXLimits.min,
 					currentXLimits.max,
-					*nearestXPercentageIt);
+					_chartData.xPercentage[nearestXIndex]);
 			const auto xLeft = currentX
 				- _details.widget->width();
 			const auto x = (xLeft >= 0)

Telegram/SourceFiles/statistics/view/abstract_chart_view.h

@@ -37,6 +37,12 @@ public:
 		int selectedXIndex,
 		float64 progress) = 0;
 
+	[[nodiscard]] virtual int findXIndexByPosition(
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const QRect &rect,
+		float64 x) = 0;
+
 	virtual void setEnabled(int id, bool enabled, crl::time now) = 0;
 	[[nodiscard]] virtual bool isEnabled(int id) const = 0;
 	[[nodiscard]] virtual bool isFinished() const = 0;

Telegram/SourceFiles/statistics/view/linear_chart_view.cpp

@@ -189,6 +189,35 @@ void LinearChartView::paintSelectedXIndex(
 	_selectedPoints.lastXLimits = xPercentageLimits;
 }
 
+int LinearChartView::findXIndexByPosition(
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const QRect &rect,
+		float64 x) {
+	if (x < rect.x()) {
+		return 0;
+	} else if (x > (rect.x() + rect.width())) {
+		return chartData.xPercentage.size() - 1;
+	}
+	const auto pointerRatio = std::clamp(
+		(x - rect.x()) / rect.width(),
+		0.,
+		1.);
+	const auto rawXPercentage = anim::interpolateF(
+		xPercentageLimits.min,
+		xPercentageLimits.max,
+		pointerRatio);
+	const auto it = ranges::lower_bound(
+		chartData.xPercentage,
+		rawXPercentage);
+	const auto left = rawXPercentage - (*(it - 1));
+	const auto right = (*it) - rawXPercentage;
+	const auto nearestXPercentageIt = ((right) > (left)) ? (it - 1) : it;
+	return std::distance(
+		begin(chartData.xPercentage),
+		nearestXPercentageIt);
+}
+
 void LinearChartView::setEnabled(int id, bool enabled, crl::time now) {
 	const auto it = _entries.find(id);
 	if (it == end(_entries)) {

Telegram/SourceFiles/statistics/view/linear_chart_view.h

@@ -41,6 +41,12 @@ public:
 		int selectedXIndex,
 		float64 progress) override;
 
+	int findXIndexByPosition(
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const QRect &rect,
+		float64 x) override;
+
 	void setEnabled(int id, bool enabled, crl::time now) override;
 	[[nodiscard]] bool isEnabled(int id) const override;
 	[[nodiscard]] bool isFinished() const override;

Telegram/SourceFiles/statistics/view/stack_chart_view.cpp

@@ -98,6 +98,14 @@ void StackChartView::paintSelectedXIndex(
 		float64 progress) {
 }
 
+int StackChartView::findXIndexByPosition(
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const QRect &rect,
+		float64 xPos) {
+	return 0;
+}
+
 void StackChartView::setEnabled(int id, bool enabled, crl::time now) {
 }
 

Telegram/SourceFiles/statistics/view/stack_chart_view.h

@@ -42,6 +42,12 @@ public:
 		int selectedXIndex,
 		float64 progress) override;
 
+	int findXIndexByPosition(
+		const Data::StatisticalChart &chartData,
+		const Limits &xPercentageLimits,
+		const QRect &rect,
+		float64 x) override;
+
 	void setEnabled(int id, bool enabled, crl::time now) override;
 	[[nodiscard]] bool isEnabled(int id) const override;
 	[[nodiscard]] bool isFinished() const override;