From 74aae29b64b8de2ecbf0ffa420b3598681bf256e Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Fri, 7 Jul 2023 11:28:50 +0300
Subject: [PATCH] Added point details widget to chart widget.

---
 .../SourceFiles/statistics/chart_widget.cpp   | 106 ++++++++++++++++--
 .../SourceFiles/statistics/chart_widget.h     |  17 ++-
 .../statistics/linear_chart_view.cpp          |  20 +++-
 .../statistics/linear_chart_view.h            |   4 +-
 .../statistics/point_details_widget.cpp       |   5 +
 .../statistics/point_details_widget.h         |   3 +
 .../SourceFiles/statistics/statistics.style   |   2 +
 .../statistics/statistics_common.h            |   6 +
 8 files changed, 151 insertions(+), 12 deletions(-)

diff --git a/Telegram/SourceFiles/statistics/chart_widget.cpp b/Telegram/SourceFiles/statistics/chart_widget.cpp
index b07375a7bb..53b8011599 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.cpp
+++ b/Telegram/SourceFiles/statistics/chart_widget.cpp
@@ -9,6 +9,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 
 #include "base/qt/qt_key_modifiers.h"
 #include "statistics/linear_chart_view.h"
+#include "statistics/point_details_widget.h"
 #include "ui/abstract_button.h"
 #include "ui/effects/animation_value_f.h"
 #include "ui/rect.h"
@@ -20,6 +21,10 @@ namespace {
 
 constexpr auto kHeightLimitsUpdateTimeout = crl::time(320);
 
+inline float64 InterpolationRatio(float64 from, float64 to, float64 result) {
+	return (result - from) / (to - from);
+};
+
 [[nodiscard]] int FindMaxValue(
 		Data::StatisticalChart &chartData,
 		int startXIndex,
@@ -424,6 +429,10 @@ Limits ChartWidget::ChartAnimationController::currentXLimits() const {
 	return { _animationValueXMin.current(), _animationValueXMax.current() };
 }
 
+Limits ChartWidget::ChartAnimationController::finalXLimits() const {
+	return { _animationValueXMin.to(), _animationValueXMax.to() };
+}
+
 Limits ChartWidget::ChartAnimationController::currentHeightLimits() const {
 	return {
 		_animationValueHeightMin.current(),
@@ -442,7 +451,7 @@ auto ChartWidget::ChartAnimationController::heightAnimationStarts() const
 
 ChartWidget::ChartWidget(not_null<Ui::RpWidget*> parent)
 : Ui::RpWidget(parent)
-, _chartArea(base::make_unique_q<Ui::RpWidget>(this))
+, _chartArea(base::make_unique_q<RpMouseWidget>(this))
 , _footer(std::make_unique<Footer>(this))
 , _animationController([=] { _chartArea->update(); }) {
 	sizeValue(
@@ -457,16 +466,31 @@ ChartWidget::ChartWidget(not_null<Ui::RpWidget*> parent)
 			0,
 			s.width(),
 			s.height() - st::countryRowHeight * 2);
-	}, _footer->lifetime());
+	}, lifetime());
 
+	setupChartArea();
+	setupFooter();
+
+	resize(width(), st::confirmMaxHeight + st::countryRowHeight * 2);
+}
+
+QRect ChartWidget::chartAreaRect() const {
+	return _chartArea->rect()
+		- QMargins(
+			st::lineWidth,
+			st::boxTextFont->height,
+			st::lineWidth,
+			st::lineWidth);
+}
+
+void ChartWidget::setupChartArea() {
 	_chartArea->paintRequest(
 	) | rpl::start_with_next([=](const QRect &r) {
 		auto p = QPainter(_chartArea.get());
 
 		_animationController.tick(crl::now(), _horizontalLines);
 
-		const auto chartRect = _chartArea->rect()
-			- QMargins{ 0, st::boxTextFont->height, 0, st::lineWidth };
+		const auto chartRect = chartAreaRect();
 
 		p.fillRect(r, st::boxBg);
 
@@ -474,20 +498,33 @@ ChartWidget::ChartWidget(not_null<Ui::RpWidget*> parent)
 			PaintHorizontalLines(p, horizontalLine, chartRect);
 		}
 
+		if (_details.currentX) {
+			const auto lineRect = QRectF(
+				_details.currentX - (st::lineWidth / 2.),
+				0,
+				st::lineWidth,
+				_chartArea->height());
+			p.setOpacity(1.);
+			p.fillRect(lineRect, st::windowSubTextFg);
+		}
+
 		if (_chartData) {
 			Statistic::PaintLinearChartView(
 				p,
 				_chartData,
 				_animationController.currentXLimits(),
 				_animationController.currentHeightLimits(),
-				chartRect);
+				chartRect,
+				{ _details.widget ? _details.widget->xIndex() : -1, 1. });
 		}
 
 		for (auto &horizontalLine : _horizontalLines) {
 			PaintCaptionsToHorizontalLines(p, horizontalLine, chartRect);
 		}
 	}, _footer->lifetime());
+}
 
+void ChartWidget::setupFooter() {
 	_footer->paintRequest(
 	) | rpl::start_with_next([=, fullXLimits = Limits{ 0., 1. }] {
 		auto p = QPainter(_footer.get());
@@ -499,7 +536,8 @@ ChartWidget::ChartWidget(not_null<Ui::RpWidget*> parent)
 				_chartData,
 				fullXLimits,
 				_footer->fullHeightLimits(),
-				_footer->rect());
+				_footer->rect(),
+				{});
 		}
 	}, _footer->lifetime());
 
@@ -526,12 +564,65 @@ ChartWidget::ChartWidget(not_null<Ui::RpWidget*> parent)
 		_animationController.resetAlpha();
 		addHorizontalLine(_animationController.finalHeightLimits(), true);
 	}, _footer->lifetime());
-	resize(width(), st::confirmMaxHeight + st::countryRowHeight * 2);
+}
+
+void ChartWidget::setupDetails() {
+	if (!_chartData) {
+		_details = {};
+		_chartArea->update();
+		return;
+	}
+	_details.widget = base::make_unique_q<PointDetailsWidget>(
+		this,
+		_chartData);
+
+	_chartArea->mouseStateChanged(
+	) | rpl::start_with_next([=](const RpMouseWidget::State &state) {
+		switch (state.mouseState) {
+		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);
+			_details.currentX = 0
+				+ chartRect.width() * InterpolationRatio(
+					currentXLimits.min,
+					currentXLimits.max,
+					*nearestXPercentageIt);
+			const auto xLeft = _details.currentX
+				- _details.widget->width();
+			const auto x = (xLeft < 0)
+				? (_details.currentX)
+				: xLeft;
+			_details.widget->moveToLeft(x, _chartArea->y());
+			_details.widget->setXIndex(nearestXIndex);
+			_details.widget->show();
+			_chartArea->update();
+		} break;
+		case QEvent::MouseButtonRelease: {
+		} break;
+		}
+	}, _details.widget->lifetime());
 }
 
 void ChartWidget::setChartData(Data::StatisticalChart chartData) {
 	_chartData = std::move(chartData);
 
+	setupDetails();
+
 	_footer->setFullHeightLimits(FindHeightLimitsBetweenXLimits(
 		_chartData,
 		{ _chartData.xPercentage.front(), _chartData.xPercentage.back() }));
@@ -543,6 +634,7 @@ void ChartWidget::setChartData(Data::StatisticalChart chartData) {
 	_animationController.finish();
 	addHorizontalLine(_animationController.finalHeightLimits(), false);
 	_chartArea->update();
+	_footer->update();
 }
 
 void ChartWidget::addHorizontalLine(Limits newHeight, bool animated) {
diff --git a/Telegram/SourceFiles/statistics/chart_widget.h b/Telegram/SourceFiles/statistics/chart_widget.h
index 2400ebbba6..781143a3fe 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.h
+++ b/Telegram/SourceFiles/statistics/chart_widget.h
@@ -17,6 +17,7 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 namespace Statistic {
 
 class RpMouseWidget;
+class PointDetailsWidget;
 
 class ChartWidget : public Ui::RpWidget {
 public:
@@ -44,6 +45,7 @@ private:
 			std::vector<ChartHorizontalLinesData> &horizontalLines);
 
 		[[nodiscard]] Limits currentXLimits() const;
+		[[nodiscard]] Limits finalXLimits() const;
 		[[nodiscard]] Limits currentHeightLimits() const;
 		[[nodiscard]] Limits finalHeightLimits() const;
 
@@ -72,10 +74,21 @@ private:
 
 	};
 
-	const base::unique_qptr<Ui::RpWidget> _chartArea;
-	std::unique_ptr<Footer> _footer;
+	[[nodiscard]] QRect chartAreaRect() const;
+
+	void setupChartArea();
+	void setupFooter();
+	void setupDetails();
+
+	const base::unique_qptr<RpMouseWidget> _chartArea;
+	const std::unique_ptr<Footer> _footer;
 	Data::StatisticalChart _chartData;
 
+	struct {
+		base::unique_qptr<PointDetailsWidget> widget;
+		float64 currentX = 0;
+	} _details;
+
 	bool _useMinHeight = false;
 
 	ChartAnimationController _animationController;
diff --git a/Telegram/SourceFiles/statistics/linear_chart_view.cpp b/Telegram/SourceFiles/statistics/linear_chart_view.cpp
index a841f0738e..3ca17e222c 100644
--- a/Telegram/SourceFiles/statistics/linear_chart_view.cpp
+++ b/Telegram/SourceFiles/statistics/linear_chart_view.cpp
@@ -10,7 +10,9 @@ https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
 #include "data/data_statistics.h"
 #include "statistics/statistics_common.h"
 #include "ui/effects/animation_value_f.h"
+#include "ui/painter.h"
 #include "styles/style_boxes.h"
+#include "styles/style_statistics.h"
 
 namespace Statistic {
 
@@ -19,10 +21,13 @@ void PaintLinearChartView(
 		const Data::StatisticalChart &chartData,
 		const Limits &xPercentageLimits,
 		const Limits &heightLimits,
-		const QRect &rect) {
+		const QRect &rect,
+		const DetailsPaintContext &detailsPaintContext) {
 	const auto currentMinHeight = rect.y(); //
 	const auto currentMaxHeight = rect.height() + rect.y(); //
 
+	PainterHighQualityEnabler hq(p);
+
 	for (const auto &line : chartData.lines) {
 		const auto additionalP = (chartData.xPercentage.size() < 2)
 			? 0.
@@ -31,6 +36,7 @@ void PaintLinearChartView(
 
 		auto first = true;
 		auto chartPath = QPainterPath();
+		auto detailsDotPoint = QPointF();
 
 		const auto startXIndex = chartData.findStartIndex(
 			xPercentageLimits.min);
@@ -53,15 +59,25 @@ void PaintLinearChartView(
 			const auto yPercentage = (line.y[i] - heightLimits.min)
 				/ float64(heightLimits.max - heightLimits.min);
 			const auto yPoint = rect.y() + (1. - yPercentage) * rect.height();
+			if ((i == detailsPaintContext.xIndex)
+				&& detailsPaintContext.progress > 0.) {
+				detailsDotPoint = QPointF(xPoint, yPoint);
+			}
 			if (first) {
 				first = false;
 				chartPath.moveTo(xPoint, yPoint);
 			}
 			chartPath.lineTo(xPoint, yPoint);
 		}
-		p.setPen(line.color);
+		p.setPen(QPen(line.color, st::statisticsChartLineWidth));
 		p.setBrush(Qt::NoBrush);
 		p.drawPath(chartPath);
+
+		if (!detailsDotPoint.isNull()) {
+			p.setBrush(st::boxBg);
+			const auto r = st::statisticsDetailsDotRadius;
+			p.drawEllipse(detailsDotPoint, r, r);
+		}
 	}
 	p.setPen(st::boxTextFg);
 }
diff --git a/Telegram/SourceFiles/statistics/linear_chart_view.h b/Telegram/SourceFiles/statistics/linear_chart_view.h
index 52b6e91b4c..b08cf61f9d 100644
--- a/Telegram/SourceFiles/statistics/linear_chart_view.h
+++ b/Telegram/SourceFiles/statistics/linear_chart_view.h
@@ -14,12 +14,14 @@ struct StatisticalChart;
 namespace Statistic {
 
 struct Limits;
+struct DetailsPaintContext;
 
 void PaintLinearChartView(
 	QPainter &p,
 	const Data::StatisticalChart &chartData,
 	const Limits &xPercentageLimits,
 	const Limits &heightLimits,
-	const QRect &rect);
+	const QRect &rect,
+	const DetailsPaintContext &detailsPaintContext);
 
 } // namespace Statistic
diff --git a/Telegram/SourceFiles/statistics/point_details_widget.cpp b/Telegram/SourceFiles/statistics/point_details_widget.cpp
index ece3b051d3..92ceaf376e 100644
--- a/Telegram/SourceFiles/statistics/point_details_widget.cpp
+++ b/Telegram/SourceFiles/statistics/point_details_widget.cpp
@@ -37,7 +37,12 @@ PointDetailsWidget::PointDetailsWidget(
 			+ st::statisticsDetailsPopupMargins.bottom());
 }
 
+int PointDetailsWidget::xIndex() const {
+	return _xIndex;
+}
+
 void PointDetailsWidget::setXIndex(int xIndex) {
+	_xIndex = xIndex;
 	_header.setText(_headerStyle, _chartData.getDayString(xIndex));
 
 	_lines.clear();
diff --git a/Telegram/SourceFiles/statistics/point_details_widget.h b/Telegram/SourceFiles/statistics/point_details_widget.h
index 5d3333aab6..c8fb63d6da 100644
--- a/Telegram/SourceFiles/statistics/point_details_widget.h
+++ b/Telegram/SourceFiles/statistics/point_details_widget.h
@@ -18,6 +18,7 @@ public:
 		not_null<Ui::RpWidget*> parent,
 		const Data::StatisticalChart &chartData);
 
+	[[nodiscard]] int xIndex() const;
 	void setXIndex(int xIndex);
 
 protected:
@@ -40,6 +41,8 @@ private:
 	QRect _innerRect;
 	QRect _textRect;
 
+	int _xIndex = -1;
+
 	std::vector<Line> _lines;
 
 };
diff --git a/Telegram/SourceFiles/statistics/statistics.style b/Telegram/SourceFiles/statistics/statistics.style
index dbc35f5d49..92a3388797 100644
--- a/Telegram/SourceFiles/statistics/statistics.style
+++ b/Telegram/SourceFiles/statistics/statistics.style
@@ -14,6 +14,8 @@ statisticsDetailsPopupWidth: 135px;
 statisticsDetailsPopupMargins: margins(8px, 8px, 8px, 8px);
 statisticsDetailsPopupPadding: margins(6px, 6px, 6px, 6px);
 statisticsDetailsPopupMidLineSpace: 8px;
+statisticsDetailsDotRadius: 4px;
+statisticsChartLineWidth: 2px;
 
 statisticsDetailsPopupStyle: TextStyle(defaultTextStyle) {
 	font: font(11px);
diff --git a/Telegram/SourceFiles/statistics/statistics_common.h b/Telegram/SourceFiles/statistics/statistics_common.h
index 397791c572..9a49ca86b8 100644
--- a/Telegram/SourceFiles/statistics/statistics_common.h
+++ b/Telegram/SourceFiles/statistics/statistics_common.h
@@ -14,4 +14,10 @@ struct Limits final {
 	float64 max = 0;
 };
 
+// Dot on line charts.
+struct DetailsPaintContext final {
+	int xIndex = -1;
+	float64 progress = 0.;
+};
+
 } // namespace Statistic