From c19a527872217c3be733de2b401ce61d00922dbc Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Tue, 26 Sep 2023 16:43:35 +0300
Subject: [PATCH] Fixed position of zoomed in slider in footer for stack linear
 chart.

---
 Telegram/SourceFiles/statistics/chart_widget.cpp      |  5 +++--
 .../statistics/view/stack_chart_common.cpp            |  4 ++++
 .../statistics/view/stack_linear_chart_view.cpp       | 11 +++++++++--
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/Telegram/SourceFiles/statistics/chart_widget.cpp b/Telegram/SourceFiles/statistics/chart_widget.cpp
index 30c60d1357..261892e989 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.cpp
+++ b/Telegram/SourceFiles/statistics/chart_widget.cpp
@@ -479,8 +479,9 @@ void ChartWidget::Footer::paintEvent(QPaintEvent *e) {
 }
 
 void ChartWidget::Footer::setXPercentageLimits(const Limits &xLimits) {
-	const auto left = xLimits.min * width();
-	const auto right = xLimits.max * _width;
+	const auto left = xLimits.min * _widthBetweenSides;
+	const auto right = xLimits.max * _widthBetweenSides
+		+ st::statisticsChartFooterSideWidth;
 	moveSide(true, left);
 	moveSide(false, right);
 	fire();
diff --git a/Telegram/SourceFiles/statistics/view/stack_chart_common.cpp b/Telegram/SourceFiles/statistics/view/stack_chart_common.cpp
index 436ea64a38..040025985a 100644
--- a/Telegram/SourceFiles/statistics/view/stack_chart_common.cpp
+++ b/Telegram/SourceFiles/statistics/view/stack_chart_common.cpp
@@ -39,6 +39,10 @@ Limits FindStackXIndicesFromRawXPercentages(
 		chartData.xPercentage[zoomedInLimitXIndices.min],
 		chartData.xPercentage[zoomedInLimitXIndices.max],
 	};
+	// Due to a specificity of the stack chart plotting,
+	// the right edge has a special offset to the left.
+	// This reduces the number of displayed points by 1,
+	// but allows the last point to be displayed.
 	const auto offset = (zoomLimit.max == 1.) ? 0 : -1;
 	const auto minIt = ranges::upper_bound(
 		chartData.xPercentage,
diff --git a/Telegram/SourceFiles/statistics/view/stack_linear_chart_view.cpp b/Telegram/SourceFiles/statistics/view/stack_linear_chart_view.cpp
index 3fd53b210b..2ed9365c90 100644
--- a/Telegram/SourceFiles/statistics/view/stack_linear_chart_view.cpp
+++ b/Telegram/SourceFiles/statistics/view/stack_linear_chart_view.cpp
@@ -585,6 +585,7 @@ void StackLinearChartView::paintZoomedFooter(
 	const auto leftStart = c.rect.x() + sideW;
 	const auto &xPercentage = c.chartData.xPercentage;
 	auto previousX = leftStart;
+	// Read FindStackXIndicesFromRawXPercentages.
 	const auto offset = (xPercentage[zoomedEnd] == 1.) ? 0 : 1;
 	for (auto i = zoomedStart; i <= zoomedEnd; i++) {
 		auto sum = 0.;
@@ -958,15 +959,21 @@ auto StackLinearChartView::maybeLocalZoom(
 			xPercentage[_transition.zoomedInLimitXIndices.max],
 			args.progress),
 	};
+	const auto oneDay = std::abs(xPercentage[localRangeIndex]
+		- xPercentage[localRangeIndex + ((xIndex == backIndex) ? -1 : 1)]);
+	// Read FindStackXIndicesFromRawXPercentages.
+	const auto offset = (_transition.zoomedInLimitXIndices.max == backIndex)
+		? -oneDay
+		: 0.;
 	const auto resultRange = Limits{
 		InterpolationRatio(
 			_transition.zoomedInLimit.min,
 			_transition.zoomedInLimit.max,
-			_transition.zoomedInRange.min),
+			_transition.zoomedInRange.min + oneDay * 0.25 + offset),
 		InterpolationRatio(
 			_transition.zoomedInLimit.min,
 			_transition.zoomedInLimit.max,
-			_transition.zoomedInRange.max),
+			_transition.zoomedInRange.max + oneDay * 0.75 + offset),
 	};
 	return { true, _transition.zoomedInLimitXIndices, resultRange };
 }