From 658db59aafd16ead0e54775a0a432398492c5e11 Mon Sep 17 00:00:00 2001
From: 23rd <23rd@vivaldi.net>
Date: Mon, 10 Jul 2023 04:06:49 +0300
Subject: [PATCH] Replace Simple with Basic for animation of chart y-axis
 captions.

---
 .../SourceFiles/statistics/chart_widget.cpp   | 60 ++++++++++++-------
 .../SourceFiles/statistics/chart_widget.h     |  8 ++-
 2 files changed, 44 insertions(+), 24 deletions(-)

diff --git a/Telegram/SourceFiles/statistics/chart_widget.cpp b/Telegram/SourceFiles/statistics/chart_widget.cpp
index 17730099b..909693612 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.cpp
+++ b/Telegram/SourceFiles/statistics/chart_widget.cpp
@@ -382,9 +382,16 @@ void ChartWidget::ChartAnimationController::resetAlpha() {
 	_animValueYAlpha = anim::value(0., 1.);
 }
 
+void ChartWidget::ChartAnimationController::restartBottomLineAlpha() {
+	_bottomLineAlphaAnimationStartedAt = crl::now();
+	_animValueBottomLineAlpha = anim::value(0., 1.);
+	start();
+}
+
 void ChartWidget::ChartAnimationController::tick(
 		crl::time now,
-		std::vector<ChartHorizontalLinesData> &horizontalLines) {
+		std::vector<ChartHorizontalLinesData> &horizontalLines,
+		std::vector<BottomCaptionLineData> &dateLines) {
 	if (!_animation.animating()) {
 		return;
 	}
@@ -409,6 +416,9 @@ void ChartWidget::ChartAnimationController::tick(
 	const auto dtAlpha = std::min(
 		(now - _alphaAnimationStartedAt) / kAlphaExpandingDuration,
 		1.);
+	const auto dtBottomLineAlpha = std::min(
+		(now - _bottomLineAlphaAnimationStartedAt) / kAlphaExpandingDuration,
+		1.);
 
 	const auto isFinished = [](const anim::value &anim) {
 		return anim.current() == anim.to();
@@ -419,8 +429,10 @@ void ChartWidget::ChartAnimationController::tick(
 	const auto yFinished = isFinished(_animationValueHeightMin)
 		&& isFinished(_animationValueHeightMax);
 	const auto alphaFinished = isFinished(_animValueYAlpha);
+	const auto bottomLineAlphaFinished = isFinished(
+		_animValueBottomLineAlpha);
 
-	if (xFinished && yFinished && alphaFinished) {
+	if (xFinished && yFinished && alphaFinished && bottomLineAlphaFinished) {
 		const auto &lines = horizontalLines.back().lines;
 		if ((lines.front().absoluteValue == _animationValueHeightMin.to())
 			&& lines.back().absoluteValue == _animationValueHeightMax.to()) {
@@ -434,6 +446,14 @@ void ChartWidget::ChartAnimationController::tick(
 		_animationValueXMin.update(dtX, anim::linear);
 		_animationValueXMax.update(dtX, anim::linear);
 	}
+	if (bottomLineAlphaFinished) {
+		_animValueBottomLineAlpha.finish();
+		_bottomLineAlphaAnimationStartedAt = 0;
+	} else {
+		_animValueBottomLineAlpha.update(
+			dtBottomLineAlpha,
+			anim::easeInCubic);
+	}
 	if (_heightAnimationStarted) {
 		_animationValueHeightMin.update(_dtCurrent.min, anim::easeInCubic);
 		_animationValueHeightMax.update(_dtCurrent.max, anim::easeInCubic);
@@ -465,6 +485,20 @@ void ChartWidget::ChartAnimationController::tick(
 		}
 	}
 
+	if (!bottomLineAlphaFinished) {
+		const auto value = _animValueBottomLineAlpha.current();
+		for (auto &date : dateLines) {
+			date.alpha = (1. - value) * date.fixedAlpha;
+		}
+		dateLines.back().alpha = value;
+	} else {
+		if (dateLines.size() > 1) {
+			const auto data = dateLines.back();
+			dateLines.clear();
+			dateLines.push_back(data);
+		}
+	}
+
 	if (yFinished && alphaFinished) {
 		_alphaAnimationStartedAt = 0;
 		_heightAnimationStarted = false;
@@ -550,7 +584,7 @@ void ChartWidget::setupChartArea() {
 
 		const auto now = crl::now();
 
-		_animationController.tick(now, _horizontalLines);
+		_animationController.tick(now, _horizontalLines, _bottomLine.dates);
 
 		const auto chartRect = chartAreaRect();
 
@@ -638,10 +672,6 @@ void ChartWidget::updateBottomDates() {
 		return;
 	}
 
-	if (_bottomLine.animation.animating()) {
-		_bottomLine.animation.stop();
-	}
-
 	constexpr auto kStepRatio = 0.2;
 	const auto stepMax = int(step + step * kStepRatio);
 	const auto stepMin = int(step - step * kStepRatio);
@@ -670,21 +700,7 @@ void ChartWidget::updateBottomDates() {
 		_bottomLine.dates.erase(begin(_bottomLine.dates));
 	}
 
-	_bottomLine.animation.start(
-		[=](float64 value) {
-			for (auto &date : _bottomLine.dates) {
-				date.alpha = (1. - value) * date.fixedAlpha;
-			}
-			_bottomLine.dates.back().alpha = value;
-			if (value >= 1.) {
-				_bottomLine.dates.clear();
-				_bottomLine.dates.push_back(data);
-			}
-			_chartArea->update();
-		},
-		0.,
-		1.,
-		200);
+	_animationController.restartBottomLineAlpha();
 }
 
 void ChartWidget::setupFooter() {
diff --git a/Telegram/SourceFiles/statistics/chart_widget.h b/Telegram/SourceFiles/statistics/chart_widget.h
index b45de16a2..1880a5e7f 100644
--- a/Telegram/SourceFiles/statistics/chart_widget.h
+++ b/Telegram/SourceFiles/statistics/chart_widget.h
@@ -48,9 +48,11 @@ private:
 		void start();
 		void finish();
 		void resetAlpha();
+		void restartBottomLineAlpha();
 		void tick(
 			crl::time now,
-			std::vector<ChartHorizontalLinesData> &horizontalLines);
+			std::vector<ChartHorizontalLinesData> &horizontalLines,
+			std::vector<BottomCaptionLineData> &dateLines);
 
 		[[nodiscard]] Limits currentXLimits() const;
 		[[nodiscard]] Limits finalXLimits() const;
@@ -66,6 +68,7 @@ private:
 
 		crl::time _lastUserInteracted = 0;
 		crl::time _alphaAnimationStartedAt = 0;
+		crl::time _bottomLineAlphaAnimationStartedAt = 0;
 		bool _heightAnimationStarted = false;
 
 		anim::value _animationValueXMin;
@@ -75,6 +78,8 @@ private:
 
 		anim::value _animValueYAlpha;
 
+		anim::value _animValueBottomLineAlpha;
+
 		Limits _finalHeightLimits;
 
 		float _dtHeightSpeed = 0.;
@@ -104,7 +109,6 @@ private:
 	struct {
 		BottomCaptionLineData current;
 		std::vector<BottomCaptionLineData> dates;
-		Ui::Animations::Simple animation;
 		int chartFullWidth = 0;
 	} _bottomLine;