Added Data class for horizontal lines on statistic charts.

Telegram/CMakeLists.txt

@@ -1282,6 +1282,8 @@ PRIVATE
     settings/settings_type.h
     settings/settings_websites.cpp
     settings/settings_websites.h
+    statistics/chart_horizontal_lines_data.cpp
+    statistics/chart_horizontal_lines_data.h
     statistics/segment_tree.cpp
     statistics/segment_tree.h
     statistics/statistics_box.cpp

Telegram/SourceFiles/statistics/chart_horizontal_lines_data.cpp

@@ -0,0 +1,100 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#include "statistics/chart_horizontal_lines_data.h"
+
+#include "lang/lang_tag.h"
+
+namespace Statistic {
+namespace {
+
+constexpr auto kMinLines = int(2);
+constexpr auto kMaxLines = int(6);
+constexpr auto kStep = 5.;
+
+[[nodiscard]] int Round(int maxValue) {
+	const auto k = int(maxValue / kStep);
+	return (k % 10 == 0) ? maxValue : ((maxValue / 10 + 1) * 10);
+}
+
+} // namespace
+
+ChartHorizontalLinesData::ChartHorizontalLinesData(
+		int newMaxHeight,
+		int newMinHeight,
+		bool useMinHeight) {
+	if (!useMinHeight) {
+		const auto v = (newMaxHeight > 100)
+			? Round(newMaxHeight)
+			: newMaxHeight;
+
+		const auto step = std::max(1, int(std::ceil(v / kStep)));
+
+		auto n = kMaxLines;
+		if (v < kMaxLines) {
+			n = std::max(2, v + 1);
+		} else if (v / 2 < kMaxLines) {
+			n = v / 2 + 1;
+			if (v % 2 != 0) {
+				n++;
+			}
+		}
+
+		lines.resize(n);
+
+		for (auto i = 1; i < n; i++) {
+			auto &line = lines[i];
+			line.absoluteValue = i * step;
+			line.caption = Lang::FormatCountToShort(
+				line.absoluteValue).string;
+		}
+	} else {
+		auto n = int(0);
+		const auto diff = newMaxHeight - newMinHeight;
+		auto step = 0.;
+		if (diff == 0) {
+			newMinHeight--;
+			n = kMaxLines / 2;
+			step = 1.;
+		} else if (diff < kMaxLines) {
+			n = std::max(kMinLines, diff + 1);
+			step = 1.;
+		} else if (diff / 2 < kMaxLines) {
+			n = diff / 2 + diff % 2 + 1;
+			step = 2.;
+		} else {
+			step = (newMaxHeight - newMinHeight) / kStep;
+			if (step <= 0) {
+				step = 1;
+				n = std::max(kMinLines, newMaxHeight - newMinHeight + 1);
+			} else {
+				n = 6;
+			}
+		}
+
+		lines.resize(n);
+		const auto diffAbsoluteValue = int((n - 1) * step);
+		for (auto i = 0; i < n; i++) {
+			auto &line = lines[i];
+			const auto value = int(i * step);
+			line.absoluteValue = newMinHeight + value;
+			line.relativeValue = value / float64(diffAbsoluteValue);
+			line.caption = (line.absoluteValue >= 10'000)
+				? Lang::FormatCountToShort(line.absoluteValue).string
+				: QString("%L1").arg(line.absoluteValue);
+		}
+	}
+}
+
+int ChartHorizontalLinesData::LookupHeight(int maxValue) {
+	const auto v = (maxValue > 100) ? Round(maxValue) : maxValue;
+
+	const auto step = int(std::ceil(v / kStep));
+	return step * kStep;
+}
+
+} // namespace Statistic

Telegram/SourceFiles/statistics/chart_horizontal_lines_data.h

@@ -0,0 +1,33 @@
+/*
+This file is part of Telegram Desktop,
+the official desktop application for the Telegram messaging service.
+
+For license and copyright information please follow this link:
+https://github.com/telegramdesktop/tdesktop/blob/master/LEGAL
+*/
+#pragma once
+
+namespace Statistic {
+
+struct ChartHorizontalLinesData final {
+public:
+	ChartHorizontalLinesData(
+		int newMaxHeight,
+		int newMinHeight,
+		bool useMinHeight);
+
+	[[nodiscard]] static int LookupHeight(int maxValue);
+
+	struct Line final {
+		float64 absoluteValue = 0.;
+		float64 relativeValue = 0.;
+		QString caption;
+	};
+
+	std::vector<Line> lines;
+	float64 alpha = 0.;
+	float64 fixedAlpha = 1.;
+
+};
+
+} // namespace Statistic