Added initial widget with full zoom static linear chart.

Telegram/SourceFiles/statistics/chart_widget.h

@@ -0,0 +1,55 @@
+/*
+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
+
+#include "data/data_statistics.h"
+#include "statistics/chart_horizontal_lines_data.h"
+#include "ui/effects/animations.h"
+#include "ui/rp_widget.h"
+
+namespace Statistic {
+
+class ChartWidget : public Ui::RpWidget {
+public:
+	ChartWidget(not_null<Ui::RpWidget*> parent);
+
+	struct Limits final {
+		float64 min = 0;
+		float64 max = 0;
+	};
+
+	void setChartData(Data::StatisticalChart chartData);
+	void setHeightLimits(Limits newHeight, bool animated);
+
+protected:
+	void paintEvent(QPaintEvent *e) override;
+
+private:
+	void measureHeightThreshold();
+
+	Data::StatisticalChart _chartData;
+
+	bool _useMinHeight = false;
+
+	Limits _currentHeight;
+	Limits _animateToHeight;
+	Limits _thresholdHeight = { -1, 0 };
+	Limits _startFrom;
+	Limits _startFromH;
+
+	float64 _minMaxUpdateStep = 0.;
+
+	crl::time _lastHeightLimitsChanged = 0;
+
+	std::vector<ChartHorizontalLinesData> _horizontalLines;
+
+	Ui::Animations::Simple _heightLimitsAnimation;
+
+};
+
+} // namespace Statistic