diff --git a/ui/effects/animation_value.h b/ui/effects/animation_value.h
index 0a7d226..dc5d530 100644
--- a/ui/effects/animation_value.h
+++ b/ui/effects/animation_value.h
@@ -11,6 +11,7 @@
 #include "ui/style/style_core.h"
 
 #include <QtGui/QPainterPath>
+#include <QtGui/QLinearGradient>
 
 namespace anim {
 
@@ -354,4 +355,53 @@ void DrawStaticLoading(
 	QPen pen,
 	QBrush brush = Qt::NoBrush);
 
+class linear_gradient {
+public:
+	linear_gradient(
+		std::vector<QColor> colors_from,
+		std::vector<QColor> colors_to,
+		QPointF point1,
+		QPointF point2)
+	: _colors_from(colors_from)
+	, _colors_to(colors_to)
+	, _point1(point1)
+	, _point2(point2)
+	, _gradient_from(gradient(colors_from))
+	, _gradient_to(gradient(colors_to)) {
+		Expects(colors_from.size() == colors_to.size());
+	}
+
+	QLinearGradient gradient(float64 b_ratio) const {
+		if (b_ratio == 0.) {
+			return _gradient_from;
+		} else if (b_ratio == 1.) {
+			return _gradient_to;
+		}
+		auto colors = std::vector<QColor>(_colors_to.size());
+		for (auto i = 0; i < colors.size(); i++) {
+			colors[i] = color(_colors_from[i], _colors_to[i], b_ratio);
+		}
+		return gradient(colors);
+	}
+
+private:
+	QLinearGradient gradient(const std::vector<QColor> &colors) const {
+		auto gradient = QLinearGradient(_point1, _point2);
+		const auto size = colors.size();
+		for (auto i = 0; i < size; i++) {
+			gradient.setColorAt(i / (size - 1), colors[i]);
+		}
+		return gradient;
+	}
+
+	std::vector<QColor> _colors_from;
+	std::vector<QColor> _colors_to;
+	QPointF _point1;
+	QPointF _point2;
+
+	QLinearGradient _gradient_from;
+	QLinearGradient _gradient_to;
+
 };
+
+} // namespace anim