diff --git a/src/scrollbar.h b/src/scrollbar.h
new file mode 100644
--- /dev/null
+++ b/src/scrollbar.h
@@ -0,0 +1,62 @@
+/*
+  Copyright © 2014 Uwe Rathmann
+
+  This file is copied from Qwt project; you can redistribute it and/or modify it
+  under the terms of the Qwt License, Version 1.0. You can obtain the original
+  source code and the details of the Qwt License from the Qwt website:
+  http://qwt.sourceforge.net/
+*/
+
+#ifndef _SCROLLBAR_H
+#define _SCROLLBAR_H 1
+
+#include <qscrollbar.h>
+
+class ScrollBar: public QScrollBar
+{
+    Q_OBJECT
+
+public:
+    ScrollBar( QWidget *parent = NULL );
+    ScrollBar( Qt::Orientation, QWidget *parent = NULL );
+    ScrollBar( double minBase, double maxBase,
+        Qt::Orientation o, QWidget *parent = NULL );
+
+    void setInverted( bool );
+    bool isInverted() const;
+
+    double minBaseValue() const;
+    double maxBaseValue() const;
+
+    double minSliderValue() const;
+    double maxSliderValue() const;
+
+    int extent() const;
+
+Q_SIGNALS:
+    void sliderMoved( Qt::Orientation, double, double );
+    void valueChanged( Qt::Orientation, double, double );
+
+public Q_SLOTS:
+    virtual void setBase( double min, double max );
+    virtual void moveSlider( double min, double max );
+
+protected:
+    void sliderRange( int value, double &min, double &max ) const;
+    int mapToTick( double ) const;
+    double mapFromTick( int ) const;
+
+private Q_SLOTS:
+    void catchValueChanged( int value );
+    void catchSliderMoved( int value );
+
+private:
+    void init();
+
+    bool d_inverted;
+    double d_minBase;
+    double d_maxBase;
+    int d_baseTicks;
+};
+
+#endif