dgradientslider.h

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/* ============================================================
 *
 * This file is a part of digiKam project
 * https://www.digikam.org
 *
 * Date        : 2008-07-03
 * Description : a color gradient slider
 *
 * Copyright (C) 2008-2022 by Gilles Caulier <caulier dot gilles at gmail dot com>
 * Copyright (C)      2008 by Cyrille Berger <cberger at cberger dot net>
 *
 * This program is free software; you can redistribute it
 * and/or modify it under the terms of the GNU General
 * Public License as published by the Free Software Foundation;
 * either version 2, or (at your option)
 * any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * ============================================================ */
 
#ifndef DIGIKAM_DGRADIENT_SLIDER_H
#define DIGIKAM_DGRADIENT_SLIDER_H
 
// Qt includes
 
#include <QWidget>
#include <QColor>
 
// Local includes
 
#include "digikam_export.h"
 
namespace Digikam
{
 
class DIGIKAM_EXPORT DGradientSlider : public QWidget
{
    Q_OBJECT
 
public:
 
    explicit DGradientSlider(QWidget* const parent = nullptr);
    ~DGradientSlider() override;
 
    void   showMiddleCursor(bool b);
    double leftValue()      const;
    double rightValue()     const;
    double middleValue()    const;
    int    gradientOffset() const;
 
    void setColors(const QColor& lcolor,
                   const QColor& rcolor);
 
public Q_SLOTS:
 
    void setLeftValue(double);
    void setRightValue(double);
    void setMiddleValue(double);
 
Q_SIGNALS:
 
    void leftValueChanged(double);
    void rightValueChanged(double);
    void middleValueChanged(double);
 
protected:
 
    void paintEvent(QPaintEvent*)        override;
    void mousePressEvent(QMouseEvent*)   override;
    void mouseReleaseEvent(QMouseEvent*) override;
    void mouseMoveEvent(QMouseEvent*)    override;
    void leaveEvent(QEvent*)             override;
 
private:
 
    void adjustMiddleValue(double newLeftValue,
                           double newRightValue);
    inline void drawCursorAt(QPainter& painter,
                             double pos,
                             const QColor& brushColor,
                             int width,
                             int height,
                             int gradientWidth);
 
private:
 
    class Private;
    Private* const d;
};
 
} // namespace Digikam
 
#endif // DIGIKAM_DGRADIENT_SLIDER_H