Qt 4.8: gradients.h Example File (demos/gradients/gradients.h)

Qt Reference Documentation

# gradients.h Example File

demos/gradients/gradients.h

     /****************************************************************************
     **
     ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
     ** All rights reserved.
     ** Contact: Nokia Corporation (qt-info@nokia.com)
     **
     ** This file is part of the demonstration applications of the Qt Toolkit.
     **
     ** $QT_BEGIN_LICENSE:LGPL$
     ** GNU Lesser General Public License Usage
     ** This file may be used under the terms of the GNU Lesser General Public
     ** License version 2.1 as published by the Free Software Foundation and
     ** appearing in the file LICENSE.LGPL included in the packaging of this
     ** file. Please review the following information to ensure the GNU Lesser
     ** General Public License version 2.1 requirements will be met:
     ** http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
     **
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     ** rights. These rights are described in the Nokia Qt LGPL Exception
     ** version 1.1, included in the file LGPL_EXCEPTION.txt in this package.
     **
     ** GNU General Public License Usage
     ** Alternatively, this file may be used under the terms of the GNU General
     ** Public License version 3.0 as published by the Free Software Foundation
     ** and appearing in the file LICENSE.GPL included in the packaging of this
     ** file. Please review the following information to ensure the GNU General
     ** Public License version 3.0 requirements will be met:
     ** http://www.gnu.org/copyleft/gpl.html.
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     ** Alternatively, this file may be used in accordance with the terms and
     ** conditions contained in a signed written agreement between you and Nokia.
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     ****************************************************************************/

     #ifndef GRADIENTS_H
     #define GRADIENTS_H

     #include "arthurwidgets.h"

     #include <QtGui>

     class HoverPoints;

     class ShadeWidget : public QWidget
     {
         Q_OBJECT
     public:
         enum ShadeType {
             RedShade,
             GreenShade,
             BlueShade,
             ARGBShade
         };

         ShadeWidget(ShadeType type, QWidget *parent);

         void setGradientStops(const QGradientStops &stops);

         void paintEvent(QPaintEvent *e);

         QSize sizeHint() const { return QSize(150, 40); }
         QPolygonF points() const;

         HoverPoints *hoverPoints() const { return m_hoverPoints; }

         uint colorAt(int x);

     signals:
         void colorsChanged();

     private:
         void generateShade();

         ShadeType m_shade_type;
         QImage m_shade;
         HoverPoints *m_hoverPoints;
         QLinearGradient m_alpha_gradient;
     };

     class GradientEditor : public QWidget
     {
         Q_OBJECT
     public:
         GradientEditor(QWidget *parent);

         void setGradientStops(const QGradientStops &stops);

     public slots:
         void pointsUpdated();

     signals:
         void gradientStopsChanged(const QGradientStops &stops);

     private:
         ShadeWidget *m_red_shade;
         ShadeWidget *m_green_shade;
         ShadeWidget *m_blue_shade;
         ShadeWidget *m_alpha_shade;
     };

     class GradientRenderer : public ArthurFrame
     {
         Q_OBJECT
     public:
         GradientRenderer(QWidget *parent);
         void paint(QPainter *p);

         QSize sizeHint() const { return QSize(400, 400); }

         HoverPoints *hoverPoints() const { return m_hoverPoints; }
         void mousePressEvent(QMouseEvent *e);

     public slots:
         void setGradientStops(const QGradientStops &stops);

         void setPadSpread() { m_spread = QGradient::PadSpread; update(); }
         void setRepeatSpread() { m_spread = QGradient::RepeatSpread; update(); }
         void setReflectSpread() { m_spread = QGradient::ReflectSpread; update(); }

         void setLinearGradient() { m_gradientType = Qt::LinearGradientPattern; update(); }
         void setRadialGradient() { m_gradientType = Qt::RadialGradientPattern; update(); }
         void setConicalGradient() { m_gradientType = Qt::ConicalGradientPattern; update(); }

     private:
         QGradientStops m_stops;
         HoverPoints *m_hoverPoints;

         QGradient::Spread m_spread;
         Qt::BrushStyle m_gradientType;
     };

     class GradientWidget : public QWidget
     {
         Q_OBJECT
     public:
         GradientWidget(QWidget *parent);

     public slots:
         void setDefault1() { setDefault(1); }
         void setDefault2() { setDefault(2); }
         void setDefault3() { setDefault(3); }
         void setDefault4() { setDefault(4); }

     private:
         void setDefault(int i);

         GradientRenderer *m_renderer;
         GradientEditor *m_editor;

         QRadioButton *m_linearButton;
         QRadioButton *m_radialButton;
         QRadioButton *m_conicalButton;
         QRadioButton *m_padSpreadButton;
         QRadioButton *m_reflectSpreadButton;
         QRadioButton *m_repeatSpreadButton;

     };

     #endif // GRADIENTS_H