Qt 5.6 | Qt Widgets | Gradients | gradients.h Example File

Qt 5.6.2 Reference Documentation

# gradients.h Example File

painting/gradients/gradients.h

      /****************************************************************************
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      ** Contact: http://www.qt.io/licensing/
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      ** This file is part of the demonstration applications of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:LGPL21$
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      ** Alternatively, this file may be used under the terms of the GNU Lesser
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      #ifndef GRADIENTS_H
      #define GRADIENTS_H

      #include "arthurwidgets.h"

      class QRadioButton;

      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) Q_DECL_OVERRIDE;

          QSize sizeHint() const Q_DECL_OVERRIDE { 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) Q_DECL_OVERRIDE;

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

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

      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