gradients.h Example File | Qt Widgets 5.12.7

Qt 5.12 | Qt Widgets | Gradients | gradients.h Example File

Qt 5.12.7 Reference Documentation

# gradients.h Example File

painting/gradients/gradients.h

      /****************************************************************************
      **
      ** Copyright (C) 2016 The Qt Company Ltd.
      ** Contact: https://www.qt.io/licensing/
      **
      ** This file is part of the demonstration applications of the Qt Toolkit.
      **
      ** $QT_BEGIN_LICENSE:BSD$
      ** Commercial License Usage
      ** Licensees holding valid commercial Qt licenses may use this file in
      ** accordance with the commercial license agreement provided with the
      ** Software or, alternatively, in accordance with the terms contained in
      ** a written agreement between you and The Qt Company. For licensing terms
      ** and conditions see https://www.qt.io/terms-conditions. For further
      ** information use the contact form at https://www.qt.io/contact-us.
      **
      ** BSD License Usage
      ** Alternatively, you may use this file under the terms of the BSD license
      ** as follows:
      **
      ** "Redistribution and use in source and binary forms, with or without
      ** modification, are permitted provided that the following conditions are
      ** met:
      **   * Redistributions of source code must retain the above copyright
      **     notice, this list of conditions and the following disclaimer.
      **   * Redistributions in binary form must reproduce the above copyright
      **     notice, this list of conditions and the following disclaimer in
      **     the documentation and/or other materials provided with the
      **     distribution.
      **   * Neither the name of The Qt Company Ltd nor the names of its
      **     contributors may be used to endorse or promote products derived
      **     from this software without specific prior written permission.
      **
      **
      ** THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
      ** "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
      ** LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
      ** A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
      ** OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
      ** SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
      ** LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
      ** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
      ** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
      ** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
      ** OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE."
      **
      ** $QT_END_LICENSE$
      **
      ****************************************************************************/

      #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) override;

          QSize sizeHint() const 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) override;

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

          HoverPoints *hoverPoints() const { return m_hoverPoints; }
          void mousePressEvent(QMouseEvent *e) 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); }
          void setPreset()     { changePresetBy(0); }
          void setPrevPreset() { changePresetBy(-1); }
          void setNextPreset() { changePresetBy(1); }

      private:
          void setDefault(int i);
          void updatePresetName();
          void changePresetBy(int indexOffset);

          GradientRenderer *m_renderer;
          GradientEditor *m_editor;

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

          int m_presetIndex = 0;
      };

      #endif // GRADIENTS_H