tabletcanvas.h Example File

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  #ifndef TABLETCANVAS_H
  #define TABLETCANVAS_H

  #include <QWidget>
  #include <QPixmap>
  #include <QPoint>
  #include <QTabletEvent>
  #include <QColor>
  #include <QBrush>
  #include <QPen>
  #include <QPoint>

  class QPaintEvent;
  class QString;

  class TabletCanvas : public QWidget
  {
      Q_OBJECT

  public:
      enum Valuator { PressureValuator, TangentialPressureValuator,
                      TiltValuator, VTiltValuator, HTiltValuator, NoValuator };
      Q_ENUM(Valuator)

      TabletCanvas();

      bool saveImage(const QString &file);
      bool loadImage(const QString &file);
      void setAlphaChannelValuator(Valuator type)
          { m_alphaChannelValuator = type; }
      void setColorSaturationValuator(Valuator type)
          { m_colorSaturationValuator = type; }
      void setLineWidthType(Valuator type)
          { m_lineWidthValuator = type; }
      void setColor(const QColor &c)
          { if (c.isValid()) m_color = c; }
      QColor color() const
          { return m_color; }
      void setTabletDevice(QTabletEvent *event)
          { updateCursor(event); }
      int maximum(int a, int b)
          { return a > b ? a : b; }

  protected:
      void tabletEvent(QTabletEvent *event) override;
      void paintEvent(QPaintEvent *event) override;
      void resizeEvent(QResizeEvent *event) override;

  private:
      void initPixmap();
      void paintPixmap(QPainter &painter, QTabletEvent *event);
      Qt::BrushStyle brushPattern(qreal value);
      static qreal pressureToWidth(qreal pressure);
      void updateBrush(const QTabletEvent *event);
      void updateCursor(const QTabletEvent *event);

      Valuator m_alphaChannelValuator;
      Valuator m_colorSaturationValuator;
      Valuator m_lineWidthValuator;
      QColor m_color;
      QPixmap m_pixmap;
      QBrush m_brush;
      QPen m_pen;
      bool m_deviceDown;

      struct Point {
          QPointF pos;
          qreal pressure;
          qreal rotation;
      } lastPoint;
  };

  #endif