Qt 5.11 | Qt Widgets | Tablet Example | tabletcanvas.h Example File

Qt 5.11.3 Reference Documentation

# tabletcanvas.h Example File

widgets/tablet/tabletcanvas.h

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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