qt5base-lts/examples/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>

QT_BEGIN_NAMESPACE
class QPaintEvent;
class QString;
QT_END_NAMESPACE

//! [0]
class TabletCanvas : public QWidget
{
    Q_OBJECT

public:
    enum AlphaChannelType { AlphaPressure, AlphaTilt, NoAlpha };
    enum ColorSaturationType { SaturationVTilt, SaturationHTilt,
                               SaturationPressure, NoSaturation };
    enum LineWidthType { LineWidthPressure, LineWidthTilt, NoLineWidth };

    TabletCanvas();

    bool saveImage(const QString &file);
    bool loadImage(const QString &file);
    void setAlphaChannelType(AlphaChannelType type)
        { alphaChannelType = type; }
    void setColorSaturationType(ColorSaturationType type)
        { colorSaturationType = type; }
    void setLineWidthType(LineWidthType type)
        { lineWidthType = type; }
    void setColor(const QColor &color)
        { myColor = color; }
    QColor color() const
        { return myColor; }
    void setTabletDevice(QTabletEvent::TabletDevice device)
        { myTabletDevice = device; }
    int maximum(int a, int b)
        { return a > b ? a : b; }

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

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

    AlphaChannelType alphaChannelType;
    ColorSaturationType colorSaturationType;
    LineWidthType lineWidthType;
    QTabletEvent::PointerType pointerType;
    QTabletEvent::TabletDevice myTabletDevice;
    QColor myColor;

    QPixmap pixmap;
    QBrush myBrush;
    QPen myPen;
    bool deviceDown;
    QPoint polyLine[3];
};
//! [0]

#endif