tabletcanvas.h Example File

 /****************************************************************************
 **
 ** Copyright (C) 2012 Nokia Corporation and/or its subsidiary(-ies).
 ** Contact: http://www.qt-project.org/
 **
 ** This file is part of the examples of the Qt Toolkit.
 **
 ** $QT_BEGIN_LICENSE:BSD$
 ** 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 Nokia Corporation and its Subsidiary(-ies) 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 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 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];
 };

 #endif