renderarea.cpp Example File

 /****************************************************************************
 **
 ** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies).
 ** All rights reserved.
 ** Contact: Nokia Corporation (qt-info@nokia.com)
 **
 ** 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."
 ** $QT_END_LICENSE$
 **
 ****************************************************************************/

 #include <QtGui>

 #include "renderarea.h"

 RenderArea::RenderArea(QWidget *parent)
     : QWidget(parent)
 {
     shape = Polygon;
     antialiased = false;
     transformed = false;
     pixmap.load(":/images/qt-logo.png");

     setBackgroundRole(QPalette::Base);
     setAutoFillBackground(true);
 }

 QSize RenderArea::minimumSizeHint() const
 {
     return QSize(100, 100);
 }

 QSize RenderArea::sizeHint() const
 {
     return QSize(400, 200);
 }

 void RenderArea::setShape(Shape shape)
 {
     this->shape = shape;
     update();
 }

 void RenderArea::setPen(const QPen &pen)
 {
     this->pen = pen;
     update();
 }

 void RenderArea::setBrush(const QBrush &brush)
 {
     this->brush = brush;
     update();
 }

 void RenderArea::setAntialiased(bool antialiased)
 {
     this->antialiased = antialiased;
     update();
 }

 void RenderArea::setTransformed(bool transformed)
 {
     this->transformed = transformed;
     update();
 }

 void RenderArea::paintEvent(QPaintEvent * /* event */)
 {
     static const QPoint points[4] = {
         QPoint(10, 80),
         QPoint(20, 10),
         QPoint(80, 30),
         QPoint(90, 70)
     };

     QRect rect(10, 20, 80, 60);

     QPainterPath path;
     path.moveTo(20, 80);
     path.lineTo(20, 30);
     path.cubicTo(80, 0, 50, 50, 80, 80);

     int startAngle = 20 * 16;
     int arcLength = 120 * 16;

     QPainter painter(this);
     painter.setPen(pen);
     painter.setBrush(brush);
     if (antialiased)
         painter.setRenderHint(QPainter::Antialiasing, true);

     for (int x = 0; x < width(); x += 100) {
         for (int y = 0; y < height(); y += 100) {
             painter.save();
             painter.translate(x, y);
             if (transformed) {
                 painter.translate(50, 50);
                 painter.rotate(60.0);
                 painter.scale(0.6, 0.9);
                 painter.translate(-50, -50);
             }

             switch (shape) {
             case Line:
                 painter.drawLine(rect.bottomLeft(), rect.topRight());
                 break;
             case Points:
                 painter.drawPoints(points, 4);
                 break;
             case Polyline:
                 painter.drawPolyline(points, 4);
                 break;
             case Polygon:
                 painter.drawPolygon(points, 4);
                 break;
             case Rect:
                 painter.drawRect(rect);
                 break;
             case RoundedRect:
                 painter.drawRoundedRect(rect, 25, 25, Qt::RelativeSize);
                 break;
             case Ellipse:
                 painter.drawEllipse(rect);
                 break;
             case Arc:
                 painter.drawArc(rect, startAngle, arcLength);
                 break;
             case Chord:
                 painter.drawChord(rect, startAngle, arcLength);
                 break;
             case Pie:
                 painter.drawPie(rect, startAngle, arcLength);
                 break;
             case Path:
                 painter.drawPath(path);
                 break;
             case Text:
                 painter.drawText(rect, Qt::AlignCenter, tr("Qt by\nNokia"));
                 break;
             case Pixmap:
                 painter.drawPixmap(10, 10, pixmap);
             }
             painter.restore();
         }
     }

     painter.setRenderHint(QPainter::Antialiasing, false);
     painter.setPen(palette().dark().color());
     painter.setBrush(Qt::NoBrush);
     painter.drawRect(QRect(0, 0, width() - 1, height() - 1));
 }