Qt Reference Documentation

# starrating.cpp Example File

itemviews/stardelegate/starrating.cpp

     /****************************************************************************
     **
     ** Copyright (C) 2012 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 <math.h>

     #include "starrating.h"

     const int PaintingScaleFactor = 20;

     StarRating::StarRating(int starCount, int maxStarCount)
     {
         myStarCount = starCount;
         myMaxStarCount = maxStarCount;

         starPolygon << QPointF(1.0, 0.5);
         for (int i = 1; i < 5; ++i)
             starPolygon << QPointF(0.5 + 0.5 * cos(0.8 * i * 3.14),
                                    0.5 + 0.5 * sin(0.8 * i * 3.14));

         diamondPolygon << QPointF(0.4, 0.5) << QPointF(0.5, 0.4)
                        << QPointF(0.6, 0.5) << QPointF(0.5, 0.6)
                        << QPointF(0.4, 0.5);
     }

     QSize StarRating::sizeHint() const
     {
         return PaintingScaleFactor * QSize(myMaxStarCount, 1);
     }

     void StarRating::paint(QPainter *painter, const QRect &rect,
                            const QPalette &palette, EditMode mode) const
     {
         painter->save();

         painter->setRenderHint(QPainter::Antialiasing, true);
         painter->setPen(Qt::NoPen);

         if (mode == Editable) {
             painter->setBrush(palette.highlight());
         } else {
             painter->setBrush(palette.foreground());
         }

         int yOffset = (rect.height() - PaintingScaleFactor) / 2;
         painter->translate(rect.x(), rect.y() + yOffset);
         painter->scale(PaintingScaleFactor, PaintingScaleFactor);

         for (int i = 0; i < myMaxStarCount; ++i) {
             if (i < myStarCount) {
                 painter->drawPolygon(starPolygon, Qt::WindingFill);
             } else if (mode == Editable) {
                 painter->drawPolygon(diamondPolygon, Qt::WindingFill);
             }
             painter->translate(1.0, 0.0);
         }

         painter->restore();
     }