Qt Reference Documentation

# pixeldelegate.cpp Example File

itemviews/pixelator/pixeldelegate.cpp

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     #include <QtGui>

     #include "pixeldelegate.h"

     PixelDelegate::PixelDelegate(QObject *parent)
         : QAbstractItemDelegate(parent)
     {
         pixelSize = 12;
     }

     void PixelDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                               const QModelIndex &index) const
     {
         if (option.state & QStyle::State_Selected)
             painter->fillRect(option.rect, option.palette.highlight());

         int size = qMin(option.rect.width(), option.rect.height());
         int brightness = index.model()->data(index, Qt::DisplayRole).toInt();
         double radius = (size/2.0) - (brightness/255.0 * size/2.0);
         if (radius == 0.0)
             return;

         painter->save();
         painter->setRenderHint(QPainter::Antialiasing, true);
         painter->setPen(Qt::NoPen);
         if (option.state & QStyle::State_Selected)
             painter->setBrush(option.palette.highlightedText());
         else
             painter->setBrush(QBrush(Qt::black));

         painter->drawEllipse(QRectF(option.rect.x() + option.rect.width()/2 - radius,
                                     option.rect.y() + option.rect.height()/2 - radius,
                                     2*radius, 2*radius));
         painter->restore();
     }

     QSize PixelDelegate::sizeHint(const QStyleOptionViewItem & /* option */,
                                   const QModelIndex & /* index */) const
     {
         return QSize(pixelSize, pixelSize);
     }

     void PixelDelegate::setPixelSize(int size)
     {
         pixelSize = size;
     }