starrating.cpp Example File | Qt Widgets 5.12.11

- Qt 5.12
- Qt Widgets
- Star Delegate Example
- starrating.cpp Example File
- Qt 5.12.11 Reference Documentation

# starrating.cpp Example File

itemviews/stardelegate/starrating.cpp

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     #include <QtWidgets>
     #include <cmath>

     #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 * std::cos(0.8 * i * 3.14),
                                    0.5 + 0.5 * std::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();
     }