bookdelegate.cpp Example File

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  #include "bookdelegate.h"

  #include <QtWidgets>

  BookDelegate::BookDelegate(QObject *parent)
      : QSqlRelationalDelegate(parent), star(QPixmap(":images/star.png"))
  {
  }

  void BookDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option,
                             const QModelIndex &index) const
  {
      if (index.column() != 5) {
          QStyleOptionViewItem opt = option;
          opt.rect.adjust(0, 0, -1, -1); // since we draw the grid ourselves
          QSqlRelationalDelegate::paint(painter, opt, index);
      } else {
          const QAbstractItemModel *model = index.model();
          QPalette::ColorGroup cg = (option.state & QStyle::State_Enabled) ?
              (option.state & QStyle::State_Active) ? QPalette::Normal : QPalette::Inactive : QPalette::Disabled;

          if (option.state & QStyle::State_Selected)
              painter->fillRect(option.rect, option.palette.color(cg, QPalette::Highlight));

          int rating = model->data(index, Qt::DisplayRole).toInt();
          int width = star.width();
          int height = star.height();
          int x = option.rect.x();
          int y = option.rect.y() + (option.rect.height() / 2) - (height / 2);
          for (int i = 0; i < rating; ++i) {
              painter->drawPixmap(x, y, star);
              x += width;
          }
          drawFocus(painter, option, option.rect.adjusted(0, 0, -1, -1)); // since we draw the grid ourselves
      }

      QPen pen = painter->pen();
      painter->setPen(option.palette.color(QPalette::Mid));
      painter->drawLine(option.rect.bottomLeft(), option.rect.bottomRight());
      painter->drawLine(option.rect.topRight(), option.rect.bottomRight());
      painter->setPen(pen);
  }

  QSize BookDelegate::sizeHint(const QStyleOptionViewItem &option,
                                   const QModelIndex &index) const
  {
      if (index.column() == 5)
          return QSize(5 * star.width(), star.height()) + QSize(1, 1);

      return QSqlRelationalDelegate::sizeHint(option, index) + QSize(1, 1); // since we draw the grid ourselves
  }

  bool BookDelegate::editorEvent(QEvent *event, QAbstractItemModel *model,
                                 const QStyleOptionViewItem &option,
                                 const QModelIndex &index)
  {
      if (index.column() != 5)
          return QSqlRelationalDelegate::editorEvent(event, model, option, index);

      if (event->type() == QEvent::MouseButtonPress) {
          QMouseEvent *mouseEvent = static_cast<QMouseEvent*>(event);
          int stars = qBound(0, int(0.7 + qreal(mouseEvent->pos().x()
              - option.rect.x()) / star.width()), 5);
          model->setData(index, QVariant(stars));
          return false; //so that the selection can change
      }

      return true;
  }

  QWidget *BookDelegate::createEditor(QWidget *parent, const QStyleOptionViewItem &option,
                                      const QModelIndex &index) const
  {
      if (index.column() != 4)
          return QSqlRelationalDelegate::createEditor(parent, option, index);

      // for editing the year, return a spinbox with a range from -1000 to 2100.
      QSpinBox *sb = new QSpinBox(parent);
      sb->setFrame(false);
      sb->setMaximum(2100);
      sb->setMinimum(-1000);

      return sb;
  }