Qt 5.11 | Qt SQL | Books | bookdelegate.cpp Example File

Qt 5.11.3 Reference Documentation

# bookdelegate.cpp Example File

books/bookdelegate.cpp

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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;
              // Since we draw the grid ourselves:
              opt.rect.adjust(0, 0, -1, -1);
              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;
              }
              // Since we draw the grid ourselves:
              drawFocus(painter, option, option.rect.adjusted(0, 0, -1, -1));
          }

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

      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));
              // So that the selection can change:
              return false;
          }

          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;
      }