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  1. Qt
  2. QTBUG-97953

Custom QItemDelegate does not work properly with Qt 6.2.1

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Details

    • Bug
    • Resolution: Duplicate
    • P1: Critical
    • None
    • 6.2.1
    • Widgets: Itemviews
    • None
    • macOS

    Description

      Custom QItemDelegate (i.e. shown in table or list view rows) do not correctly paint in macOS but work fine on other platforms. Painting works as expected with Qt 5.15

      The following code demonstrates the problem (copied from https://forum.qt.io/topic/123889/problems-with-qsytyleditemdelegate-and-qstyleoptionprogressbar-on-macos):

      #include <QtWidgets>
      #include <QTimer>
      
      class Delegate final
        : public QStyledItemDelegate
      {
      public:
        explicit Delegate (QObject * parent = nullptr)
          : QStyledItemDelegate {parent}
        {
        }
      
        void paint (QPainter * painter, QStyleOptionViewItem const& option
                    , QModelIndex const& index) const
        {
          QStyleOptionProgressBar progress_bar_option;
          progress_bar_option.rect = option.rect;
          progress_bar_option.state = QStyle::State_Enabled;
          progress_bar_option.direction = QApplication::layoutDirection ();
          progress_bar_option.fontMetrics = QApplication::fontMetrics ();
          progress_bar_option.minimum = 0;
          progress_bar_option.maximum = 100;
          auto progress = index.data ().toLongLong ();
          auto percent = int (progress * 100 / index.data (Qt::UserRole).toLongLong ());
          progress_bar_option.progress = percent;
          progress_bar_option.text = QString::number (percent) + '%';
          progress_bar_option.textVisible = true;
          progress_bar_option.textAlignment = Qt::AlignCenter;
          QApplication::style ()->drawControl (QStyle::CE_ProgressBar, &progress_bar_option, painter);
        }
      };
      
      int main (int argc, char * argv[])
      {
        QApplication a {argc, argv};
        QListWidget w;
        Delegate d;
        w.setItemDelegate (&d);
        QListWidgetItem i1 {"Item 1"};
        i1.setData (Qt::UserRole, 100);
        w.addItem (&i1);
        QListWidgetItem i2 {"Item 2"};
        w.addItem (&i2);
        i2.setData (Qt::UserRole, 100);
        w.show ();
        QTimer t;
        qint64 n1 {0};
        qint64 n2 {0};
        t.callOnTimeout ([&] {
                           i1.setData (Qt::DisplayRole, (n1 += 2));
                           i2.setData (Qt::DisplayRole, (n2 += 10));
                          });
        t.start (1000);
        QObject::connect (&a, &QApplication::lastWindowClosed, &a, &QApplication::quit);
        return a.exec ();
      }
      

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              vhilshei Volker Hilsheimer
              DanielSt Peter Staab
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              Dates

                Created:
                Updated:
                Resolved:

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