QTreeView, Qt::ItemIsEditable and Double-Clicking Issues.

[webzoid]

I have a QTreeView in which certain items are in-place editable and others are not.

Those items which are editable return the Qt::ItemIsEditable flag and those which are not do not return this flag as part of the Qt::ItemFlags <class>::flags(const QModelIndex &index) const overridden. The items which are not editable have a pop-up dialog which is displayed as part of the QTreeView::doubleClicked(QModelIndex) signal.

So, the issue I'm having is that initially, if I double-click on any of the Qt::ItemIsEditable items and edit them in-place, all is well. As soon as I double-click on a non Qt::ItemIsEditable item, see the dialog and then close it again, the in-place editing system stops working.

UPDATE

In fact, all in-place edit triggers stop working if a non-editable item is double-clicked. I've tried overriding the mouseDoubleClicked function in my subclassed QTreeView but still no joy.

[webzoid]

Ok, so I've narrowed the issue down to the qabstractitemview.cpp file and specifically, the function below.

When I attempt to edit a Qt::ItemIsEditable item first, the w = delegate->createEditor(viewport, options, index); call from below returns a QLineEdit widget and the in-place editing works. If I then edit an item which shows a dialog, then go back and attempt to edit another Qt::ItemIsEditable item, the next time this w = delegate->createEditor(viewport, options, index); is called, the result is that w is null yet the parameters passed into the createEditor function appear to be identical.

The search continues...

QWidget *QAbstractItemViewPrivate::editor(const QModelIndex &index,
                                          const QStyleOptionViewItem &options)
{
    Q_Q(QAbstractItemView);
    QWidget *w = editorForIndex(index).widget.data();
    if (!w) {
        QAbstractItemDelegate *delegate = delegateForIndex(index);
        if (!delegate)
            return 0;
        w = delegate->createEditor(viewport, options, index);
        if (w) {
            w->installEventFilter(delegate);
            QObject::connect(w, SIGNAL(destroyed(QObject*)), q, SLOT(editorDestroyed(QObject*)));
            delegate->updateEditorGeometry(w, options, index);
            delegate->setEditorData(w, index);
            addEditor(index, w, false);
            if (w->parent() == viewport)
                QWidget::setTabOrder(q, w);

            // Special cases for some editors containing QLineEdit
            QWidget *focusWidget = w;
            while (QWidget *fp = focusWidget->focusProxy())
                focusWidget = fp;
#if QT_CONFIG(lineedit)
            if (QLineEdit *le = qobject_cast<QLineEdit*>(focusWidget))
                le->selectAll();
#endif
#if QT_CONFIG(spinbox)
            if (QSpinBox *sb = qobject_cast<QSpinBox*>(focusWidget))
                sb->selectAll();
            else if (QDoubleSpinBox *dsb = qobject_cast<QDoubleSpinBox*>(focusWidget))
                dsb->selectAll();
#endif
        }
    }

    return w;
}

[webzoid]

RESOLVED

As it turns out, the dialog I was showing had a custom QWidget with its own custom editor and I was calling QItemEditorFactory::setDefaultFactory in the widgets constructor.

Calling QItemEditorFactory::setDefaultFactory(nullptr) in the destructor for this widget resolves the problem - the QTreeView item in-place editor continues to work regardless of whether I open a dialog.