QTreeWidget - disable dropping on top level

2
votes

I have a QTreeWidget and I enabled the drag and drop. Despite I would like the users to be able to drag and drop items inside the tree I don't want them to drop any dragged item on the top level. How can I do that ?

Let's say that I have predefined categories which are the top level items and I don't want to extend that list. But in the lower levels the user can create any number of items and also she/he can move those items around.

1
c++qt
Without checking I'd guess you need at least to inherit from QTreeView. I've never tried it. Try filtering selectedIndexes() and react to the normal drag events (doc.qt.io/qt-5/examples-draganddrop.html) – Ronny Brendel
Try to use QTreeWidget::invisibleRootItem to get root item and disable Qt::ItemIsDropEnabled flag for it. If this doesn't work, reimplement tree widget's dropMimeData and block dropping if parent is null or invisible root item. – Pavel Strakhov
It will be much easier to use QStandardItemModel + QTreeView for such requests. – Dmitry Sazonov

1 Answers

4
votes

Thanks for the help. It worked.

MyTreeWidget::MyTreeWidget( QWidget* aParent /*= nullptr*/ )
: QTreeWidget( aParent )
{
// ...
    auto rooItem = invisibleRootItem();
    rooItem->setFlags( rooItem->flags() ^ Qt::ItemIsDropEnabled );
}