QlistWidget->clear();

and then reloading the data from the vector.

The problem is if there are selected items in the QListWidget. The selected items must be tracked in the undo/redo operations. I do save the selected items into a QList before clearing the QlistWidget. The problem is re-selecting the item after a redo. Since I clear the list and reload it the QListWidgetItem saved doesn't match the new list so it selects the wrong item in the QListWidget.

I save the selected items by doing the following:

QList<QListWidgetItems*> selectedIndices = QListWidget->selectedItems();

then clear the QListWidget:

QListWidget->clear();

reload the QListWidget and then set the selected items:

for (QListWidgetItems *items : selectedIndices )
{
    QListWidget->setCurrentItem(items);
}