AddRemoveList

This is my Qt project demonstrating how to do add/remove with two list panel views. What I learned from this project are

• How to do model/view
• Moving items between views
• Drap/drop reorder
• Installing event filter
• Connect SIGNAL/SLOT
• Use QModelIndex
• Return item from selected view and back to its original order

Here is my idea of handling drag/drop reorder action.

1. In the constructor

// Enable drag/drop
ui->_listView->setSelectionMode(QAbstractItemView::ExtendedSelection);
ui->_listView->setDragDropOverwriteMode(false);
ui->_listView->setDragDropMode(QAbstractItemView::DragDrop);
ui->_listView->setDefaultDropAction(Qt::MoveAction);
ui->_listView->setMovement(QListView::Snap);
// Install a event filter to the QListView::viewport()
ui->_listView->viewport()->installEventFilter(this);

2. Because the default QStandardItem has Qt::ItemIsDropEnable flag set, we have to switch it off. So at the method which you create the items

QStandardItem* item = new QStandardItem();
item->setFlags(selectedItem->flags() ^ (Qt::ItemIsDropEnabled));

3. Handle the dropEvent() with the event filter. For example:

bool MyWidget::eventFilter(QObject *object, QEvent *event) {
    if (object == ui->_listView->viewport() && event->type() == QEvent::Drop) {
        // Do something when the event fired
    }
    return QObject::eventFilter(object, event);
}

4. Implement SIGNAL/SLOT for the QStandardItemModel::itemChangeCheck(), QStandardItemModel::rowsInserted(), or QStandardItemModel::rowsRemoved() if necessary as those signals would be triggered by the Drag/Drop action.