Dropping files from the windows explorer into a subclassed QTreeWidget

[wysota]

You really don't have to touch the event handlers here. All you need is already implemented by the abstract view class -- take a look at its sources, if you don't believe us, for example:

void QAbstractItemView::dragEnterEvent(QDragEnterEvent *event)
{
    if (d_func()->canDecode(event)) {
        event->accept();
        setState(DraggingState);
    } else {
        event->ignore();
    }
}

void QAbstractItemView::dragEnterEvent(QDragEnterEvent *event)
{
    if (d_func()->canDecode(event)) {
        event->accept();
        setState(DraggingState);
    } else {
        event->ignore();
    }
}

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All things you need to reimplement are:

bool QTreeWidget::dropMimeData ( QTreeWidgetItem * parent, int index, const QMimeData * data, Qt:ropAction action ) [virtual protected]
Handles the data supplied by a drag and drop operation that ended with the given action in the index in the given parent item.
See also supportedDropActions().

QStringList QTreeWidget::mimeTypes () const [virtual protected]
Returns a list of MIME types that can be used to describe a list of treewidget items.
See also mimeData().

QMimeData * QTreeWidget::mimeData ( const QList<QTreeWidgetItem *> items ) const [virtual protected]
Returns an object that contains a serialized description of the specified items. The format used to describe the items is obtained from the mimeTypes() function.
If the list of items is empty, 0 is returned rather than a serialized empty list.

First method does the actual drop, second returns a list of mime-types which can be dropped onto the widget (maybe you forgot to implement it -- that's why I asked about that "stop sign" in my previous post) and the last one returns a pointer to an object describing a particular item according to mime-types returned by the previous method.

You can take a look at equivalents of those three methods in the QAbstractItemModel class. And also remember that QTreeWidget is just a wrapper over QTreeView containing an internal model representation. For example:

bool QTreeWidget::dropMimeData(QTreeWidgetItem *parent, int index,
                               const QMimeData *data, Qt::DropAction action)
{
    QModelIndex idx;
    if (parent) idx = indexFromItem(parent);
    return model()->QAbstractItemModel::dropMimeData(data, action , index, 0, idx);
}

bool QTreeWidget::dropMimeData(QTreeWidgetItem *parent, int index,
                               const QMimeData *data, Qt::DropAction action)
{
    QModelIndex idx;
    if (parent) idx = indexFromItem(parent);
    return model()->QAbstractItemModel::dropMimeData(data, action , index, 0, idx);
}

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