Drag and drop with QTreeWidget

[JSPoly]

Hi,

I subclassed the code below from QTreeWidget to enable drag and drop. The problem is when i'm draging an item containing childrens, the childrens don't follow the parent on the drop. Is there a problem with mimeData?

Also, is there a way to obtain the index of the parent where I make the drop?

Thanks

void QMyTreeWidget::mouseMoveEvent(QMouseEvent *event)
{
	QModelIndexList liste=selectedIndexes();
	QMimeData *mimeData = model()->mimeData(liste);
	QDrag *drag = new QDrag(this);
	drag->setMimeData(mimeData);
	drag->setHotSpot(event->pos() - rect().topLeft());
	Qt::DropAction dropAction = drag->start( Qt::MoveAction);
	if (dropAction == Qt::MoveAction) {
		model()->removeRows(liste[0].row(),liste.size(),liste[0].parent());
	}
} 
 
 
void QMyTreeWidget::dropEvent(QDropEvent *e)
{
	QTreeWidget::dropEvent(e);
	e->setDropAction(Qt::MoveAction);
	e->accept();
}

void QMyTreeWidget::mouseMoveEvent(QMouseEvent *event)
{
	QModelIndexList liste=selectedIndexes();
	QMimeData *mimeData = model()->mimeData(liste);
	QDrag *drag = new QDrag(this);
	drag->setMimeData(mimeData);
	drag->setHotSpot(event->pos() - rect().topLeft());
	Qt::DropAction dropAction = drag->start( Qt::MoveAction);
	if (dropAction == Qt::MoveAction) {
		model()->removeRows(liste[0].row(),liste.size(),liste[0].parent());
	}
} 


void QMyTreeWidget::dropEvent(QDropEvent *e)
{
	QTreeWidget::dropEvent(e);
	e->setDropAction(Qt::MoveAction);
	e->accept();
}

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[jpn]

Is there any valid reason for implementing custom drag'n'drop? QTreeWidget supports drag'n'drop out of the box: Using Drag and Drop with Item Views - Using Convenience Views

[JSPoly]

Yes, I want to use the move action without using the atl key. The default drag and drop action is copy.

[wysota]

Your drop doesn't handle any moving. First you call the base class and then when the event is already handled you change its type.

[JSPoly]

Ok, so what is the good way to do it? Any example?

[wysota]

The best way to do it is to move the items yourself, if you have to reimplement the handler... If the default handler doesn't include children then you either need to change the drag to include children or change the drop to include children. Changing the action itself isn't enough, it'll just make the source remove the item it had placed into the drag (without children).