QTreeWidget loses selection while moving items down

[kei]

Hi,
i have a treewidget with items which i want to move up and down when pressing a key or button. The function "MoveUp" works fine but while using "MoveDown" it happens often (mostly after the first move downwards) that some of the selected items/rows (sometimes the first and last keep selected and sometimes one or two randomly) lose their selection.

Working moveUp():

void MainWindow::moveUp()
{
	QList<QTreeWidgetItem *> selectedItems = ui->treeWidget->selectedItems();
 
	if ( selectedItems.isEmpty())
		return;
 
	// If selection has the first line the items are on the top -> return
	int row = ui->treeWidget->indexOfTopLevelItem( selectedItems.first() );
	if ( row == 0 )
		return;
 
	QTreeWidgetItem *itemAbove;
	QListIterator<QTreeWidgetItem *> it( selectedItems );
 
	while ( it.hasNext() )
	{
		row = ui->treeWidget->indexOfTopLevelItem( it.next() );
		itemAbove = ui->treeWidget->takeTopLevelItem( row - 1 );
		ui->treeWidget->insertTopLevelItem( row, itemAbove );
	}
}

void MainWindow::moveUp()
{
	QList<QTreeWidgetItem *> selectedItems = ui->treeWidget->selectedItems();

	if ( selectedItems.isEmpty())
		return;

	// If selection has the first line the items are on the top -> return
	int row = ui->treeWidget->indexOfTopLevelItem( selectedItems.first() );
	if ( row == 0 )
		return;

	QTreeWidgetItem *itemAbove;
	QListIterator<QTreeWidgetItem *> it( selectedItems );

	while ( it.hasNext() )
	{
		row = ui->treeWidget->indexOfTopLevelItem( it.next() );
		itemAbove = ui->treeWidget->takeTopLevelItem( row - 1 );
		ui->treeWidget->insertTopLevelItem( row, itemAbove );
	}
}

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Buggy(?) moveDown():

void MainWindow::moveDown()
{
	QList<QTreeWidgetItem *> selectedItems = ui->treeWidget->selectedItems();
 
	if ( selectedItems.isEmpty() )
		return;
 
	// If selection has the first line the items are on the top -> return
	int row = ui->treeWidget->indexOfTopLevelItem( selectedItems.last() );
	if ( row == ui->treeWidget->topLevelItemCount() - 1 )
		return;
 
	QTreeWidgetItem *itemBelow;
	QListIterator<QTreeWidgetItem *> it( selectedItems );
	it.toBack();
 
	while ( it.hasPrevious() )
	{
		row = ui->treeWidget->indexOfTopLevelItem( it.previous() );
		itemBelow = ui->treeWidget->takeTopLevelItem( row + 1 );
		ui->treeWidget->insertTopLevelItem( row, itemBelow );
	}
}

void MainWindow::moveDown()
{
	QList<QTreeWidgetItem *> selectedItems = ui->treeWidget->selectedItems();

	if ( selectedItems.isEmpty() )
		return;

	// If selection has the first line the items are on the top -> return
	int row = ui->treeWidget->indexOfTopLevelItem( selectedItems.last() );
	if ( row == ui->treeWidget->topLevelItemCount() - 1 )
		return;

	QTreeWidgetItem *itemBelow;
	QListIterator<QTreeWidgetItem *> it( selectedItems );
	it.toBack();

	while ( it.hasPrevious() )
	{
		row = ui->treeWidget->indexOfTopLevelItem( it.previous() );
		itemBelow = ui->treeWidget->takeTopLevelItem( row + 1 );
		ui->treeWidget->insertTopLevelItem( row, itemBelow );
	}
}

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Edit: Not sure what's the problem but i solved it with the following better approach:

void MainWindow::moveDown()
{
	QList<QTreeWidgetItem *> selectedItems = ui->treeWidget->selectedItems();
 
	if ( selectedItems.isEmpty() )
		return;
 
	// If selection has the first line the items are on the top -> return
	int row = ui->treeWidget->indexOfTopLevelItem( selectedItems.last() );
	if ( row == ui->treeWidget->topLevelItemCount() - 1 )
		return;
 
	QTreeWidgetItem *itemBelow;
 
	row = ui->treeWidget->indexOfTopLevelItem( selectedItems.last() );
	itemBelow = ui->treeWidget->takeTopLevelItem( row + 1 );
	ui->treeWidget->insertTopLevelItem( row + 1 - selectedItems.length() , itemBelow );
 
	ui->treeWidget->scrollToItem( selectedItems.last() );
}

void MainWindow::moveDown()
{
	QList<QTreeWidgetItem *> selectedItems = ui->treeWidget->selectedItems();

	if ( selectedItems.isEmpty() )
		return;

	// If selection has the first line the items are on the top -> return
	int row = ui->treeWidget->indexOfTopLevelItem( selectedItems.last() );
	if ( row == ui->treeWidget->topLevelItemCount() - 1 )
		return;

	QTreeWidgetItem *itemBelow;

	row = ui->treeWidget->indexOfTopLevelItem( selectedItems.last() );
	itemBelow = ui->treeWidget->takeTopLevelItem( row + 1 );
	ui->treeWidget->insertTopLevelItem( row + 1 - selectedItems.length() , itemBelow );

	ui->treeWidget->scrollToItem( selectedItems.last() );
}

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If somebody finds the error in the first version it would be nice to tell me.