private void DragFromGroup(IDataSourceViewModel source, IDataSourceViewModel dest, MergedDataSourceViewModel parent)
{
parent.RemoveChild(source);
DissolveGroupIfNecessary(parent);
Drag(source, dest);
}
private void DissolveGroupIfNecessary(MergedDataSourceViewModel group)
{
if (group.ChildCount == 1)
{
int groupIndex = _observable.IndexOf(group);
_observable.RemoveAt(groupIndex);
_dataSources.Remove(group.DataSource);
IDataSourceViewModel child = group.Observable.First();
group.RemoveChild(child);
_observable.Insert(groupIndex, child);
}
}