/// <summary>
/// Retrieve the desire node effect depending on the current mouse position
/// </summary>
/// <param name="dragNodes">Node being dragged</param>
private DragDropEffects getDragDropEffect(IEnumerable <ITreeNode> dragNodes)
{
if (dragNodes == null)
{
return(DragDropEffects.None);
}
var p = _treeView.PointToClient(Control.MousePosition);
var targetNode = _treeView.CalcHitInfo(p).Node;
var treeNodes = dragNodes.ToList();
if (!treeNodes.All(_presenter.CanDrag))
{
return(DragDropEffects.None);
}
if (treeNodes.All(node => _presenter.CanDrop(node, nodeFrom(targetNode))))
{
return(DragDropEffects.Move);
}
return(DragDropEffects.None);
}