private void treeViewReorderHandler_DropNodeValidating(object sender, DropNodeValidatingEventArgs e)
{
var nodeRow = e.SourceNode.Tag as IEditableNode;
if (nodeRow != null)
{
var targetWrapper = e.TargetNode.Tag as ThemeNodeWrapper;
if (targetWrapper == null) return;
var target = targetWrapper.Node;
var newParent = e.Position == NodePosition.Inside ? target as ContainerNode : target.Parent;
if (newParent != null)
{
int newIndex;
if (e.Position == NodePosition.Inside)
newIndex = newParent.Nodes.Count;
else if (e.Position == NodePosition.Before)
newIndex = e.TargetNode.Index;
else
newIndex = e.TargetNode.Index + 1;
if (nodeRow.CanMoveTo(newParent, e.SourceNode.Index, newIndex))
return;
}
}
e.Effect = DragDropEffects.None;
}
protected virtual void OnDropNodeValidating(DragEventArgs e, TreeNode sourceNode, TreeNode targetNode, NodePosition position)
{
if (DropNodeValidating != null)
{
var args = new DropNodeValidatingEventArgs(e.Data, e.KeyState, e.X, e.Y, e.AllowedEffect, e.Effect, sourceNode, targetNode, position);
DropNodeValidating(this, args);
e.Effect = args.Effect;
}
}
