public void DragTo(NodeViewModel beDrag, NodeViewModel parent, NodeViewModel previousBrother)
{
NodeViewModel Node = beDrag;
INodeViewModel oldParent = Node.Parent;
int oldIndex = Node.IndexInParent;
if (parent == null)
{
parent = RootNode;
}
var newIndex = 0;
if (previousBrother != null)
{
///如果前一个同级节点为空，那么index则为0
///否则进入此处逻辑判断
if (previousBrother == Node)
{
///如果要拖动到的前一个同级节点就是自己
///那么index不改变
newIndex = Node.IndexInParent;
}
else
{
///否则如果拖动到的前一个同级节点和自己在同一个父节点下面
if (previousBrother.Parent == Node.Parent)
{
if (Node.IndexInParent <= previousBrother.IndexInParent)
{
newIndex = previousBrother.IndexInParent;
}
else
{
newIndex = previousBrother.IndexInParent + 1;
}
}
else
{
newIndex = previousBrother.IndexInParent + 1;
}
}
}
if (parent == oldParent && newIndex == oldIndex)
{
Debug.WriteLine("not changed");
}
else
{
Node.DragTo(parent, newIndex);
PageTreeChanged();
}
MovePageCommand cmd = new MovePageCommand(Node, Node.Parent, Node.IndexInParent, oldParent, oldIndex);
_undoManager.Push(cmd);
}
private void PageDownExecute(object cmdParameter)
{
INodeViewModel Node = NodeInfo.SelectedNode;
int oldIndex = Node.IndexInParent;
Node.MoveDown();
PageTreeChanged();
MovePageCommand cmd = new MovePageCommand(Node, Node.Parent, Node.IndexInParent, Node.Parent, oldIndex);
_undoManager.Push(cmd);
if (_pageTree != null)
{
_pageTree.Focus();
}
}