Копировать узлы с поддеревом TTreeView во второй TTreeView

Копировать узлы с поддеревом TTreeView во второй TTreeView

  {: Callback to use to copy the data of a treenode when the
  node itself is copied by CopySubtree.
  @param oldnode is the old node
  @param newnode is the new node
  @Desc Use a callback of this type to implement your own algorithm
  for a node copy. The default just uses the Assign method, which
  produces a shallow copy of the nodes Data property. }

  TCopyDataProc = procedure(oldnode, newnode : TTreenode);
 {: The default operation is to do a shallow copy of the node, via
Assign. }

 procedure DefaultCopyDataProc(oldnode, newnode : TTreenode);
 {-- CopySubtree

 {: Copies the source node with all child nodes to the target treeview.
@Param sourcenode is the node to copy
@Param target is the treeview to insert the copied nodes into
@Param targetnode is the node to insert the copy under, can be nil to
 make the copy a top-level node.
@Param CopyProc is the (optional) callback to use to copy a node.
 If Nil is passed for this parameter theDefaultCopyDataProc will be
@Precondition sourcenode <> nil, target <> nil, targetnode is either
 nil or a node of target
@Raises Exception if targetnode happens to be in the subtree rooted in
 sourcenode. Handling that special case is rather complicated, so we
 simply refuse to do it at the moment.
{ Created 2003-04-09 by P. Below -----------------------------------------------------------------------

 procedure CopySubtree(sourcenode : TTreenode; target : TTreeview;
  targetnode : TTreenode; CopyProc : TCopyDataProc = nil);
  anchor : TTreenode;
  child : TTreenode;
 begin { CopySubtree }
  'CopySubtree:sourcenode cannot be nil');
  'CopySubtree: target treeview cannot be nil');
  Assert((targetnode = nil) or (targetnode.TreeView = target),
  'CopySubtree: targetnode has to be a node in the target treeview.');
  if (sourcenode.TreeView = target) and
  (targetnode.HasAsParent(sourcenode) or (sourcenode =
  targetnode)) then
  raise Exception.Create('CopySubtree cannot copy a subtree to one of the ' +
  'subtrees nodes.');
  if not Assigned(CopyProc) then
  CopyProc := DefaultCopyDataProc;
  anchor := target.Items.AddChild(targetnode, sourcenode.Text);
  CopyProc(sourcenode, anchor);
  child := sourcenode.GetFirstChild;
  while Assigned(child) do
  CopySubtree(child, target, anchor, CopyProc);
  child := child.getSibling;
  end; { While }
 end; { CopySubtree }

 procedure TForm1.Button1Click(Sender : TObject);
  if assigned(treeview1.selected) then
  CopySubtree(treeview1.selected, treeview2, nil);

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