[news.eclipse.platform] DO / UNDO ability

["Tanut Apiwong" <tanut@xxxxxxxxx>]

Hello.
    I have created my own vector-graphic drawing editor. The editor will
have abilty to generate source code of that drawing in to Text file too. The
problem is I want my editor have do/undo ability, so how should I do? ... I
also have a look in IUndoManager (make my editor class implement
IUndoManageer) but it does not work(..The eclipse redo/undo menu still
disable).
My Eclipse version is 2.1.3

Thank you./ Tanut Apiwong