Undo in tabbed editor

Hello,

when I have tabbed editor, same Undo stack is available for both tabs (Text Editor and my GUI Editor). It is changing text in Text Editor. Can I have separate Undo stack for my GUI Editor? How?

Yes, both editors are basically changing the same file, but I would like to have separate model for my GUI editor and synchronizing it with Text Editor only when necessary - tab switch and Idea autosave (btw. where to find such event?).