Problem with Undo manager using highlighting

Question

Hello,
I am writing a little text editor with syntax highlighting, but I have a problem with the UndoManager.
Everytime I undo an action the UndoManager removes just the attributes of the text, not the text itself.
Does anybody know a way how to make the UndoManager not recognizing the attributes.
Thanks in advance.

Answer 1

In your UndoableEditListener, you can check the type of the edit, and ignore it if it's an attribute change:
    public void undoableEditHappened(UndoableEditEvent e) {
        UndoableEdit edit = e.getEdit();
        if (edit instanceof DefaultDocumentEvent &&
            ((DefaultDocumentEvent)edit).getType() ==
                DefaultDocumentEvent.EventType.CHANGE) {
            return;
        undoMgr.addEdit(edit);
    }