void resetUndoManager() {
		EventQueue.invokeLater(new Runnable() {
			public void run() {
				getModel().getUndoManager().discardAllEdits();
				if (undoUIComponent != null) {
					undoUIComponent.setEnabled(false);
					undoUIComponent.setText("Undo");
				}
				if (redoUIComponent != null) {
					redoUIComponent.setEnabled(false);
					redoUIComponent.setText("Redo");
				}
			}
		});
	}