int offset= event.start;
IRegion region= fViewer.getVisibleRegion();  int offset= event.start + region.getOffset();
	public void verifyText(VerifyEvent event) {		if (!event.doit)			return;		int offset= event.start;		int length= event.end - event.start;		// allow changes only within linked positions when coming through UI		if (!fManager.anyPositionIncludes(offset, length))			leave(UNINSTALL | COMMIT);	}