"itsme213" <itsme213 at hotmail.com> wrote in message news:fj9aos$u5u$1 at ger.gmane.org... > XComponent>> > addXAndRenderOn: r on: selector of: obj > "make change by adding one X to domain model, re-paint just the new X" In particular, this appears to work but feels very unclean - combining domain model change with UI change.