Hi,
I'm not sure it is but I think I have found a bug where elements share the same instance of a shape.
Here an example:
view := RTView new.
els := (RTBox new size: 20) elementsOn: (1 to: 10). view addAll: els.
els do: [ :e | e on: TRMouseClick do: [ :event | e shape color: Color random. e update. els atRandom update. view signalUpdate ] ].
RTHorizontalLineLayout on: els. view open
It should only change the color of one element but it doesn't. So I don't know if it is wanted or not.