Updates: Cc: tudor.girba Comment #1 on issue 396 by alexandre.bergel: Mondrian should provide teh start and end nodes in the edge action http://code.google.com/p/moose-technology/issues/detail?id=396 I started to work on this (testHandlerOnEdge). However, I am unsure for few things. view interaction on: MOMouseDown do: [ :v | ... ] What v is supposed to be? The announcement or the value on which one has clicked? It has to be the value I believe. However, it may brake already existing code. We could leave it like this, and introduce on:withValueDo: What do you think? Cheers, Alexandre