add some debug helpers

Change-Id: I03d8baab55548fde1e34b55927fd5dcf9cff58a9
don't reposition several times in complex hierarchies

We moved the object several times if the object was behind several group
shapes.

Change-Id: I984d6e9208f8924a9968820cf6f95fbb663062b6
fix transparence of bubble color

Change-Id: Ib2edf99ff4f48c12a946878740ad5d64d7deffb2