Description Guillaume Hillairet 2012-01-24 12:53:51 EST

The java bridge currently uses VisualIdentifierDispenser to generates visualID according to 
information store in a trace model. This insure to keep same visualID in gmfgen model even if 
changes have been made to gmfmap model. The qvto bridge currently does not use the trace model, and 
so visualID are generated solely according to their position in the object tree.

For example, if a Map model containing 2 nodes is used to generate a GMFGen model, at the first iteration, the visualID 
will be generated according to the position of the nodes, and a trace model is generated.
Map    ->    Gen           -> Trace
 |_n1           |_2001            |_n1->2001
 |_n2           |_2002            |_n2->2002
 
If changes are made ot the Map model, e.g. add a node at the top, thus modifying position of previous nodes. 
The only way to keep mapping of visualID is to use the trace model. This is done by  the VisualIdentifierDispenser 
implementation in java bridge.
 
 Map         ->   Gen            -> Trace
  |_n0              |_2003              |_n1->2001
  |_n1              |_2001              |_n2->2002
  |_n2              |_2002              |_n0->2003
  
QVTO bridge should have access to VisualIdentifierDispenser via a black box, allowing usage of already existing code 
to generate visualID without having to deal directly with the trace model in the qvto transformation.