class AerialPlatformResultHandler implements ResultHandler, EventListener<ActiveDataGroupsChangedEvent> {

    @Override
    public void handleGroupActivation(DataTypeInfo dataType, ActivationState state)
    {
        if (state != ActivationState.ACTIVE)
        {
            myToolbox.getTransformerRegistry().removeObjectsForSource(dataType);
        }
        else if (state == ActivationState.ACTIVE)
        {
            String typeKey = dataType.getTypeKey();
            synchronized (myVideoLayer)
            {
                if (!myVideoLayer.containsKey(typeKey))
                {
                    myVideoLayer.put(typeKey, New.list());
                }
            }
            myToolbox.getTransformerRegistry().addObjectsForSource(dataType,
                    New.list(new AerialImageryTransformer(myToolbox, myQuerier, dataType, myVideoLayer.get(typeKey))));
        }
    }

    public  AerialPlatformResultHandler(Toolbox toolbox, OSHImageQuerier querier);

}