DataFlowGraphModel::setNodeData ignores most input

[emilfors]

The DataFlowGraphModel::setNodeData function silently ignores anything except node position and size, and the nodeData function returns the model data for most node roles (except size and position). This means you can't individually set any of the other roles for a specific node, despite the setNodeData documentation's claim that you can use it to do precisely that.

Is this by design? Is the intention that if we do need this functionality, we extend the DataFlowGraphModel class and override the setNodeData and nodeData functions? Or is the class simply not quite finished yet.

Also, internally the DataFlowGraphModel keeps track of node geometry through an internal map from node ids to geometries. Why is there no concept of individual nodes anymore? Is it really the intention that each individual node role is stored in a separate map in the graph model?