Developing model/view for different type of objects (Long text - conpcetual question)

[anda_skoa]

Now I don't understand why you would recommend to use multiple models instead of a single one with different proxy models, apart of maybe being a little more complex.

It is mostly about complexity, both in terms of code complexity and runtime/processing complexity.

Code complexity: an approach with a single model and proxies is often much more complicated to develop and maintain
Runtime complexity: a proxy model has no "knowledge", e.g. for filtering it always has to traverse the full source model. A specialized model can use "knowledge" about the data.

I want it to remember expanded/collapsed nodes in the current session.

Then you need to react to the respective signals of QTreeView and store the expand/collapse state in your internal data structure.

Cheers,
_