Thank you for helping me ...

i) I will investigate on QAbstractProxyModel::mapToSource() as I didn't use it before.

ii) I'll move the signal dataChanged() but what do you mean by setData() should be called directly?

iii) I don't want checkboxes else I would have used the role as described in the model/view programming page. I need an icon to be shown when a resource is visible and another icon when the resource is hidden (a la Photoshop).