Loading animation in tree view collapse icon

[Mr Gisa]

Is it possible to put a loading animation in the tree view collapse icon when the user clicks on the collapse icon?

Like this:

I want to create a tree view that when the user clicks on the collapse icon it will add a few more items as child to that item. How to do something like that?

[JonB]

@Mr-Gisa
Are you saying you are already using http://doc.qt.io/qt-5/qtreeview.html#animated-prop ?

I don't know whether http://doc.qt.io/qt-5/qtreeview.html#expanded is emitted before or after the expansion is shown. Or whether you can use http://doc.qt.io/qt-5/qtreeview.html#expand slot to do your work.