StoreListeners need PropertyChangeEvents
I think StoreListeners should be able to determine which property that changed on the model. A controller need this to do necessary RPC calls based on certain property changes, such as model.setActive() etc.
Today a StoreListener receives a StoreEvent, which extends BaseEvent and not ChangeEvent.
The StoreEvent contains the updated model object and a record object. But the record cannot be used to determine changes because it's already committed (the StoreListener is invoked from Record.afterCommit )
There are other ways to achieve this, like registering ChangeListeners on all the Store's models, or setting up a PropertyChangeEvent yourself in the listener for the Store's widget.
But I think it should be possible to do this clean and easy in a StoreListener residing in your controller, where also the Store itself is typically hosted.
Mmm, I'm not sure it is the purpose of the Store to tell which Model property has changed