[emf-dev] EObjectObservableList incorrect diff notification

[Max Gordienko <mgordienko@xxxxxxxxx>]

Hi everyone!

I have encountered a problem with ListDiff events emitted from
EObjectObservableList during multi-remove operations (clear() in
particular).

The problem (as I can see it) is in the implementation of the
Notification.REMOVE_MANY case in the Adapter created in
EObjectObservableList#firstListenerAdded()

The index computation is incorrect. It should take the removed element
into account not just blindly increment the index. (see how the diff
is calculated in WritableList#clear())

Another problem is with clear(). The notification event index will be
set to Notification.NO_INDEX which is -1. (see
NotifyingListImpl#clear())

Here is a small test to demonstrate the issue:

----
               Container container = FACTORY.createContainer();
               container.getComponents().add(FACTORY.createComponent());
               container.getComponents().add(FACTORY.createComponent());
               IObservableList list = EMFObservables.observeList(container,
PACKAGE.getContainer_Components());

               Listener listener = new Listener();
               list.addListChangeListener(listener);

               list.clear();

               assertEquals(Arrays.asList(0, 0), listener.getIndices());
----

The actual indices are [-1, 0]

The complete test project is attached.

Could you please confirm this is an issue.

Thank you!

Attachment: notification1.zip
Description: Zip archive