Tree in MULTI selection mode does not catches SelectionChangedEvent in some case.
1. Create a tree with MULTI selection mode.
2. Select 2-3 items with ctrl or shift keys.
3. Select one of selected items by clicking on it (without ctrl/shift keys) (so other selected items are deselected now)
SelectionHandler catches SelectionEvent, but
SelectionChangedHandler DOES NOT catches SelectionChangedEvent, though selection has obviously changed.
The same actions with ListView work fine.
Neither ListView's nor Tree's BeforeSelectionHandler does not catch BeforeSelectionEvent if the component is not in the SINGLE selection mode. Is that as designed or a bug?
Thanks for reporting this - we've made a fix to resolve this in SVN, which will be available in the next release.
As you noted, it worked correctly in the ListView, because the ComboBox was looking to see if the active item was non-null. Instead, the ComboBox checks if the *list* of selected items is empty to decide if nothing has been selected so that null objects can be selected.