notifyPositionsOnRebuild property
Whether itemPositionsListener is notified after every rebuild of the
list, even when no position changed, as in scrollable_positioned_list.
When false, a rebuild notifies only when the listener, the separated mode, listController or restorePosition changed; positions that move are still reported after the layout that moves them. Rebuilds in the same frame notify once either way.
Implementation
final bool notifyPositionsOnRebuild;