- Coalesce updates: when receiving updates from the datasource while an update is being performed, only the last one will be actually executed.
- Fast updates: allows next performBatchUpdate before completion of the previous one
- Tracks visible views: keeps track of cells on-screen instead of relying of indexPathsForVisibleItems and indexPathForCell, which are unreliable on fast updates.
Now DataSource is responsible for notifying the exact type of change. This implicitly allows more flexibility in the dataSource ( like ignoring such a request! ) and reduces entry points from where changes are enqueued
Previously, due to the mapping between chatItem instance and presenter, a new presenter would be created. This fixes:
1) That new presenter will have invalid itemVisibility property (would cause a crash when long pressing a text cell)
2) If a new chatItem instance is returned by the dataSource for a previous existing message, but the previous chatItem is leaked, then the presenter would leak too (and it might try to update its cell, as in downloading an image)
This introduces ChatItemCompanion, a structure which attaches a ChatItem with its presenter and decoration attributes. This solves 1) and 2). Still new instances of presenters will be created for new instances of chatItems --> Presenters should avoid keeping any state in its internal storage.
Diego Sánchez
Diego Sanchez