tree ba3e865b929b25ed47d04d345722eb9fe4adf61a
parent 35675c8000d88a11fb73e752e5331f5fdc1100a3
author Chris Craik <ccraik@google.com> 1508885160 -0700
committer Chris Craik <ccraik@google.com> 1509048203 -0700

Add PagedList.BoundaryCallback for network use case

PagedList.BoundaryCallback
- allows network code to listen for loading-relevant events, like the user has
        scrolled near the beginning or end of PagedList data.
- allows network-only usecase to be built on top of Memory-based PagedList DataSource

Deprecates LivePagedListProvider in favor of new LivePagedListBuilder and DataSource.Factory:
- Splits concerns of DataSource construction (and providing access to data) from
        creating LiveData<PagedList>
- Allows for growth of construction parameters (including new PagedList.BoundaryCallback)
- Simplifies role of library (like Room) providing data - just implement DataSource.Factory

Bug: 68316389
Test: tests in paging-common, paging-runtime, room-integration-tests-testapp

Change-Id: Idb90d8462b286bbd794c61aa7b148cd813715cfb