©2018 Wantedly, Inc. DiffUtil and ListAdapter potatotips 50 19.Apr.2018 - Masatoshi Kubode 

©2018 Wantedly, Inc. Self introduction Masatoshi Kubode Twitter: @swiz_ard GitHub: @kubode Qiita: @kubode Wantedly Visit UserGrowth 

©2018 Wantedly, Inc. 1. DiffUtil 2. ListAdapter 3. Demo Agenda 

©2018 Wantedly, Inc. DiffUtil 

©2018 Wantedly, Inc. • Calculates the differences between 2 lists • Detects change, insert, remove, move • Move detection is optional • O(n) • 1000 / 50 modifications 4.6ms on Nexus 5X DiffUtil 

©2018 Wantedly, Inc. ListAdapter 

©2018 Wantedly, Inc. • Added in support library 27.1.0 • A RecyclerView.Adapter using DiffUtil • Just submitList(newItems) • Calculates the diff on a background thread • Notify diff results on the main thread ListAdapter 

©2018 Wantedly, Inc. Demo ListAdapter 

©2018 Wantedly, Inc. • Should not use with MutableList • Does nothing if same instance submitted ListAdapter Important point 

©2018 Wantedly, Inc. Conclusion 

©2018 Wantedly, Inc. • DiffUtil automates the adapter notification • Simplify around the adapter operations Conclusion 

©2018 Wantedly, Inc. https://github.com/kubode/DiffUtil-sample Repository 

©2018 Wantedly, Inc. Thanks