Example of usage DiffUtil utility class added originally in Support Library 24.2.0.
calculateDiff method from DiffUtill class requires DiffUtil.Callback object as parameter.
DiffUtil callback - ActorDiffCallback.kt
Implements 4 methods:
- getOldListSize - returns size of the old list
- getNewListSize - returns size of the new list
- areItemsTheSame - returns true if two items are the same, e.g. have the same ids
- areContentsTheSame - returns true if displayed content was not changed. In our case we only display actor's name so we're detecing name's change.
Applying diff result - ActorAdapter.swap()
DiffResult can be applied to adapter by calling diffResult.dispatchUpdatesTo(adapter).
fun swap(actors: List<Actor>) {
val diffCallback = ActorDiffCallback(this.actors, actors)
val diffResult = DiffUtil.calculateDiff(diffCallback)
this.actors.clear()
this.actors.addAll(actors)
diffResult.dispatchUpdatesTo(this)
}
Copyright 2016 Michał Moczulski
Licensed under the Apache License, Version 2.0 (the "License");
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