kubode/diff-util-kotlin

A sample of DiffUtils written in Kotlin

DiffUtilSample

A sample of DiffUtil written in Kotlin.

Data flow

1. Subscribe to state changes. (MainActivity.onStart)
2. When notified state changes, set new state to adapter. (MainActivity.onStart)
3. Transform new state to item list and set to items. (MainAdapter.state)
4. Calculate item list differences and dispatch updates to adapter. (MainAdapter.items)

How it works

Diffable

Diffable is an interface for simplify use DiffUtil.Callback.

Diffable.isTheSame

Diffable.isTheSame returns true if this and other has same id. Default implementation returns equals. data class should override this.

like this:

override fun isTheSame(other: Diffable) = (id == (other as? Repo)?.id)

Diffable.isContentsTheSame

Diffable.isContentsTheSame returns true if this equals to other. Default implementation returns equals.