GithubPageKeyedDataSource.kt

/**
 * A data source that uses the before/after keys returned in page requests.
 */
class GithubPageKeyedDataSource : PageKeyedDataSource<Int, Item>() {

    override fun loadInitial(params: LoadInitialParams<Int>,
                             callback: LoadInitialCallback<Int, Item>) {

        val currentPage = 1
        val nextPage = currentPage + 1

        val request = githubApi.searchUsers(
                query = searchQuery,
                page = currentPage,
                perPage = params.requestedLoadSize)

        // Retrofit Call onResponse omitted
        
        callback.onResult(items, null, nextPage)
    }

    override fun loadAfter(params: LoadParams<Int>,
                           callback: LoadCallback<Int, Item>) {

        val currentPage = params.key
        val nextPage = currentPage + 1

        val request = githubApi.searchUsersAsync(
                query = searchQuery,
                page = currentPage,
                perPage = params.requestedLoadSize)

        // Retrofit Call onResponse omitted
        
        callback.onResult(items, nextPage)
    }
}