Paging LV2 - 2 (Network Simple Ex)

// retrofit
implementation 'com.squareup.retrofit2:retrofit:2.9.0'
implementation 'com.squareup.retrofit2:converter-gson:2.9.0'

// paging
def paging_version = "3.1.1"
implementation "androidx.paging:paging-runtime:$paging_version"

// LifecycleScope
def lifecycle_version = "2.5.1"
implementation "androidx.lifecycle:lifecycle-viewmodel-ktx:$lifecycle_version"

 

	class GithubResponse : ArrayList<GithubResponseItem>()
	data class GithubResponseItem(
	val allow_forking: Boolean,
	val archive_url: String,
	val archived: Boolean,
	val assignees_url: String,
	val blobs_url: String,
	val branches_url: String,
	val clone_url: String,
	val collaborators_url: String,
	val comments_url: String,
	val commits_url: String,
	val compare_url: String,
	val contents_url: String,
	val contributors_url: String,
	val created_at: String,
	val default_branch: String,
	val deployments_url: String,
	val description: String,
	val disabled: Boolean,
	val downloads_url: String,
	val events_url: String,
	val fork: Boolean,
	val forks: Int,
	val forks_count: Int,
	val forks_url: String,
	val full_name: String,
	val git_commits_url: String,
	val git_refs_url: String,
	val git_tags_url: String,
	val git_url: String,
	val has_discussions: Boolean,
	val has_downloads: Boolean,
	val has_issues: Boolean,
	val has_pages: Boolean,
	val has_projects: Boolean,
	val has_wiki: Boolean,
	val homepage: String,
	val hooks_url: String,
	val html_url: String,
	val id: Int,
	val is_template: Boolean,
	val issue_comment_url: String,
	val issue_events_url: String,
	val issues_url: String,
	val keys_url: String,
	val labels_url: String,
	val language: String,
	val languages_url: String,
	val license: License,
	val merges_url: String,
	val milestones_url: String,
	val mirror_url: Any,
	val name: String,
	val node_id: String,
	val notifications_url: String,
	val open_issues: Int,
	val open_issues_count: Int,
	val owner: Owner,
	val `private`: Boolean,
	val pulls_url: String,
	val pushed_at: String,
	val releases_url: String,
	val size: Int,
	val ssh_url: String,
	val stargazers_count: Int,
	val stargazers_url: String,
	val statuses_url: String,
	val subscribers_url: String,
	val subscription_url: String,
	val svn_url: String,
	val tags_url: String,
	val teams_url: String,
	val topics: List<Any>,
	val trees_url: String,
	val updated_at: String,
	val url: String,
	val visibility: String,
	val watchers: Int,
	val watchers_count: Int,
	val web_commit_signoff_required: Boolean
	)
	data class License(
	val key: String,
	val name: String,
	val node_id: String,
	val spdx_id: String,
	val url: String
	)
	data class Owner(
	val avatar_url: String,
	val events_url: String,
	val followers_url: String,
	val following_url: String,
	val gists_url: String,
	val gravatar_id: String,
	val html_url: String,
	val id: Int,
	val login: String,
	val node_id: String,
	val organizations_url: String,
	val received_events_url: String,
	val repos_url: String,
	val site_admin: Boolean,
	val starred_url: String,
	val subscriptions_url: String,
	val type: String,
	val url: String
	)

view raw data.kt hosted with ❤ by GitHub

	interface GitApi {
	// https://api.github.com/users/google/repos?page=1&per_page=30
	// https://api.github.com/users/google/repos?page=1&per_page=30
	@GET("users/google/repos")
	suspend fun getData(
	@Query("page") page: Int,
	@Query("per_page") prePage: Int
	) : Response<GithubResponse>
	}

view raw GitApi.kt hosted with ❤ by GitHub

	object RetrofitInstance {
	val BASE_URL = "https://api.github.com/"
	val client = Retrofit
	.Builder()
	.baseUrl(BASE_URL)
	.addConverterFactory(GsonConverterFactory.create())
	.build()
	fun getInstance() : Retrofit {
	return client
	}
	}

view raw RetrofitInstance.kt hosted with ❤ by GitHub

	class MyAdapter : PagingDataAdapter<GithubResponseItem, MyAdapter.MyViewHolder>(DIFF_CALLBACK) {
	companion object {
	private val DIFF_CALLBACK = object : DiffUtil.ItemCallback<GithubResponseItem>() {
	override fun areItemsTheSame(oldItem: GithubResponseItem, newItem: GithubResponseItem): Boolean {
	return oldItem.id == newItem.id
	}
	override fun areContentsTheSame(oldItem: GithubResponseItem, newItem: GithubResponseItem): Boolean {
	return oldItem == newItem
	}
	}
	}
	class MyViewHolder(view : View) : RecyclerView.ViewHolder(view) {
	val textArea = view.findViewById<TextView>(R.id.textArea)
	fun bind(item : GithubResponseItem) {
	textArea.text = item.name
	}
	}
	override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
	val item = getItem(position)
	if(item != null) {
	holder.bind(item)
	}
	}
	override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
	val view = LayoutInflater.from(parent.context).inflate(R.layout.rv_item, parent, false)
	return MyViewHolder(view)
	}
	}

view raw MyAdapter.kt hosted with ❤ by GitHub

	private const val STARTING_KEY = 1
	class MyPagingSource(
	private val githubService : GitApi
	) : PagingSource<Int, GithubResponseItem>() {
	init {
	Log.d("MyPagingSource", "init")
	}
	override suspend fun load(params: LoadParams<Int>): LoadResult<Int, GithubResponseItem> {
	Log.d("MyPagingSource", "load")
	Log.d("MyPagingSource", "params.key : " + params.key.toString())
	val page = params.key ?: STARTING_KEY
	Log.d("MyPagingSource", "page : " + page.toString())
	Log.d("MyPagingSource", "size : " + params.loadSize.toString())
	val response = githubService.getData(page, params.loadSize)
	Log.d("response", response.body().toString())
	Log.d("response", response.body()?.size.toString())
	val data = response.body()
	Log.d("data", data?.size.toString())
	if(page != 1) {
	Log.d("MyPagingSource", "delay")
	delay(3000)
	}
	Log.d("loadSize", params.loadSize.toString())
	Log.d("loadSize", (params.loadSize / 30).toString())
	Log.d("data", data?.size.toString())
	// test
	if (data != null) {
	var count = 1
	for(i in data) {
	Log.d("data", i.toString())
	Log.d("count", count.toString())
	Log.d("name", i.name)
	count++
	}
	}
	if(data == null) {
	return LoadResult.Page(
	data = listOf(),
	prevKey = null,
	nextKey = null
	)
	} else {
	return LoadResult.Page(
	data = data,
	prevKey = null,
	nextKey = page + (params.loadSize / 30)
	)
	}
	}
	override fun getRefreshKey(state: PagingState<Int, GithubResponseItem>): Int? {
	return null
	}
	}

view raw MyPagingSource.kt hosted with ❤ by GitHub

	class MainActivity : AppCompatActivity() {
	lateinit var viewModel: MainViewModel
	override fun onCreate(savedInstanceState: Bundle?) {
	super.onCreate(savedInstanceState)
	setContentView(R.layout.activity_main)
	viewModel = ViewModelProvider(this).get(MainViewModel::class.java)
	val rv = findViewById<RecyclerView>(R.id.rv)
	val myAdapter = MyAdapter()
	rv.layoutManager = LinearLayoutManager(this)
	rv.adapter = myAdapter
	lifecycleScope.launch {
	viewModel.items.collect {
	Log.d("MainActivity", it.toString())
	myAdapter.submitData(it)
	}
	}
	}
	}

view raw MainActivity.kt hosted with ❤ by GitHub

	class MainViewModel : ViewModel() {
	init {
	Log.d("MainViewModel", "init")
	}
	private val api = RetrofitInstance.getInstance().create(GitApi::class.java)
	val items : Flow<PagingData<GithubResponseItem>> = Pager(
	config = PagingConfig(pageSize = 30),
	pagingSourceFactory = {
	MyPagingSource(api)
	}
	)
	.flow
	.cachedIn(viewModelScope)
	}

view raw MainViewModel.kt hosted with ❤ by GitHub

 

 

 

 

 

 

 

 

- 참조

 

https://github.com/MindorksOpenSource/Paging3-Android-Tutorial/tree/master/app/src/main/java/com/mindorks/example/paging3

GitHub - MindorksOpenSource/Paging3-Android-Tutorial: An example project to demonstrate how to use the Paging-3 in Android.