Paging Library ~ アイテムの更新 ~

Bonfire Android #5での発表資料です

Transcript

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    internal class ItemDataSource() : PageKeyedDataSource() {
    override fun loadInitial(params: LoadInitialParams, callback: LoadInitialCallback) {
    }
    override fun loadAfter(params: LoadParams, callback: LoadCallback) {
    }
    override fun loadBefore(params: LoadParams, callback: LoadCallback) {
    }
    }
    

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    %BUB4PVSDFΛ࣮૷͢Δ
    internal class ItemDataSource(
    private val itemRepository: ItemRepository
    ) : PageKeyedDataSource() {
    private val dataSourceScope = CoroutineScope(Main + Job())
    override fun loadInitial(params: LoadInitialParams, callback: LoadInitialCallback) {
    dataSourceScope.launch {
    callback.onResult(
    itemRepository.findAll(page = 0),
    null,
    1
    )
    }
    }
    override fun loadAfter(params: LoadParams, callback: LoadCallback) {
    dataSourceScope.launch {
    callback.onResult(
    itemRepository.findAll(page = params.key),
    params.key + 1
    )
    }
    }
    

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    %BUB4PVSDFΛ࣮૷͢Δ
    internal class ItemDataSource(
    private val itemRepository: ItemRepository
    ) : PageKeyedDataSource() {
    private val dataSourceScope = CoroutineScope(Main + Job())
    override fun loadInitial(params: LoadInitialParams, callback: LoadInitialCallback) {
    dataSourceScope.launch {
    callback.onResult(
    itemRepository.findAll(page = 0),
    null,
    1
    )
    }
    }
    override fun loadAfter(params: LoadParams, callback: LoadCallback) {
    dataSourceScope.launch {
    callback.onResult(
    itemRepository.findAll(page = params.key),
    params.key + 1
    )
    }
    }
    

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    %BUB4PVSDFΛ࣮૷͢Δ
    internal class ItemDataSource(
    private val itemRepository: ItemRepository
    ) : PageKeyedDataSource() {
    private val dataSourceScope = CoroutineScope(Main + Job())
    override fun loadInitial(params: LoadInitialParams, callback: LoadInitialCallback) {
    dataSourceScope.launch {
    callback.onResult(
    itemRepository.findAll(page = 0),
    null,
    1
    )
    }
    }
    override fun loadAfter(params: LoadParams, callback: LoadCallback) {
    dataSourceScope.launch {
    callback.onResult(
    itemRepository.findAll(page = params.key),
    params.key + 1
    )
    }
    }
    

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    %BUB4PVSDF'BDUPSZΛ࣮૷͢Δ
    internal class ItemDataSourceFactory(
    private val itemRepository: ItemRepository
    ) : DataSource.Factory() {
    override fun create(): DataSource = ItemDataSource(itemRepository)
    }
    

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    internal class ItemViewModel(
    itemRepository: ItemRepository
    ) : ViewModel() {
    val itemPagedList = LivePagedListBuilder(
    ItemDataSourceFactory(itemRepository),
    PagedList.Config.Builder()
    .setEnablePlaceholders(false)
    .setPageSize(30)
    .build()
    ).build()
    }
    

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    class ReadOnlyActivity : AppCompatActivity() {
    private val viewModel: ItemViewModel by viewModels {
    ItemViewModelFactory(ItemRepositoryImpl())
    }
    override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val binding = DataBindingUtil.setContentView(
    this,
    R.layout.activity_item_list
    )
    val adapter = ItemAdapter(this)
    binding.recyclerView.adapter = adapter
    viewModel.itemPagedList.observe(
    this,
    Observer {
    adapter.submitList(it)
    }
    )
    }
    }
    

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    class ReadOnlyActivity : AppCompatActivity() {
    private val viewModel: ItemViewModel by viewModels {
    ItemViewModelFactory(ItemRepositoryImpl())
    }
    override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val binding = DataBindingUtil.setContentView(
    this,
    R.layout.activity_item_list
    )
    val adapter = ItemAdapter(this)
    binding.recyclerView.adapter = adapter
    viewModel.itemPagedList.observe(
    this,
    Observer {
    adapter.submitList(it)
    }
    )
    }
    }
    

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    1BHFE-JTU"EBQUFS
    internal class ItemAdapter(context: Context) : PagedListAdapter(ITEM_CALLBACK) {
    companion object {
    private val ITEM_CALLBACK = object : DiffUtil.ItemCallback() {
    override fun areItemsTheSame(oldItem: Item, newItem: Item): Boolean = oldItem.id == newItem.id
    override fun areContentsTheSame(oldItem: Item, newItem: Item): Boolean = oldItem == newItem
    }
    }
    var onItemClickListener: OnItemClickListener? = null
    private val inflater = LayoutInflater.from(context)
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder =
    ItemViewHolder.create(inflater, parent, false)
    override fun onBindViewHolder(holder: ItemViewHolder, position: Int) =
    holder.bind(getItem(position), onItemClickListener)
    }
    

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20. X
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    internal class ItemAdapter(context: Context) : PagedListAdapter(ITEM_CALLBACK) {
    companion object {
    private val ITEM_CALLBACK = object : DiffUtil.ItemCallback() {
    override fun areItemsTheSame(oldItem: Item, newItem: Item): Boolean = oldItem.id == newItem.id
    override fun areContentsTheSame(oldItem: Item, newItem: Item): Boolean = oldItem == newItem
    }
    }
    var onItemClickListener: OnItemClickListener? = null
    private val inflater = LayoutInflater.from(context)
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder =
    ItemViewHolder.create(inflater, parent, false)
    override fun onBindViewHolder(holder: ItemViewHolder, position: Int) =
    holder.bind(getItem(position), onItemClickListener)
    }
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    internal class ItemViewModel(
    private val itemRepository: ItemRepository
    ) : ViewModel() {
    private val dataSourceFactory = ItemDataSourceFactory(itemRepository)
    val itemPagedList = LivePagedListBuilder(
    dataSourceFactory,
    PagedList.Config.Builder().setEnablePlaceholders(false).setPageSize(30).build()
    ).build()
    fun check(item: Item): Job = viewModelScope.launch {
    itemRepository.store(item.copy(checked = true))
    dataSourceFactory.sourceLiveData.value?.invalidate()
    }
    fun uncheck(item: Item): Job = viewModelScope.launch {
    itemRepository.store(item.copy(checked = false))
    dataSourceFactory.sourceLiveData.value?.invalidate()
    }
    } %BUB4PVSDFJOWBMJEBUF͢Δͱσʔλͷ࠶औಘ͕૸Δ
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    class NgActivity : AppCompatActivity() {
    private val viewModel: ItemViewModel by viewModels {
    ItemViewModelFactory(ItemRepositoryImpl())
    }
    override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val binding = DataBindingUtil.setContentView(
    this,
    R.layout.activity_item_list
    )
    val adapter = ItemAdapter(this).apply {
    onItemClickListener = object : OnItemClickListener {
    override fun onClick(item: Item) {
    if (item.checked) {
    viewModel.uncheck(item)
    } else {
    viewModel.check(item)
    }
    }
    }
    }
    binding.recyclerView.adapter = adapter
    

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    dataSource?.invalidate()
    

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    dataSource?.invalidate()
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    @Override
    protected PagedList compute() {
    @Nullable Key initializeKey = initialLoadKey;
    if (mList != null) {
    initializeKey = (Key) mList.getLastKey();
    }
    do {
    if (mDataSource != null) {
    mDataSource.removeInvalidatedCallback(mCallback);
    }
    mDataSource = dataSourceFactory.create();
    mDataSource.addInvalidatedCallback(mCallback);
    mList = new PagedList.Builder<>(mDataSource, config)
    .setNotifyExecutor(notifyExecutor)
    .setFetchExecutor(fetchExecutor)
    .setBoundaryCallback(boundaryCallback)
    .setInitialKey(initializeKey)
    .build();
    } while (mList.isDetached());
    return mList;
    }
    

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    © DMM.com
    @Override
    protected PagedList compute() {
    @Nullable Key initializeKey = initialLoadKey;
    if (mList != null) {
    initializeKey = (Key) mList.getLastKey();
    }
    do {
    if (mDataSource != null) {
    mDataSource.removeInvalidatedCallback(mCallback);
    }
    mDataSource = dataSourceFactory.create();
    mDataSource.addInvalidatedCallback(mCallback);
    mList = new PagedList.Builder<>(mDataSource, config)
    .setNotifyExecutor(notifyExecutor)
    .setFetchExecutor(fetchExecutor)
    .setBoundaryCallback(boundaryCallback)
    .setInitialKey(initializeKey)
    .build();
    } while (mList.isDetached());
    return mList;
    }
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    dataSource?.invalidate()
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    @Nullable Key initializeKey = initialLoadKey;
    if (mList != null) {
    initializeKey = (Key) mList.getLastKey();
    }
    ͳ͔ͥ
    @Nullable
    @Override
    public Object getLastKey() {
    return mDataSource.getKey(mLastLoad, mLastItem);
    }
    ContiguousPagedList
    

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    @Nullable Key initializeKey = initialLoadKey;
    if (mList != null) {
    initializeKey = (Key) mList.getLastKey();
    }
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    public Object getLastKey() {
    return mDataSource.getKey(mLastLoad, mLastItem);
    }
    ContiguousPagedList
    PageKeyedDataSource
    final Key getKey(int position, Value item) {
    // don't attempt to persist keys, since we currently don't pass them to initial load
    return null;
    }
    

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    @Nullable Key initializeKey = initialLoadKey;
    if (mList != null) {
    initializeKey = (Key) mList.getLastKey();
    }
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    public Object getLastKey() {
    return mDataSource.getKey(mLastLoad, mLastItem);
    }
    ContiguousPagedList
    PageKeyedDataSource
    final Key getKey(int position, Value item) {
    // don't attempt to persist keys, since we currently don't pass them to initial load
    return null;
    }
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36. X
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    @Dao
    internal interface ItemDao {
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    suspend fun upsert(items: ItemRecord)
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    suspend fun bulkUpsert(items: List)
    @Query("DELETE FROM item")
    suspend fun deleteAll()
    @Query("SELECT * FROM item")
    fun selectAll(): DataSource.Factory
    }
    @Database(
    entities = [ItemRecord::class],
    version = 1,
    exportSchema = false
    )
    internal abstract class InMemDatabase : RoomDatabase() {
    companion object {
    fun create(context: Context): InMemDatabase =
    Room.inMemoryDatabaseBuilder(
    context,
    InMemDatabase::class.java
    ).fallbackToDestructiveMigration().build()
    }
    abstract fun itemDao(): ItemDao
    }
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    @Dao
    internal interface ItemDao {
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    suspend fun upsert(items: ItemRecord)
    @Insert(onConflict = OnConflictStrategy.REPLACE)
    suspend fun bulkUpsert(items: List)
    @Query("DELETE FROM item")
    suspend fun deleteAll()
    @Query("SELECT * FROM item")
    fun selectAll(): DataSource.Factory
    }
    @Database(
    entities = [ItemRecord::class],
    version = 1,
    exportSchema = false
    )
    internal abstract class InMemDatabase : RoomDatabase() {
    companion object {
    fun create(context: Context): InMemDatabase =
    Room.inMemoryDatabaseBuilder(
    context,
    InMemDatabase::class.java
    ).fallbackToDestructiveMigration().build()
    }
    abstract fun itemDao(): ItemDao
    }
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    internal class ItemBoundaryCallback(
    private val itemRepository: ItemRepository,
    private val inMemDatabase: InMemDatabase
    ) : PagedList.BoundaryCallback() {
    private val boundaryCallbackScope = CoroutineScope(Main + Job())
    override fun onZeroItemsLoaded() {
    super.onZeroItemsLoaded()
    if (pageList.isNotEmpty() && pageList[0].isEndPage) return
    boundaryCallbackScope.launch {
    val itemList = itemRepository.findAll(page = 0)
    if (itemList.isNotEmpty()) {
    bulkInsertToDatabase(itemList)
    }
    …
    }
    }
    …
    

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39. X
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    internal class ItemViewModel(
    private val itemRepository: ItemRepository,
    private val inMemDatabase: InMemDatabase
    ) : ViewModel() {
    val itemPagedList = LivePagedListBuilder(
    inMemDatabase.itemDao().selectAll().map { ItemConverter.convertToItem(it) },
    PagedList.Config.Builder()
    .setEnablePlaceholders(false)
    .setPageSize(30)
    .build()
    ).setBoundaryCallback(
    ItemBoundaryCallback(
    itemRepository,
    inMemDatabase
    )
    ).build()
    }
    

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    class RoomActivity : AppCompatActivity() {
    private val viewModel: ItemViewModel by viewModels {
    ItemViewModelFactory(
    ItemRepositoryImpl(),
    InMemDatabase.create(this)
    )
    }
    override fun onCreate(savedInstanceState: Bundle?) {
    super.onCreate(savedInstanceState)
    val binding = DataBindingUtil.setContentView(
    this,
    R.layout.activity_item_list
    )
    val adapter = ItemAdapter(this)
    binding.recyclerView.adapter = adapter
    viewModel.itemPagedList.observe(
    this,
    Observer {
    adapter.submitList(it)
    }
    )
    }
    }
    

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41. X
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    internal class ItemViewModel(
    private val itemRepository: ItemRepository,
    private val inMemDatabase: InMemDatabase
    ) : ViewModel() {
    …
    fun check(item: Item): Job = viewModelScope.launch {
    val newItem = item.copy(checked = true)
    itemRepository.store(newItem)
    inMemDatabase.itemDao().upsert(ItemConverter.convertToRecord(newItem))
    }
    fun uncheck(item: Item): Job = viewModelScope.launch {
    val newItem = item.copy(checked = false)
    itemRepository.store(newItem)
    inMemDatabase.itemDao().upsert(ItemConverter.convertToRecord(newItem))
    }
    }
    

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47. X
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    internal data class Page(
    val itemList: List,
    val isEndPage: Boolean
    )
    internal class ItemDataProvider {
    val sourceLiveData = MutableLiveData>()
    private val _pageList = mutableListOf()
    val pageList: List
    get() = _pageList
    fun addPage(page: Page) {
    _pageList.add(page)
    sourceLiveData.value?.invalidate()
    }
    fun update(item: Item) {
    …
    sourceLiveData.value?.invalidate()
    }
    }
    

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48. X
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    internal class ItemBoundaryCallback(
    private val itemRepository: ItemRepository,
    private val itemDataProvider: ItemDataProvider
    ) : PagedList.BoundaryCallback() {
    private val boundaryCallbackScope = CoroutineScope(Dispatchers.Main + Job())
    override fun onZeroItemsLoaded() {
    super.onZeroItemsLoaded()
    if (itemDataProvider.pageList.isNotEmpty() && itemDataProvider.pageList[0].isEndPage) return
    boundaryCallbackScope.launch {
    val itemList = itemRepository.findAll(page = 0)
    itemDataProvider.addPage(
    page = Page(
    itemList = itemList,
    isEndPage = itemList.isEmpty()
    )
    )
    }
    }
    override fun onItemAtEndLoaded(itemAtEnd: Item) { … }
    

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49. X
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    internal class ItemViewModel(
    private val itemRepository: ItemRepository,
    private val itemDataProvider: ItemDataProvider
    ) : ViewModel() {
    …
    fun check(item: Item): Job = viewModelScope.launch {
    val newItem = item.copy(checked = true)
    itemRepository.store(newItem)
    itemDataProvider.update(newItem)
    }
    fun uncheck(item: Item): Job = viewModelScope.launch {
    val newItem = item.copy(checked = false)
    itemRepository.store(newItem)
    itemDataProvider.update(newItem)
    }
    }
    

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50. X
    © DMM.com
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51. X
    © DMM.com
    ͓ΘΓʹ
    

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52. X
    © DMM.com
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    w 1BHJOH͸ߋ৽͕ೖΓ࢝ΊΔͱਏ͍
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    αϯϓϧίʔυ https://github.com/kgmyshin/paging-sample
    

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53. X
    © DMM.com
    αϯϓϧίʔυ͋Γ㽂
    w ϦʔυΦϯϦʔύλʔϯʢVQEBUFͳ͠ʣ
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    w 3PPN࢖༻ύλʔϯ
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    https://github.com/kgmyshin/paging-sample
    

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