diff options
Diffstat (limited to 'android/support/v7/recyclerview/extensions/ListAdapterHelper.java')
| -rw-r--r-- | android/support/v7/recyclerview/extensions/ListAdapterHelper.java | 91 |
1 files changed, 41 insertions, 50 deletions
diff --git a/android/support/v7/recyclerview/extensions/ListAdapterHelper.java b/android/support/v7/recyclerview/extensions/ListAdapterHelper.java index d0c7bb3e..bb231b17 100644 --- a/android/support/v7/recyclerview/extensions/ListAdapterHelper.java +++ b/android/support/v7/recyclerview/extensions/ListAdapterHelper.java @@ -1,5 +1,5 @@ /* - * Copyright (C) 2017 The Android Open Source Project + * Copyright 2017 The Android Open Source Project * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. @@ -16,8 +16,8 @@ package android.support.v7.recyclerview.extensions; -import android.arch.lifecycle.LiveData; -import android.support.annotation.RestrictTo; +import android.support.annotation.NonNull; +import android.support.v7.util.AdapterListUpdateCallback; import android.support.v7.util.DiffUtil; import android.support.v7.util.ListUpdateCallback; import android.support.v7.widget.RecyclerView; @@ -25,17 +25,18 @@ import android.support.v7.widget.RecyclerView; import java.util.List; /** - * Helper object for displaying a List in {@link RecyclerView.Adapter RecyclerView.Adapter}, which - * signals the adapter of changes when the List is changed by computing changes with DiffUtil in the + * Helper object for displaying a List in + * {@link android.support.v7.widget.RecyclerView.Adapter RecyclerView.Adapter}, which signals the + * adapter of changes when the List is changed by computing changes with DiffUtil in the * background. * <p> * For simplicity, the {@link ListAdapter} wrapper class can often be used instead of the * helper directly. This helper class is exposed for complex cases, and where overriding an adapter * base class to support List diffing isn't convenient. * <p> - * The ListAdapterHelper can take a {@link LiveData} of List and present the data simply for an - * adapter. It computes differences in List contents via DiffUtil on a background thread as new - * Lists are received. + * The ListAdapterHelper can consume the values from a LiveData of <code>List</code> and present the + * data simply for an adapter. It computes differences in List contents via {@link DiffUtil} on a + * background thread as new <code>List</code>s are received. * <p> * It provides a simple list-like API with {@link #getItem(int)} and {@link #getItemCount()} for an * adapter to acquire and present data objects. @@ -68,10 +69,8 @@ import java.util.List; * } * * class UserAdapter extends RecyclerView.Adapter<UserViewHolder> { - * private final ListAdapterHelper<User> mHelper; - * public UserAdapter(ListAdapterHelper.Builder<User> builder) { - * mHelper = new ListAdapterHelper(this, User.DIFF_CALLBACK); - * } + * private final ListAdapterHelper<User> mHelper = + * new ListAdapterHelper(this, DIFF_CALLBACK); * {@literal @}Override * public int getItemCount() { * return mHelper.getItemCount(); @@ -84,7 +83,8 @@ import java.util.List; * User user = mHelper.getItem(position); * holder.bindTo(user); * } - * public static final DiffCallback<User> DIFF_CALLBACK = new DiffCallback<User>() { + * public static final DiffUtil.ItemCallback<User> DIFF_CALLBACK + * = new DiffUtil.ItemCallback<User>() { * {@literal @}Override * public boolean areItemsTheSame( * {@literal @}NonNull User oldUser, {@literal @}NonNull User newUser) { @@ -107,47 +107,37 @@ public class ListAdapterHelper<T> { private final ListUpdateCallback mUpdateCallback; private final ListAdapterConfig<T> mConfig; - @SuppressWarnings("WeakerAccess") - public ListAdapterHelper(ListUpdateCallback listUpdateCallback, - ListAdapterConfig<T> config) { - mUpdateCallback = listUpdateCallback; - mConfig = config; + /** + * Convenience for + * {@code PagedListAdapterHelper(new AdapterListUpdateCallback(adapter), + * new ListAdapterConfig.Builder().setDiffCallback(diffCallback).build());} + * + * @param adapter Adapter to dispatch position updates to. + * @param diffCallback ItemCallback that compares items to dispatch appropriate animations when + * + * @see DiffUtil.DiffResult#dispatchUpdatesTo(RecyclerView.Adapter) + */ + public ListAdapterHelper(@NonNull RecyclerView.Adapter adapter, + @NonNull DiffUtil.ItemCallback<T> diffCallback) { + mUpdateCallback = new AdapterListUpdateCallback(adapter); + mConfig = new ListAdapterConfig.Builder<>(diffCallback).build(); } /** - * Default ListUpdateCallback that dispatches directly to an adapter. Can be replaced by a - * custom ListUpdateCallback if e.g. your adapter has a header in it, and so has an offset - * between list positions and adapter positions. + * Create a ListAdapterHelper with the provided config, and ListUpdateCallback to dispatch + * updates to. + * + * @param listUpdateCallback Callback to dispatch updates to. + * @param config Config to define background work Executor, and DiffUtil.ItemCallback for + * computing List diffs. * - * @hide + * @see DiffUtil.DiffResult#dispatchUpdatesTo(RecyclerView.Adapter) */ - @RestrictTo(RestrictTo.Scope.LIBRARY_GROUP) - public static class AdapterCallback implements ListUpdateCallback { - private final RecyclerView.Adapter mAdapter; - - public AdapterCallback(RecyclerView.Adapter adapter) { - mAdapter = adapter; - } - - @Override - public void onInserted(int position, int count) { - mAdapter.notifyItemRangeInserted(position, count); - } - - @Override - public void onRemoved(int position, int count) { - mAdapter.notifyItemRangeRemoved(position, count); - } - - @Override - public void onMoved(int fromPosition, int toPosition) { - mAdapter.notifyItemMoved(fromPosition, toPosition); - } - - @Override - public void onChanged(int position, int count, Object payload) { - mAdapter.notifyItemRangeChanged(position, count, payload); - } + @SuppressWarnings("WeakerAccess") + public ListAdapterHelper(@NonNull ListUpdateCallback listUpdateCallback, + @NonNull ListAdapterConfig<T> config) { + mUpdateCallback = listUpdateCallback; + mConfig = config; } private List<T> mList; @@ -173,7 +163,8 @@ public class ListAdapterHelper<T> { /** * Get the number of items currently presented by this AdapterHelper. This value can be directly - * returned to {@link RecyclerView.Adapter#getItemCount()}. + * returned to {@link android.support.v7.widget.RecyclerView.Adapter#getItemCount() + * RecyclerView.Adapter.getItemCount()}. * * @return Number of items being presented. */ |