AsyncListUtil

public class AsyncListUtil
extends Object

java.lang.Object
   ↳ androidx.recyclerview.widget.AsyncListUtil<T>


A utility class that supports asynchronous content loading.

It can be used to load Cursor data in chunks without querying the Cursor on the UI Thread while keeping UI and cache synchronous for better user experience.

It loads the data on a background thread and keeps only a limited number of fixed sized chunks in memory at all times.

AsyncListUtil queries the currently visible range through AsyncListUtil.ViewCallback, loads the required data items in the background through AsyncListUtil.DataCallback, and notifies a AsyncListUtil.ViewCallback when the data is loaded. It may load some extra items for smoother scrolling.

Note that this class uses a single thread to load the data, so it suitable to load data from secondary storage such as disk, but not from network.

This class is designed to work with RecyclerView, but it does not depend on it and can be used with other list views.

Summary

Nested classes

class AsyncListUtil.DataCallback<T>

The callback that provides data access for AsyncListUtil

class AsyncListUtil.ViewCallback

The callback that links AsyncListUtil with the list view. 

Public constructors

AsyncListUtil(Class<T> klass, int tileSize, DataCallback<T> dataCallback, AsyncListUtil.ViewCallback viewCallback)

Creates an AsyncListUtil.

Public methods

T getItem(int position)

Returns the data item at the given position or null if it has not been loaded yet.

int getItemCount()

Returns the number of items in the data set.

void onRangeChanged()

Updates the currently visible item range.

void refresh()

Forces reloading the data.

Inherited methods