LivePagedListBuilder

public final class LivePagedListBuilder<Key extends Object, Value extends Object>


Builder for LiveData<PagedList> for Java users, given a androidx.paging.DataSource.Factory and a androidx.paging.PagedList.Config.

The required parameters are in the constructor, so you can simply construct and build, or optionally enable extra features (such as initial load key, or BoundaryCallback).

Parameters
<Key extends Object>

Type of input valued used to load data from the DataSource. Must be Int if you're using PositionalDataSource.

<Value extends Object>

Item type being presented.

See also
toLiveData

Summary

Public constructors

<Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull DataSource.Factory<@NonNull Key, @NonNull Value> dataSourceFactory,
    @NonNull PagedList.Config config
)

Creates a LivePagedListBuilder with required parameters.

<Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull DataSource.Factory<@NonNull Key, @NonNull Value> dataSourceFactory,
    @NonNull int pageSize
)

Creates a LivePagedListBuilder with required parameters.

<Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull Function0<@NonNull PagingSource<@NonNull Key, @NonNull Value>> pagingSourceFactory,
    @NonNull PagedList.Config config
)

Creates a LivePagedListBuilder with required parameters.

<Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull Function0<@NonNull PagingSource<@NonNull Key, @NonNull Value>> pagingSourceFactory,
    @NonNull int pageSize
)

Creates a LivePagedListBuilder with required parameters.

Public methods

final @NonNull LiveData<@NonNull PagedList<@NonNull Value>>

Constructs the LiveData<PagedList>.

final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>
setBoundaryCallback(
    @Nullable PagedList.BoundaryCallback<@NonNull Value> boundaryCallback
)

Sets a androidx.paging.PagedList.BoundaryCallback on each PagedList created, typically used to load additional data from network when paging from local storage.

final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

Set the CoroutineScope that page loads should be launched within.

final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

Sets Executor used for background fetching of PagedLists, and the pages within.

final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

First loading key passed to the first PagedList/DataSource.

Public constructors

LivePagedListBuilder

@NonNull
public final <Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull DataSource.Factory<@NonNull Key, @NonNull Value> dataSourceFactory,
    @NonNull PagedList.Config config
)

Creates a LivePagedListBuilder with required parameters.

Parameters
@NonNull DataSource.Factory<@NonNull Key, @NonNull Value> dataSourceFactory

DataSource factory providing DataSource generations.

@NonNull PagedList.Config config

Paging configuration.

LivePagedListBuilder

@NonNull
public final <Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull DataSource.Factory<@NonNull Key, @NonNull Value> dataSourceFactory,
    @NonNull int pageSize
)

Creates a LivePagedListBuilder with required parameters.

This method is a convenience for:

LivePagedListBuilder(dataSourceFactory,
new PagedList.Config.Builder().setPageSize(pageSize).build())
Parameters
@NonNull DataSource.Factory<@NonNull Key, @NonNull Value> dataSourceFactory

DataSource.Factory providing DataSource generations.

@NonNull int pageSize

Size of pages to load.

LivePagedListBuilder

@NonNull
public final <Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull Function0<@NonNull PagingSource<@NonNull Key, @NonNull Value>> pagingSourceFactory,
    @NonNull PagedList.Config config
)

Creates a LivePagedListBuilder with required parameters.

Parameters
@NonNull Function0<@NonNull PagingSource<@NonNull Key, @NonNull Value>> pagingSourceFactory

PagingSource factory providing PagingSource generations.

The returned PagingSource should invalidate itself if the snapshot is no longer valid. If a PagingSource becomes invalid, the only way to query more data is to create a new PagingSource by invoking the supplied pagingSourceFactory.

pagingSourceFactory will invoked to construct a new PagedList and PagingSource when the current PagingSource is invalidated, and pass the new PagedList through the LiveData<PagedList> to observers.

@NonNull PagedList.Config config

Paging configuration.

LivePagedListBuilder

@NonNull
public final <Key extends Object, Value extends Object> LivePagedListBuilder(
    @NonNull Function0<@NonNull PagingSource<@NonNull Key, @NonNull Value>> pagingSourceFactory,
    @NonNull int pageSize
)

Creates a LivePagedListBuilder with required parameters.

This method is a convenience for:

LivePagedListBuilder(pagingSourceFactory,
new PagedList.Config.Builder().setPageSize(pageSize).build())
Parameters
@NonNull Function0<@NonNull PagingSource<@NonNull Key, @NonNull Value>> pagingSourceFactory

PagingSource factory providing PagingSource generations.

The returned PagingSource should invalidate itself if the snapshot is no longer valid. If a PagingSource becomes invalid, the only way to query more data is to create a new PagingSource by invoking the supplied pagingSourceFactory.

pagingSourceFactory will invoked to construct a new PagedList and PagingSource when the current PagingSource is invalidated, and pass the new PagedList through the LiveData<PagedList> to observers.

@NonNull int pageSize

Size of pages to load.

Public methods

build

@NonNull
public final @NonNull LiveData<@NonNull PagedList<@NonNull Value>> build()

Constructs the LiveData<PagedList>.

No work (such as loading) is done immediately, the creation of the first PagedList is deferred until the LiveData is observed.

Returns
@NonNull LiveData<@NonNull PagedList<@NonNull Value>>

The LiveData of PagedLists

setBoundaryCallback

@NonNull
public final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value> setBoundaryCallback(
    @Nullable PagedList.BoundaryCallback<@NonNull Value> boundaryCallback
)

Sets a androidx.paging.PagedList.BoundaryCallback on each PagedList created, typically used to load additional data from network when paging from local storage.

Pass a PagedList.BoundaryCallback to listen to when the PagedList runs out of data to load. If this method is not called, or null is passed, you will not be notified when each PagingSource runs out of data to provide to its PagedList.

If you are paging from a DataSource.Factory backed by local storage, you can set a BoundaryCallback to know when there is no more information to page from local storage. This is useful to page from the network when local storage is a cache of network data.

Note that when using a BoundaryCallback with a LiveData<PagedList>, method calls on the callback may be dispatched multiple times - one for each PagedList/DataSource pair. If loading network data from a BoundaryCallback, you should prevent multiple dispatches of the same method from triggering multiple simultaneous network loads.

Parameters
@Nullable PagedList.BoundaryCallback<@NonNull Value> boundaryCallback

The boundary callback for listening to PagedList load state.

Returns
@NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

this

setCoroutineScope

@NonNull
public final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value> setCoroutineScope(@NonNull CoroutineScope coroutineScope)

Set the CoroutineScope that page loads should be launched within. The set coroutineScope allows a PagingSource to cancel running load operations when the results are no longer needed - for example, when the containing activity is destroyed.

Defaults to GlobalScope.

Parameters
@NonNull CoroutineScope coroutineScope
Returns
@NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

this

setFetchExecutor

@NonNull
public final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value> setFetchExecutor(@NonNull Executor fetchExecutor)

Sets Executor used for background fetching of PagedLists, and the pages within.

The library will wrap this as a kotlinx.coroutines.CoroutineDispatcher.

If not set, defaults to a ExecutorCoroutineDispatcher backed by ArchTaskExecutor.getIOThreadExecutor.

Parameters
@NonNull Executor fetchExecutor

Executor for fetching data from PagingSources.

Returns
@NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

this

setInitialLoadKey

@NonNull
public final @NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value> setInitialLoadKey(@Nullable Key key)

First loading key passed to the first PagedList/DataSource.

When a new PagedList/DataSource pair is created after the first, it acquires a load key from the previous generation so that data is loaded around the position already being observed.

Parameters
@Nullable Key key

Initial load key passed to the first PagedList/DataSource.

Returns
@NonNull LivePagedListBuilder<@NonNull Key, @NonNull Value>

this