The- loadInitial method is not called in PositionalDataSource… here is a solution to the problem.
The- loadInitial method is not called in PositionalDataSource
I implemented PositionalDataSource
from the Paging library in Java and ran into a problem where the constructor of the subclass of PositionalDataSource was called, but the loadInitial method was not called afterwards.
public HistoryPositionalDataSource(List<CallTable> callLogs)
{
this.callLogs = callLogs;
Log.d("PaginationDataSource", "Constructor");
}
@Override
public void loadInitial(@NonNull LoadInitialParams params, @NonNull LoadInitialCallback callback) {
Log.d("PaginationDataSource", "loadInitial");
if (callLogs!=null && !callLogs.isEmpty())
{
int totalCount = computeCount();
int position = computeInitialLoadPosition(params, totalCount);
int loadSize = computeInitialLoadSize(params, position, totalCount);
callback.onResult(loadRangeInternal(position, loadSize), position, totalCount);
}
}
@Override
public void loadRange(@NonNull LoadRangeParams params, @NonNull LoadRangeCallback callback) {
callback.onResult(loadRangeInternal(params.startPosition, params.loadSize));
}
This is my PageListConfig
private void init() {
pagedListConfig = (new PagedList.Config.Builder()).setEnablePlaceholders(true)
.setInitialLoadSizeHint(Integer.MAX_VALUE).setPageSize(Integer.MAX_VALUE).build();
Executor executor = Executors.newFixedThreadPool(3);
List<CallTable> listLogs = getCallLogs(context);
historyDataSourceFactory = new HistoryDataSourceFactory(listLogs);
LivePagedListBuilder livePagedListBuilder = new LivePagedListBuilder(historyDataSourceFactory, pagedListConfig);
pagedCallLogs = livePagedListBuilder
.setFetchExecutor(executor)
.build();
}
Factory Class:
public class HistoryDataSourceFactory extends DataSource.Factory {
private static final String TAG = HistoryDataSourceFactory.class.getSimpleName();
private HistoryPositionalDataSource historyPositionalDataSource;
public HistoryDataSourceFactory(List<CallTable> callLogs)
{
if (callLogs!=null && !callLogs.isEmpty())
{
Log.d("PaginationFactory", "NotNullLogs");
historyPositionalDataSource = new HistoryPositionalDataSource(callLogs);
}
}
@Override
public DataSource create() {
return historyPositionalDataSource;
}
}
My getPagedCallLogs method:
public synchronized LiveData<PagedList<CallTable>> getPagedCallLogs() {
if (pagedCallLogs!=null && pagedCallLogs.getValue()!=null)
{
Log.d("PagingGetData", "Done");
return pagedCallLogs;
}
else
{
Log.d("PagingGetData", "Null");
return null;
}
}
The log image is as follows.
Solution
Set the load size and offset
With PagedList.Config,
you don’t have to calculate the load range yourself.
Change your loadInitial
functionality
@Override
public void loadInitial(@NonNull LoadInitialParams params, @NonNull LoadInitialCallback callback) {
Log.d("PaginationDataSource", "loadInitial");
if (callLogs!=null && !callLogs.isEmpty())
{
callback.onResult(loadRangeInternal(0, params.requestedLoadSize), 0);
}
}
Edit:
Try this configuration as well
PagedList.Config config =
new PagedList.Config.Builder()
.setPageSize(50)
.setEnablePlaceholders(false)
.setPrefetchDistance(25)
.build();
Edit 2:
Try changing the extension from DataSource.Factory to DataSource.Factory< Integer, ModelClass>
and PositionalDataSource to PositionalDataSource
< ModelClass>