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/*
* Copyright (C) 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.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package android.arch.paging;
import android.support.annotation.NonNull;
import android.support.annotation.RestrictTo;
import android.support.annotation.WorkerThread;
import java.util.Collections;
import java.util.List;
/**
* @param <T> Type loaded by the TiledDataSource.
*
* @deprecated Use {@link PositionalDataSource}
* @hide
*/
@SuppressWarnings("DeprecatedIsStillUsed")
@Deprecated
@RestrictTo(RestrictTo.Scope.LIBRARY_GROUP)
public abstract class TiledDataSource<T> extends PositionalDataSource<T> {
@WorkerThread
public abstract int countItems();
@Override
boolean isContiguous() {
return false;
}
@WorkerThread
public abstract List<T> loadRange(int startPosition, int count);
@Override
public void loadInitial(int requestedStartPosition, int requestedLoadSize, int pageSize,
@NonNull InitialLoadCallback callback) {
int totalCount = countItems();
if (totalCount == 0) {
callback.onResult(Collections.<T>emptyList(), 0, 0);
return;
}
// bound the size requested, based on known count
final int firstLoadPosition = computeFirstLoadPosition(
requestedStartPosition, requestedLoadSize, pageSize, totalCount);
final int firstLoadSize = Math.min(totalCount - firstLoadPosition, requestedLoadSize);
// convert from legacy behavior
List<T> list = loadRange(firstLoadPosition, firstLoadSize);
if (list != null) {
callback.onResult(list, firstLoadPosition, totalCount);
} else {
invalidate();
}
}
@Override
public void loadRange(int startPosition, int count, @NonNull LoadCallback callback) {
List<T> list = loadRange(startPosition, count);
if (list != null) {
callback.onResult(list);
} else {
invalidate();
}
}
}
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