Twidere-App-Android-Twitter.../twidere.component.common/src/main/java/org/mariotaku/twidere/model/ObjectCursor.java

86 lines
2.4 KiB
Java

/*
* Twidere - Twitter client for Android
*
* Copyright (C) 2012-2015 Mariotaku Lee <mariotaku.lee@gmail.com>
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package org.mariotaku.twidere.model;
import android.database.Cursor;
import android.support.annotation.NonNull;
import android.util.SparseArray;
import java.util.AbstractList;
/**
* Created by mariotaku on 15/7/5.
*/
public class ObjectCursor<E> extends AbstractList<E> {
private final Cursor mCursor;
private final CursorIndices<E> mIndices;
private final SparseArray<E> mCache;
public ObjectCursor(@NonNull Cursor cursor, @NonNull CursorIndices<E> indies) {
mCursor = cursor;
mIndices = indies;
mCache = new SparseArray<>();
}
@Override
public E get(final int location) {
ensureCursor();
final int idxOfCache = mCache.indexOfKey(location);
if (idxOfCache >= 0) return mCache.valueAt(idxOfCache);
if (mCursor.moveToPosition(location)) {
final E object = get(mCursor, mIndices);
mCache.put(location, object);
return object;
}
throw new ArrayIndexOutOfBoundsException("length=" + mCursor.getCount() + "; index=" + location);
}
private void ensureCursor() {
if (mCursor.isClosed()) throw new IllegalStateException("Cursor is closed");
}
protected E get(final Cursor cursor, final CursorIndices<E> indices) {
return indices.newObject(cursor);
}
@Override
public int size() {
return mCursor.getCount();
}
public boolean isClosed() {
return mCursor.isClosed();
}
public void close() {
mCursor.close();
}
public static abstract class CursorIndices<T> {
public CursorIndices(@NonNull Cursor cursor) {
}
abstract T newObject(Cursor cursor);
}
}