com.laevatein.internal.loader.AlbumLoader.java Source code

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Here is the source code for com.laevatein.internal.loader.AlbumLoader.java

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/*
 * Copyright (C) 2014 nohana, Inc.
 *
 * 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 com.laevatein.internal.loader;

import com.laevatein.internal.entity.Album;

import android.content.Context;
import android.database.Cursor;
import android.database.MatrixCursor;
import android.database.MergeCursor;
import android.provider.MediaStore;
import android.support.v4.content.CursorLoader;

/**
 * Wrapper for {@link android.support.v4.content.CursorLoader} to merge custom cursors.
 * @author KeithYokoma
 * @since 2014/03/26
 * @version 1.0.0
 * @hide
 */
public class AlbumLoader extends CursorLoader {
    public static final String TAG = AlbumLoader.class.getSimpleName();
    private static final String[] PROJECTION = { MediaStore.Images.Media.BUCKET_ID,
            MediaStore.Images.Media.BUCKET_DISPLAY_NAME, MediaStore.Images.Media._ID };
    private static final String BUCKET_GROUP_BY = "1) GROUP BY 1,(2";
    private static final String BUCKET_ORDER_BY = "MAX(datetaken) DESC";
    private static final String MEDIA_ID_DUMMY = String.valueOf(-1);

    public AlbumLoader(Context context) {
        super(context, MediaStore.Images.Media.EXTERNAL_CONTENT_URI, PROJECTION, BUCKET_GROUP_BY, null,
                BUCKET_ORDER_BY);
    }

    @Override
    public Cursor loadInBackground() {
        Cursor albums = super.loadInBackground();
        MatrixCursor allAlbum = new MatrixCursor(PROJECTION);
        allAlbum.addRow(new String[] { Album.ALBUM_ID_ALL, Album.ALBUM_NAME_ALL, MEDIA_ID_DUMMY });

        return new MergeCursor(new Cursor[] { allAlbum, albums });
    }
}