SongLoader.java

package com.kabouzeid.gramophone.loader;

import android.content.Context;
import android.database.Cursor;
import android.provider.BaseColumns;
import android.provider.MediaStore;
import android.provider.MediaStore.Audio.AudioColumns;
import android.support.annotation.NonNull;
import android.support.annotation.Nullable;

import com.kabouzeid.gramophone.model.Song;
import com.kabouzeid.gramophone.util.PreferenceUtil;

import java.util.ArrayList;

/**
 * @author Karim Abou Zeid (kabouzeid)
 */
public class SongLoader {
    protected static final String BASE_SELECTION = AudioColumns.IS_MUSIC + "=1" + " AND " + AudioColumns.TITLE + " != ''";

    @NonNull
    public static ArrayList<Song> getAllSongs(@NonNull Context context) {
        Cursor cursor = makeSongCursor(context, null, null);
        return getSongs(cursor);
    }

    @NonNull
    public static ArrayList<Song> getSongs(@NonNull final Context context, final String query) {
        Cursor cursor = makeSongCursor(context, AudioColumns.TITLE + " LIKE ?", new String[]{"%" + query + "%"});
        return getSongs(cursor);
    }

    @NonNull
    public static Song getSong(@NonNull final Context context, final int queryId) {
        Cursor cursor = makeSongCursor(context, AudioColumns._ID + "=?", new String[]{String.valueOf(queryId)});
        return getSong(cursor);
    }

    @NonNull
    public static ArrayList<Song> getSongs(@Nullable final Cursor cursor) {
        ArrayList<Song> songs = new ArrayList<>();
        if (cursor != null && cursor.moveToFirst()) {
            do {
                songs.add(getSongFromCursorImpl(cursor));
            } while (cursor.moveToNext());
        }

        if (cursor != null)
            cursor.close();
        return songs;
    }

    @NonNull
    public static Song getSong(@Nullable Cursor cursor) {
        Song song;
        if (cursor != null && cursor.moveToFirst()) {
            song = getSongFromCursorImpl(cursor);
        } else {
            song = Song.EMPTY_SONG;
        }
        if (cursor != null) {
            cursor.close();
        }
        return song;
    }

    @NonNull
    private static Song getSongFromCursorImpl(@NonNull Cursor cursor) {
        final int id = cursor.getInt(0);
        final String title = cursor.getString(1);
        final int trackNumber = cursor.getInt(2);
        final int year = cursor.getInt(3);
        final long duration = cursor.getLong(4);
        final String data = cursor.getString(5);
        final long dateModified = cursor.getLong(6);
        final int albumId = cursor.getInt(7);
        final String albumName = cursor.getString(8);
        final int artistId = cursor.getInt(9);
        final String artistName = cursor.getString(10);

        return new Song(id, title, trackNumber, year, duration, data, dateModified, albumId, albumName, artistId, artistName);
    }

    @Nullable
    public static Cursor makeSongCursor(@NonNull final Context context, @Nullable final String selection, final String[] selectionValues) {
        return makeSongCursor(context, selection, selectionValues, PreferenceUtil.getInstance(context).getSongSortOrder());
    }

    @Nullable
    public static Cursor makeSongCursor(@NonNull final Context context, @Nullable final String selection, final String[] selectionValues, final String sortOrder) {
        String baseSelection = BASE_SELECTION;
        if (selection != null && !selection.trim().equals("")) {
            baseSelection += " AND " + selection;
        }

        try {
            return context.getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
                    new String[]{
                            BaseColumns._ID,// 0
                            AudioColumns.TITLE,// 1
                            AudioColumns.TRACK,// 2
                            AudioColumns.YEAR,// 3
                            AudioColumns.DURATION,// 4
                            AudioColumns.DATA,// 5
                            AudioColumns.DATE_MODIFIED,// 6
                            AudioColumns.ALBUM_ID,// 7
                            AudioColumns.ALBUM,// 8
                            AudioColumns.ARTIST_ID,// 9
                            AudioColumns.ARTIST,// 10

                    }, baseSelection, selectionValues, sortOrder);
        } catch (SecurityException e) {
            return null;
        }
    }
}