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/*
* Copyright (C) 2014 Google Inc. All Rights Reserved.
*
* 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.example.android.musicservicedemo.utils;
import android.media.MediaMetadata;
/**
* Utility class to help on queue related tasks.
*/
public class MediaIDHelper {
private static final String TAG = "MediaIDHelper";
// Media IDs used on browseable items of MediaBrowser
public static final String MEDIA_ID_ROOT = "__ROOT__";
public static final String MEDIA_ID_MUSICS_BY_GENRE = "__BY_GENRE__";
public static final String createTrackMediaID(String categoryType, String categoryValue,
MediaMetadata track) {
// MediaIDs are of the form <categoryType>/<categoryValue>|<musicUniqueId>, to make it easy to
// find the category (like genre) that a music was selected from, so we
// can correctly build the playing queue. This is specially useful when
// one music can appear in more than one list, like "by genre -> genre_1"
// and "by artist -> artist_1".
return categoryType + "/" + categoryValue + "|" +
track.getString(MediaMetadata.METADATA_KEY_MEDIA_ID);
}
public static final String createBrowseCategoryMediaID(String categoryType, String categoryValue) {
return categoryType + "/" + categoryValue;
}
/**
* Extracts unique musicID from the mediaID. mediaID is, by this sample's convention, a
* concatenation of category (eg "by_genre"), categoryValue (eg "Classical") and unique
* musicID. This is necessary so we know where the user selected the music from, when the music
* exists in more than one music list, and thus we are able to correctly build the playing queue.
*
* @param musicID
* @return
*/
public static final String extractMusicIDFromMediaID(String musicID) {
String[] segments = musicID.split("\\|", 2);
return segments.length == 2 ? segments[1] : null;
}
/**
* Extracts category and categoryValue from the mediaID. mediaID is, by this sample's
* convention, a concatenation of category (eg "by_genre"), categoryValue (eg "Classical") and
* mediaID. This is necessary so we know where the user selected the music from, when the music
* exists in more than one music list, and thus we are able to correctly build the playing queue.
*
* @param mediaID
* @return
*/
public static final String[] extractBrowseCategoryFromMediaID(String mediaID) {
if (mediaID.indexOf('|') >= 0) {
mediaID = mediaID.split("\\|")[0];
}
if (mediaID.indexOf('/') == 0) {
return new String[]{mediaID, null};
} else {
return mediaID.split("/", 2);
}
}
public static final String extractBrowseCategoryValueFromMediaID(String mediaID) {
String[] categoryAndValue = extractBrowseCategoryFromMediaID(mediaID);
if (categoryAndValue != null && categoryAndValue.length == 2) {
return categoryAndValue[1];
}
return null;
}
}
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