Android Open Source - DroidDoesMusic Playlist Manager

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License

The source code is released under:
Copyright (C) 2011 by Michael Rose, Nick Hansen, Joe Zeimen Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Soft...
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Java Source Code

package com.uid.DroidDoesMusic.util;
/*  w w w  .java2  s.com*/
import java.util.HashMap;

import android.content.ContentResolver;
import android.content.ContentValues;
import android.content.Context;
import android.content.SharedPreferences;
import android.database.Cursor;
import android.net.Uri;
import android.preference.PreferenceManager;
import android.provider.MediaStore;
import android.provider.MediaStore.Audio;
import android.util.Log;
import android.widget.ListAdapter;
import android.widget.SimpleCursorAdapter;
import android.widget.Toast;

import com.uid.DroidDoesMusic.player.Player;


/**
 * A class to manage all of the playlists for DroidDoesMusic.
 * @author jzeimen
 */
public class PlaylistManager {
  static private PlaylistManager instance;
  Context context;
  private ContentResolver cr;
  private static final String TAG = new String("DroidDoesMusic");
  private static Player mPlayer;
  private static boolean isPlayerBound;
  private static Cursor mMembersCursor;
  private static Cursor mPlaylistCursor;
  private static int mPosition;
  private static int mCurrentPlaylist;
  private static Cursor mCurrentPlaylistMembers;
  private static final String [] STAR = {"*"};
  private static SharedPreferences sp;
  

  //Positions in the next song string array
  public static final String ARTIST="ARTIST";
  public static final String ALBUM="ALBUM";
  public static final String TITLE="TITLE";
  public static final String DATAPATH="DATAPATH";
  public static final String ID = "_ID";


  /**
   * Private constructor due to Singleton pattern.
   * @param context
   */
  private PlaylistManager(Context context){

    this.context = context;
    this.cr = context.getContentResolver();
    PlaylistManager.sp = PreferenceManager.getDefaultSharedPreferences(context);

    mCurrentPlaylist = PlaylistManager.sp.getInt("PlaylistCurrentPlaylistId", 0);
  }

  /**
   * This class is a Singleton pattern so you should get the instance that is
   * all ready running.
   * Pass in the context usually just type "this" into the function; 
   * @param context
   * @return
   */
  public static PlaylistManager getInstance(Context context){
    if(instance == null){
      return new PlaylistManager(context);
    } else return instance;
  }

  /**
   * Lists the current playlists on the device in a SimpleCursorAdapter.
   * @return
   */
  public SimpleCursorAdapter listPlaylists(){

    String[] projection = {Audio.Playlists._ID,Audio.Playlists.NAME};
    String[] displayColumns = {Audio.Playlists.NAME};
    int layout = android.R.layout.simple_list_item_1;
    int[] display = new int[] { android.R.id.text1};

    mPlaylistCursor = cr.query(android.provider.MediaStore.Audio.Playlists.EXTERNAL_CONTENT_URI, projection, null, null, Audio.Playlists.DEFAULT_SORT_ORDER);

    try{
      mPlaylistCursor.moveToFirst();
    } catch (NullPointerException e){
      return null;
    }
    //TODO this line causes something crazy to happen if there is no music
    //Log.d("DroidDoesMusic","Here I am:   "+mCur.getInt(mCur.getColumnIndex(Audio.Playlists._ID)));
    SimpleCursorAdapter adapter = new SimpleCursorAdapter(context,layout,mPlaylistCursor,displayColumns,display);

    return adapter;
  }



  
  /**
   * Returns the AUDIO_ID of the song at a specific position
   * returns -1 if none exists
   * @param pos
   * @return
   */
  public int getSongIdAtPosition(int pos){
    int old = mMembersCursor.getPosition();
    int id=-1;
    if (mMembersCursor.moveToPosition(pos)){
      id = mMembersCursor.getInt(mMembersCursor.getColumnIndex(Audio.Playlists.Members.AUDIO_ID));
    }
    mMembersCursor.moveToPosition(old);
    return id;
  }

  public void setPlaylistId(int playlistId){
    PlaylistManager.mCurrentPlaylist = playlistId;

    SharedPreferences.Editor e = sp.edit();
    e.putInt("PlaylistCurrentPlaylistId", playlistId);
    e.commit();
  }
  
  
  
  /**
   * Prints the songs in the playlist given by the playlistId.
   * @param playlistId
   * @return
   */
  public ListAdapter listSongs( int playlistId){
    
    ListAdapter adapter;
    String[] displayColumns = {Audio.AudioColumns.TITLE};
    int layout = android.R.layout.simple_list_item_1;
    int[] display = new int[] { android.R.id.text1};
    Uri membersUri = MediaStore.Audio.Playlists.Members.getContentUri("external", playlistId);
    mMembersCursor = cr.query(membersUri, STAR, null, null, Audio.Playlists.Members.PLAY_ORDER+" DESC");
    adapter = new SimpleCursorAdapter(context,layout,mMembersCursor,displayColumns,display);
    //songExists(0);
    return adapter;
  }
  
  
  /**
   * Returns a string array for info on the next song.
   * use PlaylistManager.ARTIST, PlaylistManager.ALBUM
   * PlaylistManager.TITLE, PlaylistManager.DATAPATH for the
   * indexes on the string array.
   * Returns null if no next song.
   * 
   * @return
   */
  public HashMap<String,String> nextSong(){
    HashMap<String,String> hashmap = new HashMap<String,String>();
    Uri membersUri = MediaStore.Audio.Playlists.Members.getContentUri("external", mCurrentPlaylist);
    Cursor currentSongQuery = cr.query(membersUri, STAR, null, null, Audio.Playlists.Members.PLAY_ORDER+" DESC");
    currentSongQuery = mMembersCursor;
    
    if(currentSongQuery!=null){
      if(currentSongQuery.moveToPosition(mPosition)){
        
        if(currentSongQuery.moveToNext()){
          this.mPosition++;
          hashmap.put(ARTIST,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.ARTIST)));
          hashmap.put(ALBUM,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.ALBUM)));
          hashmap.put(TITLE,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.TITLE)));
          hashmap.put(DATAPATH,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.DATA)));
          hashmap.put(ID,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media._ID)));
          return hashmap;  
        } else {
          Log.d(TAG, "Could not move to next");
          return null;
        }
      } else {
        Log.d(TAG, "Could not move to position "+mPosition);
        return null;
      }
    } else {
      Log.d(TAG,"Current song query is null");
      return null;
    }
  }


  /**
   * Returns a string array for info on the previous song.
   * use PlaylistManager.ARTIST, PlaylistManager.ALBUM
   * PlaylistManager.TITLE, PlaylistManager.DATAPATH for the
   * indexes on the string array.
   * Returns null if no next song.
   * 
   * @return
   */
  public HashMap<String,String> previousSong(){
    HashMap<String,String> hashmap = new HashMap<String,String>();
    Uri membersUri = MediaStore.Audio.Playlists.Members.getContentUri("external", mCurrentPlaylist);
    Cursor currentSongQuery = cr.query(membersUri, STAR, null, null, Audio.Playlists.Members.PLAY_ORDER+" DESC");
    if(currentSongQuery!=null){
      if(currentSongQuery.moveToPosition(mPosition)){
        if(currentSongQuery.moveToPrevious()){
          this.mPosition--;
          hashmap.put(ARTIST,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.ARTIST)));
          hashmap.put(ALBUM,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.ALBUM)));
          hashmap.put(TITLE,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.TITLE)));
          hashmap.put(DATAPATH,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.DATA)));
          hashmap.put(ID,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media._ID)));
          return hashmap;  
        } else {
          return null;
        }
      } else {
        return null;
      }
    } else {
      return null;
    }
  }


  /**
   *returns a hasmap with info about the current song
   * use PlaylistManager.ARTIST, PlaylistManager.ALBUM
   * PlaylistManager.TITLE, PlaylistManager.DATAPATH for the
   * keys.
   * Returns null if there is no known current song
   * @return
   */
  public HashMap<String,String> currentSong(){
    HashMap<String,String> hashmap = new HashMap<String,String>();
    Uri membersUri = MediaStore.Audio.Playlists.Members.getContentUri("external", mCurrentPlaylist);
    Cursor currentSongQuery = cr.query(membersUri, STAR, null, null, Audio.Playlists.Members.PLAY_ORDER+" DESC");
    if(currentSongQuery!=null){
      if(currentSongQuery.moveToPosition(mPosition)){
        String song [] = new String[4];
        hashmap.put(ARTIST,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.ARTIST)));
        hashmap.put(ALBUM,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.ALBUM)));
        hashmap.put(TITLE,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.TITLE)));
        hashmap.put(DATAPATH,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media.DATA)));
        hashmap.put(ID,currentSongQuery.getString(currentSongQuery.getColumnIndex(Audio.Media._ID)));
        //Toast.makeText(context,"current playlist id: "+mCurrentPlaylist, Toast.LENGTH_SHORT).show();
        return hashmap;  
      }else {
        return null;
      }
    } else {
      return null;
    }
  } 



  //borrowed from http://stackoverflow.com/questions/3182937
  public void addToPlaylist(ContentResolver resolver, int audioId) {

    String[] cols = new String[] {
        "count(*)"
    };
    Uri uri = MediaStore.Audio.Playlists.Members.getContentUri("external", mCurrentPlaylist);

    Cursor cur = resolver.query(uri, cols, null, null, null);
    cur.moveToFirst();
    final int base = cur.getInt(0);
    cur.close();
    ContentValues values = new ContentValues();
    values.put(MediaStore.Audio.Playlists.Members.PLAY_ORDER, base+audioId);
    values.put(MediaStore.Audio.Playlists.Members.AUDIO_ID, audioId);
    uri=resolver.insert(uri, values);

  }

  public boolean removeFromPlaylist(ContentResolver resolver, int audioId) {

    String[] cols = new String[] {
        "count(*)"
    };
    Uri uri = MediaStore.Audio.Playlists.Members.getContentUri("external", mCurrentPlaylist);
    Cursor cur = resolver.query(uri, cols, null, null, null);
    cur.moveToFirst();
    final int base = cur.getInt(0);
    cur.close();
    ContentValues values = new ContentValues();
    //Toast.makeText(context,"uri path just deleted song: "+uri.getPath(), Toast.LENGTH_SHORT).show();
    return 0<resolver.delete(uri, MediaStore.Audio.Playlists.Members.AUDIO_ID +" = "+audioId, null);
  }


  /**
   * Returns a Uri to that can be used to query the currently selected playlist.
   * @return
   */
  public Uri getCurrentPlaylistUri(){
    return MediaStore.Audio.Playlists.Members.getContentUri("external", mCurrentPlaylist);
  }
  /**
   * Set's the song we are on in the playlist.
   * @param position
   */
  public void setPosition(int position) {
    mPosition = position;
  }
  /**
   * Sets the playlist we are using.
   * @param playlistId
   */
  public void setSelectedPlaylist(int playlistId){
    this.setPlaylistId(playlistId);
  }

  public boolean addToCurrentPlaylist(int id) {
    //    Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
    //    ContentResolver cr = context.getContentResolver();
    //    Cursor cur = cr.query(Audio.Media.EXTERNAL_CONTENT_URI, STAR, null, null, null);
    //    cur.moveToFirst();
    //    int id2=cur.getInt(cur.getColumnIndex(Audio.Media._ID));
    this.addToPlaylist(context.getContentResolver(), id);
    return true;
  }

  public boolean removeFromCurrentPlaylist(int id) {
    return removeFromPlaylist(context.getContentResolver(), id);
  }

  public int getCurrentPlaylistId() {
    // TODO Auto-generated method stub
    return this.mCurrentPlaylist;
  }

  
  /**
   * If it returns -1 there is no such playlist
   * if not it returns the playlist id
   * @param name
   * @return
   */
  public int idForPlaylist(String name){
    int id;
    ContentResolver cr = context.getContentResolver();
    Cursor c =cr.query(MediaStore.Audio.Playlists.EXTERNAL_CONTENT_URI, new String[] { MediaStore.Audio.Playlists._ID }, MediaStore.Audio.Playlists.NAME + "=?",
        new String[] { name }, MediaStore.Audio.Playlists.DEFAULT_SORT_ORDER);
    id=-1;
    if (c != null){
      c.moveToFirst();
      if (!c.isAfterLast()) {
        id = c.getInt(0);
      }
      c.close();
    }

    return id;
  }
  
  /**
   * Creates a playlist unless there is already a playlist called by that name 
   * @param value
   */
  public void createPlaylist(String value) {
    if(value!=null && value.length()>0){

      int id = idForPlaylist(value);
      Uri uri;
      if (id < 0) {
        ContentValues values = new ContentValues(1);
        values.put(MediaStore.Audio.Playlists.NAME, value);
        uri = context.getContentResolver().insert(MediaStore.Audio.Playlists.EXTERNAL_CONTENT_URI, values);
      }
    }
  }

  public int deletePlaylist(int position) {
    if (mPlaylistCursor.moveToPosition(position)){
      int Playlist_Id = mPlaylistCursor.getInt(mPlaylistCursor.getColumnIndex(Audio.Playlists._ID));
      //Toast.makeText(context,"uri path just deleted song: "+uri.getPath(), Toast.LENGTH_SHORT).show();
      return cr.delete(MediaStore.Audio.Playlists.EXTERNAL_CONTENT_URI, MediaStore.Audio.Playlists._ID +" = "+ Playlist_Id, null);      
    } else return 0;
  }

  public boolean songExists(int audioId){
    String filter = Audio.Media._ID;
    int colcount = mMembersCursor.getColumnCount(); 
    Uri idUri = MediaStore.Audio.Playlists.Members.getContentUri("external", this.mCurrentPlaylist);
    String[] proj = {Audio.Media._ID};
    
    Cursor cur = cr.query(idUri, proj, null, null, Audio.Playlists.Members.DEFAULT_SORT_ORDER);
    cur.moveToFirst();
    for (int i=0;i<colcount;i++){
      Log.d(TAG,"column: " +i+" = "+cur.getColumnIndex(MediaStore.Audio.Playlists.Members._ID)+  " = " + cur.getString(i));
    }
    
  //  cr.query(Audio.Media.EXTERNAL_CONTENT_URI, {"*"}, selection, selectionArgs, sortOrder)
    return true;
    
  }

}
Java Source Code List
