PlayList Task va08

PlayList.java

import java.io.BufferedReader;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.LinkedList;
import java.util.List;

public class PlayList {

       private LinkedList<AudioFile> audioFiles;
       private int currentPosition;

       /*
       Constructorul implicit care initializeaza o PlayList goala
       */
       public PlayList() {
            audioFiles = new LinkedList<>();
            currentPosition = -1; //pozitie invalida pentru inceput
       }
       /*
       constructor care initializeaza
       */
       public PlayList(String pathname) {
           this();//initializeaza obiectul folosind contructorul implicit
           loadFromM3U(pathname);
       }

       /**
         Adauga un fisier audio in lista
         @param file fisierul audio de adaugat
       */
       public void add(AudioFile file) {
           if(file != null) {
             audioFiles.add( file );
           }
       }

       public void remove(AudioFile file) {

           audioFiles.remove(file);

           //actualizam currentPosition daca este necesar
           if(audioFiles.isEmpty()) currentPosition = -1;

           else if(currentPosition >= audioFiles.size()) {
             currentPosition = 0;
           }
       }

       public int size() {

           return audioFiles.size();
       }

       public void setCurrent(int position) {

             currentPosition = position;
       }

       public int getPosition() {
            return currentPosition;
       }

       public void nextSong() {

             if(audioFiles.isEmpty()) {
                 currentPosition = -1;
                 return;
             }

             //incrementeaza pozitia si gestioneaza ciclicitatea
             currentPosition = ( currentPosition + 1 ) % audioFiles.size();
       }

       public List<AudioFile> getList() {

              return audioFiles;
       }

       public AudioFile currentAudioFile() {

             if(currentPosition >= 0 && currentPosition < audioFiles.size()) return audioFiles.get(currentPosition);

             return null;
       }


       public void loadFromM3U( String pathname ) {

             //reset the PlayList
             audioFiles.clear();
             currentPosition = -1;

             try {

                  String line;

                  while((line=reader.readLine()) != null) {

                      line = line.trim();

                      //skip comments
                      if(line.isEmpty() || line.startsWith("#")) {

                          continue;
                      }

                      try {

                          AudioFile audioFile = AudioFileFactory.createAudioFile( line );

                          add( audioFile );

                      } catch(RuntimeException e) {

                           System.err.println("Skipping file: " + e.getMessage());
                      }

                  }


             } catch(IOException e) {

                  //System.err.println("Error loading playlist from " + pathname + ": " + e.getMessage())
             }

       }

       /**
       Salveaza lista de redare in format M3U
       @param pathname calea catre fisierul de iesire
       */

       public void saveAsM3U( String pathname ) {

                 try {

                      PrintWriter writer = new PrintWriter(new FileWriter(filename));

                      for( AudioFile file: audioFile ) {

                          writer.println( file.getPathname() );
                      }

                 } catch(IOEception e) {

                     System.err.println("Error saving playlist to: " + pathname + ": " + e.getMessage());
                 }
       }