Android List View Is not Updating

Question

I am a beginner, When i add music files to Sd card the list view in my Music app isn't updating untill i reboot the device or my genymotion emulator. and the songs are also playing with lagging.

Here is my main Acivity.java code :

import com.techdsk.musicdsk.musicdsk.adapter.CustomAdapter;
import com.techdsk.musicdsk.musicdsk.controls.Controls;
import com.techdsk.musicdsk.musicdsk.service.SongService;
import com.techdsk.musicdsk.musicdsk.util.MediaItem;
import com.techdsk.musicdsk.musicdsk.util.PlayerConstants;
import com.techdsk.musicdsk.musicdsk.util.UtilFunctions;

public class MainActivity extends Activity {
    String LOG_CLASS = "MainActivity";
    CustomAdapter customAdapter = null;
    static TextView playingSong;
    Button btnPlayer;
    static Button btnPause, btnPlay, btnNext, btnPrevious;
    Button btnStop;
    LinearLayout mediaLayout;
    static LinearLayout linearLayoutPlayingSong;
    ListView mediaListView;
    ProgressBar progressBar;
    TextView textBufferDuration, textDuration;
    static ImageView imageViewAlbumArt;
    static Context context;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getActionBar().hide();
        setContentView(R.layout.activity_main);
        context = MainActivity.this;
        init();
    }

    private void init() {
        getViews();
        setListeners();
        playingSong.setSelected(true);
        progressBar.getProgressDrawable().setColorFilter(getResources().getColor(R.color.white), Mode.SRC_IN);
        if(PlayerConstants.SONGS_LIST.size() <= 0){
            PlayerConstants.SONGS_LIST = UtilFunctions.listOfSongs(getApplicationContext());
        }
        setListItems();
    }

    private void setListItems() {
        customAdapter = new CustomAdapter(this,R.layout.custom_list, PlayerConstants.SONGS_LIST);
        mediaListView.setAdapter(customAdapter);
        mediaListView.setFastScrollEnabled(true);
    }

    private void getViews() {
        playingSong = (TextView) findViewById(R.id.textNowPlaying);
        btnPlayer = (Button) findViewById(R.id.btnMusicPlayer);
        mediaListView = (ListView) findViewById(R.id.listViewMusic);
        mediaLayout = (LinearLayout) findViewById(R.id.linearLayoutMusicList);
        btnPause = (Button) findViewById(R.id.btnPause);
        btnPlay = (Button) findViewById(R.id.btnPlay);
        linearLayoutPlayingSong = (LinearLayout) findViewById(R.id.linearLayoutPlayingSong);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        btnStop = (Button) findViewById(R.id.btnStop);
        textBufferDuration = (TextView) findViewById(R.id.textBufferDuration);
        textDuration = (TextView) findViewById(R.id.textDuration);
        imageViewAlbumArt = (ImageView) findViewById(R.id.imageViewAlbumArt);
        btnNext = (Button) findViewById(R.id.btnNext);
        btnPrevious = (Button) findViewById(R.id.btnPrevious);
    }

    private void setListeners() {
        mediaListView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
            @Override
            public void onItemClick(AdapterView<?> parent, View item, int position, long id){
                Log.d("TAG", "TAG Tapped INOUT(IN)");
                PlayerConstants.SONG_PAUSED = false;
                PlayerConstants.SONG_NUMBER = position;
                boolean isServiceRunning = UtilFunctions.isServiceRunning(SongService.class.getName(), getApplicationContext());
                if (!isServiceRunning) {
                    Intent i = new Intent(getApplicationContext(),SongService.class);
                    startService(i);
                } else {
                    PlayerConstants.SONG_CHANGE_HANDLER.sendMessage(PlayerConstants.SONG_CHANGE_HANDLER.obtainMessage());
                }
                updateUI();
                changeButton();
                Log.d("TAG", "TAG Tapped INOUT(OUT)");
            }
        });

        btnPlayer.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this,AudioPlayerActivity.class);
                startActivity(i);
            }
        });
        btnPlay.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Controls.playControl(getApplicationContext());
            }
        });
        btnPause.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Controls.pauseControl(getApplicationContext());
            }
        });
        btnNext.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Controls.nextControl(getApplicationContext());
            }
        });
        btnPrevious.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Controls.previousControl(getApplicationContext());
            }
        });
        btnStop.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent i = new Intent(getApplicationContext(), SongService.class);
                stopService(i);
                linearLayoutPlayingSong.setVisibility(View.GONE);
            }
        });
        imageViewAlbumArt.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Intent i = new Intent(MainActivity.this,AudioPlayerActivity.class);
                startActivity(i);
            }
        });
    }

    @Override
    protected void onResume() {
        super.onResume();
        try{
            boolean isServiceRunning = UtilFunctions.isServiceRunning(SongService.class.getName(), getApplicationContext());
            if (isServiceRunning) {
                updateUI();
            }else{
                linearLayoutPlayingSong.setVisibility(View.GONE);
            }
            changeButton();
            PlayerConstants.PROGRESSBAR_HANDLER = new Handler(){
                @Override
                public void handleMessage(Message msg){
                    Integer i[] = (Integer[])msg.obj;
                    textBufferDuration.setText(UtilFunctions.getDuration(i[0]));
                    textDuration.setText(UtilFunctions.getDuration(i[1]));
                    progressBar.setProgress(i[2]);
                }
            };
        }catch(Exception e){}
    }

    @SuppressWarnings("deprecation")
    public static void updateUI() {
        try{
            MediaItem data = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER);
            playingSong.setText(data.getTitle() + " " + data.getArtist() + "-" + data.getAlbum());
            Bitmap albumArt = UtilFunctions.getAlbumart(context, data.getAlbumId());
            if(albumArt != null){
                imageViewAlbumArt.setBackgroundDrawable(new BitmapDrawable(albumArt));
            }else{
                imageViewAlbumArt.setBackgroundDrawable(new BitmapDrawable(UtilFunctions.getDefaultAlbumArt(context)));
            }
            linearLayoutPlayingSong.setVisibility(View.VISIBLE);
        }catch(Exception e){}
    }

    public static void changeButton() {
        if(PlayerConstants.SONG_PAUSED){
            btnPause.setVisibility(View.GONE);
            btnPlay.setVisibility(View.VISIBLE);
        }else{
            btnPause.setVisibility(View.VISIBLE);
            btnPlay.setVisibility(View.GONE);
        }
    }

    public static void changeUI(){
        updateUI();
        changeButton();
    }
}

Here is my Audioplayer Activity.java Code :

package com.techdsk.musicdsk.musicdsk;


        import android.app.Activity;
        import android.content.Context;
        import android.graphics.Bitmap;
        import android.graphics.PorterDuff.Mode;
        import android.graphics.drawable.BitmapDrawable;
        import android.os.Bundle;
        import android.os.Handler;
        import android.os.Message;
        import android.view.View;
        import android.view.View.OnClickListener;
        import android.widget.Button;
        import android.widget.LinearLayout;
        import android.widget.ProgressBar;
        import android.widget.TextView;
        import com.techdsk.musicdsk.musicdsk.controls.Controls;
        import com.techdsk.musicdsk.musicdsk.service.SongService;
        import com.techdsk.musicdsk.musicdsk.util.PlayerConstants;
        import com.techdsk.musicdsk.musicdsk.util.UtilFunctions;

public class AudioPlayerActivity extends Activity {

    Button btnBack;
    static Button btnPause;
    Button btnNext;
    static Button btnPlay;
    static TextView textNowPlaying;
    static TextView textAlbumArtist;
    static TextView textComposer;
    static LinearLayout linearLayoutPlayer;
    ProgressBar progressBar;
    static Context context;
    TextView textBufferDuration, textDuration;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        getActionBar().hide();
        setContentView(R.layout.audio_player);
        context = this;
        init();
    }

    private void init() {
        getViews();
        setListeners();
        progressBar.getProgressDrawable().setColorFilter(getResources().getColor(R.color.white), Mode.SRC_IN);
        PlayerConstants.PROGRESSBAR_HANDLER = new Handler(){
            @Override
            public void handleMessage(Message msg){
                Integer i[] = (Integer[])msg.obj;
                textBufferDuration.setText(UtilFunctions.getDuration(i[0]));
                textDuration.setText(UtilFunctions.getDuration(i[1]));
                progressBar.setProgress(i[2]);
            }
        };
    }

    private void setListeners() {
        btnBack.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Controls.previousControl(getApplicationContext());
            }
        });

        btnPause.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Controls.pauseControl(getApplicationContext());
            }
        });

        btnPlay.setOnClickListener(new OnClickListener() {

            @Override
            public void onClick(View v) {
                Controls.playControl(getApplicationContext());
            }
        });

        btnNext.setOnClickListener(new OnClickListener() {
            @Override
            public void onClick(View v) {
                Controls.nextControl(getApplicationContext());
            }
        });
    }

    public static void changeUI(){
        updateUI();
        changeButton();
    }

    private void getViews() {
        btnBack = (Button) findViewById(R.id.btnBack);
        btnPause = (Button) findViewById(R.id.btnPause);
        btnNext = (Button) findViewById(R.id.btnNext);
        btnPlay = (Button) findViewById(R.id.btnPlay);
        textNowPlaying = (TextView) findViewById(R.id.textNowPlaying);
        linearLayoutPlayer = (LinearLayout) findViewById(R.id.linearLayoutPlayer);
        textAlbumArtist = (TextView) findViewById(R.id.textAlbumArtist);
        textComposer = (TextView) findViewById(R.id.textComposer);
        progressBar = (ProgressBar) findViewById(R.id.progressBar);
        textBufferDuration = (TextView) findViewById(R.id.textBufferDuration);
        textDuration = (TextView) findViewById(R.id.textDuration);
        textNowPlaying.setSelected(true);
        textAlbumArtist.setSelected(true);
    }

    @Override
    protected void onResume() {
        super.onResume();
        boolean isServiceRunning = UtilFunctions.isServiceRunning(SongService.class.getName(), getApplicationContext());
        if (isServiceRunning) {
            updateUI();
        }
        changeButton();
    }

    public static void changeButton() {
        if(PlayerConstants.SONG_PAUSED){
            btnPause.setVisibility(View.GONE);
            btnPlay.setVisibility(View.VISIBLE);
        }else{
            btnPause.setVisibility(View.VISIBLE);
            btnPlay.setVisibility(View.GONE);
        }
    }

    private static void updateUI() {
        try{
            String songName = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER).getTitle();
            String artist = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER).getArtist();
            String album = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER).getAlbum();
            String composer = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER).getComposer();
            textNowPlaying.setText(songName);
            textAlbumArtist.setText(artist + " - " + album);
            if(composer != null && composer.length() > 0){
                textComposer.setVisibility(View.VISIBLE);
                textComposer.setText(composer);
            }else{
                textComposer.setVisibility(View.GONE);
            }
        }catch(Exception e){
            e.printStackTrace();
        }
        try{
            long albumId = PlayerConstants.SONGS_LIST.get(PlayerConstants.SONG_NUMBER).getAlbumId();
            Bitmap albumArt = UtilFunctions.getAlbumart(context, albumId);
            if(albumArt != null){
                linearLayoutPlayer.setBackgroundDrawable(new BitmapDrawable(albumArt));
            }else{
                linearLayoutPlayer.setBackgroundDrawable(new BitmapDrawable(UtilFunctions.getDefaultAlbumArt(context)));
            }
        }catch(Exception e){
            e.printStackTrace();
        }
    }
}

custom adapter .java code :

package com.techdsk.musicdsk.musicdsk.adapter;

import java.util.ArrayList;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.TextView;
import com.techdsk.musicdsk.musicdsk.R;
import com.techdsk.musicdsk.musicdsk.util.MediaItem;
import com.techdsk.musicdsk.musicdsk.util.UtilFunctions;

public class CustomAdapter extends ArrayAdapter<MediaItem>{

    ArrayList<MediaItem> listOfSongs;
    Context context;
    LayoutInflater inflator;

    public CustomAdapter(Context context, int resource, ArrayList<MediaItem> listOfSongs) {
        super(context, resource, listOfSongs);
        this.listOfSongs = listOfSongs;
        this.context = context;
        inflator = LayoutInflater.from(context);
    }

    private class ViewHolder{
        TextView textViewSongName, textViewArtist, textViewDuration;
    }

    ViewHolder holder;

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        View myView = convertView;
        if(convertView == null){
            myView = inflator.inflate(R.layout.custom_list, parent, false);
            holder = new ViewHolder();
            holder.textViewSongName = (TextView) myView.findViewById(R.id.textViewSongName);
            holder.textViewArtist = (TextView) myView.findViewById(R.id.textViewArtist);
            holder.textViewDuration = (TextView) myView.findViewById(R.id.textViewDuration);
            myView.setTag(holder);
        }else{
            holder = (ViewHolder)myView.getTag();
        }
        MediaItem detail = listOfSongs.get(position);
        holder.textViewSongName.setText(detail.toString());
        holder.textViewArtist.setText(detail.getAlbum() + " - " + detail.getArtist());
        holder.textViewDuration.setText(UtilFunctions.getDuration(detail.getDuration()));
        return myView;
    }
}

Answer 1

Your list is not getting updated because it is not informed about the data change,

the documentation in the ADW explains:

notifyDataSetChanged() Notifies the attached observers that the underlying data has been changed and any View reflecting the data set should refresh itself.

Solution

Notify yor adapter:

customAdapter.notifyDataSetChanged();

Answer 2

when you add the file you can use NotifyDatasetChanged(). this will tell your adapter to refresh its data. So when your source array is updated after adding a new file you can call NotifyDatasetChanged() method.

as Ex. if you have a method named Add() inside your adapter then.

public void Add (item e){
items.add (e);
NotifyDatasetChanged();
}

will refresh your data.