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Hello, please tell me how to send ArrayList to another activity

I tried all the possible options that I just found.
I can’t send ArrayList to another activity via the Parcelable interface.
To implement a media player
String format information it sends.
I would be very grateful, maybe there are some other options. This is the first time I'm asking a question here
Here is my activity that I use to send, the code is still very raw
public class MainActivity extends AppCompatActivity {
ScheduledExecutorService scheduledExecutorService;
public MediaPlayer mediaPlayer;
private SeekBar seekBar;
private ImageView btn_Play;
private ImageView btn_Next;
private ImageView btn_Pre;
private TextView setCurrentDuration, setTotalDuration;
private ArrayList<SoundInfo> audioList = new ArrayList<>();
SoundAdapter adapter = new SoundAdapter();
public Handler handler = new Handler();
AudioEffect audioEffect;
private int currentPosition = 0;
private SoundInfo soundInfo = new SoundInfo(this);
SoundEffects soundEffects;
boolean mediaPauseStat = false;
Context context;
PageFragmentOne pageFragmentOne;
//public MainActivity(PageFragmentOne pageFragmentOne) {
// this.pageFragmentOne = pageFragmentOne;
//}
MediaManager mediaManager = new MediaManager(this, adapter, audioList);
#Override
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Старт сервиса
//Intent i = new Intent(this, MediaPlaybackService.class);
//i.putExtra("play", "письмо от главного активити");
//startService(i);
//mediaManager.LoadSounds();
/**
SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionsPagerAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Snackbar.make(view, "Replace with your own action", Snackbar.LENGTH_LONG)
.setAction("Action", null).show();
}
});
**/
////////////////////////////////////////////////////////////////////////////////////////////
setCurrentDuration = findViewById(R.id.current_Duration);
setTotalDuration = findViewById(R.id.total_Duration);
seekBar = findViewById(R.id.seekBar);
RecyclerView list = findViewById(R.id.my_recycler_view);
list.setAdapter(adapter);
list.setLayoutManager(new LinearLayoutManager(this));
// Оформление отображения адаптера
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(this, LinearLayout.VERTICAL);
dividerItemDecoration.setDrawable(getResources().getDrawable(R.drawable.list_item_divider, null));
list.addItemDecoration(dividerItemDecoration);
///////////////////////////////////////////////
soundInfo.setMassive(audioList);
adapter.setOnItemClickListener(new SoundAdapter.OnItemClickListener() {
#Override
public void onClick(View v, final SoundInfo obj, final int position, final ImageView onNext) {
final SoundInfo path = audioList.get(position);
String audioPath = obj.getData();
prepareMedia(position);
// Задаем текующию позицию трека
currentPosition = position;
mediaPlayer.setOnPreparedListener(new MediaPlayer.OnPreparedListener() {
#Override
public void onPrepared(MediaPlayer mediaPlayer) {
// TODO Auto-generated method stub
mediaPlayer.start();
// Всегда должен быть после старта плеера, что бы не вылазило 238
updateProgressBar();
//seekBar.setProgress(0);
seekBar.setMax(mediaPlayer.getDuration());
btn_Play.setImageResource(R.drawable.btn_pause);
}
});
// Перемотка аудио
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onProgressChanged(SeekBar seekBar, int progress, boolean fromUser) {
// Слишком часто обновляет
}
#Override
public void onStartTrackingTouch(final SeekBar seekBar) {
if (mediaPlayer != null) {
soundInfo.setMediaPauseStat(false);
soundInfo.setMediaRewind(false);
mediaPlayer.pause();
seekBar.setOnTouchListener(new View.OnTouchListener() {
#Override
public boolean onTouch(View v, MotionEvent event) {
mediaPlayer.seekTo(seekBar.getProgress());
return false;
}
});
}
}
#Override
public void onStopTrackingTouch(SeekBar seekBar) {
if (mediaPlayer != null) {
soundInfo.setMediaPauseStat(true);
//soundInfo.setMediaRewind(true);
mediaPlayer.start();
}
}
});
// Кнопка проигрывания и паузы
btn_Play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if (!mediaPlayer.isPlaying()) {
onPlay();
} else {
onPaused();
}
}
});
// Следующий трек
btn_Next.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onNext();
}
});
// Предыдущий трек
btn_Pre.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
onPre();
}
});
}
});
init();
}
private MyBroadcastReceiver myReceiver;
#Override
public void onResume() {
super.onResume();
myReceiver = new MyBroadcastReceiver();
final IntentFilter intentFilter = new IntentFilter("YourAction");
LocalBroadcastManager.getInstance(this).registerReceiver(myReceiver, intentFilter);
}
#Override
public void onPause() {
super.onPause();
if (myReceiver != null)
LocalBroadcastManager.getInstance(this).unregisterReceiver(myReceiver);
myReceiver = null;
}
public class MyBroadcastReceiver extends BroadcastReceiver {
#Override
public void onReceive(Context context, Intent intent) {
// String yourValue = b.getString("ser");
Bundle bundle = intent.getExtras();
}
}
public void onMainMediaPlayList(View view) {
final Intent intent2 = new Intent(getApplicationContext(), MainMediaPlayList.class);
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("MEDIA_MASSIVE", audioList);
intent2.putExtras(bundle);
startActivity(intent2);
//Intent i = new Intent(MainActivity.this, MediaPlaybackService.class);
//startService(i);
////////////////////////////////////////////////////////////////////////////////////////////
}
public void init() {
if (ContextCompat.checkSelfPermission(this,
Manifest.permission.READ_EXTERNAL_STORAGE)
!= PackageManager.PERMISSION_GRANTED) {
// Разрешение не предоставляется
// Должны ли мы показать объяснение?
if (ActivityCompat.shouldShowRequestPermissionRationale(this,
Manifest.permission.READ_EXTERNAL_STORAGE)) {
// Показать объяснение пользователю * асинхронно* -- не блокировать
// этот поток ждет ответа пользователя! После пользователя
// увидев объяснение, попробуйте еще раз запросить разрешение.
} else {
// Никаких объяснений не требуется; запросить разрешение
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE,
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.MODIFY_AUDIO_SETTINGS,
Manifest.permission.RECORD_AUDIO},
101);
// MY_PERMISSIONS_REQUEST_READ_CONTACTS является
// app-определенная константа int. Метод обратного вызова получает
// результат запроса.
}
} else {
// Разрешение уже предоставлено
//loadSounds();
mediaManager.LoadSounds();
}
//bPlayPause = findViewById(R.id.bPlayPause);
//lv = (ListView) findViewById(R.id.lvPlayList);
btn_Play = findViewById(R.id.btn_Play);
btn_Next = findViewById(R.id.btn_Next);
btn_Pre = findViewById(R.id.btn_Pre);
}
Here is my SoundInfo
public class SoundInfo implements Parcelable {
private String data, artist, title;
private Context context;
private String pathData;
public SoundInfo(MainActivity context) {
this.context = context;
}
public SoundInfo() {
}
public SoundInfo(MainMediaPlayList context) {
this.context = context;
}
public SoundInfo(MediaPlaybackService mediaPlaybackService, String star) {
this.context = mediaPlaybackService;
this.star = star;
}
protected SoundInfo(Parcel in) {
data = in.readString();
artist = in.readString();
title = in.readString();
pathData = in.readString();
mediaPauseStat = in.readByte() != 0;
ismediaRewind = in.readByte() != 0;
audioList = in.createTypedArrayList(SoundInfo.CREATOR);
star = in.readString();
}
public static final Creator<SoundInfo> CREATOR = new Creator<SoundInfo>() {
#Override
public SoundInfo createFromParcel(Parcel in) {
return new SoundInfo(in);
}
#Override
public SoundInfo[] newArray(int size) {
return new SoundInfo[size];
}
};
public void SoundInfo(String data, String artist, String title) {
this.data = data;
this.artist = artist;
this.title = title;
}
public SoundInfo(String data, String artist, String title) {
this.data = data;
this.artist = artist;
this.title = title;
}
public String getData() {
return data;
}
public String getArtist() {
return artist;
}
public String getTitle() {
return title;
}
public void setData(String artist) {
this.data = data;
}
public void setArtist(String artist) {
this.artist = artist;
}
public void setTitle(String title) {
this.title = title;
}
public void setpathData(String pathData) {
this.pathData = pathData;
}
public String getpathData() {
return pathData;
}
// Запись в память для отображения времени
boolean mediaPauseStat = true;
boolean ismediaRewind = true;
public void setMediaPauseStat(boolean mediaPauseStat) {
this.mediaPauseStat = mediaPauseStat;
}
public boolean getMediaPauseStat() {
return mediaPauseStat;
}
public void setMediaRewind(boolean isMediaRewind) {
this.ismediaRewind = ismediaRewind;
}
public boolean getMediaRewind() {
return ismediaRewind;
}
////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////
////////////////////////////////////////////////////////////////////////////////////////////////
// Массив
private ArrayList<SoundInfo> audioList = new ArrayList<SoundInfo>();
public ArrayList<SoundInfo> getMassive() {
return audioList;
}
public void setMassive(ArrayList<SoundInfo> audioList) {
this.audioList = audioList;
}
private String star;
public String getStar() {
return star;
}
public void setStar(String star) {
this.star = star;
}
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeString(data);
dest.writeString(artist);
dest.writeString(title);
dest.writeString(pathData);
dest.writeByte((byte) (mediaPauseStat ? 1 : 0));
dest.writeByte((byte) (ismediaRewind ? 1 : 0));
dest.writeTypedList(audioList);
dest.writeString(star);
}
}
Here is my adater which I use
public class SoundAdapter extends RecyclerView.Adapter<SoundAdapter.ViewHolder> {
private ArrayList<SoundInfo> audioList = new ArrayList<SoundInfo>();
Context context;
//private String[] items;
private OnItemClickListener onItemClickListener;
public void setItems(Context context, ArrayList<SoundInfo> audioList) {
this.context = context;
this.audioList = audioList;
//audioList.addAll(items);
}
public void setOnItemClickListener(OnItemClickListener onItemClickListener) {
this.onItemClickListener = onItemClickListener;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_audio, parent, false);
return new ViewHolder(v);
}
#Override
public void onBindViewHolder(#NonNull final ViewHolder holder, final int position) {
holder.bind(audioList.get(position));
holder.clickFile.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
final SoundInfo path = audioList.get(position);
onItemClickListener.onClick(view, path, position, holder.onNext);
}
});
}
#Override
public int getItemCount() {
return audioList == null ? 0 : audioList.size();
}
static class ViewHolder extends RecyclerView.ViewHolder {
private TextView data, title, artist;
private ImageView onNext;
private View clickFile;
ViewHolder(View view) {
super(view);
title = view.findViewById(R.id.tvSoundTitle);
artist = view.findViewById(R.id.tvSoundArtist);
clickFile = view.findViewById(R.id.clickFile);
//data = view.findViewById(R.id.item_title);
//onNext = view.findViewById(R.id.imageNext);
}
public void bind(SoundInfo soundInfo) {
title.setText(soundInfo.getTitle());
artist.setText(soundInfo.getArtist());
//clickFile.setText(soundInfo.getData());
}
}
// Передача данных в основной активити
public interface OnItemClickListener {
void onClick(View view, SoundInfo obj, int position, ImageView onNext);
}
}
Here is the second activity that an ArrayList gets.
Bundle bundle = getIntent().getExtras();
ArrayList<SoundInfo> audioList = bundle.getParcelableArrayList("MEDIA_MASSIVE");
adapter.setItems(MainMediaPlayList.this, audioList);
adapter.notifyDataSetChanged();
// загрузка адаптера
RecyclerView list = findViewById(R.id.my_recycler_view);
list.setAdapter(adapter);
list.setLayoutManager(new LinearLayoutManager(MainMediaPlayList.this));
When you open a new activity, the application crashes
does not display any errors in the log, the problem is as I understand that intent can not find
audioList as it seems to me
If I remove the method everything loads
public void onMainMediaPlayList(View view) {
final Intent intent2 = new Intent(getApplicationContext(), MainMediaPlayList.class);
Bundle bundle = new Bundle();
bundle.putParcelableArrayList("MEDIA_MASSIVE", audioList);
intent2.putExtras(bundle);
startActivity(intent2);
Here I took off the launch log, it may somehow help
2020-03-08 18:09:43.406 15730-15730/com.shimmer.myapplication W/r.myapplicatio: Accessing hidden method Landroid/view/View;->computeFitSystemWindows(Landroid/graphics/Rect;Landroid/graphics/Rect;)Z (greylist, reflection, allowed)
2020-03-08 18:09:43.406 15730-15730/com.shimmer.myapplication W/r.myapplicatio: Accessing hidden method Landroid/view/ViewGroup;->makeOptionalFitsSystemWindows()V (greylist, reflection, allowed)
2020-03-08 18:09:43.431 15730-15730/com.shimmer.myapplication I/OverScrollerOptimization: start init SmartSlideOverScroller and get the overscroller config
2020-03-08 18:09:43.431 15730-15730/com.shimmer.myapplication I/OverScrollerOptimization: get the overscroller config
2020-03-08 18:09:43.466 15730-15730/com.shimmer.myapplication D/HwFrameworkSecurityPartsFactory: HwFrameworkSecurityPartsFactory in.
2020-03-08 18:09:43.466 15730-15730/com.shimmer.myapplication I/HwFrameworkSecurityPartsFactory: add HwFrameworkSecurityPartsFactory to memory.
2020-03-08 18:09:43.506 15730-15730/com.shimmer.myapplication D/ActivityThread: add activity client record, r= ActivityRecord{e3185e4 token=android.os.BinderProxy#837d3d7 {com.shimmer.myapplication/com.shimmer.myapplication.MainActivity}} token= android.os.BinderProxy#837d3d7

I don't think so, You can send an ArrayList like this.
I recommend you sending Class instead of sending an Arraylist.
So, just create a class like AudiolistHolder and put your ArrayList inside this class and don't forget to implement Parcelable interface for this class, too, and send this class between activities this should solve your problem. I always use this way.
EDIT:
You can use this to send your data
Intent intent2 = new Intent(this, MainMediaPlayList.class);
MassiveAudioList m = new MassiveAudioList(audioList);
intent2.putExtra("MEDIA_MASSIVE”, m);
startActivity(intent2);
and you can use this in your second activity to retrieve data
MassiveAudioList massiveAudio=getIntent().getParcelableExtra("MEDIA_MASSIVE");
ArrayList<SoundInfo> audioList = massiveAudio.getMassiveAudioList();

Have you tried like this with arraylist
I think it can be,
In MainActivity.java
ArrayList<String> audioList= new ArrayList<>();
audioList.add("ChipThrills");
Intent i = new Intent(MainActivity.this, Secondactivity.class);
i.putExtra("Musickey", audioList);
startActivity(i);
In SecondActivity.java
ArrayList<String> audioList = (ArrayList<String>) getIntent().getSerializableExtra("Musickey");

I am writing to you here because I did not understand how to add code to the comment
And how do I extract data by adding it to an array. If of course I did the right thing, I'm new to this field. Thanks.
public class MassiveAudioList implements Parcelable {
private ArrayList<SoundInfo> audioList = new ArrayList<>();
private Context context;
public MassiveAudioList(Context context) {
this.context = context;
}
public MassiveAudioList(ArrayList audioList) {
this.audioList = audioList;
}
protected MassiveAudioList(Parcel in) {
audioList = in.createTypedArrayList(SoundInfo.CREATOR);
}
public static final Creator<MassiveAudioList> CREATOR = new Creator<MassiveAudioList>() {
#Override
public MassiveAudioList createFromParcel(Parcel in) {
return new MassiveAudioList(in);
}
#Override
public MassiveAudioList[] newArray(int size) {
return new MassiveAudioList[size];
}
};
public ArrayList<SoundInfo> getMassiveAudioList() {
return audioList;
}
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeTypedList(audioList);
}
}
public void onMainMediaPlayList(View view) {
Log.d("TAG", "soundinfo" + soundInfo.getData());
final Intent intent2 = new Intent(getApplicationContext(), MainMediaPlayList.class);
massiveAudioList = new MassiveAudioList(this);
MassiveAudioList m = new MassiveAudioList(audioList);
Bundle bundle = new Bundle();
bundle.putParcelable("MEDIA_MASSIVE", m);
intent2.putExtras(bundle);
startActivity(intent2);
}

Can't get the fragment to bind to the service

I have been searching the internet the whole day but couldn't find the solution. I have a music player service class that plays songs in the background as a service. The problem is I can't get the fragment to bind to this service. No error is being shown in logcat nor the app crashes. When I click on one of the songs nothing happens. This is my code below:
ServiceClass:
public class MediaPlayerService extends Service implements MediaPlayer.OnCompletionListener,
MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener, MediaPlayer.OnSeekCompleteListener,
MediaPlayer.OnInfoListener, MediaPlayer.OnBufferingUpdateListener,
AudioManager.OnAudioFocusChangeListener {
private final IBinder iBinder = new LocalBinder();
private static MediaPlayer mediaPlayer = new MediaPlayer();
private String mediaFile;
private int resumePosition;
private AudioManager audioManager;
//Handle incoming phone calls
private boolean ongoingCall = false;
private PhoneStateListener phoneStateListener;
private TelephonyManager telephonyManager;
private ArrayList<SongInfoModel> songsServiceList = new ArrayList<>();
private int songPosn;
private int currentIndex ;
#Nullable
#Override
public IBinder onBind(Intent intent) {
return iBinder;
}
private void initMediaPlayer() {
//Set up MediaPlayer event listeners
mediaPlayer.setOnCompletionListener(this);
mediaPlayer.setOnErrorListener(this);
mediaPlayer.setOnPreparedListener(this);
mediaPlayer.setOnBufferingUpdateListener(this);
mediaPlayer.setOnSeekCompleteListener(this);
mediaPlayer.setOnInfoListener(this);
//Reset so that the MediaPlayer is not pointing to another data source
mediaPlayer.reset();
mediaPlayer.setAudioStreamType(AudioManager.STREAM_MUSIC);
}
#Override
public void onCreate() {
super.onCreate();
songPosn=0;
initMediaPlayer();
}
public void setList(ArrayList<SongInfoModel> theSongs){
songsServiceList=theSongs;
}
public void setSong(int songIndex){
songPosn=songIndex;
}
public void playSong(){
//play a song
mediaPlayer.reset();
//get song
SongInfoModel playSong = songsServiceList.get(songPosn);
//get id
long currSong = playSong.getSongID();
//set uri
Uri trackUri = ContentUris.withAppendedId(
android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI,
currSong);
try{
mediaPlayer.setDataSource(getApplicationContext(), trackUri);
}
catch(Exception e){
Log.e("MUSIC SERVICE", "Error setting data source", e);
}
mediaPlayer.prepareAsync();
MainActivity.handleSeekbar(mediaPlayer);
}
#Override
public void onBufferingUpdate(MediaPlayer mediaPlayer, int i) {
}
#Override
public void onCompletion(MediaPlayer mediaPlayer) {
mediaPlayer.reset();
songPosn++;
if(songPosn>=songsServiceList.size()) songPosn=0;
playSong();
}
#Override
public boolean onError(MediaPlayer mediaPlayer, int i, int i1) {
return false;
}
#Override
public boolean onInfo(MediaPlayer mediaPlayer, int i, int i1) {
return false;
}
#Override
public void onPrepared(MediaPlayer mediaPlayer) {
if (mediaPlayer.isPlaying()) {
mediaPlayer.stop();
mediaPlayer.reset();
} else {
mediaPlayer.start();
MainActivity.Handler(mediaPlayer);
}
}
public class LocalBinder extends Binder {
public MediaPlayerService getService() {
return MediaPlayerService.this;
}
}
FragmentClass:
public class Songs extends Fragment {
public static final String TAG = "Songs";
RecyclerView recyclerView;
private ArrayList<SongInfoModel> SongList = new ArrayList<SongInfoModel>();
SongAdapter songAdapter;
ScaleInAnimationAdapter alphaAdapter;
private MediaPlayerService player2;
boolean serviceBound2 = false;
private Intent playIntent2;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.songs_activity, container, false);
recyclerView = (RecyclerView) view.findViewById(R.id.recyclerView);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(linearLayoutManager);
songAdapter = new SongAdapter(getContext(), SongList, new SongAdapter.RecyclerItemClickListener() {
#Override
public void onClickListener(SongInfoModel song, int position) {
Toast.makeText(getContext(), song.getSongName(), Toast.LENGTH_SHORT).show();
MainActivity.setsongText(song);
MainActivity.ButtonPlay();
MainActivity.PauseImage();
if(serviceBound2 == true) {
player2.setSong(position);
player2.playSong();
}
}
#Override
public void onLongClickListener(SongInfoModel song, int position) {
Toast.makeText(getContext(), "You long clicked me, thank you!", Toast.LENGTH_SHORT).show();
}
});
Uri uri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String selection = MediaStore.Audio.Media.IS_MUSIC + "!=0";
Cursor cursor = getActivity().getContentResolver().query(uri, null, selection, null, null);
if (cursor != null) {
if (cursor.moveToFirst()) {
do {
long id = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media._ID));
String name = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.TITLE));
String artist = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST));
Long duration = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.DURATION));
String data = cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Media.DATA));
Long albumId = cursor.getLong(cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM_ID));
Uri sArtworkUri = Uri.parse("content://media/external/audio/albumart");
Uri albumArtUri = ContentUris.withAppendedId(sArtworkUri, albumId);
SongInfoModel s = new SongInfoModel(id, name, artist, null, null, null, duration, data,albumArtUri, albumId);
SongList.add(s);
} while (cursor.moveToNext());
}
cursor.close();
Collections.sort(SongList, new Comparator<SongInfoModel>() {
#Override
public int compare(SongInfoModel lhs, SongInfoModel rhs) {
return lhs.getSongName().compareTo(rhs.getSongName());
}
});
}
alphaAdapter = new ScaleInAnimationAdapter(songAdapter);
alphaAdapter.setDuration(1000);
alphaAdapter.setInterpolator(new OvershootInterpolator());
alphaAdapter.setFirstOnly(false);
recyclerView.setAdapter(alphaAdapter);
songAdapter.notifyDataSetChanged();
return view;
}
//Binding this Client to the AudioPlayer Service
private ServiceConnection serviceConnection2 = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
// We've bound to LocalService, cast the IBinder and get LocalService instance
MediaPlayerService.LocalBinder binder = (MediaPlayerService.LocalBinder) service;
player2 = binder.getService();
player2.setList(SongList);
serviceBound2 = true;
Toast.makeText(getContext(), "Service Bound", Toast.LENGTH_SHORT).show();
}
#Override
public void onServiceDisconnected(ComponentName name) {
serviceBound2 = false;
}
};
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
if(playIntent2==null && serviceBound2==true){
playIntent2 = new Intent(getActivity(), MediaPlayerService.class);
getActivity().bindService(playIntent2, serviceConnection2, Context.BIND_AUTO_CREATE);
getActivity().startService(playIntent2);
}
}

ViewPager does not redraw content on swipe back

Problem
I am new to android and i am using viewpager for the first time in my app and
i am suffering from very strange behavior in my app that is i am using viewpager with three fragments ( TrackFragment , AlbumFragment , ArtistFragment ) and when i swip page from TrackFragment to AlbumFragment and again come back to TrackFragment it becomes blank (but it was not at first time when i am at TrackFragment initially) and same thing happened when i jump to ArtistFragment or any other fragments from the tab layout (its become blank).
And in case when i am going to ArtistFragment from TrackFragment via AlbumFragments by swiping the pages it works correctly (that is contents are shown in pages).
Please suggest me a method to overcome the above problem or any other method to implement same thing.
Here is my code....
MainActivity
public class MainActivity extends AppCompatActivity {
private String[] mPlanetTitles={"Tracks","Album","Artist"};
private DrawerLayout mDrawerLayout;
private ListView mDrawerList;
SharedPreferences sharedPreferences;
Fragment [] fragments = {new TracksFragment(),new AlbumFragment(), new ArtistFragment()};
PagerAdapter pagerAdapter;
ViewPager viewPager;
public static ImageView im;
int pos= -1 ;
public static Context context;
MusicService musicService;
boolean mBound;
TabLayout tabLayout ;
public static Uri currentsonguri;
protected void onCreate(final Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
sharedPreferences = getSharedPreferences("lastplayed",Context.MODE_PRIVATE);
Intent i = new Intent(MainActivity.this,MusicService.class);
startService(i);
mDrawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
mDrawerList = (ListView) findViewById(R.id.left_drawer);
mDrawerList.setAdapter(new NavigationDrawerAdapter(this));
mDrawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if(position == 3)
{
Intent i = new Intent(MainActivity.this,PlaylistActivity.class);
startActivity(i);
}
if(position == 4)
{
Intent intent = new Intent();
intent.setAction("android.media.action.DISPLAY_AUDIO_EFFECT_CONTROL_PANEL");
if((intent.resolveActivity(getPackageManager()) != null)) {
startActivity(intent);
} else {
// No equalizer found :(
Toast.makeText(getBaseContext(),"No Equaliser Found",Toast.LENGTH_LONG).show();
}
}
}
});
tabLayout = (TabLayout) findViewById(R.id.tablayout);
viewPager = (ViewPager) findViewById(R.id.viewPager);
tabLayout.setTabTextColors(Color.DKGRAY,Color.WHITE);
tabLayout.setTabMode(TabLayout.MODE_SCROLLABLE);
context = getBaseContext();
pagerAdapter = new myfragment(getSupportFragmentManager());
im = (ImageView) findViewById(R.id.currentsong);
viewPager.setPageTransformer(true, new ZoomOutPageTransformer());
viewPager.setAdapter(pagerAdapter);
tabLayout.setupWithViewPager(viewPager,true);
SharedPreferences.Editor editor= sharedPreferences.edit();
if(sharedPreferences.getInt("count",0)==0)
{
editor.putInt("count",1);
}
else
{
int c= sharedPreferences.getInt("count",0);
Log.d("Uses count",c+"");
editor.putInt("count",c++);
editor.apply();
}
if(!sharedPreferences.getString("uri","").equals(""))
{
String s = sharedPreferences.getString("uri","");
Uri u = Uri.parse(s);
currentsonguri = u;
MediaMetadataRetriever data=new MediaMetadataRetriever();
data.setDataSource(getBaseContext(),u);
try {
byte[] b = data.getEmbeddedPicture();
Bitmap bitmap = BitmapFactory.decodeByteArray(b, 0, b.length);
bitmap = getRoundedCornerBitmap(bitmap);
im.setImageBitmap(bitmap);
}
catch (Exception e)
{
e.printStackTrace();
}
try {
musicService.setsongbyuri(u,getBaseContext());
musicService.setMediaPlayer();
}
catch (Exception e)
{
e.printStackTrace();
}
}
else
{
}
editor.apply();
im.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(MainActivity.this, MusicPlayerActivity.class);
intent.setData(currentsonguri);
intent.putExtra("flag",1);
startActivity(intent);
}
});
final Uri r= getIntent().getData();
if(r!=null) {
currentsonguri = r;
Intent intent = new Intent(MainActivity.this, MusicPlayerActivity.class);
intent.setData(r);
intent.putExtra("flag",0);
startActivity(intent);
}
}
public class myfragment extends FragmentPagerAdapter {
myfragment(FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return fragments[position];
}
#Override
public int getCount() {
return 3;
}
#Override
public CharSequence getPageTitle(int position) {
String s = "non";
switch (position)
{
case 0 : s= "Tracks" ;
break;
case 1: s= "Albums" ;
break;
case 2: s= "Artist" ;
break;
}
return s;
}
}
public void setview(byte [] b, int position,Uri uri)
{
currentsonguri = uri;
Log.d("position in set view",""+position);
Log.d("fail","i am here");
if(im!=null)
{
if(b!=null)
{
Bitmap bitmap = BitmapFactory.decodeByteArray(b, 0, b.length);
bitmap = getRoundedCornerBitmap(bitmap);
im.setImageBitmap(bitmap);
}
else {
songDetailloader loader = new songDetailloader(context);
String s = loader.albumartwithalbum(loader.songalbum(position));
Log.d("fail","fail to set small image");
if (s != null) {
im.setImageBitmap(BitmapFactory.decodeFile(s));
Log.d("fail","nowsetting set small image");
} else {
im.setImageResource(R.drawable.default_track_light);
Log.d("ic","ic_launcher setted");
}
}
}
else {
Log.d(""," im is null");
}
}
public static Bitmap getRoundedCornerBitmap(Bitmap bitmap) {
Bitmap output = Bitmap.createBitmap(bitmap.getWidth(),
bitmap.getHeight(), Bitmap.Config.ARGB_8888);
Canvas canvas = new Canvas(output);
final int color = 0xff424242;
final Paint paint = new Paint();
final Rect rect = new Rect(0, 0, bitmap.getWidth(), bitmap.getHeight());
final RectF rectF = new RectF(rect);
final float roundPx = 100;
paint.setAntiAlias(true);
canvas.drawARGB(0, 0, 0, 0);
paint.setColor(color);
canvas.drawRoundRect(rectF, roundPx, roundPx, paint);
paint.setXfermode(new PorterDuffXfermode(PorterDuff.Mode.SRC_IN));
canvas.drawBitmap(bitmap, rect, rect, paint);
return output;
}
private ServiceConnection serviceConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
MusicService.LocalBinder binder = (MusicService.LocalBinder) service;
musicService = binder.getService();
mBound =true;
}
#Override
public void onServiceDisconnected(ComponentName name) {
mBound =false;
}
};
#Override
protected void onDestroy() {
super.onDestroy();
Log.d("MainActivity","Get distoryed");
}
#Override
protected void onResume() {
super.onResume();
Intent i = new Intent(this,MusicService.class);
bindService(i, serviceConnection, Context.BIND_AUTO_CREATE);
}
#Override
protected void onStart() {
super.onStart();
}
#Override
protected void onStop() {
super.onStop();
unbindService(serviceConnection);
}}
Tracks Fragment
public class TracksFragment extends Fragment {
songDetailloader loader = new songDetailloader();
ArrayList<Songs> give = new ArrayList<>();
public int pos = -1;
MediaPlayer mp ;
MusicService musicService;
boolean mBound;
ImageView search;
ListViewAdapter listViewAdapter;
RelativeLayout editreltive;
ListView listView;
EditText editText;
TextView ch;
private Cursor cursor ;
int albumindex,dataindex,titleindex,durationindex,artistindex;
private final static String[] columns ={MediaStore.Audio.Media.DATA, MediaStore.Audio.Media.DURATION, MediaStore.Audio.Media.ALBUM, MediaStore.Audio.Media.ARTIST, MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.IS_MUSIC,MediaStore.Audio.Media.IS_RINGTONE,MediaStore.Audio.Media.ARTIST,MediaStore.Audio.Media.SIZE ,MediaStore.Audio.Media._ID};
private final String where = "is_music AND duration > 10000 AND _size <> '0' ";
private final String orderBy = MediaStore.Audio.Media.TITLE;
public TracksFragment() {
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Log.d("fragment created","created");
setRetainInstance(true);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable final ViewGroup container, #Nullable Bundle savedInstanceState)
{
View v =inflater.inflate(R.layout.listviewofsongs,container,false);
listView = (ListView) v.findViewById(R.id.listView);
allsongs();
intlistview();
new Thread(new Runnable() {
#Override
public void run() {
Intent i = new Intent(getActivity(),MusicService.class);
getActivity().bindService(i, serviceConnection, Context.BIND_AUTO_CREATE);
}
}).start();
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id)
{
Log.d("Uri of ",""+give.get(position).getSonguri());
musicService.setplaylist(give,give.get(position).getPosition());
musicService.setMediaPlayer();
view.setSelected(true);
}
});
listView.setOnItemLongClickListener(new AdapterView.OnItemLongClickListener() {
#Override
public boolean onItemLongClick(AdapterView<?> parent, View view, final int position, long id) {
final AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
View v =LayoutInflater.from(getContext()).inflate(R.layout.select_dialog_layout,null);
builder.setView(v);
builder.setTitle(give.get(position).gettitle()+"\n "+give.get(position).getalbum());
builder.create();
final AlertDialog d=builder.show();
//seting click listner.....
TextView play = (TextView) v.findViewById(R.id.dialogplay);
TextView playnext = (TextView) v.findViewById(R.id.dialogplaynext);
TextView queue = (TextView) v.findViewById(R.id.dialogqueue);
TextView fav = (TextView) v.findViewById(R.id.dialogaddtofav);
TextView album = (TextView) v.findViewById(R.id.dialogalbum);
TextView artist = (TextView) v.findViewById(R.id.dialogartist);
TextView playlist = (TextView) v.findViewById(R.id.dialogaddtoplaylsit);
TextView share = (TextView) v.findViewById(R.id.dialogshare);
TextView delete = (TextView) v.findViewById(R.id.dialogdelete);
TextView properties = (TextView) v.findViewById(R.id.dialogproperties);
play.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
File f= new File(give.get(position).getSonguri().getLastPathSegment());
Log.d("LENGTH IS",""+f.length());
musicService.setplaylist(give,position);
musicService.setMediaPlayer();
d.dismiss();
}
});
playnext.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
}
});
queue.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
musicService.insertinqueue(give.get(position));
}
});
fav.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
DataBaseClass db = new DataBaseClass(getContext());
int i=db.insetintoliked(give.get(position));
if(i==1)
{
Toast.makeText(getContext(),"Added to Favorites",Toast.LENGTH_SHORT).show();
}
else
Toast.makeText(getContext(),"Already in Favorites",Toast.LENGTH_SHORT).show();
}
});
album.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
Intent i = new Intent( getActivity() , AlbumDetail.class);
Bundle b= new Bundle();
b.putCharSequence("album",give.get(position).getalbum());
i.putExtras(b);
startActivity(i);
}
});
artist.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i=new Intent(getActivity(),ArtistActivity.class);
i.putExtra("artist",give.get(position).getartist());
startActivity(i);
d.dismiss();
}
});
playlist.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
}
});
delete.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder b = new AlertDialog.Builder(getContext());
b.setMessage("Audio '"+give.get(position).gettitle()+"' will be deleted permanently !");
b.setTitle("Delete ?");
b.setNegativeButton("No", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
d.dismiss();
}
});
b.setPositiveButton("Delete", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
File f= new File(give.get(position).getSonguri().getPath());
boolean b = f.delete();
Log.d("Is file exist",f.exists()+"");
Log.d("File Lenth",""+f.length());
Log.d("Return value",""+b);
loader.set(getContext());
loader.deleteSong(getContext(),give.get(position).getPosition());
give.remove(position); // give is Arraylist of Songs(datatype);
listViewAdapter.notifyDataSetChanged();
if(b)
{
Toast.makeText(getContext(),"Deleted",Toast.LENGTH_SHORT).show();
}
else
{
Toast.makeText(getContext(),"Fail to Delete",Toast.LENGTH_SHORT).show();
}
}
});
b.create().show();
d.dismiss();
}
});
share.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
d.dismiss();
Intent share = new Intent(Intent.ACTION_SEND);
share.setType("audio/*");
share.putExtra(Intent.EXTRA_STREAM, give.get(position).getSonguri());
startActivity(Intent.createChooser(share, "Share Audio"));
}
});
properties.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder b = new AlertDialog.Builder(getContext());
File f= new File(give.get(position).getSonguri().getPath());
long size = (f.length())/1024;
long mb= size/1024;
long kb= size%1024;
b.setMessage("Size:"+"\n"+"Size "+mb+"."+kb+" MB\n"+"Path:"+f.getAbsolutePath()+"\n");
b.setTitle(f.getName());
b.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
}
});
b.create().show();
d.dismiss();
}
});
return true;
}
});
return v;
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
Log.d("fragment","instance saved");
}
#Override
public void onViewStateRestored(#Nullable Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
Log.d("Fragment","Instance Restored");
}
public void intlistview()
{
listViewAdapter = new ListViewAdapter(getContext(),give);
listView.setAdapter(listViewAdapter);
}
#Override
public void onDestroy() {
super.onDestroy();
Log.d("Fragment","Destroyed");
getActivity().unbindService(serviceConnection);
}
private ServiceConnection serviceConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
MusicService.LocalBinder binder = (MusicService.LocalBinder) service;
musicService = binder.getService();
mBound =true;
}
#Override
public void onServiceDisconnected(ComponentName name) {
mBound =false;
}
};
public void allsongs()
{
cursor = getContext().getContentResolver().query(MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, columns, where, null, orderBy);
dataindex = cursor.getColumnIndex(MediaStore.Audio.Media.DATA);
albumindex = cursor.getColumnIndex(MediaStore.Audio.Media.ALBUM);
titleindex = cursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
durationindex = cursor.getColumnIndex(MediaStore.Audio.Media.DURATION);
artistindex = cursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);
cursor.moveToFirst();
for(int i=0;i<cursor.getCount();i++)
{
Songs song = new Songs();
song.setalbum(cursor.getString(albumindex));
song.settitle(cursor.getString(titleindex));
song.setSonguri(Uri.parse(cursor.getString(dataindex)));
song.setartist(cursor.getString(artistindex));
song.setDuration(Long.decode(cursor.getString(durationindex)));
song.setPosition(cursor.getPosition());
this.give.add(song);
cursor.moveToNext();
}
cursor.close();
}}
Album Fragment
public class AlbumFragment extends Fragment {
songDetailloader songDetailloader = new songDetailloader();
public AlbumFragment() {
super();
}
GridView gridView;
AlbumAdapter a;
private static ArrayList<Bitmap> image = new ArrayList<>();
LinearLayout linearLayout;
Cursor cursor ;
ImageView album;
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
final View v =inflater.inflate(R.layout.albumgridview,container,false);
gridView = (GridView) v.findViewById(R.id.gridview);
album = (ImageView) v.findViewById(R.id.albumart);
/*Animation animation = AnimationUtils.loadAnimation(getContext(),R.anim.grid_layout_anim);
GridLayoutAnimationController controller = new GridLayoutAnimationController(animation,0.2f,0.2f);
gridView.setLayoutAnimation(controller);*/
final TextView albumname = (TextView) v.findViewById(R.id.albumname);
cursor = songDetailloader.getAlbumCursor(getContext());
if(image.size()==0)
new getbitmaps().execute();
gridView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
String s = songDetailloader.albumart(position);
Intent i = new Intent( getActivity() , AlbumDetail.class);
Bundle b= new Bundle();
b.putCharSequence("album",songDetailloader.album(position));
i.putExtras(b);
startActivity(i);
}
});
return v;
}
public class getbitmaps extends AsyncTask<Void,Void,Void>
{
Bitmap b;
public getbitmaps() {
super();
}
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... params) {
for(int i=0;i<cursor.getCount();i++)
{
cursor.moveToPosition(i);
BitmapFactory.Options options = new BitmapFactory.Options();
options.inSampleSize= 2;
b=BitmapFactory.decodeFile(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART)),options);
if(b==null)
{
b=BitmapFactory.decodeFile(cursor.getString(cursor.getColumnIndex(MediaStore.Audio.Albums.ALBUM_ART)));
}
image.add(b);
}
cursor.close();
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
a =new AlbumAdapter(getContext(),image);
a.setCursor();
gridView.setAdapter(a);
new Thread(new Runnable() {
#Override
public void run() {
songDetailloader.set(getContext());
}
}).start();
}
}}
Artist Fragment
public class ArtistFragment extends Fragment {
ListView listView ;
ArrayList<Artists> aa = new ArrayList<>();
final String[] columns3 = {MediaStore.Audio.Artists._ID, MediaStore.Audio.Artists.ARTIST,MediaStore.Audio.Artists.NUMBER_OF_ALBUMS,MediaStore.Audio.Artists.NUMBER_OF_TRACKS};
final static String orderBy3 = MediaStore.Audio.Albums.ARTIST;
public Cursor cursor3;
public ArtistFragment() {
super();
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setRetainInstance(true);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.listviewofsongs,container,false);
listView = (ListView) v.findViewById(R.id.listView);
new artist().execute();
return v;
}
public class artist extends AsyncTask<Void, Void ,Void>
{
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... params) {
allartist();
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
ArtistAdapter artistAdapter = new ArtistAdapter(getActivity().getBaseContext(),aa);
listView.setAdapter(artistAdapter);
listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Intent i= new Intent(getActivity(), ArtistActivity.class);
i.putExtra("artist", aa.get(position).getArtistname());
i.putExtra("noofsongs",aa.get(position).getNofosongs());
startActivity(i);
}
});
}
}
#Override
public void setInitialSavedState(SavedState state) {
super.setInitialSavedState(state);
}
#Override
public void onViewStateRestored(#Nullable Bundle savedInstanceState) {
super.onViewStateRestored(savedInstanceState);
}
#Override
public void onDestroy() {
super.onDestroy();
}
public void allartist()
{
cursor3 = getContext().getContentResolver().query(MediaStore.Audio.Artists.EXTERNAL_CONTENT_URI, columns3, null, null, orderBy3);
cursor3.moveToFirst();
for(int i=0;i< cursor3.getCount() ;i++)
{
Artists art = new Artists();
art.setArtistname(cursor3.getString(cursor3.getColumnIndex(MediaStore.Audio.Artists.ARTIST)));
art.setNoalbums(Integer.parseInt(cursor3.getString(cursor3.getColumnIndex(MediaStore.Audio.Artists.NUMBER_OF_ALBUMS))));
art.setNofosongs(Integer.parseInt(cursor3.getString(cursor3.getColumnIndex(MediaStore.Audio.Artists.NUMBER_OF_TRACKS))));
this.aa.add(art);
cursor3.moveToNext();
}
cursor3.close();
}}

Maybe you can try to add this property to you viewpager, in the onCreate method of your MainActivity :
viewPager.setOffscreenPageLimit(fragments.size());
Update
Another thing you could try is:
In your myfragment override getItemPosition in this way:
#Override
public int getItemPosition(Object object) {
return POSITION_NONE;
}
And add this code in your onCreate of your MainActivity:
viewPager.addOnPageChangeListener(new ViewPager.OnPageChangeListener() {
int previousState;
#Override
public void onPageScrolled(int position, float positionOffset, int positionOffsetPixels) {
}
#Override
public void onPageSelected(int position) {
}
#Override
public void onPageScrollStateChanged(int state) {
if (previousState == ViewPager.SCROLL_STATE_SETTLING && state == ViewPager.SCROLL_STATE_IDLE) {
pagerAdapter.notifyDataSetChanged();
}
previousState = state;
}
});
The aim of this code is not to be efficient, but to try to understand your problem.
Hope this can help you

How to avoid multiple instances of MediaPlayer objects?

I'm devolping an music player application, when user click on an item (song) in the listview in PlayListFragment user redirects to the mediaPlayerFragment and the choosen melody starts to play. When user repeat the scenario i think that a new instance of mediaPlayer is created because there is two melodys playing at the same time.
How to avoid this problem?
(I have tried to place mediaPlayer.create(..) in onCreate() but there is probably something more that is need to be done to make it work correctly. I have also tried to create a singletonObject without success)
MediaPlayerFragment.java
public class MediaPlayerFragment extends Fragment {
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private MediaPlayer mediaPlayer;
private double endTime = 0;
private double startTime = 0;
private int forwardTime = 5000;
private int backwardTime = 5000;
public static int oneTimeOnly = 0;
private SeekBar seekBar;
private ImageButton btnPlay;
private ImageButton btnPause;
private ImageButton btnStop;
private ImageButton btnForward;
private ImageButton btnRewind;
public TextView songInfo;
public TextView txtEndTime;
public TextView txtStartTime;
private Handler mediaHandler = new Handler();
private boolean isPausePressed = false;
private boolean isPlayPressed = false;
private boolean isStopPressed = true;
private OnFragmentInteractionListener mListener;
private Song currentSong;
public static MediaPlayerFragment newInstance(String param1, String param2) {
MediaPlayerFragment fragment = new MediaPlayerFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public MediaPlayerFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View view = inflater.inflate(R.layout.fragment_media_player, container, false);
getActivity().setTitle("Media Player");
songInfo = (TextView)view.findViewById(R.id.txt_currentsong);
txtEndTime = (TextView)view.findViewById(R.id.txt_time_left);
txtStartTime = (TextView)view.findViewById(R.id.txt_time_start);
seekBar = (SeekBar)view.findViewById(R.id.seek_bar_elapsed_time);
btnPlay = (ImageButton)view.findViewById(R.id.btn_play);
btnPause = (ImageButton)view.findViewById(R.id.btn_pause);
btnStop = (ImageButton)view.findViewById(R.id.btn_stop);
btnRewind = (ImageButton)view.findViewById(R.id.btn_previous);
btnForward = (ImageButton)view.findViewById(R.id.btn_next);
songInfo.setText(currentSong.getArtist() + " - " + currentSong.getTitle());
mediaPlayer = MediaPlayer.create(getActivity(), Uri.parse(currentSong.getUri()));
seekBar.setClickable(false);
btnPause.setEnabled(false);
btnStop.setEnabled(false);
btnForward.setEnabled(false);
btnRewind.setEnabled(false);
//Click events!
btnPause.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
pause(view);
isPausePressed = true;
isPlayPressed = false;
isStopPressed = false;
}
});
btnPlay.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
play(view);
isPausePressed = false;
isPlayPressed = true;
isStopPressed = false;
}
});
btnStop.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
stop(view);
isPausePressed = false;
isPlayPressed = false;
isStopPressed = true;
}
});
btnForward.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
forward(view);
isPausePressed = false;
isPlayPressed = false;
isStopPressed = false;
}
});
btnRewind.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
rewind(view);
isPausePressed = false;
isPlayPressed = false;
isStopPressed = false;
}
});
seekBar.setOnSeekBarChangeListener(new SeekBar.OnSeekBarChangeListener() {
#Override
public void onStartTrackingTouch(SeekBar s) {
}
#Override
public void onStopTrackingTouch(SeekBar s) {
}
#Override
public void onProgressChanged(SeekBar s, int progress, boolean fromUser) {
if (mediaPlayer != null && fromUser) {
mediaPlayer.seekTo(progress);
// Check if pause, play or stop buttons is pressed
if(!isPausePressed && !isPlayPressed && !isStopPressed) {
play(view);
}
}
}
});
return view;
}
public void play(View view) {
//Check if a track has been choosen from playlist...
if(currentSong.getId() != null) {
mediaPlayer.start();
endTime = mediaPlayer.getDuration();
startTime = mediaPlayer.getCurrentPosition();
if (oneTimeOnly == 0) {
seekBar.setMax((int) endTime);
oneTimeOnly = 1;
}
txtEndTime.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) endTime),
TimeUnit.MILLISECONDS.toSeconds((long) endTime) -
TimeUnit.MILLISECONDS.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) endTime)))
);
txtStartTime.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) startTime),
TimeUnit.MILLISECONDS.toSeconds((long) startTime) -
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) startTime)))
);
seekBar.setProgress((int) startTime);
mediaHandler.postDelayed(UpdateSongTime, 100);
btnPause.setEnabled(true);
btnStop.setEnabled(true);
btnRewind.setEnabled(true);
btnForward.setEnabled(true);
}
}
private Runnable UpdateSongTime = new Runnable() {
public void run() {
startTime = mediaPlayer.getCurrentPosition();
txtStartTime.setText(String.format("%d min, %d sec",
TimeUnit.MILLISECONDS.toMinutes((long) startTime),
TimeUnit.MILLISECONDS.toSeconds((long) startTime),
TimeUnit.MINUTES.toSeconds(TimeUnit.MILLISECONDS.toMinutes((long) startTime)))
);
seekBar.setProgress((int) startTime);
mediaHandler.postDelayed(this, 100);
}
};
public void stop(View view) {
btnPause.setEnabled(false);
btnForward.setEnabled(false);
btnRewind.setEnabled(false);
btnStop.setEnabled(false);
mediaPlayer.pause();
mediaPlayer.seekTo(0);
}
public void pause(View view) {
mediaPlayer.pause();
btnPause.setEnabled(false);
btnPlay.setEnabled(true);
}
public void forward(View view) {
int temp = (int)startTime;
if ((temp + forwardTime)<= endTime) {
startTime = startTime + forwardTime;
mediaPlayer.seekTo((int) startTime);
}
}
public void rewind(View view) {
int temp = (int) startTime;
if ((temp-backwardTime)> 0) {
startTime = startTime - backwardTime;
mediaPlayer.seekTo((int)startTime);
}
}
public void setSong(Song song) {
this.currentSong = song;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}
PlayListFragment.java
public class PlayListFragment extends Fragment {
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private PlayListAdapter playListAdapter;
private ListView lstPlayList;
public static ArrayList<Song> storeSongs = new ArrayList<>();
private OnFragmentInteractionListener mListener;
public static PlayListFragment newInstance(String param1, String param2) {
PlayListFragment fragment = new PlayListFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
public PlayListFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_play_list, container, false);
getActivity().setTitle("Play List");
getSongList();
sort(storeSongs);
AddToListView(view);
lstPlayList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
Song song = new Song();
//Get clicked song from listview.
song = (Song) parent.getAdapter().getItem(position);
changeToMediaPlayerFragment(song);
}
});
return view;
}
private void getSongList() {
ContentResolver musicResolver = getActivity().getContentResolver();
Uri musicUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
Cursor musicCursor = musicResolver.query(musicUri, null, null, null, null);
if (musicCursor != null && musicCursor.moveToFirst()) {
//get columns
int titleColumns = musicCursor.getColumnIndex( MediaStore.Audio.Media.TITLE);
int idColumn = musicCursor.getColumnIndex(MediaStore.Audio.Media._ID);
int artistColumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);
int uriColumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.DATA);
//Add songs to container (storeSongs).
do {
Long thisId = musicCursor.getLong(idColumn);
String thisTitle = musicCursor.getString(titleColumns);
String thisArtist = musicCursor.getString(artistColumn);
String thisUri = musicCursor.getString(uriColumn);
storeSongs.add(new Song(thisId, thisTitle, thisArtist, thisUri));
} while (musicCursor.moveToNext());
}
}
public void changeToMediaPlayerFragment(Song song) {
MediaPlayerFragment mediaPlayerFragment = MediaPlayerFragment.newInstance("", "");
mediaPlayerFragment.setSong(song);
FragmentManager fM = getFragmentManager();
FragmentTransaction fT = fM.beginTransaction();
fT.replace(R.id.container, mediaPlayerFragment, null);
fT.addToBackStack("go to mediaPlayer fragmement");
fT.commit();
}
private void AddToListView(View view) {
if (playListAdapter == null) {
playListAdapter = new PlayListAdapter(getActivity(), storeSongs);
}
this.lstPlayList = (ListView) view.findViewById(R.id.listView_play_list);
lstPlayList.setAdapter(playListAdapter);
playListAdapter.notifyDataSetChanged();
}
private void sort(ArrayList<Song> songs) {
Collections.sort(songs, new Comparator<Song>() {
#Override
public int compare(Song lhs, Song rhs) {
return lhs.getArtist().compareTo(rhs.getArtist());
}
});
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
mListener = (OnFragmentInteractionListener) activity;
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
public void onFragmentInteraction(Uri uri);
}
}

As Dyrborg pointed out i have now made the activity responsible for holding one reference to PlayListFragment and one reference of the MediaPlayerFragment.
public void changeToPlayListFragment() {
if (playListFragment == null) {
playListFragment = PlayListFragment.newInstance("", "");
}
if (getCurrentFragment() == 2) {
return;
} else {
FragmentManager fME = getFragmentManager();
FragmentTransaction fTE = fME.beginTransaction();
fTE.replace(R.id.container, playListFragment, null);
fTE.addToBackStack("go to Playlist fragment");
fTE.commit();
}
}
private int getCurrentFragment() {
Fragment currentFragment = getFragmentManager().findFragmentById(R.id.container);
if (currentFragment instanceof MediaPlayerFragment) {
return 1;
} else if (currentFragment instanceof PlayListFragment) {
return 2;
} else {
return 0;
}
}
Link contains all java code for a simple light weight media player with knocking interaction "http://pastebin.com/BHVZYLGv"

Error while passing an ArrayList to Service public method

I am creating a music player app for android. I have a fragment in a ViewPager that displays a list of all songs on the device. I have implemented an onClick listener on the list item to start a service called PlayerService that will play the clicked music. However, I am getting a
NullPointerException
at the line
playerSrv.setList(songArray);
in the following code.
I can pass the songArray ArrayList to the listview adapter without any problem but when I try to pass it to the service, I get the error. Is there any reason why the songArray could be null? The service starts without any problem without the line that gives error.
The setList() method in the Service class is
public void setList(ArrayList<Song> theSongs) {
songs=theSongs; //where songs is a private variable of type ArrayList<Song>
}
public class AllSongsFragment extends Fragment {
private ArrayList<Song> songArray;
private ListView songListView;
private PlayerService playerSrv;
private Intent playIntent;
private boolean serviceBound=false;
//connect to the player service
private ServiceConnection serviceConnection = new ServiceConnection() {
#Override
public void onServiceConnected(ComponentName name, IBinder service) {
ServiceBinder binder = (ServiceBinder)service;
//get service
playerSrv = binder.getService();
serviceBound = true;
}
#Override
public void onServiceDisconnected(ComponentName name) {
serviceBound = false;
}
};
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
} // onCreate()
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
songListView = (ListView)getView().findViewById(R.id.all_songs_list);
songArray = new ArrayList<Song>();
getSongList();
// Sort the songs
Collections.sort(songArray, new Comparator<Song>() {
public int compare(Song a, Song b) {
// For case-insensitive sorting
String a1 = a.getTitle().toString().toLowerCase();
String b1 = b.getTitle().toString().toLowerCase();
return a1.compareTo(b1);
}
});
AllSongsAdapter songAdt = new AllSongsAdapter(getActivity(), songArray);
songListView.setAdapter(songAdt);
songListView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
if(playIntent==null) {
playIntent = new Intent(getActivity(), PlayerService.class);
getActivity().bindService(playIntent, serviceConnection, Context.BIND_AUTO_CREATE);
getActivity().startService(playIntent);
}
//pass list
playerSrv.setList(songArray); //ERROR AT THIS LINE
playerSrv.setSong(position);
playerSrv.playSong();
}
});
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.all_songs_fragment_layout, container, false);
return rootView;
} //onCreateView()
/*#Override
public void onPause() {
getActivity().stopService(playIntent);
//playerSrv=null;
super.onPause();
}*/
public void getSongList() {
//retrieve song info
ContentResolver musicResolver = getActivity().getContentResolver();
Uri musicUri = MediaStore.Audio.Media.EXTERNAL_CONTENT_URI;
String[] projection = new String[] {MediaStore.Audio.Media._ID, MediaStore.Audio.Media.TITLE, MediaStore.Audio.Media.ARTIST};
Cursor musicCursor = musicResolver.query(musicUri, projection, null, null, null);
// Iterate over the List
if(musicCursor!=null && musicCursor.moveToFirst()) {
//get columns
int idColumn = musicCursor.getColumnIndex(MediaStore.Audio.Media._ID);
int titleColumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.TITLE);
int artistColumn = musicCursor.getColumnIndex(MediaStore.Audio.Media.ARTIST);
//add songs to list
do {
String thisId = musicCursor.getString(idColumn);
String thisTitle = musicCursor.getString(titleColumn);
String thisArtist = musicCursor.getString(artistColumn);
if(thisArtist == null || thisArtist.equals(MediaStore.UNKNOWN_STRING)) {
thisArtist = "Unknown Artist";
}
songArray.add(new Song(thisId, thisTitle, thisArtist));
} while (musicCursor.moveToNext());
} // if
} //getSongList()
} //AllSongsFragment
The service class is
public class PlayerService extends Service implements MediaPlayer.OnPreparedListener, MediaPlayer.OnErrorListener, MediaPlayer.OnCompletionListener {
private MediaPlayer player;
private ArrayList<Song> songs;
private int songPosition;
private final IBinder serviceBind = new ServiceBinder();
#Override
public IBinder onBind(Intent intent) {
// TODO Auto-generated method stub
return serviceBind;
}
#Override
public boolean onUnbind(Intent intent) {
player.stop();
player.release();
return false;
}
#Override
public void onCreate() {
super.onCreate();
//initialize position
songPosition=0;
//create player
player = new MediaPlayer();
initMusicPlayer();
}
public void initMusicPlayer() {
//set player properties
player.setWakeMode(getApplicationContext(), PowerManager.PARTIAL_WAKE_LOCK);
player.setAudioStreamType(AudioManager.STREAM_MUSIC);
player.setOnPreparedListener(this);
player.setOnCompletionListener(this);
player.setOnErrorListener(this);
}
public void setList(ArrayList<Song> theSongs) {
// Used to pass music list from music browser to the Player Service
songs=theSongs;
}
public class ServiceBinder extends Binder {
PlayerService getService() {
return PlayerService.this;
}
}
public void playSong() {
//play a song
player.reset();
//get song
Song currentSong = songs.get(songPosition);
//get id
long songId = Long.parseLong(currentSong.getId());
//set uri
Uri trackUri = ContentUris.withAppendedId(android.provider.MediaStore.Audio.Media.EXTERNAL_CONTENT_URI, songId);
try {
player.setDataSource(getApplicationContext(), trackUri);
} catch(Exception e) {
Log.e("PLAYER SERVICE", "Error setting data source", e);
}
player.prepareAsync();
}
#Override
public void onPrepared(MediaPlayer mp) { //start playback
mp.start();
}
#Override
public boolean onError(MediaPlayer mp, int what, int extra) {
mp.reset();
return false;
}
#Override
public void onCompletion(MediaPlayer mp) {
}
public void setSong(int songIndex) {
songPosition=songIndex;
}
}