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Material Container Transform animation not working in Java

Im trying to use Material Container Transform in Recyclerview Adapter as described by this post MaterialContainerTransform transition is not Working on Return , but after implementing this in my project im getting null pointer exception error.
As everyone know Material Container Transform animation tutorials are in kotlin and im doing it in java.
So if anyone know how to properly use material container transform animation in recyclerview and point out my mistakes i will be very much thankful to him.
RecyclerView Adapter Class(source)
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> implements Filterable {
private Context context;
private List<Astadhyayi> wordList;
private List<Astadhyayi> filwordList;
private DictionaryDB dictionaryDB;
private OnclickListenerInterface listener;
public RecyclerViewAdapter(Context context, List<Astadhyayi> itemList, DictionaryDB dictionaryDB) {
this.context = context;
this.wordList = itemList;
this.dictionaryDB = dictionaryDB;
filwordList = new ArrayList<Astadhyayi>(itemList);
}
public void setClickListener(OnclickListenerInterface onclickListener) {
this.listener = onclickListener;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(context);
View view = inflater.inflate(R.layout.wordslist_two_rv, parent, false);
ViewHolder viewHolder = new ViewHolder(view);
return viewHolder;
}
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
Astadhyayi word = wordList.get(position);
holder.rsutras.setText(word.mSutras);
// Animation******
holder.rsutras.setTransitionName(word.getMSutras());
if (word.mStatus != null && word.mStatus.equals(DictionaryDB.BOOKMARKED)) {
holder.bookmark.setImageResource(R.drawable.cards_heart);
} else {
holder.bookmark.setImageDrawable(null);
}
}
#Override
public Filter getFilter() {
return Searched_Filter;
}
private Filter Searched_Filter = new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
List<Astadhyayi> filteredList = new ArrayList<>();
if (constraint == null || constraint.length() == 0) {
filteredList.addAll(filwordList);
} else {
String filterPattern = constraint.toString().toLowerCase().trim();
for (Astadhyayi item : filwordList) {
if (item.getMSutras().toLowerCase().contains(filterPattern)) {
filteredList.add(item);
}
}
}
FilterResults results = new FilterResults();
results.values = filteredList;
return results;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
wordList.clear();
wordList.addAll((ArrayList<Astadhyayi>)results.values);
notifyDataSetChanged();
}
};
#Override
public int getItemCount() {
return wordList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView rsutras;
private ImageView bookmark;
public ViewHolder(View itemView) {
super(itemView);
itemView.setOnClickListener(this);
rsutras = itemView.findViewById(R.id.tvSansTerm);
bookmark = itemView.findViewById(R.id.bookmarkBtn);
}
/*
#Override
public void onClick(View view) {
if(listener!=null) listener.onItemClicked(getAbsoluteAdapterPosition(), rsutras);
}
*/
#Override
public void onClick(View view) {
int position = this.getAbsoluteAdapterPosition();
Astadhyayi word = wordList.get(position);
//*************** Bundle **************\\
Bundle bundle = new Bundle();
bundle.putParcelable("allData", word);
bundle.putString("transition_name", word.getMSutras());
Fragment detailsFragment = new TermThreeDetailsFragment();
detailsFragment.setSharedElementEnterTransition(new MaterialContainerTransform());
detailsFragment.setArguments(bundle);
FragmentTransaction fT =((AppCompatActivity)context).getSupportFragmentManager().beginTransaction();
fT.setReorderingAllowed(true);
fT.addSharedElement(rsutras, rsutras.getTransitionName()); // Shared element!
fT.replace(R.id.fragment_container, detailsFragment);
fT.addToBackStack(null);
fT.commit();
}
}
}
RecyclerView Fragment Class(source)
public class ShowtermsTwoFragment extends Fragment {
private RecyclerView rv;
private EditText tV;
private Toolbar toolbar;
private LinearLayoutManager layoutManager;
private static DictionaryDB db;
private RecyclerViewAdapter rvAdapter;
private SearchView searchView = null;
private SearchView.OnQueryTextListener queryTextListener;
private List<Astadhyayi> wordsList = new ArrayList<>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setExitTransition(new MaterialElevationScale(false));
setReenterTransition(new MaterialElevationScale(true));
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_terms_recyclerview, container, false);
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
toolbar = ((Toolbar) view.findViewById(R.id.toolbar_rv));
rv = view.findViewById(R.id.rvTerms);
tV = view.findViewById(R.id.tVinput);
//*********** TOOLBAR
AppCompatActivity activity = (AppCompatActivity) getActivity();
activity.setSupportActionBar(toolbar);
setHasOptionsMenu(true);
// new Get_DbData().execute();
databaseCheck();
recyclerCheck1();
postponeEnterTransition();
((ViewGroup) view.getParent()).getViewTreeObserver()
.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
public boolean onPreDraw() {
startPostponedEnterTransition();
return true;
}
});
}
private void databaseCheck() {
String sanskritWord = getActivity().getIntent().getStringExtra("sanskritWord");
//*********** ### DATABASE OPENING ### ***********\\
db = DictionaryDB.getInstance(this.getActivity());
wordsList = db.getWords((sanskritWord));
}
private void recyclerCheck1() {
layoutManager = new LinearLayoutManager(getContext());
rv.setLayoutManager(layoutManager);
rv.setHasFixedSize(true);
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(rv.getContext(), layoutManager.getOrientation());
rv.addItemDecoration(dividerItemDecoration);
rvAdapter = new RecyclerViewAdapter(getContext(), wordsList, db);
rv.setAdapter(rvAdapter);
/////********** rvAdapter.setClickListener(this);
rvAdapter.notifyDataSetChanged();
}
}
Details Fragment Class(destination)
public class TermThreeDetailsFragment extends Fragment {
private TextView sutraTV,vrittiTV,padaTv,adhyayTV,sutraIdTV ;
private CoordinatorLayout coordinatorLayout;
private FloatingActionButton fabBtn;
private static DictionaryDB db;
private Astadhyayi word;
private BottomAppBar bottomAppBar;
private TextToSpeech pronunciation;
private AudioManager audio;
private String ttsID , trans;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
MaterialContainerTransform transform = new MaterialContainerTransform();
transform.setScrimColor(Color.TRANSPARENT);
setSharedElementEnterTransition(transform);
setSharedElementReturnTransition(transform);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.show_three_details, container, false);
view.findViewById(R.id.tvSutra).setTransitionName(word.getMSutras());
return view;
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
sutraTV = view.findViewById(R.id.tvSutra);
adhyayTV = view.findViewById(R.id.tVAdhyay);
padaTv = view.findViewById(R.id.tVPada);
sutraIdTV = view.findViewById(R.id.tVSutraId);
vrittiTV = view.findViewById(R.id.tvVritti);
fabBtn = view.findViewById(R.id.favFAB);
coordinatorLayout = view.findViewById(R.id.parentCordlayout);
bottomAppBar = view.findViewById(R.id.bottom_app_bar);
bundleCheckWithDb();
WordCheck();
}
private void bundleCheckWithDb() {
//*********** Geting Parcelable Data
word = new Astadhyayi(Parcel.obtain());
Bundle bundle = this.getArguments();
if (bundle != null) {
word = bundle.getParcelable("allData");
trans = bundle.getString("transition_name");
adhyayTV.setText(word.getMAdhyay());
padaTv.setText(word.getMPada());
sutraIdTV.setText(word.getMSutra_id());
sutraTV.setText(word.getMSutras());
vrittiTV.setText(word.getMVritti());
}
//*********** DATABASE OPENING
db = DictionaryDB.getInstance(this.getActivity());
}
private void WordCheck() {
if (word.mStatus != null && word.mStatus.equals(DictionaryDB.BOOKMARKED)) {
fabBtn.setImageResource(R.drawable.cards_heart);
} else {
fabBtn.setImageResource(R.drawable.cards_heart_white);
}
fabBtn.setOnClickListener(new View.OnClickListener() {
public void onClick(View v) {
bookMarkWord(word, fabBtn);
}
});
}
}
Error im getting
java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String com.sanskrit.mysearcher.models.Astadhyayi.getMSutras()' on a null object reference
at com.sanskrit.mysearcher.fragments.TermThreeDetailsFragment.onCreateView(TermThreeDetailsFragment.java:69)

From the current given information, I think you should do something like this:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
word = new Astadhyayi(Parcel.obtain());
Bundle bundle = this.getArguments();
if (bundle != null) {
word = bundle.getParcelable("allData");
}
View view = inflater.inflate(R.layout.show_three_details, container, false);
view.findViewById(R.id.tvSutra).setTransitionName(word.getMSutras());
return view;
}
Again, I am not sure what getMSutras() actually returns and if it's right to use that here.

How can i pass a string value from recyclerview adapter to fragment

I want to pass a string value from my adapter class to my fragment. I tried storing the string in a bundle. To retrieve the value i used Bundle b = getArguments(); b.getString("key") the problem is im getting a null pointer exception. Below is the code that saves the string in a bundle. So my question is how can i pass a string value from adapterA to fragmentB.
Thanks in advance.
Adapter.java
public class ToDoRecyclerViewAdapter extends RecyclerView.Adapter<ToDoRecyclerViewAdapter.ViewHolder> {
private Context context;
private List<Aktivnost_> mValues;
private final OnListFragmentInteractionListener mListener;
public ToDoRecyclerViewAdapter td;
public ToDoRecyclerViewAdapter(List<Aktivnost_ > items, Context context, OnListFragmentInteractionListener listener) {
mValues = items;
mListener = listener;
this.context = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.fragment_todo, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
holder.mItem = mValues.get(position);
holder.mContentView.setText(mValues.get(position).getNaziv());
holder.mDateView.setText(mValues.get(position).getDatum());
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (null != mListener) {
mListener.onListFragmentInteraction(holder.mItem);
Intent i = new Intent(context.getApplicationContext(), PodrobnostiActivity.class);
i.putExtra("task_id", mValues.get(position).getId_());
context.getApplicationContext().startActivity(i);
Toast.makeText(v.getContext(), "task - " + mValues.get(position).getId_(), Toast.LENGTH_SHORT).show();
}
}
});
holder.mView.setOnLongClickListener(new View.OnLongClickListener() {
#Override
public boolean onLongClick(final View v) {
AlertDialog.Builder adb = new AlertDialog.Builder(v.getContext());
CharSequence meni[] = new CharSequence[] {"DOING", "FINISHED"};
adb.setItems(meni, new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
if(i == 0) {
Bundle b = new Bundle();
DoingFragment d = new DoingFragment();
mValues.get(i).setStanje("doing");
b.putString("doing", mValues.get(i).getStanje());
d.setArguments(b);
} else {
mValues.get(i).setStanje("koncano");
}
}
});
AlertDialog alertDialog = adb.create();
alertDialog.setCancelable(true);
alertDialog.show();
return true;
}
});
}
#Override
public int getItemCount() {
return mValues.size();
}
public class ViewHolder extends RecyclerView.ViewHolder {
public final View mView;
public final TextView mContentView;
public final TextView mDateView;
public long id;
public Aktivnost_ mItem;
public ViewHolder(View view) {
super(view);
mView = view;
this.id = id;
mDateView = (TextView) view.findViewById(R.id.Date);
mContentView = (TextView) view.findViewById(R.id.content);
}
#Override
public String toString() {
return super.toString() + " '" + mContentView.getText() + "'";
}
}
}
And i want to get the value i set in bundle in this fragment.
Fragment.java
public class DoingFragment extends Fragment {
DoingFragmentRecyclerViewAdapter mAdapter;
private OnListFragmentInteractionListener mListener;
public DoingFragment() {
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_doingfragment_list, container, false);
RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.list_doing);
recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerView.addItemDecoration(new DividerItemDecoration(getContext(), LinearLayoutManager.VERTICAL));
mAdapter = new DoingFragmentRecyclerViewAdapter(listAktivnosti(),mListener);
recyclerView.setAdapter(mAdapter);
return view;
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnListFragmentInteractionListener) {
mListener = (OnListFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnListFragmentInteractionListener");
}
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
public interface OnListFragmentInteractionListener {
void onListFragmentInteraction1(Aktivnost_ item);
}
AppDatabase db;
public void openDB() {
db = new AppDatabase(getContext());
db.open();
}
Aktivnost_ ak;
List<Aktivnost_> array;
public List<Aktivnost_> listAktivnosti() {
array = new ArrayList<>();
openDB();
Bundle b = getArguments();
Cursor cursor = db.getAllRows(b.getString("doing"));
while(cursor.moveToNext()) {
ak = new Aktivnost_();
ak.setId_(cursor.getLong(cursor.getColumnIndex("_id")));
ak.setNaziv(cursor.getString(cursor.getColumnIndex("naziv")));
ak.setDatum(cursor.getString(cursor.getColumnIndex("datum")));
ak.setFk_projekt(cursor.getInt(cursor.getColumnIndex("fk_projekt")));
ak.setUdeleženci(cursor.getString(cursor.getColumnIndex("udelezenci")));
ak.setStanje(cursor.getString(cursor.getColumnIndex("stanje")));
array.add(ak);
}
return array;
}
}

From the code, I can see you are only setting the Bundle parameters in Fragment object, but not using that fragment object further.
You need to display that fragment object first, then it will reflect into your target fragment.

RecyclerView in Fragment is sometimes empty on BottomNavigationView item touch

My RecyclerView in Fragment (FrameLayout) is sometimes empty on BottomNavigationView item touch (sometimes you can touch 5x and it's not empty but then it's empty again until the next touch).
YouTuberFragment
public class YouTuberFragment extends Fragment {
private List<YouTuber> youtuber;
private class GetYouTuber extends AsyncTask<Void, Void, Void> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... arg0) {
try {
InputStream inputStream = getActivity().getAssets().open("youtuber.json");
BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(inputStream));
StringBuilder total = new StringBuilder();
String line;
while ((line = bufferedReader.readLine()) != null) total.append(line);
String m = total.toString();
JSONObject jsonObject = new JSONObject(m);
JSONArray jsonYouTuberArray = jsonObject.getJSONArray("youtuber");
int youTubersCount = 0;
if (jsonYouTuberArray != null) youTubersCount = jsonYouTuberArray.length();
for (int i = 0; i < youTubersCount; i++) {
JSONObject jsonYouTuberObject = jsonYouTuberArray.getJSONObject(i);
YouTuber youTuber = new YouTuber(
jsonYouTuberObject.getString("name"),
jsonYouTuberObject.getString("role"),
jsonYouTuberObject.getString("picture"),
jsonYouTuberObject.getString("episodes"),
jsonYouTuberObject.getString("youtube")
);
youtuber.add(youTuber);
}
} catch (JSONException | IOException e) {
e.printStackTrace();
}
return null;
}
#Override
protected void onPostExecute(Void aVoid) {
super.onPostExecute(aVoid);
}
}
public YouTuberFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_youtuber, container, false);
LinearLayoutManager llm = new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false);
youtuber = new ArrayList<>();
RVAdapter adapter = new RVAdapter(youtuber, getContext());
new YouTuberFragment.GetYouTuber().execute();
RecyclerView rv = (RecyclerView) v.findViewById(R.id.rv);
rv.setLayoutManager(llm);
rv.setHasFixedSize(true);
rv.setAdapter(adapter);
return v;
}
}
RVAdapter
class RVAdapter extends RecyclerView.Adapter<RVAdapter.PersonViewHolder> {
private final Context context;
private Resources res;
private List<YouTuber> youTuber;
RVAdapter(List<YouTuber> youTuber, Context context){
this.youTuber = youTuber;
this.context = context;
}
static class PersonViewHolder extends RecyclerView.ViewHolder {
CardView cv;
ImageView ytPicture;
TextView ytName;
TextView ytRole;
TextView ytEpisodes;
Button ytYoutube;
PersonViewHolder(View itemView) {
super(itemView);
cv = (CardView) itemView.findViewById(R.id.cv);
ytPicture = (ImageView) itemView.findViewById(R.id.yt_picture);
ytName = (TextView) itemView.findViewById(R.id.yt_name);
ytRole = (TextView) itemView.findViewById(R.id.yt_role);
ytEpisodes = (TextView) itemView.findViewById(R.id.yt_episodes);
ytYoutube = (Button) itemView.findViewById(R.id.yt_youtube);
}
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
#Override
public PersonViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.item_youtuber, viewGroup, false);
res = v.getResources();
PersonViewHolder pvh = new PersonViewHolder(v);
return pvh;
}
#Override
public void onBindViewHolder(final PersonViewHolder personViewHolder, final int i) {
personViewHolder.ytPicture.setImageResource(res.getIdentifier(youTuber.get(i).picture, "drawable", BuildConfig.APPLICATION_ID));
personViewHolder.ytName.setText(youTuber.get(i).name);
personViewHolder.ytRole.setText(youTuber.get(i).role);
personViewHolder.ytEpisodes.setText(res.getString(R.string.yt_episodes, youTuber.get(i).episodes));
personViewHolder.ytYoutube.setText(youTuber.get(i).youtube);
personViewHolder.ytYoutube.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Uri uri = Uri.parse("https://" + youTuber.get(i).youtube);
Intent youtube_url = new Intent(Intent.ACTION_VIEW, uri);
context.startActivity(youtube_url);
}
});
}
#Override
public int getItemCount() {
return youTuber.size();
}
}

It could be that you are running a different thread to gather your data while your adapter initialization is being ran on the main thread and is being rendered before your data can be retrieved. Have you tried rotating the device if it is blank?

fail to retrieve data to listview - android

[EDIT] I'm new to android development, so please bear with me. I have two java classes named Join Game, extends to AppCompatActivity and HintList,extends to ArrayAdapter<>. This is connected to a database. So maybe its one of the factors?
For the layout of join game, I have a listview
and for the layout of hintlist I have three textview.
The code goes this way
JoinGame
public class JoinGame extends AppCompatActivity {
ListView list;
String[] itemdescription = {};
String[] itemhints = {};
String[] itemlocasyon = {};
ProgressDialog progress;
View view;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_joingame);
Button schan = (Button)findViewById(R.id.tarascan);
schan.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent intent = new Intent(JoinGame.this,ScanActivity.class);
startActivity(intent);
}
});
}
#Override
protected void onStart() {
super.onStart();
progress = new ProgressDialog(this);
progress.setMessage("Connecting...");
progress.setCancelable(false);
progress.show();
RequestFactory.joingameitems(JoinGame.this, RequestFactory.user_id, new RequestCallback<JSONArray>() {
#Override
public void onSuccess(final JSONArray response) {
runOnUiThread(new Runnable() {
#Override
public void run() {
RequestFactory.response = response;
itemdescription = new String[response.length()];
itemhints = new String[response.length()];
itemlocasyon = new String[response.length()];
for (int hl = 0; hl < response.length(); hl++){
try{
itemdescription[hl] = ((String)(response.getJSONObject(hl)).get("description"));
itemhints[hl] = ((String)(response.getJSONObject(hl)).get("hint"));
itemlocasyon[hl] = ((String)(response.getJSONObject(hl)).get("location"));
} catch (JSONException e) {
e.printStackTrace();
}
} ////////// below this is the adapter
final HintList hladapt = new HintList(JoinGame.this,itemdescription,itemlocasyon,itemhints);
list = (ListView)findViewById(R.id.item_hints_and_location);
list.setAdapter(hladapt);
progress.dismiss();
}
});
}
#Override
public void onFailed(final String message) {
runOnUiThread(new Runnable() {
#Override
public void run() {
runOnUiThread(new Runnable() {
#Override
public void run() {
Toast.makeText(JoinGame.this, message, Toast.LENGTH_LONG).show();
progress.dismiss();
}
});
}
});
}
});
}
HintList
public class HintList extends ArrayAdapter<String> {
private final Activity context;
private String[] itemDesc = {};
private String[] itemHints = {};
private String[] itemLocation = {};
public HintList(Activity context,String[] itemDesc,String[] itemhints,String[] itemlocation) {
super(context,R.layout.hints_list);
this.context = context;
this.itemDesc = itemDesc;
itemHints = itemhints;
itemLocation = itemlocation;
}
#Override
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View rowView = inflater.inflate(R.layout.hints_list, null, true);
TextView itemDesc2 = (TextView)rowView.findViewById(R.id.itemdescription);
TextView itemHint = (TextView)rowView.findViewById(R.id.itemhint);
TextView itemLocation2 = (TextView)rowView.findViewById(R.id.itemlocation);
itemDesc2.setText(itemDesc[position]);
itemHint.setText(itemHints[position]);
itemLocation2.setText(itemLocation[position]);
return rowView;
}
}
I actually retrieved the data (here)
E/DB: [{"description":"chinese garter","location":"near Tricycle station","hint":"garter plus chinese"},{"description":"isang pinoy game","location":"near ....","hint":"may salitang baka"},{"description":"\"tinik\"","location":"below...","hint":"may salitang tinik"},{"description":"aka Tinubigan","location":"at the back...","hint":"katunog ng pintero"},{"description":"\"knock down the can\"","location":"near...","hint":"gumagamit ng lata"}]
but it doesnt display on my listview
I dont know anymore what I should do.
I actually tried making this (I added view)
final HintList hladapt = new HintList(JoinGame.this,itemdescription,itemlocasyon,itemhints);
list = (ListView)view.findViewById(R.id.item_hints_and_location);
list.setAdapter(hladapt);
progress.dismiss();
but it will only returns an error of java.lang.NullPointerException: Attempt to invoke virtual method

Change this:
View rowView = inflater.inflate(R.layout.hints_list, null, true);
to:
View rowView = inflater.inflate(R.layout.hints_list, parent, false);
Modify your getView() method to:
#Override
public View getView(int position, View view, ViewGroup parent) {
LayoutInflater inflater = context.getLayoutInflater();
View rowView = inflater.inflate(R.layout.hints_list, parent, false);
TextView itemDesc2 = (TextView)rowView.findViewById(R.id.itemdescription);
TextView itemHint = (TextView)rowView.findViewById(R.id.itemhint);
TextView itemLocation2 = (TextView)rowView.findViewById(R.id.itemlocation);
itemDesc2.setText(itemDesc[position]);
itemHint.setText(itemHints[position]);
itemLocation2.setText(itemLocation[position]);
return rowView;
}

try adding getCount
#Override
public int getCount() {
return itemHints.length;
}
Try to change your code to this
public class HintList extends ArrayAdapter<String> {
private final Activity context;
private String[] itemDesc = {};
private String[] itemHints = {};
private String[] itemLocation = {};
private LayoutInflater inflater=null;
public HintList(Activity context,String[] itemDesc,String[] itemhints,String[] itemlocation) {
super(context,R.layout.hints_list);
this.context = context;
this.itemDesc = itemDesc;
itemHints = itemhints;
itemLocation = itemlocation;
inflater = (LayoutInflater)this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return itemHints.length;
}
#Override
public View getView(int position, View view, ViewGroup parent) {
ViewHolder holder;
if (view==null){
view=inflater.inflate(R.layout.hints_list, null, true);
holder = new ViewHolder(view);
view.setTag(holder);
}else {
holder = (ViewHolder) view.getTag();
}
holder.itemDesc2.setText(itemDesc[position]);
holder.itemHint.setText(itemHints[position]);
holder.itemLocation2.setText(itemLocation[position]);
return view;
}
static class ViewHolder{
TextView itemDesc2,itemHint,itemLocation2;
ViewHolder(View view) {
itemDesc2 = (TextView)view.findViewById(R.id.itemdescription);
itemHint = (TextView)view.findViewById(R.id.itemhint);
itemLocation2 = (TextView)view.findViewById(R.id.itemlocation);
}
}
}

My suggestions is create a bean class (DetailsBean), used for setter and getter method, and also the ArrayList (details1).
List<DetailsBean> details1 = new ArrayList<>(); // declare this as global
Then add the bean to below code
public void run() {
RequestFactory.response = response;
itemdescription = new String[response.length()];
itemhints = new String[response.length()];
itemlocasyon = new String[response.length()];
for (int hl = 0; hl < response.length(); hl++){
try{
itemdescription[hl] = ((String)(response.getJSONObject(hl)).get("description"));
itemhints[hl] = ((String)(response.getJSONObject(hl)).get("hint"));
itemlocasyon[hl] = ((String)(response.getJSONObject(hl)).get("location"));
// here the bean
DetailsBean dbean = new DetailsBean(itemDescription, itemhints, itemlocasyon);
details1.add(dbean); // add all the data to details1 ArrayList
HintList hladapt = new HintList(getActivity(), details1);
(ListView)findViewById(R.id.item_hints_and_location);
list.setAdapter(hladapt);
} catch (JSONException e) {
e.printStackTrace();
}
}
Your DetailsBean should looked like this
public class DetailsBean {
private String itemDescription="";
private String itemhints="";
private String itemlocasyon ="";
public DetailsBean(String description, String hints, String itemlocasyon) {
this.itemDescription=description;
.....
}
public void setItemDescription(String itemDescription) {
this.itemDescription = itemDesription;
}
public String getItemDescription() {
return itemDescription;
}
....
}
Then your HintList
public class HintList extends BaseAdapter{
Activity context;
List<DetailsBean> details;
private LayoutInflater mInflater;
public CustomBaseAdapter(Activity context,List<DetailsBean> details) {
this.context = context;
this.details = details;
}
........
}

Add these Override methods in your adapter
#Override
public int getCount() {
return itemHints.length;
}
#Override
public Object getItem(int i) {
return i;
}
#Override
public long getItemId(int i) {
return i;
}

Custom Adapter starts before ArrayList is ready

I'm making a list of links and for that I have made a custom adapter, but the list is not ready when the adapter starts so I get the following error:
java.lang.RuntimeException: Unable to start activity ComponentInfo{}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.Object android.content.Context.getSystemService(java.lang.String)' on a null object reference
this is because when the adapter is started the list is empty, and just moments after the list is filled but it's too late here is my code:
UPDATE: the code has been changed so now I du not get the error but it doesn't run getView in the adapter:
public class Controller extends Activity {
private String TAG = Controller.class.getSimpleName();
private String http;
CustomAdapter adapter;
public Controller con = null;
private ListView lv;
private static String url;
ArrayList<Selfservice> linkList = new ArrayList<Selfservice>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main_view);
con = this;
http = this.getString(R.string.http);
url = this.getString(R.string.path1);
new GetLinks().execute();
lv = (ListView)findViewById(R.id.list);
//Resources res = getResources();
//adapter = new CustomAdapter(con, linkList, res);
//lv.setAdapter(adapter);
}
private class GetLinks extends AsyncTask<Void, Void, List<Selfservice>> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected List<Selfservice> doInBackground(Void... arg0) {
Document doc;
Elements links;
List<Selfservice> returnList = null;
try {
doc = Jsoup.connect(url).timeout(0).get();
links = doc.getElementsByClass("processlink");
returnList = ParseHTML(links);
} catch (IOException e) {
e.printStackTrace();
}
return returnList;
}
#Override
protected void onPostExecute(final List<Selfservice> result) {
super.onPostExecute(result);
runOnUiThread(new Runnable() {
#Override
public void run() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
//setSupportActionBar(toolbar);
//getSupportActionBar().setDisplayShowTitleEnabled(false);
toolbar.setTitle("");
toolbar.setSubtitle("");
Resources res = getResources();
Log.e(TAG, linkList.toString());
linkList = (ArrayList<Selfservice>) result;
adapter = new CustomAdapter(con, result, res);
adapter.notifyDataSetChanged();
lv.setAdapter(adapter);
}
});
}
}
and my adapter:
public class CustomAdapter extends BaseAdapter implements OnClickListener {
private String TAG = CustomAdapter.class.getSimpleName();
Context context;
List<Selfservice> data;
private Activity activity;
public Resources res;
Selfservice self = null;
private static LayoutInflater inflater;
int layoutResourceId = 0;
public CustomAdapter(Activity act, List<Selfservice> dataList, Resources resources) {
res = resources;
activity = act;
data = dataList;
}
private class Holder {
TextView title;
TextView link;
}
#Override
public int getCount() {
return data.size();
}
#Override
public Object getItem(int pos) {
return pos;
}
#Override
public long getItemId(int pos) {
return pos;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View rowView = convertView;
Holder holder;
if(rowView == null){
rowView = inflater.inflate(R.layout.list_item, null);
holder = new Holder();
holder.title = (TextView) rowView.findViewById(R.id.title);
holder.link = (TextView) rowView.findViewById(R.id.link);
rowView.setTag(holder);
}else{
holder = (Holder)rowView.getTag();
}
if(data.size()<=0){
holder.title.setText("did not work");
}else{
self = null;
self = (Selfservice) data.get(position);
holder.title.setText(self.getTitle());
holder.link.setText(self.getLink());
Log.i(TAG, "adapter");
rowView.setOnClickListener(new OnItemClickListener(position));
}
return rowView;
}
#Override
public void onClick(View v){
Log.v("CustomAdapter", "row clicked");
}
private class OnItemClickListener implements OnClickListener{
private int mPos;
OnItemClickListener(int position){
mPos = position;
}
#Override
public void onClick(View arg0){
Controller con = (Controller)activity;
con.onItemClick(mPos);
}
}
}
So How do I get the adapter to wait to the list is full?

firstly use ArrayAdapter<Selfservice> instead of BaseAdapter
use constructor
public CustomAdapter(Context context, int resource, List<Selfservice> objects) {
super(context, resource, objects);
data = objects;
}
then override only two methods
public int getCount()
public View getView(int position, View convertView, ViewGroup parent)
then return list.size() in getCount()
in getView() method
if (convertView == null) {
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
v = inflater.inflate(R.layout.list_item, null);
}
in doInBackground() method in the try block
instead of linkList = ParseHTML(links);
do linkList.addAll(ParseHTML(links));
and in onPostExcecute() method
adapter.notifyDatasetChanged(); in the ui thread

You can create the adapter in the onPostExecute;
Change the Async Task to this:
private class GetLinks extends AsyncTask<Void, Void, List<Selfservice>> {
#Override
protected void onPreExecute() {
super.onPreExecute();
}
#Override
protected Void doInBackground(Void... arg0) {
Document doc;
Elements links;
List<Selfservice> returnList
try {
doc = Jsoup.connect(url).timeout(10000).get();
links = doc.getElementsByClass("processlink");
returnList = ParseHTML(links);
} catch (IOException e) {
e.printStackTrace();
}
return returnList;
}
#Override
protected void onPostExecute(List<Selfservice> result) {
super.onPostExecute(result);
runOnUiThread(new Runnable() {
#Override
public void run() {
Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
//setSupportActionBar(toolbar);
//getSupportActionBar().setDisplayShowTitleEnabled(false);
toolbar.setTitle("");
toolbar.setSubtitle("");
linkList = result
adapter = new CustomAdapter(con, result, res);
lv.setAdapter(adapter);
}
});
}
This way you will only create the adapter when your list is ready.
Edit:
You are not creating the variable context inside your adapter. Change your constructor to this:
public CustomAdapter(Context context, Activity act, List<Selfservice> dataList, Resources resources) {
res = resources;
activity = act;
data = dataList;
this.context = context;
}
And you will stop seeing the NullPointerExecption