Develop Reference

I found Error " E/RecyclerView: No adapter attached; skipping layout "

Everything works, but after I check the log it shows:
"E/RecyclerView: No adapter attached; skipping layout ".
My home fragment code:
package com.apps.mathar;
import android.content.Context;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.view.PagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.ProgressBar;
import android.widget.RelativeLayout;
import android.widget.TextView;
import android.widget.Toast;
import com.apps.adapter.AdapterRecent;
import com.apps.item.ItemSong;
import com.apps.utils.Constant;
import com.apps.utils.DBHelper;
import com.apps.utils.JsonUtils;
import com.apps.utils.RecyclerItemClickListener;
import com.apps.utils.ZProgressHUD;
import com.google.android.gms.ads.AdListener;
import com.squareup.picasso.Callback;
import com.squareup.picasso.Picasso;
import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;
import java.util.ArrayList;
public class FragmentHome extends Fragment {
DBHelper dbHelper;
RecyclerView recyclerView;
ArrayList<ItemSong> arrayList;
ArrayList<ItemSong> arrayList_recent;
AdapterRecent adapterRecent;
ZProgressHUD progressHUD;
LinearLayoutManager linearLayoutManager;
public ViewPager viewpager;
ImagePagerAdapter adapter;
TextView textView_empty;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// TODO Auto-generated method stub
View rootView = inflater.inflate(R.layout.fragment_home, container, false);
setHasOptionsMenu(true);
dbHelper = new DBHelper(getActivity());
progressHUD = ZProgressHUD.getInstance(getActivity());
progressHUD.setMessage(getActivity().getResources().getString(R.string.loading));
progressHUD.setSpinnerType(ZProgressHUD.FADED_ROUND_SPINNER);
textView_empty = (TextView)rootView.findViewById(R.id.textView_recent_empty);
adapter = new ImagePagerAdapter();
viewpager = (ViewPager)rootView.findViewById(R.id.viewPager_home);
viewpager.setPadding(80,20,80,20);
viewpager.setClipToPadding(false);
viewpager.setPageMargin(40);
viewpager.setClipChildren(false);
// viewpager.setPageTransformer(true,new BackgroundToForegroundTransformer());
arrayList = new ArrayList<ItemSong>();
arrayList_recent = new ArrayList<ItemSong>();
recyclerView = (RecyclerView)rootView.findViewById(R.id.recyclerView_home_recent);
linearLayoutManager = new LinearLayoutManager(getActivity(),LinearLayoutManager.HORIZONTAL,false);
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setHasFixedSize(true);
if (JsonUtils.isNetworkAvailable(getActivity())) {
new LoadLatestNews().execute(Constant.URL_LATEST);
} else {
Toast.makeText(getActivity(), getResources().getString(R.string.internet_not_conn), Toast.LENGTH_SHORT).show();
}
recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(getActivity(), new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(View view, int position) {
if(JsonUtils.isNetworkAvailable(getActivity())) {
Constant.isOnline = true;
Constant.arrayList_play.clear();
Constant.arrayList_play.addAll(arrayList_recent);
Constant.playPos = position;
((MainActivity)getActivity()).changeText(arrayList_recent.get(position).getMp3Name(),arrayList_recent.get(position).getCategoryName(),position+1,arrayList_recent.size(),arrayList_recent.get(position).getDuration(),arrayList_recent.get(position).getImageBig(),"home");
Constant.context = getActivity();
if(position == 0) {
Intent intent = new Intent(getActivity(), PlayerService.class);
intent.setAction(PlayerService.ACTION_FIRST_PLAY);
getActivity().startService(intent);
}
} else {
Toast.makeText(getActivity(), getResources().getString(R.string.internet_not_conn), Toast.LENGTH_SHORT).show();
}
}
}));
return rootView;
}
private class LoadLatestNews extends AsyncTask<String, String, String> {
#Override
protected void onPreExecute() {
progressHUD.show();
arrayList.clear();
super.onPreExecute();
}
#Override
protected String doInBackground(String... strings) {
try {
String json = JsonUtils.getJSONString(strings[0]);
JSONObject mainJson = new JSONObject(json);
JSONArray jsonArray = mainJson.getJSONArray(Constant.TAG_ROOT);
JSONObject objJson = null;
for (int i = 0; i < jsonArray.length(); i++) {
objJson = jsonArray.getJSONObject(i);
String id = objJson.getString(Constant.TAG_ID);
String cid = objJson.getString(Constant.TAG_CAT_ID);
String cname = objJson.getString(Constant.TAG_CAT_NAME);
String artist = objJson.getString(Constant.TAG_ARTIST);
String name = objJson.getString(Constant.TAG_SONG_NAME);
String url = objJson.getString(Constant.TAG_MP3_URL);
String desc = objJson.getString(Constant.TAG_DESC);
String duration = objJson.getString(Constant.TAG_DURATION);
String image = objJson.getString(Constant.TAG_THUMB_B).replace(" ","%20");
String image_small = objJson.getString(Constant.TAG_THUMB_S).replace(" ","%20");
ItemSong objItem = new ItemSong(id,cid,cname,artist,url,image,image_small,name,duration,desc);
arrayList.add(objItem);
}
return "1";
} catch (JSONException e) {
e.printStackTrace();
return "0";
} catch (Exception ee) {
ee.printStackTrace();
return "0";
}
}
#Override
protected void onPostExecute(String s) {
if(s.equals("1")) {
progressHUD.dismissWithSuccess(getResources().getString(R.string.success));
// setLatestVariables(0);
if(Constant.isAppFirst) {
if(arrayList.size()>0) {
Constant.isAppFirst = false;
Constant.arrayList_play.addAll(arrayList);
((MainActivity)getActivity()).changeText(arrayList.get(0).getMp3Name(),arrayList.get(0).getCategoryName(),1,arrayList.size(),arrayList.get(0).getDuration(),arrayList.get(0).getImageBig(),"home");
Constant.context = getActivity();
}
}
viewpager.setAdapter(adapter);
loadRecent();
// adapterPagerTrending = new AdapterPagerTrending(getActivity(),Constant.arrayList_trending);
// viewPager_trending.setAdapter(adapterPagerTrending);
// adapterTopStories = new AdapterTopStories(getActivity(),Constant.arrayList_topstories);
// listView_topstories.setAdapter(adapterTopStories);
// setListViewHeightBasedOnChildren(listView_topstories);
} else {
progressHUD.dismissWithFailure(getResources().getString(R.string.error));
Toast.makeText(getActivity(), getResources().getString(R.string.server_no_conn), Toast.LENGTH_SHORT).show();
}
super.onPostExecute(s);
}
}
private void loadRecent() {
arrayList_recent = dbHelper.loadDataRecent();
adapterRecent = new AdapterRecent(getActivity(),arrayList_recent);
recyclerView.setAdapter(adapterRecent);
if(arrayList_recent.size() == 0) {
recyclerView.setVisibility(View.GONE);
textView_empty.setVisibility(View.VISIBLE);
} else {
recyclerView.setVisibility(View.VISIBLE);
textView_empty.setVisibility(View.GONE);
}
}
private class ImagePagerAdapter extends PagerAdapter {
private LayoutInflater inflater;
public ImagePagerAdapter() {
// TODO Auto-generated constructor stub
inflater = (LayoutInflater) getActivity().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return arrayList.size();
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view.equals(object);
}
#Override
public Object instantiateItem(ViewGroup container, int position) {
View imageLayout = inflater.inflate(R.layout.viewpager_home, container, false);
assert imageLayout != null;
ImageView imageView = (ImageView) imageLayout.findViewById(R.id.imageView_pager_home);
final ProgressBar spinner = (ProgressBar) imageLayout.findViewById(R.id.loading_home);
TextView title = (TextView) imageLayout.findViewById(R.id.textView_pager_home_title);
TextView cat = (TextView) imageLayout.findViewById(R.id.textView_pager_home_cat);
RelativeLayout rl = (RelativeLayout)imageLayout.findViewById(R.id.rl_homepager);
title.setText(arrayList.get(position).getMp3Name());
cat.setText(arrayList.get(position).getCategoryName());
Picasso.with(getActivity())
.load(arrayList.get(position).getImageBig())
.placeholder(R.mipmap.app_icon)
.into(imageView, new Callback() {
#Override
public void onSuccess() {
spinner.setVisibility(View.GONE);
}
#Override
public void onError() {
spinner.setVisibility(View.GONE);
}
});
rl.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
if(JsonUtils.isNetworkAvailable(getActivity())) {
//showInter();
playIntent();
} else {
Toast.makeText(getActivity(), getResources().getString(R.string.internet_not_conn), Toast.LENGTH_SHORT).show();
}
}
});
container.addView(imageLayout, 0);
return imageLayout;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
}
/* private void showInter() {
Constant.adCount = Constant.adCount + 1;
if(Constant.adCount % Constant.adDisplay == 0) {
((MainActivity)getActivity()).mInterstitial.setAdListener(new AdListener() {
#Override
public void onAdClosed() {
playIntent();
super.onAdClosed();
}
});
if(((MainActivity)getActivity()).mInterstitial.isLoaded()) {
((MainActivity)getActivity()).mInterstitial.show();
((MainActivity)getActivity()).loadInter();
} else {
playIntent();
}
} else {
playIntent();
}
}
*/
private void playIntent() {
Constant.isOnline = true;
int pos = viewpager.getCurrentItem();
Constant.arrayList_play.clear();
Constant.arrayList_play.addAll(arrayList);
Constant.playPos = pos;
((MainActivity)getActivity()).changeText(arrayList.get(pos).getMp3Name(),arrayList.get(pos).getCategoryName(),pos+1,arrayList.size(),arrayList.get(pos).getDuration(),arrayList.get(pos).getImageBig(),"home");
Constant.context = getActivity();
if(pos == 0) {
Intent intent = new Intent(getActivity(), PlayerService.class);
intent.setAction(PlayerService.ACTION_FIRST_PLAY);
getActivity().startService(intent);
}
}
}
I saw another question similar to this, that said to attach the adapter before running other threads but I don't believe I have any other threads running in this activity.

You start a new thread in this line:
new LoadLatestNews().execute(Constant.URL_LATEST);
and it is executed before control reaches:
recyclerView.setAdapter(adapterRecent);
This however should not be the problem you have since AsyncTask publishes to the UIThread.
Instead you should set an empty adapter in onCreateView and update it with adapterRecent.notifyDataSetChanged(); once you have loaded your data.

SharedPreferences resetting when app closes

I have a ListView fragment that has the option to save specific table values. You can click a button to toggle the table to only show saved values. When the toggle is active instead of saving you have the option to delete values. I have noticed however that while the delete will delete the value permanently so long as the app is open, If i close the app and reopen it, the value will reappear. Also if I delete the app and reinstall this same value reappears. I'm not sure how this value is getting added in and why it refuses to go. Debugging shows me saving the correct values in SharedPreferences but that does not stay.
EDIT: After some more testing it appears that the first item saved in the specific SharedPreferences remains permanently saved. It cannot be removed and all other values saved will not remain there.
Fragment:
package layout;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.preference.PreferenceManager;
import android.support.design.widget.FloatingActionButton;
import android.support.v4.widget.SwipeRefreshLayout;
import android.content.Context;
import android.content.SharedPreferences;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.ListView;
import android.widget.SearchView;
import android.widget.TextView;
import android.os.StrictMode;
import com.tble.brgo.HTMLPull;
import com.tble.brgo.InfoArticle;
import com.tble.brgo.R;
import android.widget.AdapterView.OnItemClickListener;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.ArrayList;
import android.text.TextUtils;
import java.util.HashSet;
import java.util.Set;
/**
* A simple {#link Fragment} subclass.
* Use the {#link Websites#newInstance} factory method to
* create an instance of this fragment.
*/
public class Websites extends Fragment implements SearchView.OnQueryTextListener, displayInterface {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private SearchView mSearchView;
private ListView mListView;
public Boolean toggle = false;
public ArrayList<InfoArticle> mData = new ArrayList<InfoArticle>();
public StandardCellAdapter mAdapter;
public ArrayList<InfoArticle> fDataSet = new ArrayList<InfoArticle>();
public Websites webTable;
public Websites() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #return A new instance of fragment Websites.
*/
// TODO: Rename and change types and number of parameters
public static Websites newInstance() {
Websites fragment = new Websites();
Bundle args = new Bundle();
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
toggle = false;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_websites, container, false);
StrictMode.ThreadPolicy policy = new StrictMode.ThreadPolicy.Builder()
.permitAll().build();
StrictMode.setThreadPolicy(policy);
ArrayList<InfoArticle> data = new ArrayList<InfoArticle>();
webTable = this;
try {
data = getData();
} catch (IOException e) {
e.printStackTrace();
}
mListView = (ListView) view.findViewById(R.id.WebsiteTable);
final StandardCellAdapter adapter = new StandardCellAdapter(getActivity(), data, 1,this);
fDataSet = data;
mData = data;
mListView.setAdapter(adapter);
mAdapter = adapter;
mSearchView = (SearchView) view.findViewById(R.id.searchView);
mListView.setTextFilterEnabled(true);
FloatingActionButton myFab = (FloatingActionButton) view.findViewById(R.id.dataToggle);
myFab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
toggleView();
}
});
setupSearchView();
final SwipeRefreshLayout swipeLayout = (SwipeRefreshLayout) view.findViewById(R.id.webRefresh);
swipeLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
try {
mData = getData();
mAdapter = new StandardCellAdapter(getContext(), mData, 1,webTable);
mListView.setAdapter(mAdapter);
} catch (IOException e) {
e.printStackTrace();
}
swipeLayout.setRefreshing(false);
}
});
return view;
}
private void setupSearchView() {
mSearchView.setOnQueryTextListener(this);
mSearchView.setIconifiedByDefault(true);
}
private ArrayList<InfoArticle> getData() throws IOException {
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
int school = sharedPref.getInt("School", 14273);
HTMLPull Connection = new HTMLPull();
Connection.getStaff(school);
Connection.Results.remove(0);
return Connection.Results;
}
#Override
public boolean onQueryTextChange(String newText) {
if (TextUtils.isEmpty(newText)) {
mListView.clearTextFilter();
} else {
mListView.setFilterText(newText);
}
return true;
}
public ArrayList<InfoArticle> toData(ArrayList<String> t, ArrayList<String> d) {
ArrayList<InfoArticle> temp = new ArrayList<InfoArticle>();
if (t.size() == 0) {
temp.add(new InfoArticle("Slide to Save Teachers", "google.com"));
} else {
for (int i = 0; i < t.size(); i++) {
temp.add(new InfoArticle(t.get(i), d.get(i)));
}
}
return temp;
}
#Override
public boolean onQueryTextSubmit(String query) {
return false;
}
private void toggleView(){
if (!toggle) {
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
HashSet<String> defv = new HashSet<String>();
ArrayList<String> teachers = new ArrayList<String>(sharedPref.getStringSet("teachPref", defv));
ArrayList<String> links = new ArrayList<String>(sharedPref.getStringSet("linkPref", defv));
mAdapter = new StandardCellAdapter(getContext(), toData(teachers, links),2,this);
mListView.setAdapter(mAdapter);
toggle = true;
} else {
mAdapter = new StandardCellAdapter(getContext(), mData, 1,this);
mListView.setAdapter(mAdapter);
toggle = false;
}
}
/**public void displayWebpage(int position){
if (toggle == true) {
WebsiteDisplay fullView = WebsiteDisplay.newInstance(mAdapter.getItem(position).description);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
} else {
if (!mSearchView.isIconified()) {
for (InfoArticle a : fDataSet) {
if (a.title.equals(((InfoArticle) mListView.getAdapter().getItem(position)).title)) {
WebsiteDisplay fullView = WebsiteDisplay.newInstance(a.description);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
}
}
} else {
WebsiteDisplay fullView = WebsiteDisplay.newInstance(fDataSet.get(position).description);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
}
}
}*/
public void displayWebpage(String Link){
WebsiteDisplay fullView = WebsiteDisplay.newInstance(Link);
FragmentTransaction transfer = getActivity().getSupportFragmentManager().beginTransaction();
transfer.replace(R.id.fragmentcontainer, fullView).addToBackStack("tag").commit();
}
}
CellAdapter:
package layout;
import android.app.AlertDialog;
import android.content.DialogInterface;
import android.content.SharedPreferences;
import android.media.Image;
import android.nfc.Tag;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.widget.RecyclerView;
import android.widget.ArrayAdapter;
import android.content.Context;
import android.view.View;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Set;
import android.preference.PreferenceManager;
import android.widget.ImageView;
import android.widget.TextView;
import android.view.LayoutInflater;
import android.view.ViewGroup;
import com.chauthai.swipereveallayout.SwipeRevealLayout;
import com.tble.brgo.InfoArticle;
import com.tble.brgo.R;
import android.graphics.Typeface;
import android.widget.Filterable;
import android.widget.Filter;
import org.w3c.dom.Text;
/**
* Created by Praveen on 8/21/16.
*/
public class StandardCellAdapter extends ArrayAdapter<InfoArticle> implements Filterable {
public ArrayList<InfoArticle> orig;
public ArrayList<InfoArticle> Teachers;
public SwipeRevealLayout swipeV;
public TextView deleteButton;
public TextView saveButton;
public int tableType;
public displayInterface activity;
public Context ct;
public StandardCellAdapter(Context context, ArrayList<InfoArticle> titles, int tableType, displayInterface inter) {
super(context, 0, titles);
this.Teachers = titles;
this.tableType = tableType;
saveButton = new TextView(context);
deleteButton = new TextView(context);
activity = inter;
ct = context;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
// Get the data item for this position
String title = getItem(position).title;
String desc = getItem(position).description;
Holder TagHolder = null;
TextView Ctitle;
// Check if an existing view is being reused, otherwise inflate the view
if (convertView == null) {
if (tableType == 0) {
convertView = LayoutInflater.from(getContext()).inflate(R.layout.nclayout, parent, false);
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
}
else if(tableType == 1){
convertView = LayoutInflater.from(getContext()).inflate(R.layout.sclayout, parent, false);
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
TagHolder = new Holder();
swipeV = (SwipeRevealLayout)convertView.findViewById(R.id.scSwipe);
saveButton = (TextView)convertView.findViewById(R.id.saveButton);
TagHolder.Save = saveButton;
TagHolder.Cell = Ctitle;
convertView.setTag(TagHolder);
}
else{
convertView = LayoutInflater.from(getContext()).inflate(R.layout.tclayout, parent, false);
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
TagHolder = new Holder();
swipeV = (SwipeRevealLayout)convertView.findViewById(R.id.tcSwipe);
deleteButton = (TextView) convertView.findViewById(R.id.deleteButton);
TagHolder.Delete = deleteButton;
TagHolder.Cell = Ctitle;
convertView.setTag(TagHolder);
}
}
else {
TagHolder = (Holder) convertView.getTag();
Ctitle = (TextView) convertView.findViewById(R.id.cellTitle);
}
if(tableType == 1) {
TagHolder.Save.setTag(position);
TagHolder.Save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
saveTeacher((int)v.getTag());
}
});
TagHolder.Cell.setTag(position);
TagHolder.Cell.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
activity.displayWebpage(getItem((int)v.getTag()).description);
}
});
}
else if(tableType == 2) {
TagHolder.Delete.setTag(position);
deleteButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
deleteTeacher((int)v.getTag());
if(Teachers.size() == 0)
Teachers.add(new InfoArticle("Slide to Save Teachers", "google.com"));
notifyDataSetChanged();
}
});
TagHolder.Cell.setTag(position);
TagHolder.Cell.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
activity.displayWebpage(getItem((int)v.getTag()).description);
}
});
}
Typeface customFont = Typeface.SERIF;
Ctitle.setTypeface(customFont);
Ctitle.setText(title);
return convertView;
}
public Filter getFilter() {
return new Filter() {
#Override
protected FilterResults performFiltering(CharSequence constraint) {
final FilterResults oReturn = new FilterResults();
final ArrayList<InfoArticle> results = new ArrayList<InfoArticle>();
if (orig == null)
orig = Teachers;
if (constraint != null) {
if (orig != null && orig.size() > 0) {
for (final InfoArticle g : orig) {
if (g.title.toLowerCase()
.contains(constraint.toString().toLowerCase())) {
results.add(g);
}
}
}
oReturn.values = results;
}
return oReturn;
}
#SuppressWarnings("unchecked")
#Override
protected void publishResults(CharSequence constraint,
FilterResults results) {
Teachers = (ArrayList<InfoArticle>)results.values;
notifyDataSetChanged();
}
};
}
#Override
public void notifyDataSetChanged() {
super.notifyDataSetChanged();
}
public ArrayList<InfoArticle> toIA(ArrayList<String> data){
ArrayList<InfoArticle> converted = new ArrayList<InfoArticle>();
for(String a: data)
{
converted.add(new InfoArticle(a,""));
}
return converted;
}
#Override
public int getCount() {
return Teachers.size();
}
#Override
public InfoArticle getItem(int position) {
return Teachers.get(position);
}
public void saveTeacher(int position){
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
SharedPreferences.Editor editor = sharedPref.edit();
Set<String> teach = sharedPref.getStringSet("teachPref", new HashSet<String>());
teach.add(Teachers.get(position).title);
Set<String> link = sharedPref.getStringSet("linkPref", new HashSet<String>());
link.add(Teachers.get(position).description);
editor.putStringSet("teachPref", teach);
editor.putStringSet("linkPref", link);
editor.apply();
new AlertDialog.Builder(getContext())
.setTitle("Teacher Saved")
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// continue with delete
}
}).setIcon(android.R.drawable.ic_dialog_alert)
.show();
swipeV.close(true);
}
private void deleteTeacher(int position){
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(getContext());
SharedPreferences.Editor editor = sharedPref.edit();
Set<String> teach = sharedPref.getStringSet("teachPref", new HashSet<String>());
Set<String> link = sharedPref.getStringSet("linkPref", new HashSet<String>());
teach.remove(Teachers.get(position).title);
link.remove(Teachers.get(position).description);
editor.putStringSet("teachPref", teach);
editor.putStringSet("linkPref", link);
editor.apply();
HashSet<String> defv = new HashSet<String>();
Teachers.remove(position);
new AlertDialog.Builder(getContext())
.setTitle("Teacher Deleted")
.setPositiveButton("Ok", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int which) {
// continue with delete
}
}).setIcon(android.R.drawable.ic_dialog_alert)
.show();
swipeV.close(false);
}
class Holder{
TextView Delete;
TextView Save;
TextView Cell;
}
}

Can't open fragment from RecyclerView item Click

Hi I have a simple app that features a recyclerView with list items (each representing a "Movie" object. The content for the movie list items is generated from an API call (themoviedb.org). I'm trying to open a "detail fragment" by clicking on a recyclerView list item. I want all of the content from the Movie item clicked to appear in the next fragment as well. Right now when I click the list item, nothing happens. No crash, even. I thought I had set up the listener interface correctly, but maybe that's the problem. Can anyone see where I'm going wrong? Thanks in advance.
Here is the Fragment where the RecyclerView (movie list) first appears:
public class ResultsFragment extends Fragment {
private RecyclerView mRecyclerView;
Movie_Results_Adapter results_adapter;
ArrayList<Movie> movieList;
onMovieSelectedListener listener;
public ResultsFragment(){
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_layout_1, container, false);
mRecyclerView = (RecyclerView) rootView.findViewById(R.id.recycler);
mRecyclerView.setVisibility(View.VISIBLE);
results_adapter = new Movie_Results_Adapter(movieList, listener);
listener = new onMovieSelectedListener() {
#Override
public void onMovieSelected(Movie selectedMovie) {
Intent launchIntent = new Intent(getContext(), MovieDetailActivity.class);
launchIntent.putExtra(MovieDetailActivity.EXTRA_MOVIE, "movie");
Log.d("PaulsApp", selectedMovie + "");
launchIntent.putExtra(MovieDetailActivity.NEW_EXTRA, (Serializable) selectedMovie);
startActivity(launchIntent);
}
};
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getContext());
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(results_adapter);
Log.d("TAGG", "AAAH" + movieList.toString());
return rootView;
}
public void parseJson(String jsonToParse) throws JSONException {
JSONObject responseObject= new JSONObject(jsonToParse);
JSONArray resultsArray = responseObject.getJSONArray("results");
for(int i = 0; i < resultsArray.length(); i++){
JSONObject movie = resultsArray.getJSONObject(i);
String movieName = movie.getString("title");
String movieReleaseDate = movie.getString("release_date");
String movieScore = movie.getString("vote_average");
String moviePopularity = movie.getString("vote_count");
String movieImage = movie.getString("poster_path");
String movieDescription = movie.getString("overview");
Movie movie1 = new Movie(movieName, movieReleaseDate, movieScore, moviePopularity, movieImage, movieDescription);
movieList.add(movie1);
}
}
#Override
public void setArguments(Bundle args) {
movieList = new ArrayList<>();
String arguments = args.getString("JSON_STRING");
try {
parseJson(arguments);
} catch (JSONException e) {
e.printStackTrace();
}
super.setArguments(args);
}
public interface onMovieSelectedListener{
public void onMovieSelected(Movie selectedMovie);
}
}
Here is the RecyclerView Adapter for the "results" fragment:
public class Movie_Results_Adapter extends RecyclerView.Adapter<Movie_Results_Adapter.ResultViewHolder>{
ArrayList<Movie> MovieListArray;
ResultsFragment.onMovieSelectedListener listener;
private Activity mActivity;
public class ResultViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
TextView titleText;
TextView dateText;
TextView scoreText;
TextView popularityText;
ImageView movieImage;
public Movie movie;
public ResultViewHolder(View itemView){
super(itemView);
titleText = (TextView) itemView.findViewById(R.id.movie_title_text);
dateText = (TextView) itemView.findViewById(R.id.movie_date_text);
scoreText = (TextView) itemView.findViewById(R.id.movie_score_text);
popularityText = (TextView) itemView.findViewById(R.id.movie_popularity_text);
movieImage = (ImageView) itemView.findViewById(R.id.movie_image);
}
#Override
public void onClick(View view) {
if (listener != null) {
listener.onMovieSelected(MovieListArray.get(getAdapterPosition()));
Toast.makeText(view.getContext(), "clicked: " + MovieListArray.get(getAdapterPosition()), Toast.LENGTH_SHORT).show();
}
}
}
public Movie_Results_Adapter(ArrayList<Movie> movieList, ResultsFragment.onMovieSelectedListener listener){
MovieListArray = movieList;
this.listener = listener;
}
#Override
public ResultViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.movie_result_list_item, parent, false);
ResultViewHolder vh = new ResultViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(ResultViewHolder holder, int position) {
holder.titleText.setText(MovieListArray.get(position).getmTitle());
Log.d("TAGG", MovieListArray.toString());
holder.dateText.setText("Released "+MovieListArray.get(position).getmReleaseYear());
holder.scoreText.setText("TMDB Score: "+MovieListArray.get(position).getmScore());
holder.popularityText.setText(MovieListArray.get(position).getmPopularity()+" votes");
Context context = holder.movieImage.getContext();
Picasso.with(context).load(Constants.TMDB_POSTER+MovieListArray.get(position).getmImage()).into(holder.movieImage);
}
#Override
public int getItemCount() {
return MovieListArray.size();
}
}
Here is the detail fragment (and accompanying activity):
package jetsetpaul.movienerd;
import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.squareup.picasso.Picasso;
/**
* Created by pauljoiner on 8/17/16.
*/
public class MovieDetailFragment extends Fragment {
public String movieTitle;
public String movieImage;
public String movieDate;
public String movieDescription;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.movie_detail_fragment, container, false);
TextView mTitleText = (TextView) rootView.findViewById(R.id.movie_detail_title);
ImageView mMovieImage = (ImageView) rootView.findViewById(R.id.movie_detail_image);
TextView mDateText = (TextView) rootView.findViewById(R.id.movie_detail_release_date);
TextView mDescriptionText = (TextView) rootView.findViewById(R.id.movie_detail_description);
mTitleText.setText(movieTitle);
mDateText.setText(movieDate);
mDescriptionText.setText(movieDescription);
Context context = mMovieImage.getContext();
Picasso.with(context).load(Constants.TMDB_POSTER+movieImage);
return rootView;
}
public void setMovieTitle(String title){
this.movieTitle = title;
}
public void setMovieImage(String image){
this.movieImage = image;
}
public void setMovieDate(String date){
this.movieDate = date;
}
public void setMovieDescription(String description){
this.movieDescription = description;
}
}
Activity:
package jetsetpaul.movienerd;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentTransaction;
import android.support.v7.app.AppCompatActivity;
import android.util.Log;
/**
* Created by pauljoiner on 8/17/16.
*/
public class MovieDetailActivity extends AppCompatActivity {
public static final String EXTRA_MOVIE = "movie";
public static final String NEW_EXTRA = "movie2";
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_movie_detail);
Intent i = getIntent();
if(i.hasExtra(NEW_EXTRA)) {
Log.d("PaulsApp", "Had Extra!");
//set the text in my fragment
Movie movie = (Movie) i.getSerializableExtra(NEW_EXTRA);
Fragment newFragment = new MovieDetailFragment();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.detail_fragment, newFragment);
transaction.commit();
((MovieDetailFragment) newFragment).setMovieTitle(movie.getmTitle());
((MovieDetailFragment) newFragment).setMovieImage(movie.getmImage());
((MovieDetailFragment) newFragment).setMovieDate(movie.getmReleaseYear());
((MovieDetailFragment) newFragment).setMovieDescription(movie.getmDescription());
}
}
}
I can post more code if necessary. Thanks again!

Your listener needs to be created before your results_adapter
listener = new onMovieSelectedListener() {
#Override
public void onMovieSelected(Movie selectedMovie) {
Intent launchIntent = new Intent(getContext(), MovieDetailActivity.class);
launchIntent.putExtra(MovieDetailActivity.EXTRA_MOVIE, "movie");
Log.d("PaulsApp", selectedMovie + "");
launchIntent.putExtra(MovieDetailActivity.NEW_EXTRA, (Serializable) selectedMovie);
startActivity(launchIntent);
}
};
results_adapter = new Movie_Results_Adapter(movieList, listener);
To be honest though, it would be best for your fragment to implement the listener (interface) instead of having to create it by using new onMovieSelectedListener().

RecyclerView does not update or refresh when calling notifyDataSetChanged()

I have an app that uses RecyclerView. When user selects "Add New Row" from the options menu, I output a test message to the screen, and some values get appended to two different ArrayLists. That part is working great, as I have confirmed these values are successfully added by looking at the ArrayList values using the debugger.
Anyhow I am not able to get the RecyclerView to redraw the screen and show the new information. My attempt to redraw / update the screen is by using this code (line 78 of MainActivity.java):
//call notify data set changed method for the adapter
adapter.notifyDataSetChanged();
Maybe I am not calling notifyDataSetChanged on the same adapter that actually is used for RecycleView??
Here is the complete code for MainActivity.java (see options menu code at end):
package com.joshbgold.ironmax;
import android.os.Bundle;
import android.support.v7.app.ActionBar;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.ImageView;
import android.widget.Toast;
public class MainActivity extends AppCompatActivity {
private static final int ADD_ROW = 1; //used for case statement statement to select menu item
private RecyclerView recyclerView;
public Exercises exercises = new Exercises();
public ExerciseRow adapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
assert getSupportActionBar() != null;
ActionBar actionBar = getSupportActionBar();
actionBar.setDisplayShowHomeEnabled(true);
actionBar.setIcon(R.mipmap.barbell);
actionBar.setTitle(" " + "Iron Max");
recyclerView = (RecyclerView) findViewById(R.id.recyclerView);
//ExerciseRow adapter = new ExerciseRow(this);
adapter = new ExerciseRow(this);
recyclerView.setAdapter(adapter);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setHasFixedSize(true);
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
/* MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.add_row, menu);
return super.onCreateOptionsMenu(menu);*/
menu.add(0, ADD_ROW, 0, "Add New Row");
menu.getItem(0).setIcon(R.drawable.plus);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onPrepareOptionsMenu(Menu menu) {
menu.getItem(0).setIcon(R.drawable.plus);
return super.onPrepareOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int length;
switch (item.getItemId()) {
case 1:
Toast msg = Toast.makeText(MainActivity.this, "Test code for adding an exercise", Toast.LENGTH_LONG);
msg.show();
exercises.addExercise("Some exercise");
exercises.addPersonalBest(500);
length = exercises.getExercisesArrayLength();
//call notify data set changed method for the adapter
adapter.notifyItemInserted(length - 1);
adapter.notifyDataSetChanged();
return super.onOptionsItemSelected(item);
default:
return super.onOptionsItemSelected(item);
}
}
}
Here is Exercises.java:
import android.support.v7.app.AppCompatActivity;
import java.util.ArrayList;
public class Exercises extends AppCompatActivity {
public ArrayList<String> exercisesArrayList = new ArrayList<>(); //stores all the lifts
private ArrayList<Integer> personalBestsArrayList = new ArrayList<>(); //stores personal bests in pounds
public ArrayList<String> getExercisesArray() { //returns the whole exercises arraylist
return exercisesArrayList;
}
public ArrayList<Integer> getPersonalBests() { //returns the whole personal bests arraylist
return personalBestsArrayList;
}
public String getExercise(int position) { //returns individual exercise from array
return exercisesArrayList.get(position);
}
public void addExercise(String exercise) {
exercisesArrayList.add(exercise);
}
public void removeExercise(int position) {
exercisesArrayList.remove(position);
}
public void editExercise(int position, String exercise) {
exercisesArrayList.set(position, exercise);
}
public int getExercisesArrayLength() {
return exercisesArrayList.size();
}
public Integer getPersonalBest(int position) { //returns individual personal best from array
return personalBestsArrayList.get(position);
}
public void addPersonalBest(int personalBest) {
personalBestsArrayList.add(personalBest);
}
public void removePersonalBest(int position) {
personalBestsArrayList.remove(position);
}
public void editPersonalBest(int position, int personalBest) {
personalBestsArrayList.set(position, personalBest);
}
public Exercises() {} //constructor
}
Here is ExerciseRow.java:
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.v7.app.AlertDialog;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.EditText;
import android.widget.ImageView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.ArrayList;
public class ExerciseRow extends RecyclerView.Adapter<ExerciseRow.ExerciseViewHolder> {
String exerciseName = "burpee";
String exercisePR = "100"; // user's personal record for this exercise in pounds
private Context context;
Exercises exercises = new Exercises();
public ExerciseRow(Context context) {
this.context = context;
}
#Override
public ExerciseViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.exercise_list_item, parent, false);
return new ExerciseViewHolder(view);
}
#Override
public void onBindViewHolder(ExerciseViewHolder holder, int position) {
ArrayList<String> exercisesArray = exercises.getExercisesArray();
holder.bindExercises(exercisesArray.get(position));
}
#Override
public int getItemCount() {
return exercises.getExercisesArrayLength();
}
public class ExerciseViewHolder extends RecyclerView.ViewHolder {
public TextView exerciseNameTextView;
public TextView personalRecordTextView;
public ImageView edit_Icon;
public ImageView percentages_Icon;
public ImageView trash_Icon;
public ImageView plus_icon;
public ImageView facebook_icon;
public ImageView twitter_icon;
public ExerciseViewHolder(View itemView) {
super(itemView);
exerciseNameTextView = (TextView) itemView.findViewById(R.id.list_item_exercise_textview);
personalRecordTextView = (TextView) itemView.findViewById(R.id.list_item_amount_textview);
edit_Icon = (ImageView) itemView.findViewById(R.id.list_item_pencil);
percentages_Icon = (ImageView) itemView.findViewById(R.id.list_item_percent);
trash_Icon = (ImageView) itemView.findViewById(R.id.list_item_trash);
plus_icon = (ImageView) itemView.findViewById(R.id.list_item_plus);
facebook_icon = (ImageView) itemView.findViewById(R.id.list_item_facebook);
twitter_icon = (ImageView) itemView.findViewById(R.id.list_item_twitter);
View.OnClickListener plus = new View.OnClickListener() {
#Override
public void onClick(View view) {
// allow user to add a new exercise and personal best
exercises.addExercise("Some exercise");
exercises.addPersonalBest(500);
notifyDataSetChanged();
}
};
View.OnClickListener edit = new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = getLayoutPosition(); //use getAdapterPosition() if getLayoutPosition causes a problem
if (position == 0) { //prevent user from deleting the first row.
Toast.makeText(context, "Sorry, example row cannot be edited.", Toast.LENGTH_LONG).show();
}
else{
editRow(position); //edit the row at the current position
notifyDataSetChanged();
}
}
};
View.OnClickListener percentages = new View.OnClickListener() {
#Override
public void onClick(View view) {
//get exercise name
exerciseName = exerciseNameTextView.getText().toString();
exercisePR = personalRecordTextView.getText().toString();
//show percentages layout
startPercentagesActivity(exerciseName, exercisePR);
}
};
View.OnClickListener trash = new View.OnClickListener() {
#Override
public void onClick(View view) {
int position = getLayoutPosition(); //use getAdapterPosition() if getLayoutPosition causes a problem
if (position == 0) { //prevent user from deleting the first row.
Toast.makeText(context, "Sorry, example row cannot be deleted.", Toast.LENGTH_LONG).show();
} else {
exercises.removeExercise(position);
exercises.removePersonalBest(position);
notifyItemRemoved(position);
notifyItemRangeChanged(position, exercises.getExercisesArrayLength());
}
}
};
plus_icon.setOnClickListener(plus);
edit_Icon.setOnClickListener(edit);
percentages_Icon.setOnClickListener(percentages);
trash_Icon.setOnClickListener(trash);
}
public void bindExercises(String exercises) {
Exercises exercisesObject = new Exercises();
exerciseNameTextView.setText(exercisesObject.getExercise(getAdapterPosition()));
personalRecordTextView.setText((exercisesObject.getPersonalBest(getAdapterPosition())).toString() + " pounds");
}
}
private void startPercentagesActivity(String some_exercise, String personal_record) {
Intent intent = new Intent(context, PercentagesActivity.class);
intent.putExtra("exerciseName", some_exercise);
intent.putExtra("personalRecord", personal_record);
context.startActivity(intent);
}
protected void editRow(final int position) {
LayoutInflater layoutInflater = LayoutInflater.from(context);
//text_entry is an Layout XML file containing two text field to display in alert dialog
final View textEntryView = layoutInflater.inflate(R.layout.text_entry, null);
final EditText liftName = (EditText) textEntryView.findViewById(R.id.liftNameEditText);
final EditText PersonalBestInPounds = (EditText) textEntryView.findViewById(R.id.personalBestEditText);
final AlertDialog.Builder alert = new AlertDialog.Builder(context);
alert.setIcon(R.mipmap.barbell)
.setTitle("Please make your changes:")
.setView(textEntryView)
.setPositiveButton("Save",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
//retrieve the user's input
String lift = liftName.getText().toString();
int personalBest = Integer.parseInt(PersonalBestInPounds.getText().toString());
//save the user's input to the appropriate arrays
exercises.editExercise(position, lift);
exercises.editPersonalBest(position, personalBest);
}
})
.setNegativeButton("Cancel",
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog,
int whichButton) {
}
});
alert.show();
}
}
If you have read this far, I give you credit! Please understand I am completely new to RecyclerView, so whatever error(s) I have made could be something quite simple even.

The issue is that you have two different instances of ExercisesOne in MainActivity and another in ExerciseRow You are adding the data to the wrong one.
A few other things that may help you along your way.
Exercises Should not extend AppCompatActivity (or really anything as far as I can tell)
You should avoid saving a reference to the context (as you are doing in Exercises) it can great memory issues. Instead try one of the following.
A. Use the context to get the LayoutInflater in the constructor
B. Call parent.getContext() in onCreateViewHolder

RecyclerView save position on device orientation change

In my App I have a RecyclerView connected with an adapter but everytime my device changes from landscape to portrait or something else, the view get reloaded and I'll get to the top again. I want to save my scroll position to the last item I saw.
Here is what I tried:
I have a Fragment that extends from another fragment the state should be save within the MainPageFragment. I tried to save the last position loaded and put it into the savedState, it gets correctly retrieved but If I call "scrollToPosition" nothing happens.
package com.pr0.pr0grammreloaded.fragment;
/**
* Created by Dominik on 22.02.2015.
*/
import android.app.Activity;
import android.app.FragmentManager;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import com.pr0.pr0grammreloaded.MainActivity;
import com.pr0.pr0grammreloaded.R;
import com.pr0.pr0grammreloaded.config.FilterConfig;
import com.pr0.pr0grammreloaded.util.FixedRecyclerView;
import com.pr0.pr0grammreloaded.util.MainPageSaveParcelable;
import com.pr0.pr0grammreloaded.util.MyLayoutManager;
import com.pr0.pr0grammreloaded.util.RecyclerViewDelegate;
import java.util.ArrayList;
import uk.co.senab.actionbarpulltorefresh.extras.actionbarsherlock.PullToRefreshLayout;
import uk.co.senab.actionbarpulltorefresh.library.ActionBarPullToRefresh;
import uk.co.senab.actionbarpulltorefresh.library.listeners.OnRefreshListener;
import uk.co.senab.actionbarpulltorefresh.library.viewdelegates.AbsListViewDelegate;
/**
* Created by Dominik on 17.01.2015.
*/
public class MainPageFragment extends Pr0MainPageFragment {
/**
* The fragment argument representing the section number for this
* fragment.
*/
private static final String ARG_SECTION_NUMBER = "section_number";
/**
* Returns a new instance of this fragment for the given section
* number.
*/
public static MainPageFragment newInstance(FilterConfig config) {
MainPageFragment fragment = new MainPageFragment();
fragment.config = config;
return fragment;
}
public MainPageFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
if(savedInstanceState != null){
MainPageSaveParcelable saveParcelable = savedInstanceState.getParcelable("save");
View rootView = inflater.inflate(R.layout.mainpage_fragment, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.list);
adapter = new ItemAdapter();
itemList = saveParcelable.itemList;
config = saveParcelable.config;
// use better layout manager, maybe write our own?
recyclerView.setLayoutManager(new GridLayoutManager(MainActivity.getActivity(), 3));
recyclerView.setAdapter(adapter);
restorePositon = saveParcelable.position;
mPullToRefreshLayout = (PullToRefreshLayout) rootView.findViewById(R.id.ptr_layout);
// Now setup the PullToRefreshLayout
ActionBarPullToRefresh.from(getActivity())
// Mark All Children as pullable
.allChildrenArePullable()
// Set a OnRefreshListener
.listener(new OnRefreshListener() {
#Override
public void onRefreshStarted(View view) {
if (!isBlocked()) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, MainPageFragment.newInstance(MainActivity.filterConfig))
.commit();
}
}
})
// Finally commit the setup to our PullToRefreshLayout
.useViewDelegate(FixedRecyclerView.class, new RecyclerViewDelegate())
.setup(mPullToRefreshLayout);
loadFeed();
// recyclerView.scrollToPosition(saveParcelable.);
return rootView;
}else {
View rootView = inflater.inflate(R.layout.mainpage_fragment, container, false);
recyclerView = (RecyclerView) rootView.findViewById(R.id.list);
adapter = new ItemAdapter();
itemList = new ArrayList<>();
// use better layout manager, maybe write our own?
recyclerView.setLayoutManager(new GridLayoutManager(MainActivity.getActivity(), 3));
recyclerView.setAdapter(adapter);
mPullToRefreshLayout = (PullToRefreshLayout) rootView.findViewById(R.id.ptr_layout);
// Now setup the PullToRefreshLayout
ActionBarPullToRefresh.from(getActivity())
// Mark All Children as pullable
.allChildrenArePullable()
// Set a OnRefreshListener
.listener(new OnRefreshListener() {
#Override
public void onRefreshStarted(View view) {
if (!isBlocked()) {
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction()
.replace(R.id.container, MainPageFragment.newInstance(MainActivity.filterConfig))
.commit();
}
}
})
// Finally commit the setup to our PullToRefreshLayout
.useViewDelegate(FixedRecyclerView.class, new RecyclerViewDelegate())
.setup(mPullToRefreshLayout);
loadFeed();
return rootView;
}
}
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
}
#Override
public void onSaveInstanceState(Bundle state){
super.onSaveInstanceState(state);
restorePositon = lastPositon;
MainPageSaveParcelable saveParcelable = new MainPageSaveParcelable(itemList,firstChunk,config,restorePositon);
state.putParcelable("save",saveParcelable);
}
}
Pr0MainPageFragment
package com.pr0.pr0grammreloaded.fragment;
import android.app.Fragment;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import com.google.gson.Gson;
import com.google.gson.GsonBuilder;
import com.pr0.pr0grammreloaded.MainActivity;
import com.pr0.pr0grammreloaded.R;
import com.pr0.pr0grammreloaded.api.Api;
import com.pr0.pr0grammreloaded.api.Feed;
import com.pr0.pr0grammreloaded.api.InstantDeserializer;
import com.pr0.pr0grammreloaded.config.FilterConfig;
import com.squareup.picasso.Picasso;
import org.joda.time.Instant;
import java.util.ArrayList;
import java.util.List;
import retrofit.RestAdapter;
import retrofit.converter.GsonConverter;
import rx.functions.Action1;
import uk.co.senab.actionbarpulltorefresh.extras.actionbarsherlock.PullToRefreshLayout;
import static rx.android.observables.AndroidObservable.bindActivity;
/**
* Created by Dominik on 22.02.2015.
*/
public class Pr0MainPageFragment extends Fragment {
protected ItemAdapter adapter;
protected boolean firstChunk = true;
protected List<Feed.Item> itemList;
protected FilterConfig config;
private boolean blockLoading = false;
protected PullToRefreshLayout mPullToRefreshLayout;
protected int restorePositon = 0;
protected int lastPositon = 0;
protected RecyclerView recyclerView;
protected boolean isRestore = false;
/**
* Loads the feed from pr0gramm. This should be put into some kind of service
* that is injected into our activities.
*/
protected void loadFeed() {
if(!blockLoading) {
blockLoading = true;
Log.e("Pr0","Blocked loading!");
Gson gson = new GsonBuilder()
.registerTypeAdapter(Instant.class, new InstantDeserializer())
.create();
Api api = new RestAdapter.Builder()
.setEndpoint("http://pr0gramm.com")
.setConverter(new GsonConverter(gson))
.setLogLevel(RestAdapter.LogLevel.BASIC)
.build()
.create(Api.class);
// perform api request in the background and call
// back to the main thread on finish
if (firstChunk) {
bindActivity(MainActivity.getActivity(), api.itemsGet(config.getFlag(), 1)).subscribe(new Action1<Feed>() {
#Override
public void call(Feed feed) {
// we are now back in the main thread
firstChunk = false;
handleFeedResponse(feed);
}
});
} else {
//Log.e("Pr0", "Loading after ID : " + itemList.get(0).getId());
for(int x = 0; x < itemList.size();x ++){
Log.e("Pr0", "POS: " + x + ", ID : " + itemList.get(x).getId());
}
bindActivity(MainActivity.getActivity(), api.olderGet(itemList.get(itemList.size() - 1).getPromoted(), config.getFlag(), 1)).subscribe(new Action1<Feed>() {
#Override
public void call(Feed feed) {
// we are now back in the main thread
handleFeedResponse(feed);
}
});
}
}
}
/**
* Display the elements from the feed
*
* #param feed The feed to display
*/
private void handleFeedResponse(Feed feed) {
// display feed now.
//Log.i("MainActivity", "Number of items: " + feed.getItems().size());
adapter.addItems(feed.getItems());
mPullToRefreshLayout.setRefreshComplete();
restorePostion();
}
protected class ItemAdapter extends RecyclerView.Adapter<ItemView> {
ItemAdapter() {
setHasStableIds(true);
}
#Override
public ItemView onCreateViewHolder(ViewGroup viewGroup, int i) {
LayoutInflater inflater = LayoutInflater.from(MainActivity.getActivity());
View view = inflater.inflate(R.layout.item_view, viewGroup, false);
return new ItemView(view);
}
#Override
public void onBindViewHolder(ItemView itemView, int i) {
// Log.e("Pr0","load id : " + i);
//Log.e("Pr0",String.valueOf(itemList.get(i).getId()));
String url = "http://thumb.pr0gramm.com/" + itemList.get(i).getThumb();
Picasso.with(getActivity())
.setIndicatorsEnabled(true);
Picasso.with(getActivity())
.load(url)
.into(itemView.image);
lastPositon = i;
Log.w("Pr0","last positon : " + i);
if(i > itemList.size() - 5){
//Log.e("Pr0","SIZE : " + itemList.size());
//Log.e("Pr0","End Reached Load After ID : " + itemList.get(0).getId());
loadFeed();
}
}
#Override
public int getItemCount() {
return itemList.size();
}
public void addItems(List<Feed.Item> itemsToAdd) {
int oldCount = itemList.size();
itemList.addAll(itemsToAdd);
notifyItemRangeInserted(oldCount, itemList.size());
/*
for(Feed.Item item : itemsToAdd) {
//Log.e("Pr0","Added image ID : " + item.getId());
int oldCount = itemList.size();
itemList.add(item);
notifyItemRangeInserted(oldCount, itemList.size());
}
*/
blockLoading = false;
Log.e("Pr0","Unblocked Loading");
//
}
#Override
public long getItemId(int position) {
return itemList.get(position).getId();
}
}
/**
* View holder for a view in the list of items
*/
private class ItemView extends RecyclerView.ViewHolder {
final ImageView image;
public ItemView(View itemView) {
super(itemView);
image = (ImageView) itemView.findViewById(R.id.image);
}
}
public boolean isBlocked(){
return this.blockLoading;
}
public void reset(){
itemList.clear();
firstChunk = true;
}
public void restorePostion(){
Log.w("Pr0", "Restore : " + restorePositon);
recyclerView.scrollToPosition(restorePositon);
}
}
And here is my Parcelable
package com.pr0.pr0grammreloaded.util;
import android.os.Parcel;
import android.os.Parcelable;
import com.pr0.pr0grammreloaded.account.User;
import com.pr0.pr0grammreloaded.api.Feed;
import com.pr0.pr0grammreloaded.config.FilterConfig;
import java.util.List;
/**
* Created by Dominik on 27.02.2015.
*/
public class MainPageSaveParcelable implements Parcelable{
public boolean firstChunk;
public List<Feed.Item> itemList;
public FilterConfig config;
public int position;
public MainPageSaveParcelable(List<Feed.Item> itemList, boolean firstChunk, FilterConfig config, int position){
this.firstChunk = firstChunk;
this.itemList = itemList;
this.config = config;
this.position = position;
}
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeList(itemList);
dest.writeValue(config);
dest.writeValue(firstChunk);
dest.writeInt(position);
}
/** Static field used to regenerate object, individually or as arrays */
public static final Parcelable.Creator<MainPageSaveParcelable> CREATOR = new Parcelable.Creator<MainPageSaveParcelable>() {
public MainPageSaveParcelable createFromParcel(Parcel pc) {
return new MainPageSaveParcelable(pc);
}
public MainPageSaveParcelable[] newArray(int size) {
return new MainPageSaveParcelable[size];
}
};
/**Ctor from Parcel, reads back fields IN THE ORDER they were written */
public MainPageSaveParcelable(Parcel pc){
pc.readList(itemList,List.class.getClassLoader());
config = (FilterConfig) pc.readValue(FilterConfig.class.getClassLoader());
firstChunk = (boolean) pc.readValue(Boolean.class.getClassLoader());
position = pc.readInt();
}
}

you can use scroll listener and save first items or RecyclerView state on scrolling in SharedPreference or whatever you prefer
define these variables as private variables in your activity or fragment
int firstCompleteVisibleItemPosition;
int firstVisibleItemPosition;
Parcelable recyclerViewState;
use recyclerview on scroll listener
recyclerView.addOnScrollListener(new RecyclerView.OnScrollListener() {
#Override
public void onScrollStateChanged(RecyclerView recyclerView, int newState) {
super.onScrollStateChanged(recyclerView, newState);
}
#Override
public void onScrolled(RecyclerView recyclerView, int dx, int dy) {
super.onScrolled(recyclerView, dx, dy);
firstCompleteVisibleItemPosition = recyclerView.getLayoutManager().findFirstCompletelyVisibleItemPosition();
firstVisibleItemPosition = recyclerView.getLayoutManager().findFirstVisibleItemPosition();
recyclerViewState = recyclerView.getLayoutManager().onSaveInstanceState();
}
});
and if orientation changes you can start your recyclerview by last position u saved by this method
linearLayoutManager.scrollToPositionWithOffset(firstVisibleItemPosition, 0);
or by last state of recyclerview
rv.getLayoutManager().onRestoreInstanceState(recyclerViewState);