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RecyclerView inside fragment is not clickable

I am programming a music player app and having a problem with a RecyclerView inside a fragment(which connects to tab layout in my main activity) from some reason the RecyclerView is not clickable and when I am pressing an item the app just close.
Can you please help me with that?
I added the fragment class and the adapter class.
public class MusicAdapter extends RecyclerView.Adapter<MusicAdapter.MusicviewHolder> {
private List<Music> songs;
public Resources res;
Context context;
public MusicAdapter(Context context, List<Music> songs) {
String s = String.valueOf(R.drawable.lionkingposter);
songs.add(new Music("jgggug", "Circle of life", "Alton John ", "Lion King",s));
// }
this.songs = songs;//constructor
this.context=context;
}
interface MusicListener {
void onMusicClicked(int position, View view);
// void onDeleteClicked(int position);
}
MusicListener listener;
public void setListener(MusicListener listener) {
this.listener = listener;
}
#Override
public MusicviewHolder onCreateViewHolder(ViewGroup parent, int viewType) {//function design the cell
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cell, parent, false);
MusicviewHolder musicviewholder = new MusicviewHolder(view);
return musicviewholder;
}
#Override
public void onBindViewHolder(MusicviewHolder holder, int position) {//this function takes the object and put it in the cell
Music music = songs.get(position);
if (music.getPhoto() != null) {
try {
holder.songImg.setImageResource(Integer.parseInt(music.getPhoto()));
} catch (Exception e) {
//holder.songImg.setImageURI(Uri.parse(music.getPhoto()));
byte[] decodedString = Base64.decode(music.getPhoto(), Base64.DEFAULT);
Bitmap decodedByte = BitmapFactory.decodeByteArray(decodedString, 0, decodedString.length);
holder.songImg.setImageBitmap(decodedByte);
}
} else {
holder.songImg.setImageResource(0);
}
holder.songName.setText(music.getTitle());
holder.movieName.setText(music.getAlbum());
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Intent intent=new Intent(context,MediaPlayer.class);
//intent.putExtra("song",position);
//context.startActivity(intent);
Toast.makeText(context,"hello",Toast.LENGTH_SHORT);
}
});
}
#Override
public int getItemCount() {
return songs.size();
}
public class MusicviewHolder extends RecyclerView.ViewHolder {
TextView songName;
TextView movieName;
ImageView songImg;
public MusicviewHolder(#NonNull View itemView) {
super(itemView);
songName = itemView.findViewById(R.id.song_title);
movieName = itemView.findViewById(R.id.movie_title);
songImg = itemView.findViewById(R.id.song_img);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null)
listener.onMusicClicked(getAdapterPosition(), v);
}
}
);
}
}
}
public class SongFragment extends Fragment {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private RecyclerView recyclerview;
private RecyclerView.Adapter myadapter;
private RecyclerView.LayoutManager layoutManager;
View view;
private ArrayList<Music> songs=new ArrayList<>();
private Resources res;
public Context context;
Bundle bundle;
// private ShowSongActivity show;
public SongFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment SongsFragment.
*/
// TODO: Rename and change types and number of parameters
public static SongFragment newInstance(String param1, String param2) {
SongFragment fragment = new SongFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
ArrayList<Music> listTemp = MusicManager.getInstance(getContext()).getMusics();
if (listTemp != null)
songs.addAll((Collection<? extends Music>) listTemp.clone());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_songs, container, false);
recyclerview = (RecyclerView) view.findViewById(R.id.songs_recycler);
MusicAdapter musicAdapter = new MusicAdapter(context,songs);
recyclerview.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerview.setAdapter(musicAdapter);
recyclerview.setLayoutManager(new LinearLayoutManager(getContext(), RecyclerView.VERTICAL, false));
return view;
}
}

Try to set onClickListener on the holder into the onBindViewHolder method and when invoke the listener it need to be passed into the setListener(MusicListener listener) method. Something like this:
holder.itemView.setOnClickListener(v -> this.listener.onMusicClicked(position, v);});
In my opinion, it's better to change the interface MusicListener like that:
interface MusicListener {
void onMusicClicked(int position, Music item);
}
And return the clicked item directly like this:
holder.itemView.setOnClickListener(v -> this.listener.onMusicClicked(position, songs.get(position);});
Furthermore, it is better to pass the MusicListener when you create the RecyclerView Adapter because you can easily forget to set it and this will cause the Nullpointer Exception.
I am not sure why you are doing this: String s = String.valueOf(R.drawable.lionkingposter); If you want to keep the Drawable resource in the class make property int (Integer) and keep only the R.drawable.lionkingposter when you set the drawable resource to an ImageView use setBackgroundResource method as described here
I hope this helped ;)

I faced the same problem, Don't know the actual cause of this but I found a working solution.
You need to create a Listener class which implements RecyclerView.OnItemTouchListener
public class MatchClickListener implements RecyclerView.OnItemTouchListener {
private GestureDetector gestureDetector;
private ClickListener clickListener;
public MatchClickListener(Context context, final RecyclerView recyclerView, final ClickListener clickListener) {
this.clickListener = clickListener;
gestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
#Override
public boolean onSingleTapUp(MotionEvent e) {
return true;
}
#Override
public void onLongPress(MotionEvent e) {
View child = recyclerView.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null) {
clickListener.onLongClick(child, recyclerView.getChildPosition(child));
}
}
});
}
#Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View child = rv.findChildViewUnder(e.getX(), e.getY());
if (child != null && clickListener != null && gestureDetector.onTouchEvent(e)) {
clickListener.onClick(child, rv.getChildPosition(child));
}
return false;
}
#Override
public void onTouchEvent(#NotNull RecyclerView rv, MotionEvent e) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
public interface ClickListener {
void onClick(View view, int position);
void onLongClick(View view, int position);}
}
Then call it from your fragment or mainactivity where recyler view is created
recyclerView.addOnItemTouchListener(new MatchClickListener
(getActivity(),recyclerView, new MatchClickListener.ClickListener() {
#Override
public void onClick(View view, int position) {
Intent in =new Intent(getActivity(), TournamentPage.class);
startActivity(in);
}
#Override
public void onLongClick(View view, int position) {
}
}));

First, implement the interface in fragment something like that.
public class SongFragment extends Fragment implements MusicAdapter.MusicListener
Second, override the method.
#Override
public void onMusicClicked(int position, View view) {
}
Third, Pass the view to the method. but below the adapter object
musicAdapter.setListener(this::onItemClick);
Here is the complete solution.
public class SongFragment extends Fragment implements MusicAdapter.MusicListener {
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "param1";
private static final String ARG_PARAM2 = "param2";
// TODO: Rename and change types of parameters
private String mParam1;
private String mParam2;
private RecyclerView recyclerview;
private RecyclerView.Adapter myadapter;
private RecyclerView.LayoutManager layoutManager;
View view;
private ArrayList<Music> songs=new ArrayList<>();
private Resources res;
public Context context;
Bundle bundle;
// private ShowSongActivity show;
public SongFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment SongsFragment.
*/
// TODO: Rename and change types and number of parameters
public static SongFragment newInstance(String param1, String param2) {
SongFragment fragment = new SongFragment();
Bundle args = new Bundle();
args.putString(ARG_PARAM1, param1);
args.putString(ARG_PARAM2, param2);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
mParam1 = getArguments().getString(ARG_PARAM1);
mParam2 = getArguments().getString(ARG_PARAM2);
}
ArrayList<Music> listTemp = MusicManager.getInstance(getContext()).getMusics();
if (listTemp != null)
songs.addAll((Collection<? extends Music>) listTemp.clone());
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_songs, container, false);
recyclerview = (RecyclerView) view.findViewById(R.id.songs_recycler);
MusicAdapter musicAdapter = new MusicAdapter(context,songs);
recyclerview.setLayoutManager(new LinearLayoutManager(getActivity()));
recyclerview.setAdapter(musicAdapter);
recyclerview.setLayoutManager(new LinearLayoutManager(getContext(), RecyclerView.VERTICAL, false));
musicAdapter.setListener(this::onItemClick);
return view;
}
#Override
public void onMusicClicked(int position, View view) {
// here implement which you want
}
}

Android Tabview + Webview

I want to make the webview content change (url change) when tab is changed.
However, my code is late. When I change tabs, it shows the last tab's content.
For example,
App Initialize -> shows first tab and first tab's webview (success)
Click Tab 2 -> shows second tab but first tab's webview (fail)
Click Tab 3 -> shows third tab but first tab's webview (fail)
Return to Tab 2 -> shows second tab and second tab's webview (success)
Please help.
MainActivity.java
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
SectionsPagerAdapter sectionsPagerAdapter = new SectionsPagerAdapter(this, getSupportFragmentManager());
final ViewPager viewPager = findViewById(R.id.view_pager);
viewPager.setAdapter(sectionsPagerAdapter);
TabLayout tabs = findViewById(R.id.tabs);
tabs.setupWithViewPager(viewPager);
tabs.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
#Override
public void onTabSelected(TabLayout.Tab tab) {
}
#Override
public void onTabUnselected(TabLayout.Tab tab) {
}
#Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
}
SectionsPagerAdapter.java
/**
* A [FragmentPagerAdapter] that returns a fragment corresponding to
* one of the sections/tabs/pages.
*/
public class SectionsPagerAdapter extends FragmentPagerAdapter {
#StringRes
private static final int[] TAB_TITLES = new int[]{R.string.tab_text_1, R.string.tab_text_2, R.string.tab_text_3, R.string.tab_text_4, R.string.tab_text_5, R.string.tab_text_6, R.string.tab_text_7};
private final Context mContext;
public SectionsPagerAdapter(Context context, FragmentManager fm) {
super(fm);
mContext = context;
}
#Override
public Fragment getItem(int position) {
// getItem is called to instantiate the fragment for the given page.
// Return a PlaceholderFragment (defined as a static inner class below).
return PlaceholderFragment.newInstance(position + 1);
}
#Nullable
#Override
public CharSequence getPageTitle(int position) {
return mContext.getResources().getString(TAB_TITLES[position]);
}
#Override
public int getCount() {
// Show 2 total pages.
return 7;
}
}
PlaceholderFragment.java
/**
* A placeholder fragment containing a simple view.
*/
public class PlaceholderFragment extends Fragment {
String type;
private static final String ARG_SECTION_NUMBER = "section_number";
private PageViewModel pageViewModel;
public static PlaceholderFragment newInstance(int index) {
PlaceholderFragment fragment = new PlaceholderFragment();
Bundle bundle = new Bundle();
bundle.putInt(ARG_SECTION_NUMBER, index);
fragment.setArguments(bundle);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
pageViewModel = ViewModelProviders.of(this).get(PageViewModel.class);
int index = 1;
if (getArguments() != null) {
index = getArguments().getInt(ARG_SECTION_NUMBER);
}
pageViewModel.setIndex(index);
}
#Override
public View onCreateView(
#NonNull LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_main, container, false);
final WebView webView = (WebView)root.findViewById(R.id.webView);
webView.setWebViewClient( new WebViewClient(){
#Override
public boolean shouldOverrideUrlLoading(WebView view, String url){
webView.loadUrl(url);
return true;
}
});
webView.getSettings().setJavaScriptEnabled(true);
webView.getSettings().setRenderPriority(WebSettings.RenderPriority.HIGH);
pageViewModel.getText().observe(this, new Observer<String>() {
#Override
public void onChanged(#Nullable String s) {
type = s;
}
});
if(type == null)
{
type="1";
}
webView.loadUrl("https://my.domain/list.php?type="+type);
return root;
}
}
PageViewModel.java
public class PageViewModel extends ViewModel {
private MutableLiveData<Integer> mIndex = new MutableLiveData<>();
private LiveData<String> mText = Transformations.map(mIndex, new Function<Integer, String>() {
#Override
public String apply(Integer input) {
return input.toString();
}
});
public void setIndex(int index) {
mIndex.setValue(index);
}
public LiveData<String> getText() {
return mText;
}
}

You can add a loader till the webview loads in respective tabs. onPageFinished() is a callback when webview has completed loading
web_view.webViewClient = object : WebViewClient() {
override fun onPageFinished(view: WebView, weburl: String) {
// Stop loading
}
}

My recommendation is that you should change
webView.loadUrl("https://my.domain/list.php?type="+type);
to
webView.loadUrl("https://my.domain/list.php?type=" + getArguments().getInt(ARG_SECTION_NUMBER));
and see how it works. If it works as you expected, I think you don't need the PageViewModel.java at all.
The root cause of unexpected behavior
In PageViewModel, the value of mIndex is updated by the following line of onCreate in PlaceholderFragment
pageViewModel.setIndex(index);
It also changes the value of mText, which is observed by the following block of onCreateView in PlaceholderFragment:
pageViewModel.getText().observe(this, new Observer<String>() {
#Override
public void onChanged(#Nullable String s) {
type = s;
}
});
Therefore, PageViewModel and PlaceholderFragment are in a race unexpectedly.
ViewPager creates more Fragment early, as written in setOffscreenPageLimit. It is not a good idea to update the value of mIndex in onCreate of PlaceholderFragment.

FragmentStateAdapter removing last tab instead of current ViewPager2

ViewPager2 is removing last tab instead of current tab, same problem was occurring when i was using viewpager.
Also when selected tab is last one it removes last tab correctly
dependency
implementation "androidx.viewpager2:viewpager2:1.0.0"
This is main activity code
MainActivity.java
public class MainActivity extends AppCompatActivity {
TabLayout tabLayout;
ViewPager2 viewPager;
ViewPagerAdapter adapter;
Button btnAddTab,btnRemoveCurrentTab;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
viewPager = findViewById(R.id.view_pager);
tabLayout = findViewById(R.id.tabs);
btnAddTab=findViewById(R.id.btn_add);
btnRemoveCurrentTab=findViewById(R.id.btn_remove);
adapter=new ViewPagerAdapter(this);
viewPager.setAdapter(adapter);
new TabLayoutMediator(tabLayout, viewPager,
new TabLayoutMediator.TabConfigurationStrategy() {
#Override public void onConfigureTab(#NonNull TabLayout.Tab tab, int position) {
tab.setText("Store " + (position + 1));
}
}).attach();
btnRemoveCurrentTab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
adapter.removeFrag(tabLayout.getSelectedTabPosition());
}
});
btnAddTab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
DynamicFragment fView = new DynamicFragment();
adapter.addFrag(fView,"Store "+(adapter.getmFragmentIdList().contains(adapter.getItemCount()+1)?adapter.getItemCount()+2:adapter.getItemCount()+1),(adapter.getmFragmentIdList().contains(adapter.getItemCount()+1)?adapter.getItemCount()+2:adapter.getItemCount()+1));
}
});
}
}
ViewPagerAdapter
This is FragentStateAdapter
public class ViewPagerAdapter extends FragmentStateAdapter {
private final List<DynamicFragment> mFragmentList = new ArrayList<>();
private final List<Integer> mFragmentIdList = new ArrayList<>();
public ViewPagerAdapter(#NonNull FragmentActivity fragmentActivity) {
super(fragmentActivity);
}
#NonNull #Override public Fragment createFragment(int position) {
return DynamicFragment.newInstance(String.valueOf(position),mFragmentIdList.get(position));
}
public void addFrag(DynamicFragment fragment, String title, int id) {
mFragmentList.add(fragment);
Log.e("fragment id " ,""+id);
Log.e("fragment array " ,title+ mFragmentList.size());
mFragmentIdList.add(id);
notifyDataSetChanged();
}
public void removeFrag(int pos) {
Log.e("deleted frag",mFragmentIdList.get(pos)+" "+pos);
mFragmentList.remove(pos);
mFragmentIdList.remove(pos);
notifyDataSetChanged();
}
public List<Integer> getmFragmentIdList() {
return mFragmentIdList;
}
#Override
public long getItemId(int position) {
return super.getItemId(position);
}
#Override public int getItemCount() {
return mFragmentList.size();
}
}
Fragment
This is my dynamic fragment which i want to add and remove
public class DynamicFragment extends Fragment {
private static final String ARG_SECTION_NUMBER = "section_number";
private static final String ARG_ID = "id";
private String sectionNumber;
int id;
TextView textView;
EditText editText1,editText2;
public DynamicFragment() {
// Required empty public constructor
}
public static DynamicFragment newInstance(String sectionNumber, int id) {
DynamicFragment fragment = new DynamicFragment();
Bundle args = new Bundle();
args.putString(ARG_SECTION_NUMBER, sectionNumber);
args.putInt(ARG_ID, id);
fragment.setArguments(args);
Log.e("StoreDynamic","dynamic new instance");
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View rootView= inflater.inflate(R.layout.fragment_dynamic, container, false);
textView=rootView.findViewById(R.id.textView);
editText1=rootView.findViewById(R.id.et1);
editText2=rootView.findViewById(R.id.et2);
sectionNumber = getArguments().getString(ARG_SECTION_NUMBER);
id=getArguments().getInt(ARG_ID);
editText1.setText(id+" "+sectionNumber);
textView.setText(id+" "+sectionNumber);
return rootView;
}
}

I ran into the same problem and the solution to this question: remove fragment in viewPager2 use FragmentStateAdapter, but still display worked for me. Mostly the part about overriding the getItemId function to return something other than the position to identify the item because the item's position changes when adding and removing fragments.

You need to overwrite the methods getItemId() and containsItemId()
as shown in this post: https://stackoverflow.com/a/57944197/870242
items variable holds your fragment (mFragmentList )
private val pageIds= items.map { it.hashCode().toLong() }
override fun getItemId(position: Int): Long {
return items[position].hashCode().toLong() // make sure notifyDataSetChanged() works
}
override fun containsItem(itemId: Long): Boolean {
return pageIds.contains(itemId)
}

ViewPager setCurrentItem(position) not working after orientation change

i'm facing an issue i can't seem to resolve and i'd like some help.
My app is composed by an activity containing a fragment. After the user taps on a suggestion, activity's method onSuggestionClicked(String cardId) is called and activity's content is replaced with a new PagerFragment_new.
#Override
public void onSuggestionClicked(String cardId) {
Log.d("activity","ID:\t" + cardId);
PagerFragment_new pagerFragment = PagerFragment_new.getInstance(
Injection.provideMtgDatabase(getApplicationContext()),
activityPresenter.getAllCardExpansionIds(cardId),
this);
ActivityUtils.replaceFragment(getSupportFragmentManager(), pagerFragment, R.id.MTGRecallActivity_container);
}
PagerFragment_new contains a ViewPager to display CardInfoFragment_new
public class PagerFragment_new extends MtgRecallFragment_new implements PagerFragmentContract.View {
private View fragmentView;
private ViewPager viewPager;
private PagerFragmentContract.Presenter presenter;
private ScreenSlidePageAdapter_new adapter;
private MtgDatabase database;
private String[] printingsIds;
private ScreenSlidePageAdapter_new.ActivePresenterListener listener;
public PagerFragment_new() {
//Required empty constructor
}
public static PagerFragment_new getInstance(MtgDatabase database, String[] printingsIds, ScreenSlidePageAdapter_new.ActivePresenterListener listener) {
PagerFragment_new instance = new PagerFragment_new();
instance.setDatabase(database);
instance.setPrintingsIds(printingsIds);
instance.listener = listener;
return instance;
}
//other stuff
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
setRetainInstance(true);
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
setHasOptionsMenu(true);
fragmentView = inflater.inflate(R.layout.fragment_pager, container, false);
viewPager = (ViewPager) fragmentView.findViewById(R.id.PAGERFRAG_VIEWPAGER);
adapter = new ScreenSlidePageAdapter_new(getChildFragmentManager(), printingsIds, database, viewPager);
adapter.setListener(listener);
viewPager.setAdapter(adapter);
viewPager.setOffscreenPageLimit(1);
return fragmentView;
}
#Override
public void setPresenter(PagerFragmentContract.Presenter presenter) {
this.presenter = presenter;
}
}
The adapter to manage ViewPager's element's is ScreenSlidePageAdapter_new, it is responsible of instantiating CardInfoFragments.
public class ScreenSlidePageAdapter_new extends FragmentStatePagerAdapter {
private String[] printingsIds;
private String firstItemId;
private MtgDatabase database;
public ActivePresenterListener activity;
private ViewPager viewPager;
public ScreenSlidePageAdapter_new(FragmentManager fm, String[] printingsIds, MtgDatabase database, ViewPager viewPager) {
super(fm);
this.printingsIds =printingsIds;
this.database = database;
this.firstItemId = printingsIds[0];
this.viewPager = viewPager;
}
#Override
public Fragment getItem(int position) {
//todo create a bundle with cardId
Bundle bundle = new Bundle();
bundle.putString("CardID", printingsIds[position]);
bundle.putString("FirstItemId", firstItemId);
CardInfoFragment_new cardInfoFragment_new = CardInfoFragment_new.getInstance(viewPager);
cardInfoFragment_new.setArguments(bundle);
CardInfoPresenter cardInfoPresenter = new CardInfoPresenter(cardInfoFragment_new, database);
activity.setActivePresenter(cardInfoPresenter);
return cardInfoFragment_new;
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
super.destroyItem(container, position, object);
}
public void setListener(ActivePresenterListener listener) {
this.activity = listener;
}
#Override
public int getCount() {
return printingsIds.length;
}
public interface ActivePresenterListener {
void setActivePresenter(BasePresenter presenter);
}}
Finally, here's the code of CardInfoFragment:
public class CardInfoFragment_new extends MtgRecallFragment_new
implements CardInfoContract.View,
CardPrintingsAdapter.OnItemClickListener {
private ViewPager viewPager;
public CardInfoContract.Presenter presenter;
private View fragmentView;
private MTGCard mtgCard;
RecyclerView printingsRecyclerView;
CardPrintingsAdapter cardPrintingsAdapter;
private String firstItemId; //the first id
public CardInfoFragment_new() {
//required empty constructor
}
private void setViewPager(ViewPager viewPager) {
this.viewPager = viewPager;
}
public static CardInfoFragment_new getInstance(ViewPager viewPager) {
CardInfoFragment_new cardInfoFragment_new = new CardInfoFragment_new();
cardInfoFragment_new.setViewPager(viewPager);
return cardInfoFragment_new;
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
setRetainInstance(true);
presenter.start();
String cardId = getArguments().getString("CardID");
firstItemId = getArguments().getString("FirstItemId");
mtgCard = presenter.getCardData(cardId);
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
fragmentView = inflater.inflate(R.layout.fragment_card_info_new, container, false);
setUpCardInfoView(fragmentView);
return fragmentView;
}
public void setUpCardInfoView(final View view){
//others view set-up action omitted
cardprintingsContainer = (LinearLayout) view.findViewById(R.id.CARDINFO_printingsContainer);
printingsRecyclerView = (RecyclerView)fragmentView.findViewById(R.id.CARDINFO_printings_recyclerView);
final List<String> printings = presenter.getCardPrintings(firstItemId, mtgCard.getName());
if (printings.size() < 40) {
setupPrintings(printings,printingsRecyclerView);
}
else {
LayoutInflater inflater = (LayoutInflater) getContext().getSystemService(Context.LAYOUT_INFLATER_SERVICE);
LinearLayout printingsRow = new LinearLayout(getContext());
printingsRow = (LinearLayout)inflater.inflate(R.layout.card_info_printings_row,printingsRow,true);
printingsRow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
setupPrintings(printings, printingsRecyclerView);
}
});
ImageView printingssetImage = (ImageView)printingsRow.findViewById(R.id.CARDINFO_printingsRow_setImage);
printingssetImage.setVisibility(View.INVISIBLE);
TextView printingssetName = (TextView)printingsRow.findViewById(R.id.CARDINFO_printingsRow_setName);
printingssetName.setText("Click to see all the "+printings.size()+ " versions");
cardprintingsContainer.addView(printingsRow);
}
}
public void setupPrintings(List<String> printings, RecyclerView recyclerView) {
cardPrintingsAdapter =
new CardPrintingsAdapter(getContext(), printings);
cardPrintingsAdapter.setOnItemClickListener(this);
UnscrollableLayoutManager layoutManager = new UnscrollableLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false);
recyclerView.setAdapter(cardPrintingsAdapter);
recyclerView.setLayoutManager(layoutManager);
}
#Override
public void onItemClick(View itemView, int position) {
int i = viewPager.getAdapter().getCount();
viewPager.setCurrentItem(position);
}
#Override
public void onDestroy() {
presenter = null;
mtgCard = null;
super.onDestroy();
}}
When user click on a RecyclerView item, CardInfoFragment's method onItemClick(View itemView, int position) is called and the viewpager is set to current position. Everything as expected.
THE PROBLEM
When the orientation changes, fragments are able to retain their states, but viewPager.setCurrentItem(position) does nothing, and i'm not able to change displayed fragment.
I already checked:
ViewPager instance and adapters instances corresponds to those passed to Fragments
onItemClick is fired
this questions question1 question2
If i use
android:configChanges="orientation|screenSize"
in manifest it works even after config changes, but i don't want to use this option since is discouraged.
Thanks in advance!

By default, when certain key configuration changes happen on Android (a common example is an orientation change), Android fully restarts the running Activity to help it adjust to such changes.
When you define android:configChanges="keyboardHidden|orientation" in your AndroidManifest, you are telling Android: "Please don't do the default reset when the keyboard is pulled out, or the phone is rotated; I want to handle this myself. Yes, I know what I'm doing".
So use configChanges.
The use of this is discouraged, IF you don't know how to use it. But for a case like this, I would suggest you use it. IF not, still the activity will be recreated. which just takes time, resources, and I don't see why you would want that to happen.

Java android access of member fields of inner class in outer class

public class chapterIndexFragment extends Fragment implements view.OnClickListener,parsexml.AsyncResponse{
// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private static final String ARG_PARAM1 = "xml";
//private static final String ARG_PARAM2 = "param2";
private XmlResourceParser xrp;
private View rootview;
private OnFragmentInteractionListener mListener;
private RecyclerView mRecyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
public chapterIndexFragment() {
// Required empty public constructor
}
/**
* Use this factory method to create a new instance of
* this fragment using the provided parameters.
*
* #param param1 Parameter 1.
* #param param2 Parameter 2.
* #return A new instance of fragment chapterIndexFragment.
*/
// TODO: Rename and change types and number of parameters
public static chapterIndexFragment newInstance(int xmlid) {
chapterIndexFragment fragment = new chapterIndexFragment();
Bundle args = new Bundle();
args.putInt(ARG_PARAM1,xmlid);
fragment.setArguments(args);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if (getArguments() != null) {
xrp = getResources().getXml(getArguments().getInt(ARG_PARAM1));
//Async Task.
parsexml pxml = new parsexml(this);
pxml.execute(xrp);
}
}
#Override
public void postProgress(String progress) {
// Why this does not resolve ????
mAdapter.mDataset
}
#Override
public void onFinish(Boolean result) {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
rootview = inflater.inflate(R.layout.fragment_recycler_view, container, false);
mRecyclerView = (RecyclerView) rootview.findViewById(R.id.recycler_view);
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
mRecyclerView.setHasFixedSize(true);
// use a linear layout manager
mLayoutManager = new LinearLayoutManager(getActivity());
mRecyclerView.setLayoutManager(mLayoutManager);
// When coming back to this fragment from another fragment with back button. Although view hierarchy is to
//be built again but Adapter will have its data preserved so dont initialize again.
//String[] TempData = new String[]{"One","Two","three","four"};
if(mAdapter == null)
mAdapter = new MyAdapter();
mRecyclerView.setAdapter(mAdapter);
return rootview;
}
// TODO: Rename method, update argument and hook method into UI event
public void onButtonPressed(Uri uri) {
if (mListener != null) {
mListener.onFragmentInteraction(uri);
}
}
#Override
public void onAttach(Context context) {
super.onAttach(context);
if (context instanceof OnFragmentInteractionListener) {
mListener = (OnFragmentInteractionListener) context;
} else {
throw new RuntimeException(context.toString()
+ " must implement OnFragmentInteractionListener");
}
}
#Override
public void onActivityCreated(#Nullable Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Toolbar toolbar = (Toolbar) getActivity().findViewById(R.id.toolbar);
toolbar.setTitle("Title");
toolbar.setNavigationIcon(R.drawable.ic_menu_hamburger);
//toolbar navigation button (Home Button\Hamburger button) at the start of the toolbar.
toolbar.setNavigationOnClickListener(this);
//Toolbar menu item click listener.
//toolbar.setOnMenuItemClickListener(this);
}
#Override
public void onDetach() {
super.onDetach();
mListener = null;
}
#Override
public void onClick(View view) {
int id = view.getId();
switch(id)
{
case -1: // Toolbar's Navigation button click retruns -1. Hamburger icon.
if (view instanceof ImageView)
{
if (((MainActivity)getActivity()).drawer.isDrawerOpen(GravityCompat.START))
{
((MainActivity)getActivity()).drawer.closeDrawer(GravityCompat.START);
}
else
{
((MainActivity)getActivity()).drawer.openDrawer(GravityCompat.START);
}
}
break;
}
}
/**
* This interface must be implemented by activities that contain this
* fragment to allow an interaction in this fragment to be communicated
* to the activity and potentially other fragments contained in that
* activity.
* <p>
* See the Android Training lesson <a href=
* "http://developer.android.com/training/basics/fragments/communicating.html"
* >Communicating with Other Fragments</a> for more information.
*/
public interface OnFragmentInteractionListener {
// TODO: Update argument type and name
void onFragmentInteraction(Uri uri);
}
class MyAdapter extends RecyclerView.Adapter implements MyViewHolder.IItemClickListener{
private ArrayList<String> mDataset;
// Provide a suitable constructor (depends on the kind of dataset)
MyAdapter(){
if(mDataset == null)
{
mDataset = new ArrayList<String>();
}
}
// Create new views (invoked by the layout manager)
#Override
public MyViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.recycler_viewholder,parent,false);
// set the view's size, margins, paddings and layout parameters
MyViewHolder vh = new MyViewHolder(v,this);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
MyViewHolder vh = (MyViewHolder)holder;
vh.mtv_Title.setText(mDataset.get(position));
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return mDataset.size();
}
//MyViewHolder.IItemClickListener
#Override
public void onItemClick(View view, int position) {
}
}
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
static class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
// each data item is just a string in this case
TextView mtv_Title;
IItemClickListener mItemClickListener;
//View.OnClickListener
#Override
public void onClick(View view) {
mItemClickListener.onItemClick(view,getAdapterPosition());
}
interface IItemClickListener
{
void onItemClick(View view, int position);
}
MyViewHolder(View v,IItemClickListener itemClickListener) {
super(v);
mtv_Title = (TextView)v.findViewById(R.id.tv_title);
mItemClickListener = itemClickListener;
v.setOnClickListener(this);
}
}
}
In #Override
public void postProgress(String progress) {
// Why this does not resolve ????
mAdapter.mDataset
}

You should be aware of that,
private members can't be accessed via dot notation. To access them we use getter/setter methods.
You have to make a public function to get them, add this method in you inner class,
public ArrayList<String> getDataSet() {
return mDataSet;
}
Also you should change as pointed by #android_hub
private RecyclerView.Adapter mAdapter;
should be private
private MyAdapter mAdapter;