Develop Reference

Passing events from DialogFragment back to RecyclerView Adapter

My fragment has a Recycler View. Therefore I have a RecyclerView Adapter too. From this Adapter, I am opening an AlertDialog. When I click OK, I need to pass the onclick event from my DialogFragment back to my RecyclerView Adapter.
Currently, I am doing it like here, but this passes the event back to the activity and not to the RecyclerView Adapter.
public class FreshwaterRecyclerViewAdapter extends RecyclerView.Adapter<FreshwaterRecyclerViewAdapter.ViewHolder> implements BiotopeDialogFragment.NoticeDialogListener {
private List<Biotope> data;
private LayoutInflater layoutInflater;
FreshwaterRecyclerViewAdapter(Context context, List<Biotope> data) {
this.layoutInflater = LayoutInflater.from(context);
this.data = data;
}
//The dialog fragment receives a reference to this Activity through the
//Fragment.onAttach() callback, which it uses to call the following methods
//defined by the NoticeDialogFragment.NoticeDialogListener interface
#Override
public void onDialogPositiveClick(DialogFragment dialog) {
notifyItemInserted(getItemCount()-1);
}
#Override
public void onDialogNegativeClick(DialogFragment dialog) {
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View itemView;
if (viewType == R.layout.biotope_cardview){
itemView = layoutInflater.inflate(R.layout.biotope_cardview, parent, false);
} else {
itemView = layoutInflater.inflate(R.layout.biotope_add_button, parent, false);
}
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
if (position == data.size()) {
holder.imageButtonAddBiotope.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FragmentManager fragmentManager = ((AppCompatActivity) layoutInflater.getContext()).getSupportFragmentManager();
DialogFragment dialog = new BiotopeDialogFragment();
dialog.show(fragmentManager, "NoticeDialogFragment");
}
});
} else {
holder.textViewBiotopeTitle.setText(getItem(position).name);
Picasso.get().load(Uri.parse(getItem(position).imageUri)).into(holder.imageViewBiotope);
LastValuesRecyclerViewAdapter recyclerAdapter = new LastValuesRecyclerViewAdapter(layoutInflater.getContext(), getData());
holder.recyclerViewLastValues.setLayoutManager(new LinearLayoutManager(layoutInflater.getContext(), LinearLayoutManager.HORIZONTAL, false));
holder.recyclerViewLastValues.setAdapter(recyclerAdapter);
}
}
//total number of rows
#Override
public int getItemCount() {
return data.size() + 1; //+1 for the add button
}
#Override
public int getItemViewType(int position) {
return (position == data.size()) ? R.layout.biotope_add_button : R.layout.biotope_cardview;
}
public static class ViewHolder extends RecyclerView.ViewHolder {
private TextView textViewBiotopeTitle;
private ImageView imageViewBiotope;
private RecyclerView recyclerViewLastValues;
private ImageButton imageButtonAddBiotope;
public ViewHolder(View view) {
super(view);
textViewBiotopeTitle = (TextView) view.findViewById(R.id.textViewBiotopeTitle);
imageViewBiotope = (ImageView) view.findViewById(R.id.imageViewBiotopeCardview);
recyclerViewLastValues = (RecyclerView) view.findViewById(R.id.recyclerViewLastValues);
imageButtonAddBiotope = (ImageButton) view.findViewById(R.id.imageButtonAddBiotope);
}
}
Biotope getItem(int id) {
return data.get(id);
}
private List<String> getData() {
List<String> data = new ArrayList<>();
data.add("PO4");
data.add("NO3");
return data;
}
}
This is my dialog.
public class BiotopeDialogFragment extends DialogFragment {
private NoticeDialogListener listener;
public interface NoticeDialogListener {
public void onDialogPositiveClick(DialogFragment dialog);
public void onDialogNegativeClick(DialogFragment dialog);
}
//Override the Fragment.onAttach() method to instantiate the NoticeDialogListener
#Override
public void onAttach(#NonNull Context context) {
super.onAttach(context);
//Verify that the host activity implements the callback interface
try {
//Instantiate the NoticeDialogListener so we can send events to the host
listener = (NoticeDialogListener) context;
} catch (ClassCastException e) {
//The activity doesn't implement the interface, throw exception
throw new ClassCastException("FreshwaterRecyclerViewAdapter must implement NoticeDialogListener | Context: " + context.toString());
}
}
public static final String TAG = "biotope_dialog_fragment";
private ActivityResultLauncher<Intent> activityResultLauncher;
private Uri imageUri = null;
#NonNull
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
MaterialAlertDialogBuilder builder = new MaterialAlertDialogBuilder(getContext());
LayoutInflater inflater = requireActivity().getLayoutInflater();
//Inflate and set the layout for the dialog
//Pass null as the parent view because its going in the dialog layout
View view = inflater.inflate(R.layout.fragment_dialog_biotope, null, false);
builder.setView(view);
View colorPickerPreviewView = view.findViewById(R.id.colorPickerPreviewView);
ColorPickerView colorPickerView = view.findViewById(R.id.colorPickerView);
ImageView imageViewBiotope = view.findViewById(R.id.imageViewBiotopePreview);
TextInputEditText textFieldBiotopeName = view.findViewById(R.id.textFieldBiotopeName);
builder.setTitle("New biotope")
.setPositiveButton("ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int id) {
BiotopeDatabase database = BiotopeDatabase.getDbInstance(requireContext().getApplicationContext());
Biotope biotope = new Biotope();
if (textFieldBiotopeName.getText() != null) {
biotope.name = textFieldBiotopeName.getText().toString();
} else {
biotope.name = "";
}
if (imageUri != null) {
biotope.imageUri = imageUri.toString();
} else {
biotope.imageUri = "";
}
biotope.color = colorPickerView.getColor();
database.biotopeDao().insertAll(biotope);
//Send the positive button event back to the host activity
listener.onDialogPositiveClick(BiotopeDialogFragment.this);
}
})
.setNegativeButton("noke", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
//Send the negative button event back to the host activity
listener.onDialogNegativeClick(BiotopeDialogFragment.this);
Objects.requireNonNull(BiotopeDialogFragment.this.getDialog()).cancel();
}
});
return builder.create();
}
public static BiotopeDialogFragment display(FragmentManager fragmentManager) {
BiotopeDialogFragment fragment = new BiotopeDialogFragment();
fragment.show(fragmentManager, TAG);
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public void onViewCreated(#NonNull View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
}
This is my fragment building the RecyclerView. Alternatively, I can pass the event back to the fragment if it is not possible to pass it to the adapter.
public class BiotopesFragment extends Fragment {
private FreshwaterRecyclerViewAdapter recyclerAdapter;
public static BiotopesFragment newInstance(String param1, String param2) {
BiotopesFragment fragment = new BiotopesFragment();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View root = inflater.inflate(R.layout.fragment_biotopes, container, false);
RecyclerView recyclerViewFreshwater = (RecyclerView) root.findViewById(R.id.recyclerViewFreshwater);
recyclerAdapter = new FreshwaterRecyclerViewAdapter(getContext(), getData());
recyclerViewFreshwater.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.HORIZONTAL, false));
recyclerViewFreshwater.setAdapter(recyclerAdapter);
DividerItemDecoration dividerItemDecoration = new DividerItemDecoration(getContext(), DividerItemDecoration.VERTICAL);
recyclerViewFreshwater.addItemDecoration(dividerItemDecoration);
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(new ItemTouchHelper.SimpleCallback(ItemTouchHelper.START | ItemTouchHelper.END, 0) {
#Override
public boolean onMove(#NonNull RecyclerView recyclerView, #NonNull RecyclerView.ViewHolder viewHolder, #NonNull RecyclerView.ViewHolder target) {
int fromPosition = viewHolder.getAdapterPosition();
int toPosition = target.getAdapterPosition();
Collections.swap(getData(), fromPosition, toPosition);
recyclerView.getAdapter().notifyItemMoved(fromPosition, toPosition);
return false;
}
#Override
public void onSwiped(#NonNull RecyclerView.ViewHolder viewHolder, int direction) {
}
});
itemTouchHelper.attachToRecyclerView(recyclerViewFreshwater);
return root;
}
private List<Biotope> getData() {
BiotopeDatabase database = BiotopeDatabase.getDbInstance(requireContext().getApplicationContext());
BiotopeDao biotopeDao = database.biotopeDao();
return biotopeDao.getAll();
}
}

Ideal Way to do this to create all UI component in Fragment not in the adapter . Create an interface to handle events in the fragment and provide callback to the fragment from adapter. now your Fragment should create all the UI component .
Now coming to the
How to provide callback from dialog fragment to Fragment.
You can use setTargetFragment but its deprecated . Now you can use setFragmentResultListener instead of setTargetFragment(), its the safest way i think. Once you get the result back in fragment you can call any method of your adapter.

Adding click listener to two buttons in PagerAdpater CardViews

In my project, I have a PagerAdapter to inflate CardViews that hold text objects created by the user.
On each CardView I have edit and delete buttons to access methods to do with the ArrayList holding the text objects.
I have coded an interface in my adapter to handle clicks made within the text object creation activity. However, my instatiateItem method in my adapter is now showing on the #Override annotation "Method does not override method from its superclass". When I remove the #Override annotation I get an error in my Logcat:
java.lang.UnsupportedOperationException: Required method instantiateItem was not overridden
How do I implement a click listener for buttons on a CardView in a PagerAdapter?
Adapter code:
public class CreateAdapter extends PagerAdapter {
private List<PdfPage> pagesList;
private LayoutInflater layoutInflater;
private Context context;
private onItemClickListener mListener;
public interface onItemClickListener{
//click method for edit button
void onEditClick(int position);
//click method for delete button
void onDeleteClick(int position);
}
public void setOnItemClickListener(onItemClickListener listener){
mListener = listener;
}
public CreateAdapter(List<PdfPage> pagesList, Context context) {
this.pagesList = pagesList;
this.context = context;
}
#Override
public int getCount() {
return pagesList.size();
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view.equals(object);
}
#NonNull
#Override
public Object instantiateItem(#NonNull ViewGroup container, final int position, final onItemClickListener listener) {
layoutInflater = LayoutInflater.from(context);
View view = null;
if(pagesList.get(position).getPageType() == "Text") {
view = layoutInflater.inflate(R.layout.create_text_cardview, container, false);
TextView inputText = view.findViewById(R.id.inputTextView);
ImageButton editButton = view.findViewById(R.id.imageButtonEdit);
ImageButton deleteButton = view.findViewById(R.id.imageButtonDelete);
//if this works, see 12:30 of video for image getter
inputText.setText(pagesList.get(position).getPageText());
//edit click listener
editButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null){
int position2 = pagesList.indexOf(pagesList.get(position));
listener.onEditClick(position2);
}
}
});
//delete click listener
deleteButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null){
int position3 = pagesList.indexOf(pagesList.get(position));
listener.onDeleteClick(position3);
}
}
});
container.addView(view, 0);
}
//put else statement here for image cardView
assert view != null;
return view;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((View)object);
}
Activity code:
public class CreateActivity extends AppCompatActivity {
ViewPager viewPager;
CreateAdapter createAdapter;
List<PdfPage> pdfPageList;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_create);
pdfPageList = new ArrayList<>();
createAdapter = new CreateAdapter(pdfPageList, this);
viewPager = findViewById(R.id.viewPager);
viewPager.setAdapter(createAdapter);
viewPager.setPadding(130, 0, 130, 0);
}
#Override
protected void onStart() {
super.onStart();
createAdapter = new CreateAdapter(pdfPageList, this);
viewPager = findViewById(R.id.viewPager);
viewPager.setAdapter(createAdapter);
viewPager.setPadding(130, 0, 130, 0);
createAdapter.setOnItemClickListener(new CreateAdapter.onItemClickListener() {
#Override
public void onEditClick(int position) {
}
#Override
public void onDeleteClick(int position) {
pdfPageList.remove(position);
}
});
}

Your instantiateItem method does not override from it's superclass because you added an extra argument final onItemClickListener listener.
As you are using the same clickListener for all entries and passing the item position as an argument, I suggest that you pass the onItemClickListener in the adapter constructor, or just set it via
public void setOnItemClickListener(onItemClickListener listener){
mListener = listener;
}
Adapter code:
public class CreateAdapter extends PagerAdapter {
private List<PdfPage> pagesList;
private LayoutInflater layoutInflater;
private Context context;
private onItemClickListener mListener;
public interface onItemClickListener{
//click method for edit button
void onEditClick(int position);
//click method for delete button
void onDeleteClick(int position);
}
public void setOnItemClickListener(onItemClickListener listener){
mListener = listener;
}
public CreateAdapter(List<PdfPage> pagesList, Context context) {
this.pagesList = pagesList;
this.context = context;
}
#Override
public int getCount() {
return pagesList.size();
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view.equals(object);
}
#NonNull
#Override
public Object instantiateItem(#NonNull ViewGroup container, final int position) {
layoutInflater = LayoutInflater.from(context);
View view = null;
if(pagesList.get(position).getPageType() == "Text") {
view = layoutInflater.inflate(R.layout.create_text_cardview, container, false);
TextView inputText = view.findViewById(R.id.inputTextView);
ImageButton editButton = view.findViewById(R.id.imageButtonEdit);
ImageButton deleteButton = view.findViewById(R.id.imageButtonDelete);
//if this works, see 12:30 of video for image getter
inputText.setText(pagesList.get(position).getPageText());
//edit click listener
editButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mlistener != null){
int position2 = pagesList.indexOf(pagesList.get(position));
mlistener.onEditClick(position2);
}
}
});
//delete click listener
deleteButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mlistener != null){
int position3 = pagesList.indexOf(pagesList.get(position));
mlistener.onDeleteClick(position3);
}
}
});
container.addView(view, 0);
}
//put else statement here for image cardView
assert view != null;
return view;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((View)object);
}
And your Activity code could stay as it is.

onClick for images in ViewPager

I've a image slider made with the help of ViewPager. I want to show different toast messages when clicked in different images loaded by ViewPager, how can i do that?
this my activity where image slider is shown:
public class MainActivity extends AppCompatActivity{
public static final String MAIN = "OTHER";
private static ViewPager mPager;
private static int currentPage = 0;
private static final Integer[] XMEN=
{R.drawable.benz2, R.drawable.benz2,
R.drawable.benz2};
private ArrayList<Integer> XMENArray = new ArrayList<Integer>();
#Override
protected void onCreate(...);
init();
}
private void init() {
for(int i=0;i<XMEN.length;i++)
XMENArray.add(XMEN[i]);
mPager = (ViewPager) findViewById(R.id.pager);
mPager.setAdapter(new com.example.nepali_test.MyAdapter(MainActivity.this,XMENArray));
CircleIndicator indicator = (CircleIndicator) findViewById(R.id.indicator);
indicator.setViewPager(mPager);
final Handler handler = new Handler();
final Runnable Update = new Runnable() {
public void run() {
if (currentPage == XMEN.length) {
currentPage = 0;
}
mPager.setCurrentItem(currentPage++, true);
}
};
Timer swipeTimer = new Timer();
swipeTimer.schedule(new TimerTask() {
#Override
public void run() {
handler.post(Update);
}
}, 3000, 3000);
}
and this is the adapter of the viewpager:
public class MyAdapter extends PagerAdapter {
private ArrayList<Integer> images;
private LayoutInflater inflater;
private Context context;
public MyAdapter(Context context, ArrayList<Integer> images) {
this.context = context;
this.images=images;
inflater = LayoutInflater.from(context);
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
#Override
public int getCount() {
return images.size();
}
#Override
public Object instantiateItem(ViewGroup view, int position) {
View myImageLayout = inflater.inflate(R.layout.slide, view, false);
ImageView myImage = (ImageView) myImageLayout
.findViewById(R.id.image);
myImage.setImageResource(images.get(position));
view.addView(myImageLayout, 0);
return myImageLayout;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view.equals(object);
}
}
I tried to make by adding
if (currentPage==1){
Toast.makeText(this, "page 1", Toast.LENGTH_SHORT).show();
}
in init() but it didn't work.

From what i could understand you need to display the toast when clicking on the image in each page of a ViewPager in which case an easy way is to add an onClickListener to your ImageView inside your adapter's instantiateItem method. So you should change/replace your method with this:
#NonNull
#Override
public Object instantiateItem(#NonNull final ViewGroup view, final int position) {
View myImageLayout = inflater.inflate(R.layout.slide, view, false);
ImageView myImage = (ImageView) myImageLayout
.findViewById(R.id.image);
myImage.setImageResource(images.get(position));
myImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context.getApplicationContext(), "page "+position, Toast.LENGTH_SHORT).show();
}
});
view.addView(myImageLayout, 0);
return myImageLayout;
}

Try this:
#Override
public Object instantiateItem(View collection, final int pos) { //have to make final so we can see it inside of onClick()
LayoutInflater inflater = (LayoutInflater) collection.getContext()
.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
View page = inflater.inflate(R.layout.YOUR_PAGE, null);
page.setOnClickListener(new OnClickListener(){
public void onClick(View v){
//this will log the page number that was click
Log.i("TAG", "This page was clicked: " + pos);
}
});
((ViewPager) collection).addView(page, 0);
return page;
}
Hope this will work!

Make Image click interface in adapter class
public class MyAdapter extends PagerAdapter {
private ArrayList<Integer> images;
private LayoutInflater inflater;
private Context context;
MyClassImage myClassImage;
public interface MyClassImage{
void imageClick(String id);
}
public ViewPagerAdapter(Context context, ArrayList<Integer> images,MyClassImage myClassImage) {
this.context = context;
this.images=images;
this.myClassImage=myClassImage;
inflater = LayoutInflater.from(context);
}
#Override
public void destroyItem(ViewGroup container, int position, Object object) {
container.removeView((View) object);
}
#Override
public int getCount() {
return images.size();
}
#Override
public Object instantiateItem(ViewGroup view, int position) {
View myImageLayout = inflater.inflate(R.layout.z_slide_pager_item, view, false);
ImageView myImage = (ImageView) myImageLayout.findViewById(R.id.image);
myImage.setImageResource(images.get(position));
view.addView(myImageLayout, 0);
final int id=images.get(position);
final String imgId=String.valueOf(id);
myImage.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
myClassImage.imageClick(imgId);
}
});
return myImageLayout;
}
#Override
public boolean isViewFromObject(View view, Object object) {
return view.equals(object);
}
}
and implement it on your MainActivity class
public class MainActivity extends AppCompatActivity implements MyAdapter.MyClassImage {
public static final String MAIN = "OTHER";
private static ViewPager mPager;
private static int currentPage = 0;
private static final Integer[] XMEN= {R.drawable.benz2, R.drawable.benz2, R.drawable.benz2};
private ArrayList<Integer> XMENArray = new ArrayList<Integer>();
#Override
protected void onCreate(...);
init();
}
private void init() {
for(int i=0;i<XMEN.length;i++)
XMENArray.add(XMEN[i]);
mPager = (ViewPager) findViewById(R.id.pager);
mPager.setAdapter(new com.example.nepali_test.MyAdapter(MainActivity.this,XMENArray,this));
CircleIndicator indicator = (CircleIndicator) findViewById(R.id.indicator);
indicator.setViewPager(mPager);
final Handler handler = new Handler();
final Runnable Update = new Runnable() {
public void run() {
if (currentPage == XMEN.length) {
currentPage = 0;
}
mPager.setCurrentItem(currentPage++, true);
}
};
Timer swipeTimer = new Timer();
swipeTimer.schedule(new TimerTask() {
#Override
public void run() {
handler.post(Update);
}
}, 3000, 3000);
}
#Override
public void imageClick(String id) {
Toast.makeText(this, "page "+id, Toast.LENGTH_SHORT).show();
}
Hope it will be helpful to you.
Thanks.

add next, prev buttons in slider image made by picasso and viewpager

I've made a image slider with help of viewpager and picasso, now i want to add next, prev button on the image, how can i do that?
I saw different answers of this but all of them are showing error
This is main activity where image slider is shown:
public class MainActivity extends AppCompatActivity {
private int[] imageUrls = new int[]{
R.drawable.after_cookie,
R.drawable.before_cookie
};
private WebBackForwardList viewPager;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ViewPager viewPager = findViewById(R.id.view_pager);
ViewPageAdapter adapter = new ViewPageAdapter(this, imageUrls);
viewPager.setAdapter(adapter);
}
}
This is ViewPageAdapter:
public class ViewPageAdapter extends PagerAdapter {
private Context context;
private int[] imageUrls;
ViewPageAdapter(Context context, int[] imageUrls) {
this.context = context;
this.imageUrls = imageUrls;
}
#Override
public int getCount() {
return imageUrls.length;
}
#Override
public boolean isViewFromObject(#NonNull View view, #NonNull Object object) {
return view == object;
}
#NonNull
#Override
public Object instantiateItem(#NonNull ViewGroup container, int position) {
ImageView imageView = new ImageView(context);
Picasso.get()
.load(imageUrls[position])
.fit()
.centerCrop()
.into(imageView);
container.addView(imageView);
return imageView;
}
#Override
public void destroyItem(#NonNull ViewGroup container, int position, #NonNull Object object) {
container.removeView((View) object);
}
}

add this method to your code
private int getItem(int i) {
return viewPager.getCurrentItem() + i;
}
then use this for next button
Button NextButton = (Button)findViewById(R.id.button1);
yourButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
viewPager.setCurrentItem(getItem(+1), true); //getItem(+1) for next
}
});
and use this for the previous button
Button PreviousButton = (Button)findViewById(R.id.button2);
PreviousButton.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View view) {
viewPager.setCurrentItem(getItem(-1), true); //getItem(-1) for previous
}
});
it will work fine ;)

query() method of Content provider returns data twice in recycler View adapter

I am working on a android project, here i have a class CategoryProvider which extends ContentProvider class and i also implements LoaderManager.LoaderCallbacks<Cursor> in my main Activity and I also have CategoryAdapter class which extends RecyclerView.Adapter<CategoryAdapter.ViewHolder>. I have 3 records in my Sqlite database, now after initialization of Loader in main Activity when data is loading in the adapter it loads each record twice so how to fix that.
CategotyAdapter.java
public class CategoryAdapter extends RecyclerView.Adapter<CategoryAdapter.ViewHolder> {
Cursor dataCursor;
Context context;
String global_lang = "English";
public static class ViewHolder extends RecyclerView.ViewHolder {
public TextView name;
ImageView imageView;
public ViewHolder(View itemView) {
super(itemView);
name = (TextView) itemView.findViewById(R.id.titleText);
imageView = (ImageView) itemView.findViewById(R.id.icons);
}
}
public CategoryAdapter(Activity mContext, Cursor cursor) {
dataCursor = cursor;
context = mContext;
}
#Override
public CategoryAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View cardview = LayoutInflater.from(parent.getContext())
.inflate(R.layout.option_layout, parent, false);
return new ViewHolder(cardview);
}
#Override
public void onBindViewHolder(CategoryAdapter.ViewHolder holder, int position) {
dataCursor.moveToPosition(position);
String imagePath = dataCursor.getString(dataCursor.getColumnIndex(CategoryContract.CategoryEntry.COLUMN_IMAGE_PATH));
String cEn_name = dataCursor.getString(dataCursor.getColumnIndex(CategoryContract.CategoryEntry.COLUMN_CONTENT_EN));
String cHi_name = dataCursor.getString(dataCursor.getColumnIndex(CategoryContract.CategoryEntry.COLUMN_CONTENT_HI));
if(global_lang.equals("English"))
holder.name.setText(cEn_name);
else
holder.name.setText(cHi_name);
Glide.with(context)
.load(imagePath)
.apply(new RequestOptions()
.placeholder(R.drawable.loading))
.into(holder.imageView);
}
public Cursor swapCursor(Cursor cursor) {
if(dataCursor == cursor) {
return null;
}
Cursor oldCursor = dataCursor;
this.dataCursor = cursor;
if(cursor != null) {
this.notifyDataSetChanged();
}
return oldCursor;
}
#Override
public int getItemCount() {
if(dataCursor != null)
Log.d("datacursor count", " " +dataCursor.getCount());
else
Log.d("datacursor count", "datacursor is null");
return (dataCursor == null) ? 0 : dataCursor.getCount();
}
public void changeLang(String lang) {
this.global_lang = lang;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public int getItemViewType(int position) {
return position;
}
}
MainActivity.java
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
firstTimeUser();
ActivityToolbar = (Toolbar) findViewById(R.id.toolbar);
ActivitySpinner = (Spinner) findViewById(R.id.spinner);
ActivityToolbar.setTitle(R.string.app_name);
ActivityAdapter = ArrayAdapter.createFromResource(this, R.array.languages, R.layout.drop_menu);
ActivityAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
ActivitySpinner.getBackground().setColorFilter(getResources().getColor(R.color.white), PorterDuff.Mode.SRC_ATOP);
ActivitySpinner.setAdapter(ActivityAdapter);
listeners();
recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
recyclerView.setHasFixedSize(true);
if(this.getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {
recyclerView.setLayoutManager(new GridLayoutManager(this, 2));
} else {
recyclerView.setLayoutManager(new GridLayoutManager(this, 4));
}
categoryAdapter = new CategoryAdapter(this, null);
recyclerView.setAdapter(categoryAdapter);
getLoaderManager().initLoader(CATEGORY_LOADER, null, this);
}
public void listeners() {
ActivitySpinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
categoryAdapter.changeLang(ActivitySpinner.getSelectedItem().toString());
getLoaderManager().restartLoader(CATEGORY_LOADER, null, MainActivity.this);
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
});
}
#Override
public Loader<Cursor> onCreateLoader(int id, Bundle args) {
String[] data = {
CategoryContract.CategoryEntry._ID,
CategoryContract.CategoryEntry.COLUMN_IMAGE_PATH,
CategoryContract.CategoryEntry.COLUMN_CONTENT_EN,
CategoryContract.CategoryEntry.COLUMN_CONTENT_HI
};
return new CursorLoader(
this,
CategoryContract.CategoryEntry.CONTENT_URI,
data,
null,
null,
null
);
}
#Override
protected void onResume() {
super.onResume();
loader_flag = 0;
}
#Override
public void onLoadFinished(Loader<Cursor> loader, Cursor data) {
categoryAdapter.swapCursor(data);
}
#Override
public void onLoaderReset(Loader<Cursor> loader) {
categoryAdapter.swapCursor(null);
}
Thanks!!

Ok, I got it after a lot of debugging. Here I am using Sync Adapter framework in my App which syncs the data at the background, when it trying to reload data the duplicate data is synced rapidly with new ID and it was rendered by recyclerView. so now I am using some constraints and changing my Database structure.