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How to update listview in Fragment with custom adapter

I am giving product id with barcode scanner. I can add product to listView but when i try to increase or decrease amount of the product. It doesn't update UI. I used Toast message to see weather list is updated, it updates list but doesn't update UI
I have tried to use runOnUiThread() but i couldn't find any solution. How to update UI can you please help me
custom_lisView_row
BaseActivity which keeps MainFragment on it
public class BaseActivity extends AppCompatActivity {
public static final String MAIN_FRAGMENT = "mainFragment";
public static final String PRODUCTS = "products";
FragmentManager fragmentManager;
Dialog dialog ;
public static ArrayList<MyProduct> myProductList = new ArrayList<>();
public static MyTablet myTablet = new MyTablet();
Activity mActivity;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_base);
//Initialize fragment manager
fragmentManager = getSupportFragmentManager();
fragmentManager.beginTransaction().replace(R.id.fl_BaseActivity, new MainFragment()).commit();
//Create database
mDatabase = FirebaseDatabase.getInstance().getReference();
dialog = new Dialog(this);
//Runs when i enter product id
initScanner();
}
public void updateMyProductList(MyProduct myProduct){
for(int i= 0 ; i< myProductList.size() ; i++ ){
MyProduct temp = myProductList.get(i);
if (temp.getId().equals(myProduct.getId())) {
temp.setAmount(temp.getAmount() + myProduct.getAmount());
myProductList.set(i, temp);
return;
}
}
myProductList.add(myProduct);
updateMainFragment();
}
private void initScanner() {
mDatabase.child(PRODUCTS).child(finalData).get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
#Override
public void onComplete(#NonNull Task<DataSnapshot> task) {
MyProduct myProduct = task.getResult().getValue(MyProduct.class);
myProduct.setAmount(1);
dialog.setContentView(R.layout.custom_product_dialog);
dialog.getWindow().setBackgroundDrawable(new ColorDrawable(Color.TRANSPARENT));
dialog.setCancelable(false);
TextView tv_addBasket_product_dialog = dialog.findViewById(R.id.tv_addBasket_product_dialog);
tv_addBasket_product_dialog.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
updateMyProductList(myProduct);
dialog.dismiss();
}
});
dialog.show();
}
};
}
public void updateMainFragment() {
if (isExist(MAIN_FRAGMENT)) {
Fragment fragment = findFragment(MAIN_FRAGMENT);
((MainFragment) fragment).updateMyList();
}
}
//Add fragments to BaseActivity
public void addFragments(Fragment fragment, String tag) {
fragmentManager.beginTransaction().add(R.id.fl_BaseActivity, fragment, tag).commit();
}
//Replace fragments to BaseActivity
public void replaceFragments(Fragment fragment, String tag) {
fragmentManager.beginTransaction().replace(R.id.fl_BaseActivity, fragment, tag).commit();
}
//Remove fragment from BaseActivity
public void removeFragment(String tag) {
Fragment fragmentB = fragmentManager.findFragmentByTag(tag);
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
if (fragmentB != null) {
fragmentTransaction.remove(fragmentB);
fragmentTransaction.commit();
}
}
// finds fragment and returns it
// It may return null first check fragment is exist. use isExist() method
public Fragment findFragment(String tag) {
Fragment fragment = fragmentManager.findFragmentByTag(tag);
return fragment;
}
//Check fragment exist in BaseActivity
public boolean isExist(String tag) {
Fragment fragmentB = fragmentManager.findFragmentByTag(tag);
if (fragmentB != null) {
return true;
}
return false;
}
}
MainFragment
public class MainFragment extends Fragment {
ListView lv_MainFragment;
public MyProductListAdapter myListAdapter;
public static ArrayList<MyProduct> myProductList;
Activity mActivity;
#Override
public void onAttach(Context context) {
super.onAttach(context);
mActivity = getActivity();
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
myProductList = BaseActivity.myProductList;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_main, container, false);
lv_MainFragment = view.findViewById(R.id.lv_MainFragment);
myListAdapter = new MyProductListAdapter(mActivity.getApplicationContext(), R.layout.custom_product_list_row, myProductList);
lv_MainFragment.setAdapter(myListAdapter);
return view;
}
public void updateMyList() {
myProductList = BaseActivity.myProductList;
myListAdapter.notifyDataSetChanged();
}
}
MyProductListAdapter
public class MyProductListAdapter extends ArrayAdapter<MyProduct> {
private Context mContext;
private ArrayList<MyProduct> list;
AppCompatButton acb_DecreaseAmount_productListRow, acb_IncreaseAmount_productListRow;
public MyProductListAdapter(Context context, int resource, ArrayList<MyProduct> objects) {
super(context, resource, objects);
this.mContext = context;
this.list = objects;
}
#Override
public View getView(int position, #Nullable View convertView, #NonNull ViewGroup parent) {
View view = convertView;
if (view == null) {
LayoutInflater inflater = (LayoutInflater) mContext.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
view = inflater.inflate(R.layout.custom_product_list_row, parent, false);
tv_ProductAmount_productListRow = view.findViewById(R.id.tv_ProductAmount_productListRow);
acb_DecreaseAmount_productListRow = view.findViewById(R.id.acb_DecreaseAmount_productListRow);
acb_IncreaseAmount_productListRow = view.findViewById(R.id.acb_IncreaseAmount_productListRow);
tv_ProductAmount_productListRow.setText(String.valueOf(list.get(position).getAmount()));
acb_IncreaseAmount_productListRow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
double productPrice = list.get(position).getPrice();
int productAmount = list.get(position).getAmount();
productAmount++;
list.get(position).setAmount(productAmount);
Toast.makeText(mContext, String.valueOf(productAmount), Toast.LENGTH_SHORT).show();
tv_ProductAmount_productListRow.setText(String.valueOf(list.get(position).getAmount()));
}
});
acb_DecreaseAmount_productListRow.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int productAmount = list.get(position).getAmount();
if (productAmount > 1) {
double productPrice = list.get(position).getPrice();
productAmount--;
list.get(position).setAmount(productAmount);
Toast.makeText(mContext, String.valueOf(productAmount), Toast.LENGTH_SHORT).show();
tv_ProductAmount_productListRow.setText(String.valueOf(list.get(position).getAmount()));
}
}
});
}
return view;
}
}

Hej Metehan,
your use case sounds perfect for a RecyclerView with a ListAdapter. You just submit a new list of products to the adapter and it will handle the updating and notifying for you.

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.

get context after returning from adapter to fragment

I am using contextual action bar in my fragment("UnitsFragment.java") to delete and edit items of recyclerview. But when I come back from recyclerview adapter class("UnitsRv.java"). The context seems to be null. I tried returning context from adapter and it worked for function "prepareSelection". However for "onActionItemClicked" under ActionMode.callback, I need to get context so that I can use alertdialog for editing the items.
The "requireContext()" throws this error: Fragment UnitsFragment{e3a36c8 (b4957397-055a-4b1c-8af2-fee89a3e9b35)} not attached to a context.
Here are my codes.
UnitsFragment.java
public class UnitsFragment extends Fragment {
private static final String TAG = "UnitsFragment";
private RecyclerView recyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager layoutManager;
ArrayList<UnitsList> unitsLists = new ArrayList<>();
Activity mcontext = getActivity();
Context dcontext;
ActionMode actionMode;
public static ArrayList<UnitsList> selectionList = new ArrayList<>();
public static boolean isInActionMode = false;
List<String> list = DatabaseClient.getInstance(getContext())
.getUserDatabase()
.getUnitDao().findUnitNameList();
public UnitsFragment() {
}
private ActionMode.Callback actionModeCallback = new ActionMode.Callback() {
#Override
public boolean onCreateActionMode(ActionMode mode, Menu menu) {
mode.getMenuInflater().inflate(R.menu.menu_item_action, menu);
return true;
}
#Override
public boolean onPrepareActionMode(ActionMode mode, Menu menu) {
return false;
}
#Override
public boolean onActionItemClicked(ActionMode mode, MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_item_edit:
if (selectionList.size() == 1) {
final EditText editText = new EditText(requireContext());
new AlertDialog.Builder(requireContext())
.setTitle("Rename unit name").setView(editText)
.setPositiveButton("Rename", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
UnitsList unitsList = selectionList.get(0);
unitsList.setUnit_name(editText.getText().toString().trim());
isInActionMode = false;
((UnitsRv) mAdapter).changeDataItem(getCheckedLastPosition(), unitsList);
actionMode.finish();
selectionList.clear();
}
})
.create()
.show();
Toast.makeText(getContext(), "Edit", Toast.LENGTH_SHORT).show();
mode.finish();
return true;
}
case R.id.menu_item_delete:
isInActionMode = false;
((UnitsRv) mAdapter).removeData(selectionList);
Toast.makeText(getContext(), "Delete", Toast.LENGTH_SHORT).show();
actionMode.finish();
selectionList.clear();
return true;
default:
return false;
}
}
#Override
public void onDestroyActionMode(ActionMode mode) {
actionMode = null;
}
};
private int getCheckedLastPosition() {
ArrayList<UnitsList> dataSet = UnitsRv.getDataSet();
for (int i = 0; i < dataSet.size(); i++) {
if (dataSet.get(i).equals(selectionList.get(0))) {
return i;
}
}
return 0;
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_units, container, false);
setHasOptionsMenu(true);
dcontext = rootView.getContext();
Log.d(TAG, "onCreateView1: " + dcontext);
recyclerView = rootView.findViewById(R.id.rv_units);
recyclerView.setHasFixedSize(true);
recyclerView.addItemDecoration(new DividerItemDecoration(getContext(),
DividerItemDecoration.HORIZONTAL));
recyclerView.addItemDecoration(new DividerItemDecoration(getContext(),
DividerItemDecoration.VERTICAL));
layoutManager = new GridLayoutManager(getContext(), 2);
recyclerView.setLayoutManager(layoutManager);
for (String string : list) {
unitsLists.add(new UnitsList(string));
}
Log.d(TAG, "onCreateView: " + getContext());
mAdapter = new UnitsRv(mcontext,unitsLists);
recyclerView.setAdapter(mAdapter);
return rootView;
}
#Override
public void onCreateOptionsMenu(#NonNull Menu menu, #NonNull MenuInflater inflater) {
inflater.inflate(R.menu.add, menu);
super.onCreateOptionsMenu(menu, inflater);
}
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()) {
case R.id.menu_item_new:
final View customLayout = getLayoutInflater().inflate(R.layout.add_unit_dialog, null);
final EditText edt_unit_name = customLayout.findViewById(R.id.edt_new_unit_name);
final AlertDialog dialog = new AlertDialog.Builder(getContext())
.setView(customLayout)
.setTitle("Unit name")
.setPositiveButton(android.R.string.ok, null) //Set to null. We override the onclick
.setNegativeButton(android.R.string.cancel, null)
.create();
dialog.setOnShowListener(new DialogInterface.OnShowListener() {
#Override
public void onShow(DialogInterface dialogInterface) {
Button ok_btn = dialog.getButton(AlertDialog.BUTTON_POSITIVE);
Button cancel_btn = dialog.getButton(AlertDialog.BUTTON_NEGATIVE);
ok_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String unit_name = edt_unit_name.getText().toString().trim();
if (!TextUtils.isEmpty(unit_name)) {
String old_unit_name = DatabaseClient.getInstance(getContext())
.getUserDatabase()
.getUnitDao()
.findByUnitName(unit_name);
if (old_unit_name == null) {
DatabaseClient.getInstance(getContext())
.getUserDatabase()
.getUnitDao()
.insertUnits(new UnitsList(unit_name));
unitsLists.add(new UnitsList(unit_name));
dialog.dismiss();
} else {
edt_unit_name.setError("Unit already exists");
}
} else {
edt_unit_name.setError("Can't be empty");
}
}
});
cancel_btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialog.dismiss();
}
});
}
});
dialog.show();
return true;
}
return super.onOptionsItemSelected(item);
}
public void prepareSelection(Context context,int position) {
if(actionMode == null) {
isInActionMode = true;
for (String string : list) {
unitsLists.add(new UnitsList(string));
}
mAdapter = new UnitsRv(context, unitsLists);
Log.d(TAG, "prepareSelection: " + mAdapter);
Log.d(TAG, "prepareSelection1: " + dcontext);
mcontext = (Activity)context;
actionMode = mcontext.startActionMode(actionModeCallback);
mAdapter.notifyDataSetChanged();
if (!selectionList.contains(unitsLists.get(position))) {
selectionList.add(unitsLists.get(position));
}
updateViewCounter();
}
}
private void updateViewCounter() {
int counter = selectionList.size();
if (counter == 1) {
actionMode.setTitle(counter + "item selected");
} else {
actionMode.setTitle(counter + "items selected");
}
}
}
This is my Adapter class.
UnitsRv.java
public class UnitsRv extends RecyclerView.Adapter<UnitsRv.ViewHolder> {
private static final String TAG = "UnitsRv";
private static ArrayList<UnitsList> munitsLists = new ArrayList<>();
UnitsFragment unitsFragment = new UnitsFragment();
Context mcontext;
public UnitsRv(Context context,ArrayList<UnitsList> unitsLists) {
mcontext = context;
munitsLists = unitsLists;
}
class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
TextView unit_name;
public ViewHolder(View v) {
super(v);
unit_name = v.findViewById(R.id.unit_name);
v.setOnLongClickListener(this);
}
#Override
public void onClick(View view) {
if (UnitsFragment.isInActionMode){
unitsFragment.prepareSelection(mcontext,getAdapterPosition());
notifyItemChanged(getAdapterPosition());
}
}
#Override
public boolean onLongClick(View view) {
Log.d(TAG, "onLongClick: " + getAdapterPosition());
unitsFragment.prepareSelection(view.getContext(),getAdapterPosition());
return true;
}
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.units_item, parent, false);
return new ViewHolder(itemView);
}
#Override
public void onBindViewHolder(#NonNull final ViewHolder holder, final int position) {
holder.unit_name.setText(munitsLists.get(position).getUnit_name());
if (UnitsFragment.isInActionMode){
if (UnitsFragment.selectionList.contains(munitsLists.get(position))){
holder.itemView.setBackgroundResource(R.color.colorSelected);
}
}
}
#Override
public int getItemCount() {
return munitsLists.size();
}
public static ArrayList<UnitsList> getDataSet() {
return munitsLists;
}
public void changeDataItem(int position, UnitsList unitsList) {
munitsLists.set(position, unitsList);
notifyDataSetChanged();
}
public void removeData(ArrayList<UnitsList> list) {
for (UnitsList unitsList : list) {
munitsLists.remove(unitsList);
}
notifyDataSetChanged();
}
}

First, you should not create instance of your UnitsFragment inside your adapter.
You can use EventBus to communicate between Activities, Fragments, Adapters, etc.
Or You can do your task using interface. like below.
Create an interface like this
public interface AdapterCallback {
void prepareSelection(Context context,int position);
}
In your UnitsFragment implement the above interface. like the following
public class UnitsFragment extends Fragment implements AdapterCallback{
// your other codes
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_units, container, false);
setHasOptionsMenu(true);
// .... your other codes
Log.d(TAG, "onCreateView: " + getContext());
// modify below line like this
mAdapter = new UnitsRv(mcontext, unitsLists, this); // here you have to pass an extra parameter that will implement your callback method from adapter.
recyclerView.setAdapter(mAdapter);
return rootView;
}
// ... you other codes
#Override
public void prepareSelection(Context context,int position) {
if(actionMode == null) {
isInActionMode = true;
for (String string : list) {
unitsLists.add(new UnitsList(string));
}
mAdapter = new UnitsRv(context, unitsLists,this); // add this as parameter.
Log.d(TAG, "prepareSelection: " + mAdapter);
Log.d(TAG, "prepareSelection1: " + dcontext);
mcontext = (Activity)context;
actionMode = mcontext.startActionMode(actionModeCallback);
mAdapter.notifyDataSetChanged();
if (!selectionList.contains(unitsLists.get(position))) {
selectionList.add(unitsLists.get(position));
}
updateViewCounter();
}
}
// other codes
}
Now, inside your Adapter you need to add an extra argument in constructor of UnitsRv and call your interface method from adapter ussing mAdapterCallback.
public class UnitsRv extends RecyclerView.Adapter<UnitsRv.ViewHolder> {
private static final String TAG = "UnitsRv";
private static ArrayList<UnitsList> munitsLists = new ArrayList<>();
UnitsFragment unitsFragment = new UnitsFragment(); // remove this line
private AdapterCallback mAdapterCallback; // add this line
Context mcontext;
public UnitsRv(Context context,ArrayList<UnitsList> unitsLists, AdapterCallback callback) {
mcontext = context;
munitsLists = unitsLists;
this.mAdapterCallback = callback; // add this line
}
class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener, View.OnLongClickListener {
TextView unit_name;
public ViewHolder(View v) {
super(v);
unit_name = v.findViewById(R.id.unit_name);
v.setOnLongClickListener(this);
}
#Override
public void onClick(View view) {
if (UnitsFragment.isInActionMode){
mAdapterCallback.prepareSelection(mcontext,getAdapterPosition()); // modify this line
notifyItemChanged(getAdapterPosition());
}
}
#Override
public boolean onLongClick(View view) {
Log.d(TAG, "onLongClick: " + getAdapterPosition());
mAdapterCallback.prepareSelection(view.getContext(),getAdapterPosition()); // modify this line
return true;
}
}
// your other codes....
}

You should check for your fragment is attached or not with isAdded()
place if(!isAdded()) return in your onActionItemClicked. and replace requireContext() with getContext() because requireContext() always throws IllegalStateException if fragment is not attached.

override onAttach method to save context in your fragment.
#Override
public void onAttach(Context context) {
super.onAttach(context);
this.context= context;
}
Hope this helps.

New fetch data is not show on recycler list when pull down to refresh

I want to implement one code where data will come on Scroll and if the data is add on list then we pull down(SwipeRefreshLayout) the new data will come on that list. In my below code the add on data is coming in response but not come in list? I have read many tutorials like this but data is coming on Swipe refresh but not shown on list. Thank you in advance
public class UpdatesFragment extends Fragment implements SwipeRefreshLayout.OnRefreshListener{
SwipeRefreshLayout mSwipeRefreshLayout;
UserSessionManager session;
private List<SuperHero> listSuperHeroes;
private RecyclerView recyclerView;
private RecyclerView.LayoutManager layoutManager;
private RecyclerView.Adapter adapter;
public ProgressBar progressBar;
public String user_id;
TextView textView;
FloatingActionButton fab;
public int a=1;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view= inflater.inflate(R.layout.fragment_updates, container, false);
session = new UserSessionManager(getActivity());
// get user data from session
HashMap<String, String> user = session.getUserDetails();
user_id = user.get(UserSessionManager.KEY_USER_ID);
// SwipeRefreshLayout
mSwipeRefreshLayout = (SwipeRefreshLayout) view.findViewById(R.id.swipe_container);
mSwipeRefreshLayout.setOnRefreshListener(this);
mSwipeRefreshLayout.setColorSchemeResources(R.color.colorPrimary,
android.R.color.holo_green_dark,
android.R.color.holo_orange_dark,
android.R.color.holo_blue_dark);
/**
* Showing Swipe Refresh animation on activity create
* As animation won't start on onCreate, post runnable is used
*/
mSwipeRefreshLayout.post(new Runnable() {
#Override
public void run() {
mSwipeRefreshLayout.setRefreshing(true);
// Fetching data from server
getDataFromServer(1);
}
});
return view;
}
public void onViewCreated(View v, Bundle savedInstanceState) {
super.onViewCreated(v, savedInstanceState);
fab = (FloatingActionButton)v.findViewById(R.id.fab);
recyclerView = (RecyclerView) v.findViewById(R.id.updatesRecycler);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(getContext());
recyclerView.setLayoutManager(layoutManager);
listSuperHeroes = new ArrayList<>();
adapter = new CardAdapter(listSuperHeroes, getActivity());
recyclerView.setAdapter(adapter);
textView = (TextView)v.findViewById(R.id.text);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(getContext(), AddWebPostActivity.class);
startActivity(i);
}
});
getDataFromServer(a);
recyclerView.setOnScrollListener(new EndlessRecyclerOnScrollListener((LinearLayoutManager) layoutManager) {
#Override
public void onLoadMore(int current_page) {
getDataFromServer(current_page);
}
});
}
public void getDataFromServer(int requestCount) {
Log.e("count",String.valueOf(requestCount));
final String DATA_URL = "https://XYZ.php?username="+user_id + "&page="+requestCount;
JsonArrayRequest jsonArrayRequest = new JsonArrayRequest(DATA_URL,
new Response.Listener<JSONArray>() {
#Override
public void onResponse(JSONArray response) {
mSwipeRefreshLayout.setRefreshing(false);
Log.e("URL___________",DATA_URL);
Log.e("response___________", String.valueOf(response));
parseData(response);
adapter.notifyDataSetChanged();
}
},
new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Toast.makeText(getContext(), "No More Items Available", Toast.LENGTH_SHORT).show();
}
});
RequestQueue requestQueue = Volley.newRequestQueue(getContext());
requestQueue.getCache().clear();
requestQueue.add(jsonArrayRequest);
}
private void parseData(JSONArray array) {
for (int i = 0; i < array.length(); i++) {
SuperHero superHero = new SuperHero();
JSONObject json = null;
try {
json = array.getJSONObject(i);
superHero.setPost_title(json.getString(Config.TAG_POST_TITLE));
superHero.setPost_content(json.getString(Config.TAG_POST_CONTENT));
superHero.setPost_parent(json.getString(Config.TAG_POST_PARENT));
superHero.setPost_date(json.getString(Config.TAG_POST_DATE));
superHero.setPost_date_gmt(json.getString(Config.TAG_POST_DATE_GMT));
superHero.setScheduled_date(json.getString(Config.TAG_SCHEDULED_DATE));
superHero.setTo_ping(json.getString(Config.TAG_IP_ADDRESS));
superHero.setVisit_post(json.getString(Config.TAG_VISIT_POST));
superHero.setUr_id(json.getString(Config.TAG_UR_ID));
} catch (JSONException e) {
e.printStackTrace();
}
listSuperHeroes.add(superHero);
}
}
/**
* Called when a swipe gesture triggers a refresh.
*/
#Override
public void onRefresh() {
getDataFromServer(1);
}
}
Adapter
public class CardAdapter extends RecyclerView.Adapter<CardAdapter.ViewHolder> {
UserSessionManager session;
public String user_id;
public String ur_id;
private Context context;
//String visit;
//List to store all superheroes
List<SuperHero> superHeroes;
//Constructor of this class
public CardAdapter(List<SuperHero> superHeroes, Context context){
super();
//Getting all superheroes
this.superHeroes = superHeroes;
this.context = context;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext())
.inflate(R.layout.web_post, parent, false);
// Session class instance
session = new UserSessionManager(context);
session.checkLogin();
// get user data from session
HashMap<String, String> user = session.getUserDetails();
user_id = user.get(UserSessionManager.KEY_USER_ID);
ViewHolder viewHolder = new ViewHolder(v);
return viewHolder;
}
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
//Getting the particular item from the list
final SuperHero superHero = superHeroes.get(position);
holder.tvPostTitle.setText(superHero.getPost_title());
holder.tvPostContent.setText(superHero.getPost_content());
holder.tvPostDateTime1.setText(superHero.getPost_date() +" / " +superHero.getPost_date_gmt());
final String visit = superHero.getVisit_post();
holder.tvVisitPost.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent(context,VisitWebView.class);
i.putExtra("visitURL",visit);
context.startActivity(i);
}
});
}
#Override
public int getItemCount() {
return superHeroes.size();
}
#Override
public int getItemViewType(int position) {
return position;
}
class ViewHolder extends RecyclerView.ViewHolder{
//Views
public TextView tvPostTitle,tvPostContent,tvPostDateTime1,tvVisitPost;
public ImageButton removeButton;
//Initializing Views
public ViewHolder(final View itemView) {
super(itemView);
tvPostTitle = (TextView) itemView.findViewById(R.id.tvPostTitle);
tvPostContent = (TextView) itemView.findViewById(R.id.tvPostContent);
tvPostDateTime1 = (TextView) itemView.findViewById(R.id.tvPostDateTime1);
tvVisitPost = (TextView) itemView.findViewById(R.id.tvVisitPost);
removeButton = (ImageButton) itemView.findViewById(R.id.removeButton);
}
}
}

use this method
mSwipeRefreshLayout.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
mSwipeRefreshLayout.setRefreshing(true);
getDataFromServer(1);
}
instead of this
mSwipeRefreshLayout.post(new Runnable() {
#Override
public void run() {
mSwipeRefreshLayout.setRefreshing(true);
// Fetching data from server
getDataFromServer(1);
}
});

Please call adapter and pass fresh list data after this line
listSuperHeroes.add(superHero) in parseData(response) function ;
adapter = new CardAdapter(listSuperHeroes, getActivity());
recyclerView.setAdapter(adapter)
adapter.notifyDataSetChanged();

Passing RecyclerView CardView Clicked Item Data To Activity

I have a question about passing clicked cardview data to activity, and here the full story :
I have an Activity called "Details", which contains 2 TextViews in it's layout, Title & Description .
I have setup a fragment ( tab_1 ) which contain the recyclerview codes and the the items data, each item of those contain : title & description .
What i want :
When the user click the item, it will open the Details Activity, and change Details layout title, with clicked item title, and the same for description .
I've manged to create the other activity as an example, and made intent to start it, plus adding "addOnTouchlistener" thanks to Stackoverflow, i've found the way to make it .
So, how to make this alive? I've tried many ways of the available answers on Stackoverflow, but all of them not working, or not related to my request .
Here are my files :
itemsdata.java :
public class itemsdata {
int CatPic;
String title;
String Descr;
int Exapnd;
int expand_no;
tab_1.java ( fragment )
public class tab_1 extends Fragment implements SearchView.OnQueryTextListener {
private RecyclerView mRecyclerView;
public RecyclingViewAdapter adapter;
private Activity context;
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View layout = inflater.inflate(R.layout.tab_1, container, false);
mRecyclerView = (RecyclerView)layout.findViewById(R.id.recycler_view);
mRecyclerView.addOnItemTouchListener(new RecyclerItemClickListener
(getContext(), new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(View view, int position) {
Intent i = new Intent(view.getContext(), DetailsActivity.class);
view.getContext().startActivity(i);
}
}));
mRecyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
adapter = new RecyclingViewAdapter(getActivity(),Listed());
mRecyclerView.setAdapter(adapter);
return layout;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
inflater.inflate(R.menu.main, menu);
final MenuItem item = menu.findItem(R.id.action_search);
final SearchView searchView = (SearchView) MenuItemCompat.getActionView(item);
searchView.setOnQueryTextListener(this);
}
#Override
public boolean onQueryTextChange(String query) {
final List<itemsdata> filteredModelList = filter(Listed(), query);
adapter.animateTo(filteredModelList);
mRecyclerView.scrollToPosition(0);
return true;
}
#Override
public boolean onQueryTextSubmit(String query) {
return true;
}
private List<itemsdata> filter(List<itemsdata> models, String query) {
query = query.toLowerCase();
final List<itemsdata> filteredModelList = new ArrayList<>();
for (itemsdata model : models) {
final String text = model.title.toLowerCase();
if (text.contains(query)) {
filteredModelList.add(model);
}
}
return filteredModelList;
}
public List<itemsdata> Listed()
{
//Titles Strings
String sys_title1 = getString(R.string.system_item_title_1);
String sys_title2 = getString(R.string.system_item_title_2);
String sys_title3 = getString(R.string.system_item_title_3);
//Description Strings
String sys_descr1 = getString(R.string.system_item_desc_1);
String sys_descr2 = getString(R.string.system_item_desc_2);
String sys_descr3 = getString(R.string.system_item_desc_3);
//Adding New Cards
List<itemsdata> data = new ArrayList<>();
//Categories Icons New Items ** Make It The Same
int[] icons = {
R.drawable.facebook_icon ,
R.drawable.twitter_icon ,
R.drawable.twitter_icon
};
//Expand Button New Items
int[] expandbutton = {
R.drawable.expanded ,
R.drawable.expanded ,
R.drawable.expanded
};
//UnExpand Button New Items
int[] unexpandbutton = {
R.drawable.ca_expand ,
R.drawable.ca_expand ,
R.drawable.ca_expand
};
//Titles New Items
String[] titles = {
sys_title1 ,
sys_title2 ,
sys_title3
};
//Description New Items
String[] Description = {
sys_descr1 ,
sys_descr2 ,
sys_descr3
};
for(int i = 0;i<titles.length && i < icons.length && i < Description.length && i < unexpandbutton.length && i < expandbutton.length ; i++)
{
itemsdata current = new itemsdata();
current.CatPic = icons[i];
current.title = titles[i];
current.Descr = Description[i];
current.expand_no = unexpandbutton[i];
current.Exapnd = expandbutton[i];
data.add(current);
}
return data;
}
}
Details Activity :
public class DetailsActivity extends AppCompatActivity{
TextView title;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.details);
title = (TextView)findViewById(R.id.details_title);
}
EDIT : I've made it, i have added a button which open the fragment, and passed the data, in the Adapter, but i want it via tab_1.java, not the Adapter, i mean i want to click on the item to open the fragment, not on a button, here a snap from my Adapter code ( i've added it in OnBindViewHolder )
I've setup a OnClick and implemented the Vew.setOnClick ..etc, but when i click the item, nothing happen.
#Override
public void onBindViewHolder(final MyRecycleViewHolder holder, int position) {
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(),DetailsActivity.class);
v.getContext().startActivity(i);
}
});
//Referencing Data
final itemsdata currentobject = mdata.get(position);
//Referencing Items
holder.ProbTitle.setText(currentobject.title);
holder.ProbDescr.setText(currentobject.Descr);
holder.CategoryPic.setImageResource(currentobject.CatPic);
holder.ExpandButton.setImageResource(currentobject.Exapnd);
holder.ExpandNoButton.setImageResource(currentobject.expand_no);
//What Happen When You Click Expand Button .
holder.ExpandButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent i = new Intent(v.getContext(), DetailsActivity.class);
i.putExtra("TitleKey",holder.ProbTitle.getText().toString());
v.getContext().startActivity(i);
}
}
);
public static class MyRecycleViewHolder extends RecyclerView.ViewHolder
{
SwipeLayout swipeLayout;
//Defining Items .
TextView ProbTitle;
ImageButton ExpandButton;
TextView ProbDescr;
ImageButton ExpandNoButton;
ImageView CategoryPic;
/*
TextView Card_Star;
TextView Card_UnStar;
*/
TextView Card_Share;
//Referencing Resources
public MyRecycleViewHolder(final View itemView) {
super(itemView);
ProbTitle = (TextView) itemView.findViewById(R.id.prob_title);
CategoryPic = (ImageView) itemView.findViewById(R.id.cat_pic);
ProbDescr = (TextView) itemView.findViewById(R.id.prob_descr);
ExpandButton = (ImageButton) itemView.findViewById(R.id.expand_button);
ExpandNoButton = (ImageButton) itemView.findViewById(R.id.expand_no_button);
/*
Card_Star = (TextView) itemView.findViewById(R.id.card_star);
Card_UnStar = (TextView) itemView.findViewById(R.id.card_unstar);
*/
Card_Share = (TextView) itemView.findViewById(R.id.card_share);
swipeLayout = (SwipeLayout) itemView.findViewById(R.id.swipe);
}

create an Interface inside your adapter containing methods. And while implementing your Adapter, those methods will be implemented in your activity and you can perform whatever action you want.
public class Adapter extends RecyclerView.Adapter<MyRecycleViewHolder> {
public interface Callbacks {
public void onButtonClicked(String titleKey);
}
private Callbacks mCallbacks;
public Adapter() {
}
#Override
public MyRecycleViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
View v = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.layout_details, null);
return new MyRecycleViewHolder(v);
}
#Override
public void onBindViewHolder(final MyRecycleViewHolder holder, final int i) {
holder.ExpandButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mCallbacks != null) {
mCallbacks.onButtonClicked(holder.ProbTitle.getText().toString());
}
}
});
}
#Override
public int getItemCount() {
return;
}
public void setCallbacks(Callbacks callbacks) {
this.mCallbacks = callbacks;
}
}

you may try do this on your onItemClick()
Intent i = new Intent(view.getContext(), DetailsActivity.class);
i.putExtra("title", yourTitle);
i.putExtra("description", yourDescription);
view.getContext().startActivity(i);
and when oncreate in your DetailActivity,do this
String title = getIntent().getStringExtra("title");
String description = getIntent().getStringExtra("description");
so you can pass title and description to DetailActivity

IMO, you implement setOnClickListener inside Adapter of RecyclerView. You can refer to my following sample code, then apply its logic to your code. Hope it helps!
public class MyRVAdapter extends RecyclerView.Adapter<MyRVAdapter.ViewHolder> {
Context mContext;
List<String> mStringList;
public MyRVAdapter(Context mContext, List<String> mStringList) {
this.mContext = mContext;
this.mStringList = mStringList;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.cardview, parent, false);
v.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
TextView textView1 = (TextView) v.findViewById(R.id.textView1);
TextView textView2 = (TextView) v.findViewById(R.id.textView2);
Bundle bundle = new Bundle();
bundle.putString("key1", textView1.getText().toString());
bundle.putString("key2", textView2.getText().toString());
passToAnotherActivity(bundle);
}
});
return new ViewHolder(v);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// do something...
}
#Override
public int getItemCount() {
if (mStringList != null) {
return mStringList.size();
}
return 0;
}
private void passToAnotherActivity(Bundle bundle) {
if (mContext == null)
return;
if (mContext instanceof MainActivity) {
MainActivity activity = (MainActivity) mContext;
activity.passToAnotherActivity(bundle); // this method must be implemented inside `MainActivity`
}
}
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public ViewHolder(View itemView) {
super(itemView);
// do something...
}
#Override
public void onClick(View v) {
}
}
}

First of all make your "itemsdata" object to implement Parcelable. You can check it here . In your onItemClick method you pass the object to your Details activity using intent.putExtra("key",listOfDataItems.get(position));
In your DetailsActivity you can get your custom object with getParcelable("key")

All above methods worked, but kinda long, so this one worked for me :
Cardview cardview;
cardView = (CardView)itemView.findViewById(R.id.cv);
cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Intent i = new Intent (view.getContext(), DetailsActivity.class);
i.putExtra("TitleKey",ProbTitle.getText().toString());
i.putExtra("DescrKey",ProbDescr.getText().toString());
view.getContext().startActivity(i);
}
});
And in Details.java :
TextView title;
TextView Descr;
title = (TextView)findViewById(R.id.details_title);
Descr = (TextView)findViewById(R.id.details_descr);
String titleresult = result.getExtras().getString("TitleKey");
String Descrresult = result.getExtras().getString("DescrKey");
title.setText(titleresult);
Descr.setText(Descrresult);