Is RecyclerView refreshed when AlertDialog's positive button gets pressed

Is RecyclerView refreshed when AlertDialog's positive button gets pressed - java

My MainActivity has a RecyclerView adapter, and data to this RecyclerView is added through a AlertDialog which passes the entered text to the MainActivity. The recycler view gets refreshed somehow when the positive button in the dialog is pressed even though I never call notifyItemInserted() or notifyDatasetChange() after passing the new input. I want to know how this happens, my guess is the recyclerview is somehow refreshed after the positive button is pressed in the dialog box
Custom AlertDialog Code:
public class CustomDialog extends AppCompatDialogFragment {
OnNoteAddedListener onNoteAddedListener;
public interface OnNoteAddedListener {
public void onClick(String note);
}
public CustomDialog(OnNoteAddedListener onNoteAddedListener) {
this.onNoteAddedListener = onNoteAddedListener;
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
AlertDialog.Builder builder = new AlertDialog.Builder(getActivity());
// Get the layout inflater
final LayoutInflater inflater = getActivity().getLayoutInflater();
final View dialogLayout = inflater.inflate(R.layout.dialog_box, null);
// Inflate and set the layout for the dialog
// Pass null as the parent view because its going in the dialog layout
builder.setView(dialogLayout).setPositiveButton("Ok", new DialogInterface.OnClickListener() {#Override
public void onClick(DialogInterface dialog, int id) {
EditText addNote = dialogLayout.findViewById(R.id.note_text);
String note = addNote.getText().toString();
onNoteAddedListener.onClick(note);
}
}).setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
CustomDialog.this.getDialog().cancel();
}
});
return builder.create();
}
}
Adapter code:
class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder>
{
private static final String TAG = "RecyclerViewAdapter";
private List<String> notesList;
private Context mContext;
private SendPositionConnector sendPositionConnector;
public interface SendPositionConnector
{
public void sendPosition(int position);
}
public RecyclerViewAdapter(List<String> notesList, Context mContext)
{
this.notesList = notesList;
this.mContext = mContext;
this.sendPositionConnector = (MainActivity)mContext;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType)
{
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.layout_listitem, parent, false);
ViewHolder holder = new ViewHolder(view);
return holder;
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, final int position)
{
Log.d(TAG, "onBindViewHandler: called");
viewHolder.noteContent.setText(notesList.get(position));
viewHolder.parentLayout.setOnLongClickListener(new View.OnLongClickListener(){
#Override
public boolean onLongClick(View view)
{
Log.d(TAG, "onLongClick: long clicked on");
sendPositionConnector.sendPosition(position);
return false;
}
});
}
#Override
public int getItemCount()
{
return notesList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder
{
TextView noteContent;
RelativeLayout parentLayout;
ImageView bullet;
public ViewHolder(#NonNull View itemView)
{
super(itemView);
bullet = itemView.findViewById(R.id.bullet);
noteContent = itemView.findViewById(R.id.text_content);
parentLayout = itemView.findViewById(R.id.parent_layout);
}
}
}
Activity Code:
public class MainActivity extends AppCompatActivity implements RecyclerViewAdapter.SendPositionConnector
{
private static final String TAG = "MainActivity";
private List<String> notesList = new ArrayList<>();
private RecyclerView recyclerView;
private RecyclerViewAdapter adapter;
private int position;
public AgentAsyncTask agentAsyncTask;
#Override
protected void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
recyclerView = findViewById(R.id.my_recycler_view);
registerForContextMenu(recyclerView);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
agentAsyncTask = new AgentAsyncTask(notesList, getApplicationContext(), true, new AgentAsyncTask.OnRead(){
#Override
public void onRead(List<String> notesList)
{
if(!notesList.isEmpty())
MainActivity.this.notesList = notesList;
adapter = new RecyclerViewAdapter(notesList, MainActivity.this);
recyclerView.setAdapter(adapter);
}
});
agentAsyncTask.execute();
}
#Override
public boolean onCreateOptionsMenu(Menu menu)
{
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.add_menu, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item)
{
// Handle item selection
switch (item.getItemId())
{
case R.id.add_note:
showDialogBox(item);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
#Override
protected void onStop()
{
super.onStop();
new AgentAsyncTask(notesList, getApplicationContext(), false, new AgentAsyncTask.OnRead(){
#Override
public void onRead(List<String> notesList)
{
if(!notesList.isEmpty())
MainActivity.this.notesList = notesList;
}
}).execute();
}
#Override
protected void onDestroy()
{
super.onDestroy();
}
private boolean showDialogBox(MenuItem menuItem)
{
AppCompatDialogFragment dialogFragment = new CustomDialog(new CustomDialog.OnNoteAddedListener(){
#Override
public void onClick(String note)
{
Log.d(TAG, "onClick: "+ note);
notesList.add(note);
}
});
dialogFragment.show(getSupportFragmentManager(),"Adding");
return true;
}
#Override
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo)
{
super.onCreateContextMenu(menu, v, menuInfo);
MenuInflater inflater = getMenuInflater();
inflater.inflate(R.menu.context_menu, menu);
}
#Override
public boolean onContextItemSelected(MenuItem menuItem)
{
switch(menuItem.getItemId())
{
case R.id.delete:
notesList.remove(position);
adapter.notifyItemRemoved(position);
adapter.notifyItemRangeChanged(position, notesList.size());
return true;
default:
return false;
}
}
#Override
public void sendPosition(int position)
{
this.position = position;
}
private static class AgentAsyncTask extends AsyncTask<Void, Void, List<String>>
{
private List<String> notesList;
private boolean flag;
OnRead onRead;
Context context;
AppDataBase dataBase;
private static final String TAG = "AgentAsyncTask";
public interface OnRead
{
public void onRead(List<String> notesList);
}
private AgentAsyncTask(List<String> notesList,Context context,boolean flag, OnRead onRead)
{
this.notesList = notesList;
this.onRead = onRead;
this.flag = flag;
this.context = context;
}
#Override
protected List<String> doInBackground(Void... params)
{
dataBase = Room.databaseBuilder(context, AppDataBase.class, "database-name").build();
if(!flag)
{
Gson gson = new Gson();
Type type = new TypeToken<List<String>>() {}.getType();
String json = gson.toJson(notesList, type);
Log.d(TAG, "doInBackground: "+json);
Notes notes = new Notes();
notes.setNoteContent(json);
notes.setUid(1);
dataBase.notesDao().insertNotes(notes);
return notesList;
}
else
{
Gson gson = new Gson();
String notesListContent = dataBase.notesDao().getNotes();
if(dataBase.notesDao().getCount() != 0)
{
notesList = gson.fromJson(notesListContent, new TypeToken<List<String>>()
{
}.getType());
}
else
{
return notesList;
}
return notesList;
}
}
#Override
protected void onPostExecute(List<String> notesList)
{
super.onPostExecute(notesList);
if(flag)
onRead.onRead(notesList);
}
}
}

What's probably happening is that when the dialog returns, it causes a re-layout of the RecyclerView, which rebinds the views. This is prone to bugs though, since it may not have updated the recycler about stuff like the list length or item view types, etc, so the appropriate notify method should always be used.

When you get the text from the dialog to main activity after pressing the positive button.
Append your list with that new text that you are passing to adapter and call method
adapter.notifyDataSetChanged();

Related

Nested RecyclerView OnclickListener to new fragment

**I want to know how to click the items in childRecyclerview show different fragment, I think we should try to modify childAdapter, I am searching for a long time on net. But no use. Please help or try to give some ideas how to achieve this.
hear is my code
**
//workflow fragment
public class WorkflowFragment extends Fragment {
private Context mContext;
private String[] workflowHeading;
private String[] workflowContent;
private int[] imageResourceId;
private RecyclerView recyclerview;
private List<Workflow> workflowList;
private WorkflowAdapter workflowAdapter;
private View view;
public static WorkflowFragment newInstance(String param1, String param2) {
WorkflowFragment fragment = new WorkflowFragment();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
mContext = getActivity();
setHasOptionsMenu(true);
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
if(view==null) {
view = inflater.inflate(R.layout.fragment_workflow, container, false);
}
return view;
}
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
dataInitialize();
recyclerview = view.findViewById(R.id.workflow_recyclerview);
recyclerview.setLayoutManager(new LinearLayoutManager(getContext()));
recyclerview.setHasFixedSize(true);
workflowAdapter =new WorkflowAdapter(getContext(),workflowList);
recyclerview.setAdapter(workflowAdapter);
workflowAdapter.notifyDataSetChanged();
}
private void dataInitialize() {
//list1
List<String> nestedList1 = new ArrayList<>();
nestedList1.add("A");
nestedList1.add("B");
nestedList1.add("C");
nestedList1.add("D");
nestedList1.add("E");
nestedList1.add("F");
nestedList1.add("G");
//list2
List<String>nestedList2 = new ArrayList<>();
nestedList2.add("H");
nestedList2.add("I");
nestedList2.add("G");
nestedList2.add("K");
//list3
List<String>nestedList3 = new ArrayList<>();
nestedList3.add("L");
nestedList3.add("M");
nestedList3.add("N");
nestedList3.add("P");
nestedList3.add("P");
nestedList3.add("Q");
nestedList3.add("R");
nestedList3.add("S");
//list4
List<String>nestedList4 = new ArrayList<>();
nestedList4.add("T");
nestedList4.add("U");
nestedList4.add("V");
nestedList4.add("W");
//list5
List<String>nestedList5 = new ArrayList<>();
nestedList5.add("X");
//list6
List<String>nestedList6 = new ArrayList<>();
nestedList6.add("Y");
nestedList6.add("Z");
workflowList = new ArrayList<>();
workflowList.add(new Workflow("1",nestedList1));
workflowList.add(new Workflow("2",nestedList2));
workflowList.add(new Workflow("3",nestedList3));
workflowList.add(new Workflow("4",nestedList4));
workflowList.add(new Workflow("5",nestedList5));
workflowList.add(new Workflow("6",nestedList6));
}
#Override
public void onCreateOptionsMenu(#NonNull Menu menu, #NonNull MenuInflater inflater) {
inflater.inflate(R.menu.menu_item,menu);
MenuItem searchItem = menu.findItem(R.id.search_action);
if(searchItem!=null){
SearchView searchView = (SearchView) searchItem.getActionView(); //here stop working
searchView.setMaxWidth(Integer.MAX_VALUE);
searchView.setQueryHint("Search Here!");
searchView.setIconified(false);
searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
#Override
public boolean onQueryTextSubmit(String query) {
workflowAdapter.getFilter().filter(query);
return false;
}
#Override
public boolean onQueryTextChange(String newText) {
notifyItemChanged()
workflowAdapter.getFilter().filter(newText);
return false;
}
});
}
super.onCreateOptionsMenu(menu, inflater);
}
}
//ParentAdapter
public class WorkflowAdapter extends RecyclerView.Adapter<WorkflowAdapter.WorkflowViewHolder> implements Filterable{
Context context;
List<Workflow> worflowArrayList;
List<Workflow> worflowArrayListFull;
private List<String>nestedlist = new ArrayList<>();
public WorkflowAdapter(Context context, List<Workflow> worflowArrayList) {
this.context = context;
this.worflowArrayListFull = worflowArrayList;
this.worflowArrayList = new ArrayList<>(worflowArrayListFull);
}
#NonNull
#Override
public WorkflowViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(context).inflate(R.layout.general_list_item,parent,false);
return new WorkflowViewHolder(v);
}
#Override
public void onBindViewHolder(#NonNull WorkflowViewHolder holder, int parentPosition) {
//-get element from your dataset at this position
//-replace the contents of the view with that element
Workflow workflow = worflowArrayList.get(parentPosition);
holder.tvHeading.setText(workflow.getItemText());
//holder.titleImage.setImageResource(model.titleImage);
boolean isExpandable = workflow.isExpandable();
holder.expandableLayout.setVisibility(isExpandable ? View.VISIBLE:View.GONE);
if(isExpandable){
holder.mArrowImage.setImageResource(R.drawable.ic_baseline_arrow_upward_24);
}else{
holder.mArrowImage.setImageResource(R.drawable.ic_baseline_arrow_downward_24);
}
NestedAdapter childAdapter = new NestedAdapter(nestedlist);
holder.nestedRecyclerView.setLayoutManager(new LinearLayoutManager(holder.itemView.getContext()));
holder.nestedRecyclerView.setHasFixedSize(true);
holder.nestedRecyclerView.setAdapter(childAdapter);
holder.linearLayout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
switch(holder.getAdapterPosition()){
case 1:
Toast.makeText(holder.itemView.getContext(), "Item 11 clicked. ", Toast.LENGTH_SHORT).show();
break;
}
workflow.setExpandable(!workflow.isExpandable());
nestedlist = workflow.getNestedList();
notifyItemChanged(holder.getAdapterPosition());
}
});
}
#Override
public int getItemCount() {
return worflowArrayList.size();
}
#Override
public Filter getFilter() {
return workflowFilter;
}
private final Filter workflowFilter = new Filter(){
#Override
protected FilterResults performFiltering(CharSequence constraint) {
ArrayList<Workflow> filteredWorkflowList = new ArrayList<>();
if (constraint == null || constraint.length() == 0){
filteredWorkflowList.addAll(worflowArrayListFull);
}else{
String filterPattern = constraint.toString().toLowerCase().trim();
for (Workflow workflow: worflowArrayListFull){
if(workflow.itemText.toLowerCase().contains(filterPattern))
filteredWorkflowList.add(workflow);
}
}
FilterResults results = new FilterResults();
results.values = filteredWorkflowList;
results.count = filteredWorkflowList.size();
return results;
}
#Override
protected void publishResults(CharSequence constraint, FilterResults results) {
worflowArrayList.clear();
worflowArrayList.addAll((ArrayList)results.values);
notifyDataSetChanged();
}
};
public static class WorkflowViewHolder extends RecyclerView.ViewHolder{
private TextView tvHeading;
private LinearLayout linearLayout;
private RelativeLayout expandableLayout;
private ImageView mArrowImage;
private RecyclerView nestedRecyclerView;
public WorkflowViewHolder(#NonNull View itemView) {
super(itemView);
linearLayout=itemView.findViewById(R.id.linear_layout);
expandableLayout=itemView.findViewById(R.id.expandable_layout);
tvHeading = itemView.findViewById(R.id.tvHeading);
mArrowImage=itemView.findViewById(R.id.arro_imageview);
nestedRecyclerView = itemView.findViewById(R.id.child_rv);
}
}
}
//childAdapter
public class NestedAdapter extends RecyclerView.Adapter<com.larntech.myassistant_java.workflow.NestedAdapter.NestedViewHolder> {
private List<String> childItemList; /
public NestedAdapter(List<String> childItemList){
this.childItemList = childItemList;
}
#NonNull
#Override
public com.larntech.myassistant_java.workflow.NestedAdapter.NestedViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.nested_item,parent,false);
return new com.larntech.myassistant_java.workflow.NestedAdapter.NestedViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull com.larntech.myassistant_java.workflow.NestedAdapter.NestedViewHolder holder, int childPosition) {
holder.mTv.setText(childItemList.get(childPosition));
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
switch(holder.getAdapterPosition()){
case 0:
DemoFragment demoFragment =new DemoFragment();
AppCompatActivity activity=(AppCompatActivity) view.getContext();
activity.getSupportFragmentManager().beginTransaction().replace(R.id.fragment_workflow,demoFragment).addToBackStack(null).commit();
break;
case 1:
FragmentTwo fragmentTwo =new FragmentTwo();
AppCompatActivity activity2=(AppCompatActivity) view.getContext();
activity2.getSupportFragmentManager().beginTransaction().replace(R.id.fragment_workflow,fragmentTwo).addToBackStack(null).commit();
break;
case 2:
Toast.makeText(holder.itemView.getContext(), "Item clicked. ", Toast.LENGTH_SHORT).show();
break;
}
}
});
}
#Override
public int getItemCount() {
return childItemList.size();
}
public class NestedViewHolder extends RecyclerView.ViewHolder{
private TextView mTv;
public NestedViewHolder(#NonNull View itemView) {
super(itemView);
mTv=itemView.findViewById(R.id.nestedItemTv);
}
}
}

Recyclerview doesn't show any data after swiping one of the rows

I've added swipe to my app, to delete specified note. For couple of days, I've facing problem with displaying data after swipe. For clarify:
Let's say, we have two items in recycler view. Whenever we swipe one of them, the second one should be visible, but it's not until I'll re-run the app. How I may solve it?
Main Activity
public class MainActivity extends AppCompatActivity implements MemoAdapter.OnNoteListener {
private static final String TAG = "MainActivity";
//Vars
private ArrayList<Note> mNotes = new ArrayList<>();
private MemoRepository mRepository;
private MemoAdapter mMemoAdapter;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mRepository = new MemoRepository(this);
Toolbar toolbar = (Toolbar) findViewById(R.id.memoToolbar);
setSupportActionBar(toolbar);
setTitle("My memos");
initRecyclerView();
}
//This method would be called after getting result from memo_content such as new memo, or edited existing memo.
#Override
protected void onResume() {
super.onResume();
getMemos();
}
private void getMemos(){
mRepository.getAllMemos().observe(this, new Observer<List<Note>>() {
#Override
public void onChanged(List<Note> notes) {
if (mNotes.size() > 0){
notes.clear();
}
if (notes != null){
mNotes.addAll(notes);
mMemoAdapter.watchMemoChanges((ArrayList<Note>) notes);
}
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.icon_menu, menu);
return super.onCreateOptionsMenu(menu);
}
#Override
public boolean onOptionsItemSelected(#NonNull MenuItem item) {
switch (item.getItemId()){
case R.id.addNewNote:
Toast.makeText(this, "Click!", Toast.LENGTH_SHORT).show();
startActivity(new Intent(this, memo_content.class));
break;
case R.id.deleteAllNotes:
Toast.makeText(this, "Delete!", Toast.LENGTH_SHORT).show();
mRepository.deleteAllMemos();
break;
}
return super.onOptionsItemSelected(item);
}
private void initRecyclerView(){
//UI
RecyclerView mRecyclerView = findViewById(R.id.recyclerView);
mRecyclerView.setHasFixedSize(true);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(this);
mMemoAdapter = new MemoAdapter(mNotes, this);
new ItemTouchHelper(itemTouch).attachToRecyclerView(mRecyclerView);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mMemoAdapter);
}
#Override
public void onMemoClick(int position) {
Intent intent = new Intent(this, memo_content.class);
intent.putExtra("memo_content", mNotes.get(position));
startActivity(intent);
}
private ItemTouchHelper.SimpleCallback itemTouch = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.START | ItemTouchHelper.LEFT) {
#Override
public boolean onMove(#NonNull RecyclerView recyclerView, #NonNull RecyclerView.ViewHolder viewHolder, #NonNull RecyclerView.ViewHolder target) {
return false;
}
#Override
public void onSwiped(#NonNull RecyclerView.ViewHolder viewHolder, int direction) {
mRepository.deleteMemo(mNotes.get(viewHolder.getAdapterPosition()));
Log.d(TAG, "onSwiped: "+mNotes.get(viewHolder.getAdapterPosition()));
}
};
}
Adapter
public class MemoAdapter extends RecyclerView.Adapter<MemoAdapter.MemoViewHolder> {
private ArrayList<Note> mNotes;
private OnNoteListener mListener;
public class MemoViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
TextView title, timestamp;
private MemoViewHolder(#NonNull final View itemView) {
super(itemView);
this.title = (TextView) itemView.findViewById(R.id.title);
this.timestamp = (TextView) itemView.findViewById(R.id.timestamp);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
mListener.onMemoClick(getAdapterPosition());
}
}
public MemoAdapter(ArrayList<Note> notes, OnNoteListener listener) {
this.mNotes = notes;
this.mListener = listener;
}
#NonNull
#Override
public MemoViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.single_memo, parent, false);
return new MemoViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull MemoViewHolder holder, int position) {
holder.title.setText(mNotes.get(position).getTitle());
holder.timestamp.setText(mNotes.get(position).getTimestamp());
}
public void watchMemoChanges(ArrayList<Note> notes){
this.mNotes = notes;
notifyDataSetChanged();
}
#Override
public int getItemCount() {
return mNotes.size();
}
public interface OnNoteListener{
void onMemoClick(int position);
}

Short answer:
You need to remove the statement notes.clear() when you receive a change in the LiveData list from the database via the observer.
Detailed answer
When you first run your app, it will show all right list because the condition if (mNotes.size() > 0) is not met, and so the received list won't be cleared via notes.clear(), so the RecyclerView will display the right data.
But when you delete a note, then when the observer is triggered again with the new list, the condition if (mNotes.size() > 0) will be met, so you will clear the list that is coming from the database before feeding the adapter with it, so the RecyclerView will be free of data.
So to solve this please replace notes.clear(); with mNotes.clear();
So the right code will be:
private void getMemos(){
mRepository.getAllMemos().observe(this, new Observer<List<Note>>() {
#Override
public void onChanged(List<Note> notes) {
if (mNotes.size() > 0){
mNotes.clear();
}
if (notes != null){
mNotes.addAll(notes);
mMemoAdapter.watchMemoChanges((ArrayList<Note>) notes);
}
}
});
}
Wish that help you out.
I didn't examine the rest of code, please let me know if there is another issue to help more

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.

How to use an AlertDialog to add an item in a RecyclerView?

I'm building a list using a RecyclerView. When the user clicks the '+' button in the toolbar an AlertDialog is launched that prompts the users to add an item in the list. I've built the AlertDialog in a separate class that extends DialogFragment. How can I make so that the item is added to the List<Task>?
What I've done so far in my adapter class is make List<Task> mTaskList a public static variable and I also created a static method that will return this list. I call this static method in the DialogFragment class so I can retrieve the list. But I don't think this is good practice. Is there a better way I can be adding an item to my list?
TaskListFragment.java
public class TaskListFragment extends Fragment {
private RecyclerView mRecyclerView;
private TaskAdapter mAdapter;
private List<Task> mTaskList;
private static final String ADD_DIALOG = "add_dialog";
public TaskListFragment() {
// Required empty public constructor
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setHasOptionsMenu(true);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_task_list, container, false);
mRecyclerView = view.findViewById(R.id.recycler_view);
mRecyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
//mTaskList = createTasks();
//mAdapter = new TaskAdapter(mTaskList);
mRecyclerView.setAdapter(updateUI());
return view;
}
#Override
public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
super.onCreateOptionsMenu(menu, inflater);
inflater.inflate(R.menu.menu_list_item, menu);
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
switch(item.getItemId()) {
case R.id.add_new_task:
FragmentManager manager = getFragmentManager();
AddTaskFragment dialog = new AddTaskFragment();
dialog.show(manager, ADD_DIALOG);
return true;
default:
return super.onOptionsItemSelected(item);
}
}
/*
public List<Task> createTasks() {
List<Task> tasks = new ArrayList<>();
for(int i = 1; i <= 100; i++) {
Task task = new Task();
task.setTitle("Task #" + i);
task.setSolved(i % 2 == 0);
tasks.add(task);
}
return tasks;
}
*/
public TaskAdapter updateUI(){
if(mAdapter == null) {
mTaskList = new ArrayList<>();
mAdapter = new TaskAdapter(mTaskList);
}else {
mAdapter.notifyDataSetChanged();
}
return mAdapter;
}
}
TaskAdapter.java
public class TaskAdapter extends RecyclerView.Adapter<TaskAdapter.ViewHolder> {
public static List<Task> mTaskList;
public TaskAdapter(List<Task> taskList) {
mTaskList = taskList;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent,false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
Task currentTask = mTaskList.get(position);
holder.bindData(currentTask);
}
#Override
public int getItemCount() {
return mTaskList.size();
}
public class ViewHolder extends RecyclerView.ViewHolder{
private TextView mTitle;
private CheckBox mSolved;
private ViewHolder(View itemView) {
super(itemView);
mTitle = itemView.findViewById(R.id.task_title);
mSolved = itemView.findViewById(R.id.task_solved);
}
private void bindData(Task task) {
mTitle.setText(task.getTitle());
mSolved.setChecked(task.isSolved());
}
}
public static List<Task> getTaskList(){
return mTaskList;
}
}
AddTaskFragment.java
public class AddTaskFragment extends DialogFragment {
private EditText mTaskTitle;
private List<Task> mTaskList;
private void addTask() {
if(!mTaskTitle.getText().toString().equals("")) {
Task task = new Task();
task.setTitle(mTaskTitle.getText().toString());
mTaskList = TaskAdapter.getTaskList();
mTaskList.add(task);
}
}
#Override
public Dialog onCreateDialog(Bundle savedInstanceState) {
//return super.onCreateDialog(savedInstanceState);
View view = LayoutInflater.from(getActivity()).inflate(R.layout.fragment_task_dialog,null);
mTaskTitle = view.findViewById(R.id.task_title);
return new AlertDialog.Builder(getContext())
.setView(view)
.setTitle("Add Task")
.setPositiveButton("Add", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialogInterface, int i) {
addTask();
}
})
.create();
}
}

You could call startActivityForResult when starting addTask(), which would put the Task to add inside an Intent which you would receive in your activity's onActivityResult(int requestCode, int resultCode, Intent data).

You can look into using the ViewModel pattern that Google introduced last IO.
The section talking about sharing would be especially beneficial in your situation.

Making RecyclerView clickable not working

I have been working on making my RecyclerView list clickable. I have not successfully retrieve any results from clicks yet. I have searched through stackoverflow and youtube, but not understanding what I am implementing wrong. My Adapter is
Food Adapter
ublic class FoodAdapter extends RecyclerView.Adapter<FoodAdapter.FoodViewHolder> {
private Context mCtx;
private List<Food> foodList;
public FoodAdapter(Context mCtx, List<Food> foodList) {
this.mCtx = mCtx;
this.foodList = foodList;
}
#Override
public FoodViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mCtx);
View view = inflater.inflate(R.layout.list_item, null);
FoodViewHolder foodView = new FoodViewHolder(view, mCtx, foodList);
return foodView;
}
#Override
public void onBindViewHolder(FoodViewHolder holder, int position) {
Food food = foodList.get(position);
holder.txtFoodTitle.setText(food.getFoodTitle());
holder.txtFoodDesc.setText(food.getFoodDesc());
holder.txtFoodLoc.setText(food.getFoodLoc() + ", CA");
holder.txtFoodAuthor.setText(food.getFoodAuthor());
holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(food.getImage(), null));
}
#Override
public int getItemCount() {
return foodList.size();
}
class FoodViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
ImageView imageView;
TextView txtFoodTitle, txtFoodDesc, txtFoodLoc, txtFoodAuthor;
List<Food> foods;
Context ctx;
public FoodViewHolder(View itemView, Context ctx, List<Food> foods) {
super(itemView);
itemView.setOnClickListener(this);
this.ctx = ctx;
this.foods = foods;
imageView = itemView.findViewById(R.id.foodImg);
txtFoodTitle = itemView.findViewById(R.id.foodTitle);
txtFoodDesc = itemView.findViewById(R.id.foodDesc);
txtFoodLoc = itemView.findViewById(R.id.foodLoc);
txtFoodAuthor = itemView.findViewById(R.id.foodAuthor);
}
#Override
public void onClick(View view) {
int position = getAdapterPosition();
//Food food = this.foods.get(position);
Log.i(TAG, "Clicked!");
}
}
}
FragmentList
public class FragmentList extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_fragment_list, container, false);
RecyclerView recyclerView;
final FoodAdapter adapter;
final List<Food> foodList = new ArrayList<>();
recyclerView = v.findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
adapter = new FoodAdapter(getActivity(), foodList);
recyclerView.setAdapter(adapter);
String url = "url";
StringRequest sr = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.i(TAG, response);
try {
JSONArray foodResp = new JSONArray(response);
for (int i = 0; i < foodResp.length(); i++) {
JSONObject foodObj = foodResp.getJSONObject(i);
foodList.add(
new Food(
foodObj.getInt("u_id"),
R.drawable.ic_launcher_background,
foodObj.getString("mealTitle"),
foodObj.getString("mealDesc"),
foodObj.getString("cityName"),
foodObj.getString("userName")
));
}
if (adapter != null) {
adapter.notifyDataSetChanged();
}
} catch (Exception e) {
Log.i(TAG, "Error: " + e.getMessage());
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.i(TAG, "err: " + error.toString());
}
}){
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("data", "value");
return params;
}
};
Volley.newRequestQueue(getActivity()).add(sr);
return v;
}
One of the original videos I was watching showed it done with an ArrayList<>, but I already set up my RecyclerView with List. I do not imagine that that would matter. Any advice would be appreciated. Thanks!

Try to set Click Listener in your FragmentList.java.
Food Adapter
public class FoodAdapter extends RecyclerView.Adapter<FoodAdapter.FoodViewHolder> {
private Context mCtx;
private List<Food> foodList;
public FoodAdapter(Context mCtx, List<Food> foodList) {
this.mCtx = mCtx;
this.foodList = foodList;
}
public static class FoodViewHolder extends RecyclerView.FoodViewHolder {
ImageView imageView;
TextView txtFoodTitle, txtFoodDesc, txtFoodLoc, txtFoodAuthor;
//List<Food> foods;
//Context ctx;
public FoodViewHolder(View v) {
super(v);
imageView = itemView.findViewById(R.id.foodImg);
txtFoodTitle = itemView.findViewById(R.id.foodTitle);
txtFoodDesc = itemView.findViewById(R.id.foodDesc);
txtFoodLoc = itemView.findViewById(R.id.foodLoc);
txtFoodAuthor = itemView.findViewById(R.id.foodAuthor);
}
}
#Override
public FoodAdapter.FoodViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(mCtx);
View view = inflater.inflate(R.layout.list_item, parent, false);
return FoodViewHolder(view);
}
#Override
public void onBindViewHolder(FoodViewHolder holder, int position) {
Food food = foodList.get(position);
holder.txtFoodTitle.setText(food.getFoodTitle());
holder.txtFoodDesc.setText(food.getFoodDesc());
holder.txtFoodLoc.setText(food.getFoodLoc() + ", CA");
holder.txtFoodAuthor.setText(food.getFoodAuthor());
holder.imageView.setImageDrawable(mCtx.getResources().getDrawable(food.getImage(), null));
}
#Override
public int getItemCount() {
return foodList.size();
}
}
FragmentList
public class FragmentList extends Fragment {
RecyclerView recyclerView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View v = inflater.inflate(R.layout.fragment_fragment_list, container, false);
final FoodAdapter adapter;
final List<Food> foodList = new ArrayList<>();
recyclerView = v.findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(new LinearLayoutManager(getActivity()));
adapter = new FoodAdapter(getActivity(), foodList);
recyclerView.setAdapter(adapter);
String url = "url";
StringRequest sr = new StringRequest(Request.Method.POST, url, new Response.Listener<String>() {
#Override
public void onResponse(String response) {
Log.i(TAG, response);
try {
JSONArray foodResp = new JSONArray(response);
for (int i = 0; i < foodResp.length(); i++) {
JSONObject foodObj = foodResp.getJSONObject(i);
foodList.add(
new Food(
foodObj.getInt("u_id"),
R.drawable.ic_launcher_background,
foodObj.getString("mealTitle"),
foodObj.getString("mealDesc"),
foodObj.getString("cityName"),
foodObj.getString("userName")
));
}
if (adapter != null) {
adapter.notifyDataSetChanged();
}
} catch (Exception e) {
Log.i(TAG, "Error: " + e.getMessage());
}
}
}, new Response.ErrorListener() {
#Override
public void onErrorResponse(VolleyError error) {
Log.i(TAG, "err: " + error.toString());
}
}){
#Override
protected Map<String, String> getParams() throws AuthFailureError {
Map<String, String> params = new HashMap<>();
params.put("data", "value");
return params;
}
};
Volley.newRequestQueue(getActivity()).add(sr);
return v;
}
#Override
public void onViewCreated(final View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
/* --- Adding the Listener here --- */
recyclerView.addOnItemTouchListener(new RecyclerItemClickListener(getContext(), new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(View itemView, int position) {
//Food food = this.foods.get(position);
Log.i(TAG, "Clicked!");
}
}));
}
}
And this will be your RecyclerItemClickListener.java file:
public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
private OnItemClickListener mListener;
GestureDetector mGestureDetector;
public interface OnItemClickListener{
void onItemClick(View view, int position);
}
public RecyclerItemClickListener(Context context, OnItemClickListener listener) {
mListener = listener;
mGestureDetector = new GestureDetector(context, new GestureDetector.SimpleOnGestureListener() {
#Override public boolean onSingleTapUp(MotionEvent e) {
return true;
}
});
}
#Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e) {
View childView = rv.findChildViewUnder(e.getX(),e.getY());
if(childView != null && mListener != null && mGestureDetector.onTouchEvent(e)){
mListener.onItemClick(childView, rv.getChildAdapterPosition(childView));
return true;
}
return false;
}
#Override
public void onTouchEvent(RecyclerView rv, MotionEvent e) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
Hope it will help :)

You need to set the click listener on the specific element.
For example if you want to do something when you click on the image then :
You need to call holder.imageview.setOnClickListener(this);
Try this !!
If you want to set the click listener to the entire row, then you might want to set the click listener on the root element of your row item.

handling clicks for the entire item "the viewholder"
1. create custom listener
public class RecyclerClickListener implements RecyclerView.OnItemTouchListener {
private OnItemClickListener mListener;
public interface OnItemClickListener {
public void onItemClick(View view, int position);
public void onLongItemClick(View view, int position);
}
GestureDetector mGestureDetector;
public RecyclerClickListener(Context context, final RecyclerView recyclerView, OnItemClickListener listener) {
mListener = listener;
mGestureDetector = 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 && mListener != null) {
mListener.onLongItemClick(child, recyclerView.getChildAdapterPosition(child));
}
}
});
}
#Override
public boolean onInterceptTouchEvent(RecyclerView view, MotionEvent e) {
View childView = view.findChildViewUnder(e.getX(), e.getY());
if (childView != null && mListener != null && mGestureDetector.onTouchEvent(e)) {
mListener.onItemClick(childView, view.getChildAdapterPosition(childView));
return true;
}
return false;
}
#Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
2. listen for clicks using our listener inside your
recyclerView.addOnItemTouchListener(
//use getActivity() if you are using fragment instead of MyActivity.this
new RecyclerClickListener(MyActivity.this, recyclerView, new RecyclerClickListener.OnItemClickListener() {
#Override
public void onItemClick(View view, int position) {
Food food= foodList.get(position);
//do whatever
}
#Override
public void onLongItemClick(View view, int position) {
// to be implement add to favourite
}
})
);
if you are listening to a specifc item inside the view holder.
1.create an inner interface inside your adapter and create an instance of it.
private OnItemClickListener mListener;
public interface OnItemClickListener {
void onItemClick(Food item);
}
//and also the constructor
public MyAdapter(List<Food> foodList,Context ctx,OnItemClickListener
listener){
// ......
this.mListener=mListener;
}
2.inside your viewholder class create setListener() method
public void SetListener(final Food item, final OnItemClickListener listener) {
mButton.setOnClickListener(new View.OnClickListener() {
#Override public void onClick(View v) {
listener.onItemClick(item);
}
});
}
3.inside you onBindView
#Override
public void onBindViewHolder(FoodViewHolder holder, int position) {
//...
viewHolder.setListener(foodList.get(position), mListener);
}
4.inside your activity or fragment
MyAdapter adapter=new MyAdapter(foodList,getActivity(),new MyAdapter.OnItemClickListener(){
#Override
public void onItemClick(Food item){
}
});

Develop Reference

Java is a programming language and computing platform first released by Sun Microsystems in 1995.

Is RecyclerView refreshed when AlertDialog's positive button gets pressed - java

When you get the text from the dialog to main activity after pressing the positive button. Append your list with that new text that you are passing to adapter and call method adapter.notifyDataSetChanged();

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