On itemclick of recyclerView - java

I tried to make an app in which I made a recycler View of Array List Of items and I want that when I will click on particular item of Array List the it should open a activity in which I could add some text with edit text and again if I want to open another item of Array List so it should open the same activity but not the previous saved data .
I want to add different data in each list of items. but its not happening for every list of items the same saved data is loading in the activity....
is there any solution..
this is second activity..
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.student_list);
loadData();
toolbar = findViewById(R.id.toolbar);
bundle = getIntent().getExtras();
String subName = bundle.getString("Subject Name");
if (bundle != null) {
toolbar.setTitle(subName);
}
fabButton();
buildRecyclerView();
}
private void buildRecyclerView() {
recyclerView = findViewById(R.id.recyclerView2);
recyclerView.hasFixedSize();
layoutManager = new LinearLayoutManager(StudentListActivity.this);
rAdapter = new AdapterForStudentList(listOfNames);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(rAdapter);
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleCallback);
itemTouchHelper.attachToRecyclerView(recyclerView);
}
public void insertData(String text, String t1, String t2) {
ListOfNames lt = new ListOfNames(text, t1, t2);
listOfNames.add(lt);
rAdapter.notifyDataSetChanged();
}
public void saveData() {
sharedPreferences = getSharedPreferences("SHARED PREF", MODE_PRIVATE);
editor = sharedPreferences.edit();
Gson gson = new Gson();
String json = gson.toJson(listOfNames);
editor.putString("text", json);
editor.apply();
}
public void loadData() {
sharedPreferences = getSharedPreferences("SHARED PREF", MODE_PRIVATE);
Gson gson = new Gson();
String json = sharedPreferences.getString("text", null);
Type type = new TypeToken<ArrayList<ListOfNames>>() {
}.getType();
listOfNames = gson.fromJson(json, type);
if (listOfNames == null) {
listOfNames = new ArrayList<>();
}
}
ListOfNames deletedItem = null;
ItemTouchHelper.SimpleCallback simpleCallback = new ItemTouchHelper.SimpleCallback(0, 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) {
final int position = viewHolder.getAdapterPosition();
String name = listOfNames.get(position).getStudentName();
deletedItem = listOfNames.get(position);
listOfNames.remove(deletedItem);
sharedPreferences = getSharedPreferences("SHARED PREF", MODE_PRIVATE);
editor = sharedPreferences.edit();
editor.remove("text");
saveData();
editor.apply();
rAdapter.notifyItemRemoved(position);
Snackbar.make(recyclerView, name + "Deleted", Snackbar.LENGTH_LONG)
.setAction("Undo", new View.OnClickListener() {
#Override
public void onClick(View v) {
listOfNames.add(position, deletedItem);
rAdapter.notifyItemInserted(position);
saveData();
}
}).show();
}
#Override
public void onChildDrawOver(#NonNull Canvas c, #NonNull RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
new RecyclerViewSwipeDecorator.Builder(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
.addSwipeLeftBackgroundColor(ContextCompat.getColor(StudentListActivity.this, R.color.my_background))
.addSwipeLeftActionIcon(R.drawable.ic_delete_black_24dp)
.create()
.decorate();
super.onChildDrawOver(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
};
public void fabButton() {
FloatingActionButton floatingActionButton = findViewById(R.id.fab2);
floatingActionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
AlertDialog.Builder b = new AlertDialog.Builder(StudentListActivity.this);
View view = getLayoutInflater().inflate(R.layout.dialogbox_frontpage, null);
final EditText editText = view.findViewById(R.id.editText);
b.setView(view);
b.setTitle("Student name");
b.setPositiveButton("ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
String text = editText.getText().toString();
if (text.isEmpty()) {
Toast.makeText(StudentListActivity.this, "Please add subject name", Toast.LENGTH_SHORT).show();
} else {
insertData(text, t1, t2);
saveData();
}
}
});
b.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
b.setCancelable(false);
b.show();
}
});
}
}
**MainActivity**
`public class ScrollingActivity extends AppCompatActivity {
private RecyclerView recyclerView;
private AdaptreForRecycler adapter;
private RecyclerView.LayoutManager layoutManager;
private ArrayList<ExampleItem> mExampleList;
RecyclerView.ViewHolder viewHolder;
private Gson gson;
private String json;
private Type type;
private SharedPreferences sharedPreferences;
private SharedPreferences.Editor editor;
EditText editText;
private ExampleItem ex;
public static final String t2 = "new";
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_scrolling);
Toolbar toolbar = findViewById(R.id.toolbar);
setSupportActionBar(toolbar);
loadData();
buildRecyclerView();
editText = findViewById(R.id.editText);
fabButoonClick();
}
public void saveData() {
sharedPreferences = getSharedPreferences("SHARED_PREFS", MODE_PRIVATE);
editor = sharedPreferences.edit();
gson = new Gson();
json = gson.toJson(mExampleList);
editor.putString("text", json);
editor.apply();
}
public void loadData() {
sharedPreferences = getSharedPreferences("SHARED_PREFS", MODE_PRIVATE);
gson = new Gson();
json = sharedPreferences.getString("text", null);
type = new TypeToken<ArrayList<ExampleItem>>() {
}.getType();
mExampleList = gson.fromJson(json, type);
if (mExampleList == null) {
mExampleList = new ArrayList<>();
}
}
public void insertItem(String text, String t2) {
ex = new ExampleItem(text, t2);
mExampleList.add(ex);
adapter.notifyDataSetChanged();
}
ExampleItem deletedIndex = null;
ItemTouchHelper.SimpleCallback simpleCallback = new ItemTouchHelper.SimpleCallback(0, 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) {
final int position = viewHolder.getAdapterPosition();
String name = mExampleList.get(position).getText1();
deletedIndex = (mExampleList.get(position));
mExampleList.remove(position);
sharedPreferences = getSharedPreferences("SHARED_PREFS", MODE_PRIVATE);
editor = sharedPreferences.edit();
editor.remove("text");
saveData();
editor.apply();
adapter.notifyItemRemoved(position);
Snackbar.make(recyclerView, name + " Deleted", Snackbar.LENGTH_LONG)
.setAction("Undo", new View.OnClickListener() {
#Override
public void onClick(View v) {
mExampleList.add(position, deletedIndex);
adapter.notifyItemInserted(position);
saveData();
}
}).show();
}
#Override
public void onChildDraw(#NonNull Canvas c, #NonNull RecyclerView recyclerView, #NonNull RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
new RecyclerViewSwipeDecorator.Builder(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive)
.addSwipeLeftBackgroundColor(ContextCompat.getColor(ScrollingActivity.this, R.color.my_background))
.addSwipeLeftActionIcon(R.drawable.ic_delete_black_24dp)
.create()
.decorate();
super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
};
private void buildRecyclerView() {
recyclerView = findViewById(R.id.recyclerView);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(ScrollingActivity.this);
adapter = new AdaptreForRecycler(mExampleList);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(adapter);
adapter.setOnItemClickListener(new AdaptreForRecycler.OnItemCLickListener() {
#Override
public void onItemClick(int position) {
Intent i =new Intent(ScrollingActivity.this,StudentListActivity.class);
i.putExtra("Subject Name",mExampleList.get(position).getText1());
startActivity(i);
}
});
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleCallback);
itemTouchHelper.attachToRecyclerView(recyclerView);
}
public void fabButoonClick() {
FloatingActionButton fab = findViewById(R.id.fab);
fab.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
AlertDialog.Builder b = new AlertDialog.Builder(ScrollingActivity.this);
View mview = getLayoutInflater().inflate(R.layout.dialogbox_frontpage, null);
final EditText editText = mview.findViewById(R.id.editText);
b.setView(mview);
b.setTitle("Add subject name");
b.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
});
b.setPositiveButton("ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
String text = editText.getText().toString();
if (text.isEmpty()) {
Toast.makeText(ScrollingActivity.this, "Please add subject name", Toast.LENGTH_SHORT).show();
} else {
insertItem(text, t2);
saveData();
}
}
});
b.setCancelable(false);
b.show();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.menu_scrolling, menu);
return true;
}
#Override
public boolean onOptionsItemSelected(MenuItem item) {
int id = item.getItemId();
if (id == R.id.action_settings) {
return true;
}
return super.onOptionsItemSelected(item);
}
}AdaptreOfFirstActivity`
public class AdaptreForRecycler extends RecyclerView.Adapter<AdaptreForRecycler.ProgrammingViewHolder> {
private OnItemCLickListener mListener;
public interface OnItemCLickListener {
void onItemClick(int position);
}
public void setOnItemClickListener(OnItemCLickListener listener) {
mListener = listener;
}
private ArrayList<ExampleItem> mExampleList;
public class ProgrammingViewHolder extends RecyclerView.ViewHolder {
public TextView mTextView1, mTextView2;
public ProgrammingViewHolder(#NonNull View itemView, final OnItemCLickListener listener) {
super(itemView);
mTextView1 = itemView.findViewById(R.id.tv1);
mTextView2 = itemView.findViewById(R.id.tv2);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION)
listener.onItemClick(position);
}
}
});
}
}
public AdaptreForRecycler(ArrayList<ExampleItem> exampleList) {
mExampleList = exampleList;
}
#NonNull
#Override
public AdaptreForRecycler.ProgrammingViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.list_item_layout, parent, false);
return new ProgrammingViewHolder(view, mListener);
}
#Override
public void onBindViewHolder(#NonNull AdaptreForRecycler.ProgrammingViewHolder holder, int position) {
ExampleItem currentItem = mExampleList.get(position);
holder.mTextView1.setText(currentItem.getText1());
holder.mTextView2.setText(currentItem.getText2());
}
#Override
public int getItemCount() {
return mExampleList.size();
}
} AdaptreForSecondActivity
public class AdapterForStudentList extends RecyclerView.Adapter<AdapterForStudentList.StudentViewHolder> {
private ArrayList<ListOfNames> mListOfNames;
public static class StudentViewHolder extends RecyclerView.ViewHolder {
public TextView studentName, attendence, percentage;
public StudentViewHolder(#NonNull View itemView) {
super(itemView);
studentName = itemView.findViewById(R.id.studentName);
attendence = itemView.findViewById(R.id.attendence);
percentage = itemView.findViewById(R.id.percentage);
}
}
public AdapterForStudentList(ArrayList<ListOfNames> listOfNames) {
mListOfNames = listOfNames;
}
#NonNull
#Override
public StudentViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
LayoutInflater inflater = LayoutInflater.from(parent.getContext());
View view = inflater.inflate(R.layout.check_box_cardview, parent, false);
return new StudentViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull StudentViewHolder holder, int position) {
ListOfNames currentItems = mListOfNames.get(position);
holder.studentName.setText(currentItems.getStudentName());
holder.attendence.setText(currentItems.getAttendent());
holder.percentage.setText(currentItems.getPercetage());
}
#Override
public int getItemCount() {
return mListOfNames.size();
}
}

Now I saw that you did what I said in my first original answer, I compliment you for it.
Also, this thread/post can end here seeing that you already implemented the onClick for RecyclerView. I'd appreciate it if you mark my answer as the solution.
But of course, you raised another problem which is:
I want to add different data in each list of items. but its not
happening for every list of items the same saved data is loading in
the activity...
That's because you're loading and also saving with the same key:
editor.putString("text", json);
editor.apply();
See there? You were loading and saving to the key "text" in each subject. (You mentioned that you have a list of subjects hence I used the word subject)
I suggest you create a means to change the key for each different subject. In this case, your subject's name can be the key instead of plain "text".
I also suggest you to use a private static final String variable for "text" and also make it more clear. A key called "text" is a bit ambiguous don't you think?
Now I will post the modified code part of your StudentListActivity, I encourage you to analyse it and paste it to your code. I'm sure it will work now.
Modified part in StudentListActivity
// Added a string variable here as key for saving/loading your data
String subName; // I kept your naming the same which is 'subName'
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.student_list);
// I placed this bit of code above loadData() now that we
// use subName as the key
// Or else loadData() will use the initial value of
// subName which is going to be null first
bundle = getIntent().getExtras();
subName = bundle.getString("Subject Name");
if (bundle != null) {
toolbar.setTitle(subName);setTitle(subName);
}
loadData();
toolbar = findViewById(R.id.toolbar);
fabButton();
buildRecyclerView();
}
// Other code... Which in your code are:
// private void buildRecyclerView() { ... }
// public void insertData(String text, String t1, String t2) { ... }
public void saveData() {
sharedPreferences = getSharedPreferences("SHARED PREF", MODE_PRIVATE);
editor = sharedPreferences.edit();
Gson gson = new Gson();
String json = gson.toJson(listOfNames);
// Now here use the name of your subject as key
// Which is of course the variable 'subName'
editor.putString(subName, json);
editor.apply();
}
public void loadData() {
sharedPreferences = getSharedPreferences("SHARED PREF", MODE_PRIVATE);
Gson gson = new Gson();
// Same here
// Use 'subName' as key
String json = sharedPreferences.getString(subName, null);
Type type = new TypeToken<ArrayList<ListOfNames>>() {
}.getType();
listOfNames = gson.fromJson(json, type);
if (listOfNames == null) {
listOfNames = new ArrayList<>();
}
}
// Other code ...
By the way, I tried making the layouts myself in order to test your application and I noticed something: I guess you have an EditText inside your dialogbox_frontpage.xml file. And you still wrote a code to get the view in to your ScrollingActivity which is unnecessary. In fact, you re-defined it inside the fab's onClick method. You can remove that global variable.
Last notes: This is just a suggestion but you could try and learn about the Singleton pattern. Use that pattern to save your data.
Also, SharedPreferences is not really a good idea to save huge amount of data. So I also encourage you to try to look up Room databases.
I hope your program works now and as always, happy coding! (This has been a very long answer, hahaha)
Original answer (modified it a bit)
I suggest to create an interface that will pass the position of the clicked item because we only care about the position of the item to be able to do something to it. Besides, it's better that way so that we can put in the activity the code to be executed when an item has been clicked.
This is how the interface should look like:
public interface OnItemClickListener {
void onItemClick(int position);
}
Add a new variable inside your adapter, that is, the OnItemClickListener:
private OnItemCLickListener listener;
You could either define its implementation by implementing it to the activity or pass its implementation by creating another method called addOnItemClickListener in to your adapter:
addOnItemClickListener(OnItemClickListener listener) {
this.listener = listener;
}
Then inside your onBindViewHolder method, get the layout of the item from the ViewHolder and set its onClick listener and finally inside its onClick method, call your interface's method onItemClick inside it and pass the position there. Like this:
#Override
public void onBindViewHolder(#NonNull CustomRecyclerView.ViewHolder holder, final int position) {
holder.layout.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
listener.onItemClick(position);
}
});
}
Edit: Explanation on why I set the listener inside the onBindViewHolder method
The itemView or the View we get from the constructor of the ViewHolder depends on the View returned by the LayoutInflater inside your onCreateViewHolder. Hence, the layout resource you're passing in the inflate method, whatever the main layout you're using there (e.g. ConstraintLayout, LinearLayout, it can also be a TextView, Button, etc.), will be the View returned. To test this, try and copy/paste this simple line of code in your onCreateViewHolder then run your app and check Logcat:
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(context).inflate(R.layout.YOUR_LAYOUT_HERE, parent, false);
Log.i("View", view.getClass().getSimpleName()); // Logs the main view in our layout
return new YourCustomViewHolderHere(view);
}
The ViewHolder is only responsible for getting our views because using the findViewById method is an extensive task if we do it inside onBindViewHolder so we don't do it there because it'll slow down the performance of our application.
We do all settings like changing the texts of the TextViews for example or setting onClick listeners inside the onBindViewHolder to avoid creating unnecessary complexity in our code. We don't want codes floating around now, would we?
Also, the Observer pattern is quite dangerous.
There was a talk in an Android Conference, I don't remember which, that talked about RecyclerView. Do you know why it's called like that? Because it recycles views. (It needs a proper explanation how they recycle views so I won't be covering it here. I think you can find it on YouTube if you search for "Android Conference RecyclerView", it's quite long, maybe around an hour, but it's worth to watch it.)
The Observer pattern (i.e. Listener) may cause memory leaks in which will affect our application's performance. Hence, it's better to set it up inside our onBindViewHolder method because whenever we scroll down or up on our RecyclerView, it'll recycle views and we risk on creating multiple instances of the same listener inside the ViewHolder.
According to Wikipedia on Observer pattern:
The observer pattern can cause memory leaks, known as the lapsed
listener problem, because in basic implementation it requires both
explicit registration and explicit deregistration, as in the dispose
pattern, because the subject holds strong references to the observers,
keeping them alive. This can be prevented by the subject holding weak
references to the observers.
Another way to set an onClick is inside onCreateViewHolder but the catch is you don't have a way on knowing which item was clicked.
I hope this answers your question in the comment.

Related

Android: Sending a cardview from one fragment to another

I need some help for a summer project
This is my Events fragment
This is my MyList fragment
I'm using a RecyclerView+Cardview to display the Events. The idea is that the user can click the big plus on the right side of each card, and the card would be displayed in the MyList fragment. I would like to ask if it's possible to transfer a card directly from one fragment to another? Also, both fragments are contained within the same activity, which makes it a little trickier(I haven't found any available solutions).
If that is not possible, another way is to transfer the reference type object contained in the CardView to the MyList fragment. However, this is even less straightforward. This is because the button is inflated in the adapter, but there is no reference type object created here. I have seen many tutorials on using the Parcelable interface, however, I don't know how to implement it here when I'm unable to even create the object in the adapter. The reference object is created in another activity and stored in Firebase before it is read and displayed.
I'm going to attach my EventsAdapter.java and EventsItem.java and EventsFragment.java code below, but please let me know if I should include more code to describe the problem.
Thanks for reading my very long post!!
public class EventsAdapter extends RecyclerView.Adapter<EventsAdapter.EventsViewHolder> implements Filterable {
private ArrayList<EventsItem> mEventsList;
private ArrayList<EventsItem> mEventsListFull;
private EventsAdapter.OnItemClickListener mListener;
private Context mContext;
private DateFormat df = DateFormat.getDateInstance(DateFormat.MEDIUM, Locale.UK);
public interface OnItemClickListener {
void onItemClick(int position);
}
//the ViewHolder holds the content of the card
public static class EventsViewHolder extends RecyclerView.ViewHolder {
public ImageView mImageView;
public ImageView mAddButton;
public TextView mTextView1;
public TextView mTextView2;
public TextView mTextView3;
public TextView mTextView4;
public TextView mTextView5;
public EventsViewHolder(Context context, View itemView, final EventsAdapter.OnItemClickListener listener) {
super(itemView);
final Context context1 = context;
mImageView = itemView.findViewById(R.id.imageView);
mAddButton = itemView.findViewById(R.id.image_add);
mTextView1 = itemView.findViewById(R.id.title);
mTextView2 = itemView.findViewById(R.id.event_description);
mTextView3 = itemView.findViewById(R.id.date);
mTextView4 = itemView.findViewById(R.id.location);
mTextView5 = itemView.findViewById(R.id.time);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null) {
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
listener.onItemClick(position);
}
}
}
});
mAddButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String str1 = mTextView1.getText().toString();
String str2 = mTextView2.getText().toString();
String str3 = mTextView3.getText().toString();
String str4 = mTextView4.getText().toString();
String str5 = mTextView5.getText().toString();
Bundle bundle = new Bundle();
bundle.putString("title", str1);
bundle.putString("event description", str2);
bundle.putString("date", str3);
bundle.putString("location", str4);
bundle.putString("time", str5);
MylistFragment mlf = new MylistFragment();
mlf.setArguments(bundle);
}
});
}
}
//Constructor for EventsAdapter class. This ArrayList contains the
//complete list of items that we want to add to the View.
public EventsAdapter(Context context, ArrayList<EventsItem> EventsList) {
mEventsList = EventsList;
mContext = context;
mEventsListFull = new ArrayList<>(EventsList); // copy of EventsList for SearchView
}
//inflate the items in a EventsViewHolder
#NonNull
#Override
public EventsAdapter.EventsViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.event_item, parent, false);
EventsAdapter.EventsViewHolder evh = new EventsAdapter.EventsViewHolder(mContext, v, mListener);
return evh;
}
#Override
public void onBindViewHolder(#NonNull EventsAdapter.EventsViewHolder holder, int position) {
EventsItem currentItem = mEventsList.get(position);
holder.mImageView.setImageResource(currentItem.getProfilePicture());
holder.mTextView1.setText(currentItem.getTitle());
holder.mTextView2.setText(currentItem.getDescription());
holder.mTextView3.setText(df.format(currentItem.getDateInfo()));
holder.mTextView4.setText(currentItem.getLocationInfo());
holder.mTextView5.setText(currentItem.getTimeInfo());
}
#Override
public int getItemCount() {
return mEventsList.size();
}
public class EventsItem implements Occasion, Parcelable {
//fields removed for brevity
//constructor removed for brevity
}
public EventsItem() {
}
public EventsItem(Parcel in) {
profilePicture = in.readInt();
timeInfo = in.readString();
hourOfDay = in.readInt();
minute = in.readInt();
locationInfo = in.readString();
title = in.readString();
description = in.readString();
}
public static final Creator<EventsItem> CREATOR = new Creator<EventsItem>() {
#Override
public EventsItem createFromParcel(Parcel in) {
return new EventsItem(in);
}
#Override
public EventsItem[] newArray(int size) {
return new EventsItem[size];
}
};
//getter methods have been removed for brevity
#Override
public int describeContents() {
return 0;
}
#Override
public void writeToParcel(Parcel dest, int flags) {
dest.writeInt(profilePicture);
dest.writeString(timeInfo);
dest.writeString(locationInfo);
dest.writeString(title);
dest.writeString(description);
dest.writeString(df.format(dateInfo));
dest.writeInt(hourOfDay);
dest.writeInt(minute);
}
}
public class EventsFragment extends Fragment {
ArrayList<EventsItem> EventsItemList;
FirebaseDatabase mDatabase;
DatabaseReference mDatabaseReference;
ValueEventListener mValueEventListener;
private RecyclerView mRecyclerView;
private RecyclerView.LayoutManager mLayoutManager;
private EventsAdapter mAdapter;
private View rootView;
public FloatingActionButton floatingActionButton;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_events, container, false);
mDatabase = FirebaseDatabase.getInstance();
mDatabaseReference = mDatabase.getReference().child("Events");
createEventsList();
buildRecyclerView();
floatingActionButton = rootView.findViewById(R.id.fab);
floatingActionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Intent intent = new Intent(getActivity(), EventsAdder.class);
startActivity(intent);
}
});
mValueEventListener = new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot : dataSnapshot.getChildren()) {
EventsItemList.add(snapshot.getValue(EventsItem.class));
}
EventsAdapter eventsAdapter = new EventsAdapter(getActivity(), EventsItemList);
mRecyclerView.setAdapter(eventsAdapter);
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
};
mDatabaseReference.addValueEventListener(mValueEventListener);
setHasOptionsMenu(true);
Toolbar toolbar = rootView.findViewById(R.id.events_toolbar);
AppCompatActivity activity = (AppCompatActivity) getActivity();
activity.setSupportActionBar(toolbar);
return rootView;
}
public void createEventsList() {
EventsItemList = new ArrayList<>();
}
public void buildRecyclerView() {
mRecyclerView = rootView.findViewById(R.id.recyclerview);
mLayoutManager = new LinearLayoutManager(getContext());
mAdapter = new EventsAdapter(getActivity(), EventsItemList);
mRecyclerView.setLayoutManager(mLayoutManager);
mRecyclerView.setAdapter(mAdapter);
mRecyclerView.setItemAnimator(new DefaultItemAnimator());
}
}
If you would like to see the same CardView within the MyListFragment, you could have the MyListFragment contain a RecyclerView, and reuse the same EventsAdapter and EventsViewHolder. The only difference is that rather than populating the adapter with all the children of the "Events" from your database, you would only populate it with the single Event that you want.
Also, since you have made your Event class implement parcelable, you do not need to manually create the bundle when clicking the plus button.
I am assuming you have a single Activity, and you simply want to replace the EventsFragment with the MyListFragment. Checkout the docs for replacing one fragment with another.
Step 1:
Extend your onItemClickListener to look like:
public interface OnItemClickListener {
void onItemClick(int position);
void onPlusButtonClick(int position);
}
and adjust the code in your EventsViewHolder constructor to look like this when the plus button is clicked:
mAddButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
if (listener != null) {
// no need to manually create the bundle here
// you already have all the information you need
int position = getAdapterPosition();
if (position != RecyclerView.NO_POSITION) {
listener.onPlusButtonClick(position);
}
}
}
});
Step 2:
Implement our new method onPlusButtonClick. As per our discussion in the comments, it seems you do not implement this interface anywhere. You can implement it inside the constructor to your EventsAdapter:
public EventsAdapter(Context context, ArrayList<EventsItem> EventsList) {
mEventsList = EventsList;
mContext = context;
mEventsListFull = new ArrayList<>(EventsList); // copy of EventsList for SearchView
mListener = new OnItemClickListener() {
#Override
public void onItemClick() {
// handle clicking the entire view holder
// NOTE: inside your EventsViewHolder, it looks like you call this method on the entire itemView. This could 'swallow' the click on the plus button. You may need to adjust your code to handle this.
}
#Override
public void onPlusButtonClick(int position) {
MyListFragment myListFragment = new MyListFragment();
Event event = mEventsList.get(position);
Bundle bundle = new Bundle();
bundle.putExtra("event", event); // this will work due to implementing parcelable
myListFragment.setArguments(bundle);
// use mContext since im assuming we areinside adapter
// if in an Activity, no need to use context to get the fragment manager
FragmentTransaction transaction = mContext.getSupportFragmentManager().beginTransaction();
// Replace the EventsFragment with the MyListFragment
// and add the transaction to the back stack so the user can navigate back
transaction.replace(R.id.fragment_container, myListFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
}
}
}
Step 3:
Inside your MyListFragments onCreateView() method:
#Override
public View onCreateView (
LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState
) {
Bundle bundle = getArguments();
Event event = bundle.getExtra("event"); // again, will work due to implementing parcelable
// from here you should bind to a recycler view, and you can even reuse your adapter like so:
List<EventsItem> singleEventList = new List<EventsItem>();
singleEventList.add(event);
EventsAdapter adapter = new EventsAdapter(getActivity(), singleEventList);
// be sure to inflate and return your view here...
}
and you should be good to go!
I have left out bits of code here and there for simplicity.. but I hope this is understandable.
As a side note.. in your firebase database listener, it is bad practice to create a new EventsAdapter every single time your data is updated. Instead, you should update the data in the adapter with the new values. Do this by creating a public method inside the adapter such as replaceEvents(List<EventsItem> newEvents), and inside, replace mEventsList with the new events, then call notifyDataSetChanged().

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

Not Able to get Text In recycle view

I Am working on project where users recognizes text(OCR) and then see all their text(OCR) history in another activity
App Link : https://play.google.com/store/apps/details?id=com.thetechroot.vision
I added shared preference and recycle view,
but i am only getting the first Text that was recognized
Working :-
Users Recognize Text(OCR) in Textactivity, then to view users history of scanned text(OCR) the history is shown in different activity
How Can I Saved Textview From One Activity to diff activity, and show it into recycleview using shared preference
TEXTACTIVTY.JAVA
textRecognizer.processImage(image)
.addOnSuccessListener(new OnSuccessListener<FirebaseVisionText>() {
#Override
public void onSuccess(final FirebaseVisionText firebaseVisionText) {
translatelan(firebaseVisionText);
cd_text_re.setVisibility(View.VISIBLE);
spinnerlan.setVisibility(View.VISIBLE);
txtrecog.setText(firebaseVisionText.getText());
String th = SharedCommon.getSharedPreferencesString(getApplicationContext(), texthistory,firebaseVisionText.getText());
//int i = SharedCommon.getPreferencesInt(getApplicationContext(), key1,50);
final SharedCommon scth = new SharedCommon();
if (txtrecog.equals("")){
Toast.makeText(TextActivity.this, "Text: "+th, Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(TextActivity.this, "Text: "+th, Toast.LENGTH_SHORT).show();
scth.putSharedPreferencesString(getApplicationContext(), SharedCommon.texthistory, th);
}
/* SharedPreferences.Editor editor = getSharedPreferences(MY_PREFS_NAME, MODE_PRIVATE).edit();
editor.putString("name", String.valueOf(txtrecog.getText()));
editor.putInt("idName", 1);
editor.apply();*/
drawtextvision(firebaseVisionText);
}
}).addOnFailureListener(new OnFailureListener() {
#Override
public void onFailure(#NonNull Exception e) {
MyAdapter.java
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
private List<String> values;
ArrayList personNames;
Context context;
// Provide a reference to the views for each data item
// Complex data items may need more than one view per item, and
// you provide access to all the views for a data item in a view holder
public class ViewHolder extends RecyclerView.ViewHolder {
// each data item is just a string in this case
public TextView txtHeader;
public TextView txtFooter;
public View layout;
public ViewHolder(View v) {
super(v);
layout = v;
txtHeader = (TextView) v.findViewById(R.id.firstLine);
txtFooter = (TextView) v.findViewById(R.id.secondLine);
}
}
public void add(int position, String item) {
values.add(position, item);
notifyItemInserted(position);
}
public void remove(int position) {
values.remove(position);
notifyItemRemoved(position);
}
public MyAdapter(Context context, ArrayList personNames) {
this.context = context;
this.personNames = personNames;
}
// Provide a suitable constructor (depends on the kind of dataset)
public MyAdapter(List<String> myDataset) {
values = myDataset;
}
// Create new views (invoked by the layout manager)
#Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent,
int viewType) {
// create a new view
/*final String th = SharedCommon.getSharedPreferencesString(getApplicationContext(), texthistory,"");
*/
LayoutInflater inflater = LayoutInflater.from(
parent.getContext());
View v =
inflater.inflate(R.layout.layout_history_text, parent, false);
// set the view's size, margins, paddings and layout parameters
ViewHolder vh = new ViewHolder(v);
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
// - get element from your dataset at this position
// - replace the contents of the view with that element
final String name = values.get(position);
holder.txtHeader.setText(name);
holder.txtHeader.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
holder.txtFooter.setText("Footer: " + name);
}
});
//holder.txtFooter.setText("Footer: " + name);
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return values.size();
}
}
HISTORYACTIVITY.JAVA
public class AboutActivity extends AppCompatActivity {
/* WebView webView;*/
ProgressDialog mprogreeinternet;
String apppackagename = "com.thetechroot.vision";
int versionCode = BuildConfig.VERSION_CODE;
String versionName = BuildConfig.VERSION_NAME;
String appid = BuildConfig.APPLICATION_ID;
Button btnlimit;
WebView webview;
/* private RecyclerView recyclerView;
private RecyclerView.Adapter mAdapter;
private RecyclerView.LayoutManager layoutManager;*/
private RecyclerView recyclerView;
private MyAdapter mAdapter;
private RecyclerView.LayoutManager mLayoutManager;
LinearLayout layouthide,layoutcredit;
int[] photos={R.drawable.logoam, R.drawable.iconshandwrit52,R.drawable.productsearch52,R.drawable.iconsqrcode52};
ImageButton arrdown,arrup,arrcre,arrcreup;
TextView txthistory;
TextView mItemDescription;
ImageButton mDescriptionImg,mupImg;
CardView cdhistory;
#SuppressLint("WrongViewCast")
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_about);
/* btnlimit = (Button) findViewById(R.id.btnlimit);*/
final String th = SharedCommon.getSharedPreferencesString(getApplicationContext(), texthistory,"");
// Toast.makeText(this, ""+th, Toast.LENGTH_SHORT).show();
recyclerView = (RecyclerView) findViewById(R.id.my_recycler_view);
// use this setting to improve performance if you know that changes
// in content do not change the layout size of the RecyclerView
// recyclerView.setHasFixedSize(true);
// use a linear layout manager
mLayoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(mLayoutManager);
// Use the default animator
// recyclerView.setItemAnimator(new DefaultItemAnimator());
// you could add item decorators
// RecyclerView.ItemDecoration itemDecoration = new DividerItemDecoration(this, DividerItemDecoration.VERTICAL_LIST);
// recyclerView.addItemDecoration(itemDecoration);
ArrayList<String> values = new ArrayList<String>();
/*for (int i = 0; i < 100; i++) {
values.add("Test" + i);
}*/
Toast.makeText(this, ""+String.valueOf(th), Toast.LENGTH_SHORT).show();
values.add(""+String.valueOf(th));
// specify an adapter (see also next example)
mAdapter = new MyAdapter(values);
recyclerView.setAdapter(mAdapter);
ItemTouchHelper.SimpleCallback simpleItemTouchCallback =
new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.LEFT | ItemTouchHelper.RIGHT) {
#Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder
target) {
return false;
}
#Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int swipeDir) {
// input.remove(viewHolder.getAdapterPosition());
mAdapter.notifyItemRemoved(viewHolder.getAdapterPosition());
}
};
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleItemTouchCallback);
itemTouchHelper.attachToRecyclerView(recyclerView);
}
#Override
public void onBackPressed() {
super.onBackPressed();
Intent startIntent = new Intent(AboutActivity.this, TextActivity.class);
startActivity(startIntent);
finish();
}
}
It's a position issue, you have to use setTag() and getTag(), check this
final String name = values.get(position);
**holder.txtFooter.setTag(name);**
holder.txtHeader.setText(name);
holder.txtHeader.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
**holder.txtFooter.setText("Footer: " + v.getTag());**
}
});
Here TEXTACTIVTY.JAVA you are using single string, so instead of appending it to previous strings in shared preference you are replacing the history. Ideally you should save Strings array and retrieve the same. Currently values have size one because it has only one string.
First use Sting Array. To save String Array in shared preferences do the following
StringBuilder sb = new StringBuilder();
for (int i = 0; i < playlists.length; i++) {
sb.append(playlists[i]).append(",");
}
prefsEditor.putString(PLAYLISTS, sb.toString());
Then when you get the String from SharedPreferences simply parse it like this:
String[] playlists = playlist.split(",");
Refer Put and get String array from shared preferences
And https://blog.fossasia.org/storing-a-data-list-in-phimpme-android/ for more.

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);

Why doesn't RecyclerView have onItemClickListener()?

I was exploring RecyclerView and I was surprised to see that RecyclerView does not have onItemClickListener().
I've two question.
Main Question
I want to know why Google removed onItemClickListener()?
Is there a performance issue or something else?
Secondary Question
I solved my problem by writing onClick in my RecyclerView.Adapter:
public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {
public TextView txtViewTitle;
public ImageView imgViewIcon;
public ViewHolder(View itemLayoutView) {
super(itemLayoutView);
txtViewTitle = (TextView) itemLayoutView.findViewById(R.id.item_title);
imgViewIcon = (ImageView) itemLayoutView.findViewById(R.id.item_icon);
}
#Override
public void onClick(View v) {
}
}
Is this ok / is there any better way?
tl;dr 2016 Use RxJava and a PublishSubject to expose an Observable for the clicks.
public class ReactiveAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
String[] mDataset = { "Data", "In", "Adapter" };
private final PublishSubject<String> onClickSubject = PublishSubject.create();
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
final String element = mDataset[position];
holder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onClickSubject.onNext(element);
}
});
}
public Observable<String> getPositionClicks(){
return onClickSubject.asObservable();
}
}
Original Post:
Since the introduction of ListView, onItemClickListener has been problematic. The moment you have a click listener for any of the internal elements the callback would not be triggered but it wasn't notified or well documented (if at all) so there was a lot of confusion and SO questions about it.
Given that RecyclerView takes it a step further and doesn't have a concept of a row/column, but rather an arbitrarily laid out amount of children, they have delegated the onClick to each one of them, or to programmer implementation.
Think of Recyclerview not as a ListView 1:1 replacement but rather as a more flexible component for complex use cases. And as you say, your solution is what google expected of you. Now you have an adapter who can delegate onClick to an interface passed on the constructor, which is the correct pattern for both ListView and Recyclerview.
public static class ViewHolder extends RecyclerView.ViewHolder implements OnClickListener {
public TextView txtViewTitle;
public ImageView imgViewIcon;
public IMyViewHolderClicks mListener;
public ViewHolder(View itemLayoutView, IMyViewHolderClicks listener) {
super(itemLayoutView);
mListener = listener;
txtViewTitle = (TextView) itemLayoutView.findViewById(R.id.item_title);
imgViewIcon = (ImageView) itemLayoutView.findViewById(R.id.item_icon);
imgViewIcon.setOnClickListener(this);
itemLayoutView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v instanceof ImageView){
mListener.onTomato((ImageView)v);
} else {
mListener.onPotato(v);
}
}
public static interface IMyViewHolderClicks {
public void onPotato(View caller);
public void onTomato(ImageView callerImage);
}
}
and then on your adapter
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder> {
String[] mDataset = { "Data" };
#Override
public MyAdapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.my_layout, parent, false);
MyAdapter.ViewHolder vh = new ViewHolder(v, new MyAdapter.ViewHolder.IMyViewHolderClicks() {
public void onPotato(View caller) { Log.d("VEGETABLES", "Poh-tah-tos"); };
public void onTomato(ImageView callerImage) { Log.d("VEGETABLES", "To-m8-tohs"); }
});
return vh;
}
// Replace the contents of a view (invoked by the layout manager)
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
// Get element from your dataset at this position
// Replace the contents of the view with that element
// Clear the ones that won't be used
holder.txtViewTitle.setText(mDataset[position]);
}
// Return the size of your dataset (invoked by the layout manager)
#Override
public int getItemCount() {
return mDataset.length;
}
...
Now look into that last piece of code: onCreateViewHolder(ViewGroup parent, int viewType) the signature already suggest different view types. For each one of them you'll require a different viewholder too, and subsequently each one of them can have a different set of clicks. Or you can just create a generic viewholder that takes any view and one onClickListener and applies accordingly. Or delegate up one level to the orchestrator so several fragments/activities have the same list with different click behaviour. Again, all flexibility is on your side.
It is a really needed component and fairly close to what our internal implementations and improvements to ListView were until now. It's good that Google finally acknowledges it.
Why the RecyclerView has no onItemClickListener
The RecyclerView is a toolbox, in contrast of the old ListView it has less build in features and more flexibility. The onItemClickListener is not the only feature being removed from ListView. But it has lot of listeners and method to extend it to your liking, it's far more powerful in the right hands ;).
In my opinion the most complex feature removed in RecyclerView is the Fast Scroll. Most of the other features can be easily re-implemented.
If you want to know what other cool features RecyclerView added read this answer to another question.
Memory efficient - drop-in solution for onItemClickListener
This solution has been proposed by Hugo Visser, an Android GDE, right after RecyclerView was released. He made a licence-free class available for you to just drop in your code and use it.
It showcase some of the versatility introduced with RecyclerView by making use of RecyclerView.OnChildAttachStateChangeListener.
Edit 2019: kotlin version by me, java one, from Hugo Visser, kept below
Kotlin / Java
Create a file values/ids.xml and put this in it:
<?xml version="1.0" encoding="utf-8"?>
<resources>
<item name="item_click_support" type="id" />
</resources>
then add the code below to your source
Kotlin
Usage:
recyclerView.onItemClick { recyclerView, position, v ->
// do it
}
(it also support long item click and see below for another feature I've added).
implementation (my adaptation to Hugo Visser Java code):
typealias OnRecyclerViewItemClickListener = (recyclerView: RecyclerView, position: Int, v: View) -> Unit
typealias OnRecyclerViewItemLongClickListener = (recyclerView: RecyclerView, position: Int, v: View) -> Boolean
class ItemClickSupport private constructor(private val recyclerView: RecyclerView) {
private var onItemClickListener: OnRecyclerViewItemClickListener? = null
private var onItemLongClickListener: OnRecyclerViewItemLongClickListener? = null
private val attachListener: RecyclerView.OnChildAttachStateChangeListener = object : RecyclerView.OnChildAttachStateChangeListener {
override fun onChildViewAttachedToWindow(view: View) {
// every time a new child view is attached add click listeners to it
val holder = this#ItemClickSupport.recyclerView.getChildViewHolder(view)
.takeIf { it is ItemClickSupportViewHolder } as? ItemClickSupportViewHolder
if (onItemClickListener != null && holder?.isClickable != false) {
view.setOnClickListener(onClickListener)
}
if (onItemLongClickListener != null && holder?.isLongClickable != false) {
view.setOnLongClickListener(onLongClickListener)
}
}
override fun onChildViewDetachedFromWindow(view: View) {
}
}
init {
// the ID must be declared in XML, used to avoid
// replacing the ItemClickSupport without removing
// the old one from the RecyclerView
this.recyclerView.setTag(R.id.item_click_support, this)
this.recyclerView.addOnChildAttachStateChangeListener(attachListener)
}
companion object {
fun addTo(view: RecyclerView): ItemClickSupport {
// if there's already an ItemClickSupport attached
// to this RecyclerView do not replace it, use it
var support: ItemClickSupport? = view.getTag(R.id.item_click_support) as? ItemClickSupport
if (support == null) {
support = ItemClickSupport(view)
}
return support
}
fun removeFrom(view: RecyclerView): ItemClickSupport? {
val support = view.getTag(R.id.item_click_support) as? ItemClickSupport
support?.detach(view)
return support
}
}
private val onClickListener = View.OnClickListener { v ->
val listener = onItemClickListener ?: return#OnClickListener
// ask the RecyclerView for the viewHolder of this view.
// then use it to get the position for the adapter
val holder = this.recyclerView.getChildViewHolder(v)
listener.invoke(this.recyclerView, holder.adapterPosition, v)
}
private val onLongClickListener = View.OnLongClickListener { v ->
val listener = onItemLongClickListener ?: return#OnLongClickListener false
val holder = this.recyclerView.getChildViewHolder(v)
return#OnLongClickListener listener.invoke(this.recyclerView, holder.adapterPosition, v)
}
private fun detach(view: RecyclerView) {
view.removeOnChildAttachStateChangeListener(attachListener)
view.setTag(R.id.item_click_support, null)
}
fun onItemClick(listener: OnRecyclerViewItemClickListener?): ItemClickSupport {
onItemClickListener = listener
return this
}
fun onItemLongClick(listener: OnRecyclerViewItemLongClickListener?): ItemClickSupport {
onItemLongClickListener = listener
return this
}
}
/** Give click-ability and long-click-ability control to the ViewHolder */
interface ItemClickSupportViewHolder {
val isClickable: Boolean get() = true
val isLongClickable: Boolean get() = true
}
// Extension function
fun RecyclerView.addItemClickSupport(configuration: ItemClickSupport.() -> Unit = {}) = ItemClickSupport.addTo(this).apply(configuration)
fun RecyclerView.removeItemClickSupport() = ItemClickSupport.removeFrom(this)
fun RecyclerView.onItemClick(onClick: OnRecyclerViewItemClickListener) {
addItemClickSupport { onItemClick(onClick) }
}
fun RecyclerView.onItemLongClick(onLongClick: OnRecyclerViewItemLongClickListener) {
addItemClickSupport { onItemLongClick(onLongClick) }
}
(Remember you also need to add an XML file, see above this section)
Bonus feature of Kotlin version
Sometimes you do not want all the items of the RecyclerView to be clickable.
To handle this I've introduced the ItemClickSupportViewHolder interface that you can use on your ViewHolder to control which item is clickable.
Example:
class MyViewHolder(view): RecyclerView.ViewHolder(view), ItemClickSupportViewHolder {
override val isClickable: Boolean get() = false
override val isLongClickable: Boolean get() = false
}
Java
Usage:
ItemClickSupport.addTo(mRecyclerView)
.setOnItemClickListener(new ItemClickSupport.OnItemClickListener() {
#Override
public void onItemClicked(RecyclerView recyclerView, int position, View v) {
// do it
}
});
(it also support long item click)
Implementation (comments added by me):
public class ItemClickSupport {
private final RecyclerView mRecyclerView;
private OnItemClickListener mOnItemClickListener;
private OnItemLongClickListener mOnItemLongClickListener;
private View.OnClickListener mOnClickListener = new View.OnClickListener() {
#Override
public void onClick(View v) {
if (mOnItemClickListener != null) {
// ask the RecyclerView for the viewHolder of this view.
// then use it to get the position for the adapter
RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
mOnItemClickListener.onItemClicked(mRecyclerView, holder.getAdapterPosition(), v);
}
}
};
private View.OnLongClickListener mOnLongClickListener = new View.OnLongClickListener() {
#Override
public boolean onLongClick(View v) {
if (mOnItemLongClickListener != null) {
RecyclerView.ViewHolder holder = mRecyclerView.getChildViewHolder(v);
return mOnItemLongClickListener.onItemLongClicked(mRecyclerView, holder.getAdapterPosition(), v);
}
return false;
}
};
private RecyclerView.OnChildAttachStateChangeListener mAttachListener
= new RecyclerView.OnChildAttachStateChangeListener() {
#Override
public void onChildViewAttachedToWindow(View view) {
// every time a new child view is attached add click listeners to it
if (mOnItemClickListener != null) {
view.setOnClickListener(mOnClickListener);
}
if (mOnItemLongClickListener != null) {
view.setOnLongClickListener(mOnLongClickListener);
}
}
#Override
public void onChildViewDetachedFromWindow(View view) {
}
};
private ItemClickSupport(RecyclerView recyclerView) {
mRecyclerView = recyclerView;
// the ID must be declared in XML, used to avoid
// replacing the ItemClickSupport without removing
// the old one from the RecyclerView
mRecyclerView.setTag(R.id.item_click_support, this);
mRecyclerView.addOnChildAttachStateChangeListener(mAttachListener);
}
public static ItemClickSupport addTo(RecyclerView view) {
// if there's already an ItemClickSupport attached
// to this RecyclerView do not replace it, use it
ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
if (support == null) {
support = new ItemClickSupport(view);
}
return support;
}
public static ItemClickSupport removeFrom(RecyclerView view) {
ItemClickSupport support = (ItemClickSupport) view.getTag(R.id.item_click_support);
if (support != null) {
support.detach(view);
}
return support;
}
public ItemClickSupport setOnItemClickListener(OnItemClickListener listener) {
mOnItemClickListener = listener;
return this;
}
public ItemClickSupport setOnItemLongClickListener(OnItemLongClickListener listener) {
mOnItemLongClickListener = listener;
return this;
}
private void detach(RecyclerView view) {
view.removeOnChildAttachStateChangeListener(mAttachListener);
view.setTag(R.id.item_click_support, null);
}
public interface OnItemClickListener {
void onItemClicked(RecyclerView recyclerView, int position, View v);
}
public interface OnItemLongClickListener {
boolean onItemLongClicked(RecyclerView recyclerView, int position, View v);
}
}
How it works (why it's efficient)
This class works by attaching a RecyclerView.OnChildAttachStateChangeListener to the RecyclerView. This listener is notified every time a child is attached or detached from the RecyclerView. The code use this to append a tap/long click listener to the view. That listener ask the RecyclerView for the RecyclerView.ViewHolder which contains the position.
This is more efficient then other solutions because it avoid creating multiple listeners for each view and keep destroying and creating them while the RecyclerView is being scrolled.
You could also adapt the code to give you back the holder itself if you need more.
Final remark
Keep in mind that it's COMPLETELY fine to handle it in your adapter by setting on each view of your list a click listener, like other answer proposed.
It's just not the most efficient thing to do (you create a new listener every time you reuse a view) but it works and in most cases it's not an issue.
It is also a bit against separation of concerns cause it's not really the Job of the Adapter to delegate click events.
I like this way and I'm using it
Inside
public Adapter.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType)
Put
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.view_image_and_text, parent, false);
v.setOnClickListener(new MyOnClickListener());
And create this class anywhere you want it
class MyOnClickListener implements View.OnClickListener {
#Override
public void onClick(View v) {
int itemPosition = recyclerView.indexOfChild(v);
Log.e("Clicked and Position is ",String.valueOf(itemPosition));
}
}
I've read before that there is a better way but I like this way is easy and not complicated.
Android Recyclerview With onItemClickListener,
Why we cant try this is working like ListView only.
Source : Link
public class RecyclerItemClickListener implements RecyclerView.OnItemTouchListener {
private OnItemClickListener mListener;
public interface OnItemClickListener {
public void onItemClick(View view, int position);
}
GestureDetector mGestureDetector;
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 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 false;
}
#Override
public void onTouchEvent(RecyclerView view, MotionEvent motionEvent) {
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
}
And Set this to RecyclerView:
recyclerView = (RecyclerView)rootView. findViewById(R.id.recyclerView);
RecyclerView.LayoutManager mLayoutManager = new LinearLayoutManager(getActivity());
recyclerView.setLayoutManager(mLayoutManager);
recyclerView.addOnItemTouchListener(
new RecyclerItemClickListener(getActivity(), new RecyclerItemClickListener.OnItemClickListener() {
#Override
public void onItemClick(View view, int position) {
// TODO Handle item click
Log.e("#####",""+position);
}
})
);
Thanks to #marmor, I updated my answer.
I think it's a good solution to handle the onClick() in the ViewHolder class constructor and pass it to the parent class via OnItemClickListener interface.
MyAdapter.java
public class MyAdapter extends RecyclerView.Adapter<MyAdapter.ViewHolder>{
private LayoutInflater layoutInflater;
private List<MyObject> items;
private AdapterView.OnItemClickListener onItemClickListener;
public MyAdapter(Context context, AdapterView.OnItemClickListener onItemClickListener, List<MyObject> items) {
layoutInflater = LayoutInflater.from(context);
this.items = items;
this.onItemClickListener = onItemClickListener;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = layoutInflater.inflate(R.layout.my_row_layout, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(ViewHolder holder, int position) {
MyObject item = items.get(position);
}
public MyObject getItem(int position) {
return items.get(position);
}
class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private TextView title;
private ImageView avatar;
public ViewHolder(View itemView) {
super(itemView);
title = itemView.findViewById(R.id.title);
avatar = itemView.findViewById(R.id.avatar);
title.setOnClickListener(this);
avatar.setOnClickListener(this);
itemView.setOnClickListener(this);
}
#Override
public void onClick(View view) {
//passing the clicked position to the parent class
onItemClickListener.onItemClick(null, view, getAdapterPosition(), view.getId());
}
}
}
Usage of adapter in other classes:
MyFragment.java
public class MyFragment extends Fragment implements AdapterView.OnItemClickListener {
private RecyclerView recycleview;
private MyAdapter adapter;
.
.
.
private void init(Context context) {
//passing this fragment as OnItemClickListener to the adapter
adapter = new MyAdapter(context, this, items);
recycleview.setAdapter(adapter);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
//you can get the clicked item from the adapter using its position
MyObject item = adapter.getItem(position);
//you can also find out which view was clicked
switch (view.getId()) {
case R.id.title:
//title view was clicked
break;
case R.id.avatar:
//avatar view was clicked
break;
default:
//the whole row was clicked
}
}
}
> How RecyclerView is different from Listview?
One difference is that there is LayoutManager class with RecyclerView by which you can manage your RecyclerView like-
Horizontal or Vertical scrolling by LinearLayoutManager
GridLayout by GridLayoutManager
Staggered GridLayout by StaggeredGridLayoutManager
Like for horizontal scrolling for RecyclerView-
LinearLayoutManager llm = new LinearLayoutManager(context);
llm.setOrientation(LinearLayoutManager.HORIZONTAL);
recyclerView.setLayoutManager(llm);
Guys use this code in Your main activity. Very Efficient Method
RecyclerView recyclerView = (RecyclerView) findViewById(R.id.users_list);
UsersAdapter adapter = new UsersAdapter(users, this);
recyclerView.setAdapter(adapter);
adapter.setOnCardClickListner(this);
Here is your Adapter class.
public class UsersAdapter extends RecyclerView.Adapter<UsersAdapter.UserViewHolder> {
private ArrayList<User> mDataSet;
OnCardClickListner onCardClickListner;
public UsersAdapter(ArrayList<User> mDataSet) {
this.mDataSet = mDataSet;
}
#Override
public UserViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.user_row_layout, parent, false);
UserViewHolder userViewHolder = new UserViewHolder(v);
return userViewHolder;
}
#Override
public void onBindViewHolder(UserViewHolder holder, final int position) {
holder.name_entry.setText(mDataSet.get(position).getUser_name());
holder.cardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
onCardClickListner.OnCardClicked(v, position);
}
});
}
#Override
public int getItemCount() {
return mDataSet.size();
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
public static class UserViewHolder extends RecyclerView.ViewHolder {
CardView cardView;
TextView name_entry;
public UserViewHolder(View itemView) {
super(itemView);
cardView = (CardView) itemView.findViewById(R.id.user_layout);
name_entry = (TextView) itemView.findViewById(R.id.name_entry);
}
}
public interface OnCardClickListner {
void OnCardClicked(View view, int position);
}
public void setOnCardClickListner(OnCardClickListner onCardClickListner) {
this.onCardClickListner = onCardClickListner;
}
}
After this you will get this override method in your activity.
#Override
public void OnCardClicked(View view, int position) {
Log.d("OnClick", "Card Position" + position);
}
How to put it all together example...
onClick() handling
Cursor - RecyclerView
ViewHolder types
public class OrderListCursorAdapter extends CursorRecyclerViewAdapter<OrderListCursorAdapter.ViewHolder> {
private static final String TAG = OrderListCursorAdapter.class.getSimpleName();
private static final int ID_VIEW_HOLDER_ACTUAL = 0;
private static final int ID_VIEW_HOLDER = 1;
public OrderListCursorAdapter(Context context, Cursor cursor) {
super(context, cursor);
}
public static class ViewHolderActual extends ViewHolder {
private static final String TAG = ViewHolderActual.class.getSimpleName();
protected IViewHolderClick listener;
protected Button button;
public ViewHolderActual(View v, IViewHolderClick listener) {
super(v, listener);
this.listener = listener;
button = (Button) v.findViewById(R.id.orderList_item_button);
button.setOnClickListener(this);
}
public void initFromData(OrderData data) {
Log.d(TAG, "><initFromData(data=" + data + ")");
orderId = data.getId();
vAddressStart.setText(data.getAddressStart());
vAddressEnd.setText(data.getAddressEnd());
}
#Override
public void onClick(View view) {
if (view instanceof Button) {
listener.onButtonClick((Button) view, getPosition(), this);
} else {
super.onClick(view);
}
}
public interface IViewHolderClick extends ViewHolder.IViewHolderClick {
public void onButtonClick(Button button, int position, ViewHolder viewHolder);
}
}
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
private static final String TAG = ViewHolder.class.getSimpleName();
protected long orderId;
protected IViewHolderClick listener;
protected TextView vAddressStart;
protected TextView vAddressEnd;
protected TextView vStatus;
public ViewHolder(View v, IViewHolderClick listener) {
super(v);
this.listener = listener;
v.setOnClickListener(this);
vAddressStart = (TextView) v.findViewById(R.id.addressStart);
vAddressEnd = (TextView) v.findViewById(R.id.addressEnd);
vStatus = (TextView) v.findViewById(R.id.status);
}
public void initFromData(OrderData data) {
Log.d(TAG, "><initFromData(data=" + data + ")");
orderId = data.getId();
vAddressStart.setText(data.getAddressStart());
vAddressEnd.setText(data.getAddressEnd());
}
public long getOrderId() {
return orderId;
}
#Override
public void onClick(View view) {
listener.onCardClick(view, getPosition(), this);
}
public interface IViewHolderClick {
public void onCardClick(View view, int position, ViewHolder viewHolder);
}
}
#Override
public int getItemViewType(int position) {
return position == 0 ? ID_VIEW_HOLDER_ACTUAL : ID_VIEW_HOLDER;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
Log.d(TAG, ">>onCreateViewHolder(parent=" + parent + ", viewType=" + viewType + ")");
ViewHolder result;
switch (viewType) {
case ID_VIEW_HOLDER_ACTUAL: {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_layout_actual, parent, false);
result = new ViewHolderActual(itemView, new ViewHolderActual.IViewHolderClick() {
#Override
public void onCardClick(View view, int position, ViewHolder viewHolder) {
Log.d(TAG, "><onCardClick(view=" + view + ", position=" + position + ", viewHolder=" + viewHolder + ")");
Intent intent = new Intent(view.getContext(), OrderDetailActivity.class);
intent.putExtra(OrderDetailActivity.ARG_ORDER_ID, viewHolder.getOrderId());
view.getContext().startActivity(intent);
}
#Override
public void onButtonClick(Button button, int position, ViewHolder viewHolder) {
Log.d(TAG, "><onButtonClick(button=" + button + ", position=" + position + ", viewHolder=" + viewHolder + ")");
Intent intent = new Intent(button.getContext(), OrderMapActivity.class);
intent.putExtra(OrderMapActivity.ARG_ORDER_ID, viewHolder.getOrderId());
button.getContext().startActivity(intent);
}
});
break;
}
case ID_VIEW_HOLDER:
default: {
View itemView = LayoutInflater.from(parent.getContext()).inflate(R.layout.card_layout, parent, false);
result = new ViewHolder(itemView, new ViewHolder.IViewHolderClick() {
#Override
public void onCardClick(View view, int position, ViewHolder viewHolder) {
Log.d(TAG, "><onCardClick(view=" + view + ", position=" + position + ", viewHolder=" + viewHolder + ")");
Intent intent = new Intent(view.getContext(), OrderDetailActivity.class);
intent.putExtra(OrderDetailActivity.ARG_ORDER_ID, viewHolder.getOrderId());
view.getContext().startActivity(intent);
}
});
break;
}
}
Log.d(TAG, "<<onCreateViewHolder(parent=" + parent + ", viewType=" + viewType + ")= " + result);
return result;
}
#Override
public void onBindViewHolder(ViewHolder viewHolder, Cursor cursor) {
Log.d(TAG, "><onBindViewHolder(viewHolder=" + viewHolder + ", cursor=" + cursor + ")");
final OrderData orderData = new OrderData(cursor);
viewHolder.initFromData(orderData);
}
}
Following up MLProgrammer-CiM's excellent RxJava solution
Consume / Observe clicks
Consumer<String> mClickConsumer = new Consumer<String>() {
#Override
public void accept(#NonNull String element) throws Exception {
Toast.makeText(getApplicationContext(), element +" was clicked", Toast.LENGTH_LONG).show();
}
};
ReactiveAdapter rxAdapter = new ReactiveAdapter();
rxAdapter.getPositionClicks().subscribe(mClickConsumer);
RxJava 2.+
Modify the original tl;dr as:
public Observable<String> getPositionClicks(){
return onClickSubject;
}
PublishSubject#asObservable() was removed. Just return the PublishSubject which is an Observable.
RecyclerView doesn't have an onItemClickListener because RecyclerView is responsible for recycling views (surprise!), so it's the responsibility of the view that is recycled to handle the click events it receives.
This actually makes it much easier to use, especially if you had items that can be clicked in multiple places.
Anyways, detecting click on a RecyclerView item is very easy. All you need to do is define an interface (if you're not using Kotlin, in which case you just pass in a lambda):
public class MyAdapter extends RecyclerView.Adapter<MyViewHolder> {
private final Clicks clicks;
public MyAdapter(Clicks clicks) {
this.clicks = clicks;
}
private List<MyObject> items = Collections.emptyList();
public void updateData(List<MyObject> items) {
this.items = items;
notifyDataSetChanged(); // TODO: use ListAdapter for diffing instead if you need animations
}
public interface Clicks {
void onItemSelected(MyObject myObject, int position);
}
public class MyViewHolder extends RecyclerView.ViewHolder {
private MyObject myObject;
public MyViewHolder(View view) {
super(view);
// bind views
view.setOnClickListener((v) -> {
int adapterPosition = getBindingAdapterPosition();
if(adapterPosition >= 0) {
clicks.onItemSelected(myObject, adapterPosition);
}
});
}
public void bind(MyObject myObject) {
this.myObject = myObject;
// bind data to views
}
}
}
Same code in Kotlin:
class MyAdapter(val itemClicks: (MyObject, Int) -> Unit): RecyclerView.Adapter<MyViewHolder>() {
private var items: List<MyObject> = Collections.emptyList()
fun updateData(items: List<MyObject>) {
this.items = items
notifyDataSetChanged() // TODO: use ListAdapter for diffing instead if you need animations
}
inner class MyViewHolder(val myView: View): RecyclerView.ViewHolder(myView) {
private lateinit var myObject: MyObject
init {
// binds views
myView.onClick {
val adapterPosition = getBindingAdapterPosition()
if(adapterPosition >= 0) {
itemClicks.invoke(myObject, adapterPosition)
}
}
}
fun bind(myObject: MyObject) {
this.myObject = myObject
// bind data to views
}
}
}
Thing you DON'T need to do:
1.) you don't need to intercept touch events manually
2.) you don't need to mess around with child attach state change listeners
3.) you don't need PublishSubject/PublishRelay from RxJava
Just use a click listener.
As far as I understand MLProgrammer-CiM answer, simply it's possible to just do this:
class MyViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
private ImageView image;
private TextView title;
private TextView price;
public MyViewHolder(View itemView) {
super(itemView);
image = (ImageView)itemView.findViewById(R.id.horizontal_list_image);
title = (TextView)itemView.findViewById(R.id.horizontal_list_title);
price = (TextView)itemView.findViewById(R.id.horizontal_list_price);
image.setOnClickListener(this);
title.setOnClickListener(this);
price.setOnClickListener(this);
}
#Override
public void onClick(View v) {
Toast.makeText(context, "Item click nr: "+getLayoutPosition(), Toast.LENGTH_SHORT).show();
}
}
After reading #MLProgrammer-CiM's answer, here is my code:
class NormalViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener{
#Bind(R.id.card_item_normal)
CardView cardView;
public NormalViewHolder(View itemView) {
super(itemView);
ButterKnife.bind(this, itemView);
cardView.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if(v instanceof CardView) {
// use getAdapterPosition() instead of getLayoutPosition()
int itemPosition = getAdapterPosition();
removeItem(itemPosition);
}
}
}
I have done this way, its very simple:
Just add 1 Line for Clicked RecyclerView position:
int position = getLayoutPosition()
Full code for ViewHolder class:
private class ChildViewHolder extends RecyclerView.ViewHolder {
public ImageView imageView;
public TextView txtView;
public ChildViewHolder(View itemView) {
super(itemView);
imageView= (ImageView)itemView.findViewById(R.id.imageView);
txtView= (TextView) itemView.findViewById(R.id.txtView);
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
Log.i("RecyclerView Item Click Position", String.valueOf(getLayoutPosition()));
}
});
}
}
Hope this will help you.
I use this method to start an Intent from RecyclerView:
#Override
public void onBindViewHolder(ViewHolder viewHolder, int i) {
final MyClass myClass = mList.get(i);
viewHolder.txtViewTitle.setText(myclass.name);
...
viewHolder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v){
Intent detailIntent = new Intent(mContext, type.class);
detailIntent.putExtra("MyClass", myclass);
mContext.startActivity(detailIntent);
}
}
);
See my approach on this:
First declare an interface like this:
/**
* Interface used for delegating item click events in a {#link android.support.v7.widget.RecyclerView}
* Created by Alex on 11/28/2015.
*/
public interface OnRecyclerItemClickListener<T> {
/**
* Called when a click occurred inside a recyclerView item view
* #param view that was clicked
* #param position of the clicked view
* #param item the concrete data that is displayed through the clicked view
*/
void onItemClick(View view, int position, T item);
}
Then create the adapter:
public class CustomRecyclerAdapter extends RecyclerView.Adapter {
private class InternalClickListener implements View.OnClickListener{
#Override
public void onClick(View v) {
if(mRecyclerView != null && mItemClickListener != null){
// find the position of the item that was clicked
int position = mRecyclerView.getChildAdapterPosition(v);
Data data = getItem(position);
// notify the main listener
mItemClickListener.onItemClick(v, position, data);
}
}
}
private final OnRecyclerItemClickListener mItemClickListener;
private RecyclerView mRecyclerView;
private InternalClickListener mInternalClickListener;
/**
*
* #param itemClickListener used to trigger an item click event
*/
public PlayerListRecyclerAdapter(OnRecyclerItemClickListener itemClickListener){
mItemClickListener = itemClickListener;
mInternalClickListener = new InternalClickListener();
}
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.recycler_item, parent, false);
v.setOnClickListener(mInternalClickListener);
ViewHolder viewHolder = new ViewHolder(v);
return viewHolder;
}
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, int position) {
// do your binding here
}
#Override
public int getItemCount() {
return mDataSet.size();
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
mRecyclerView = recyclerView;
}
#Override
public void onDetachedFromRecyclerView(RecyclerView recyclerView) {
super.onDetachedFromRecyclerView(recyclerView);
mRecyclerView = null;
}
public Data getItem(int position){
return mDataset.get(position);
}
}
And now let's see how to integrate this from a fragment:
public class TestFragment extends Fragment implements OnRecyclerItemClickListener<Data>{
private RecyclerView mRecyclerView;
#Override
public void onItemClick(View view, int position, Data item) {
// do something
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.test_fragment, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
mRecyclerView = view.findViewById(idOfTheRecycler);
mRecyclerView .setAdapter(new CustomRecyclerAdapter(this));
}
If you want to add onClick() to the child view of items, for example, a button in item, I found that you can do it easily in onCreateViewHolder() of your own RecyclerView.Adapter just like this:
#Override
public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater
.from(parent.getContext())
.inflate(R.layout.cell, null);
Button btn = (Button) v.findViewById(R.id.btn);
btn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//do it
}
});
return new MyViewHolder(v);
}
i don't know whether it's a good way, but it works well. If anyone has a better idea, very glad to tell me and correct my answer! :)
Here is a way to implement it quite easily if you have a list of POJOs and want to retrieve one on click from outside the adapter.
In your adapter, create a listener for the click events and a method to set it:
public class MyAdapter extends RecyclerView.Adapter<SitesListAdapter.ViewHolder> {
...
private List<MyPojo> mMyPojos;
private static OnItemClickListener mOnItemClickListener;
...
public interface OnItemClickListener {
public void onItemClick(MyPojo pojo);
}
...
public void setOnItemClickListener(OnItemClickListener onItemClickListener){
mOnItemClickListener = onItemClickListener;
}
...
}
In your ViewHolder, implement onClickListener and create a class member to temporarily store the POJO the view is presenting, that way (this is an example, creating a setter would be better):
public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
public MyPojo mCurrentPojo;
...
public ViewHolder(View view) {
super(v);
...
view.setOnClickListener(this); //You could set this on part of the layout too
}
...
#Override
public void onClick(View view) {
if(mOnItemClickListener != null && mCurrentPojo != null){
mOnItemClickListener.onItemClick(mCurrentPojo);
}
}
Back in your adapter, set the current POJO when the ViewHolder is bound (or to null if the current view doesn't have one):
#Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
final MyPojo currentPojo = mMyPojos.get(position);
holder.mCurrentPojo = currentPojo;
...
That's it, now you can use it like this from your fragment/activity:
mMyAdapter.setOnItemClickListener(new mMyAdapter.OnItemClickListener() {
#Override
public void onItemClick(MyPojo pojo) {
//Do whatever you want with your pojo here
}
});
Yes you can
public ViewHolder onCreateViewHolder(ViewGroup parent,int viewType) {
//inflate the view
View view = LayoutInflator.from(parent.getContext()).inflate(R.layout.layoutID,null);
ViewHolder holder = new ViewHolder(view);
//here we can set onClicklistener
view.setOnClickListener(new View.OnClickListeener(){
public void onClick(View v)
{
//action
}
});
return holder;
This worked for me:
#Override
public void onBindViewHolder(PlacesListViewAdapter.ViewHolder holder, int position) {
----
----
----
// Set setOnClickListener(holder);
}
#Override
public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
----
----
----
#Override
public void onClick(View view) {
// Use to get the item clicked getAdapterPosition()
}
}
Here you can handle multiple onclick see below code and it is very efficient
public class RVNewsAdapter extends RecyclerView.Adapter<RVNewsAdapter.FeedHolder> {
private Context context;
List<News> newsList;
// Allows to remember the last item shown on screen
private int lastPosition = -1;
public RVNewsAdapter(List<News> newsList, Context context) {
this.newsList = newsList;
this.context = context;
}
public static class FeedHolder extends RecyclerView.ViewHolder implements OnClickListener {
ImageView img_main;
TextView tv_title;
Button bt_facebook, bt_twitter, bt_share, bt_comment;
public FeedHolder(View itemView) {
super(itemView);
img_main = (ImageView) itemView.findViewById(R.id.img_main);
tv_title = (TextView) itemView.findViewById(R.id.tv_title);
bt_facebook = (Button) itemView.findViewById(R.id.bt_facebook);
bt_twitter = (Button) itemView.findViewById(R.id.bt_twitter);
bt_share = (Button) itemView.findViewById(R.id.bt_share);
bt_comment = (Button) itemView.findViewById(R.id.bt_comment);
img_main.setOnClickListener(this);
bt_facebook.setOnClickListener(this);
bt_twitter.setOnClickListener(this);
bt_comment.setOnClickListener(this);
bt_share.setOnClickListener(this);
}
#Override
public void onClick(View v) {
if (v.getId() == bt_comment.getId()) {
Toast.makeText(v.getContext(), "Comment " , Toast.LENGTH_SHORT).show();
} else if (v.getId() == bt_facebook.getId()) {
Toast.makeText(v.getContext(), "Facebook " , Toast.LENGTH_SHORT).show();
} else if (v.getId() == bt_twitter.getId()) {
Toast.makeText(v.getContext(), "Twitter " , Toast.LENGTH_SHORT).show();
} else if (v.getId() == bt_share.getId()) {
Toast.makeText(v.getContext(), "share " , Toast.LENGTH_SHORT).show();
}
else {
Toast.makeText(v.getContext(), "ROW PRESSED = " + String.valueOf(getAdapterPosition()), Toast.LENGTH_SHORT).show();
}
}
}
#Override
public void onAttachedToRecyclerView(RecyclerView recyclerView) {
super.onAttachedToRecyclerView(recyclerView);
}
#Override
public FeedHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.feed_row, parent, false);
FeedHolder feedHolder = new FeedHolder(view);
return feedHolder;
}
#Override
public void onBindViewHolder(FeedHolder holder, int position) {
holder.tv_title.setText(newsList.get(position).getTitle());
// Here you apply the animation when the view is bound
setAnimation(holder.img_main, position);
}
#Override
public int getItemCount() {
return newsList.size();
}
/**
* Here is the key method to apply the animation
*/
private void setAnimation(View viewToAnimate, int position) {
// If the bound view wasn't previously displayed on screen, it's animated
if (position > lastPosition) {
Animation animation = AnimationUtils.loadAnimation(context, android.R.anim.slide_in_left);
viewToAnimate.startAnimation(animation);
lastPosition = position;
}
}
}
Modified my comment...
public class MyViewHolder extends RecyclerView.ViewHolder {
private Context mContext;
public MyViewHolder(View itemView) {
super(itemView);
mContext = itemView.getContext();
itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
int itemPosition = getLayoutPosition();
Toast.makeText(mContext, "" + itemPosition, Toast.LENGTH_SHORT).show();
}
});
}
Check this one in which I have implemented all the things with a proper way
RecyclerViewHolder Class
public class RecyclerViewHolder extends RecyclerView.ViewHolder {
//view holder is for girdview as we used in the listView
public ImageView imageView,imageView2;
public RecyclerViewHolder(View itemView) {
super(itemView);
this.imageView=(ImageView)itemView.findViewById(R.id.image);
}
}
Adapter
public class RecyclerView_Adapter extends RecyclerView.Adapter<RecyclerViewHolder> {
//RecyclerView will extend to recayclerview Adapter
private ArrayList<ModelClass> arrayList;
private Context context;
private static RecyclerViewClickListener itemListener;
//constructor of the RecyclerView Adapter
RecyclerView_Adapter(Context context,ArrayList<ModelClass> arrayList,RecyclerViewClickListener itemListener){
this.context=context;
this.arrayList=arrayList;
this.itemListener=itemListener;
}
#Override
public RecyclerViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
//this method will inflate the custom layout and return as viewHolder
LayoutInflater layoutInflater=LayoutInflater.from(parent.getContext());
ViewGroup mainGroup=(ViewGroup) layoutInflater.inflate(R.layout.single_item,parent,false);
RecyclerViewHolder listHolder=new RecyclerViewHolder(mainGroup);
return listHolder;
}
#Override
public void onBindViewHolder(RecyclerViewHolder holder, final int position) {
final ModelClass modelClass=arrayList.get(position);
//holder
RecyclerViewHolder mainHolder=(RecyclerViewHolder)holder;
//convert the drawable image into bitmap
Bitmap image= BitmapFactory.decodeResource(context.getResources(),modelClass.getImage());
//set the image into imageView
mainHolder.imageView.setImageBitmap(image);
//to handle on click event when clicked on the recyclerview item and
// get it through the RecyclerViewHolder class we have defined the views there
mainHolder.itemView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//get the position of the image which is clicked
itemListener.recyclerViewListClicked(v,position);
}
});
}
#Override
public int getItemCount() {
return (null!=arrayList?arrayList.size():0);
}
}
The interface
public interface RecyclerViewClickListener {
//this is method to handle the event when clicked on the image in Recyclerview
public void recyclerViewListClicked(View v,int position);
}
//and to call this method in activity
RecyclerView_Adapter adapter=new RecyclerView_Adapter(Wallpaper.this,arrayList,this);
recyclerView.setAdapter(adapter);
adapter.notifyDataSetChanged();
#Override
public void recyclerViewListClicked(View v,int position){
imageView.setImageResource(wallpaperImages[position]);
}
Access the mainView of rowLayout(cell) for you RecyclerView and in your OnBindViewHolder write this code:
#Override
public void onBindViewHolder(MyViewHolder holder, final int position) {
Movie movie = moviesList.get(position);
holder.mainView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
System.out.println("pos " + position);
}
});
}
it worked for me. Hope it will help. Most simplest way.
Inside View Holder
class GeneralViewHolder extends RecyclerView.ViewHolder {
View cachedView = null;
public GeneralViewHolder(View itemView) {
super(itemView);
cachedView = itemView;
}
Inside OnBindViewHolder()
#Override
public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {
final GeneralViewHolder generalViewHolder = (GeneralViewHolder) holder;
generalViewHolder.cachedView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(context, "item Clicked at "+position, Toast.LENGTH_SHORT).show();
}
});
And let me know, do you have any question about this solution ?
main_recyclerview.addOnItemTouchListener(new RecyclerView.OnItemTouchListener() {
#Override
public boolean onInterceptTouchEvent(RecyclerView rv, MotionEvent e)
{
int position=rv.getChildAdapterPosition(rv.findChildViewUnder(e.getX(),e.getY()));
switch (position)
{
case 0:
{
wifi(position);
adapter2.notifyDataSetChanged();
}
break;
case 1:
{
sound(position);
adapter2.notifyDataSetChanged();
}
break;
case 2:
{
bluetooth(position);
adapter2.notifyDataSetChanged();
}
break;
}
return true;
}
#Override
public void onTouchEvent(RecyclerView rv, MotionEvent e)
{
}
#Override
public void onRequestDisallowInterceptTouchEvent(boolean disallowIntercept) {
}
});
Instead of implementing interface View.OnClickListener inside view holder or creating and interface and implementing interface in your activity..
I used this code for simple on OnClickListener implementation.
public static class SimpleStringRecyclerViewAdapter
extends RecyclerView.Adapter<SimpleStringRecyclerViewAdapter.ViewHolder> {
// Your initializations goes here...
private List<String> mValues;
public static class ViewHolder extends RecyclerView.ViewHolder {
//create a variable mView
public final View mView;
/*All your row widgets goes here
public final ImageView mImageView;
public final TextView mTextView;*/
public ViewHolder(View view) {
super(view);
//Initialize it here
mView = view;
/* your row widgets initializations goes here
mImageView = (ImageView) view.findViewById(R.id.avatar);
mTextView = (TextView) view.findViewById(android.R.id.text1);*/
}
}
public String getValueAt(int position) {
return mValues.get(position);
}
public SimpleStringRecyclerViewAdapter(Context context, List<String> items) {
mBackground = mTypedValue.resourceId;
mValues = items;
}
#Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.list_item, parent, false);
view.setBackgroundResource(mBackground);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(final ViewHolder holder, int position) {
holder.mBoundString = mValues.get(position);
holder.mTextView.setText(mValues.get(position));
//Here it is simply write onItemClick listener here
holder.mView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Context context = v.getContext();
Intent intent = new Intent(context, ExampleActivity.class);
context.startActivity(intent);
}
});
}
#Override
public int getItemCount() {
return mValues.size();
}
}
use PlaceHolderView
#Layout(R.layout.item_view_1)
public class View1{
#View(R.id.txt)
public TextView txt;
#Resolve
public void onResolved() {
txt.setText(String.valueOf(System.currentTimeMillis() / 1000));
}
#Click(R.id.btn)
public void onClick(){
txt.setText(String.valueOf(System.currentTimeMillis() / 1000));
}
}
I wrote a library to handle android recycler view item click event. You can find whole tutorial in https://github.com/ChathuraHettiarachchi/RecycleClick
RecycleClick.addTo(YOUR_RECYCLEVIEW).setOnItemClickListener(new RecycleClick.OnItemClickListener() {
#Override
public void onItemClicked(RecyclerView recyclerView, int position, View v) {
// YOUR CODE
}
});
or to handle item long press you can use
RecycleClick.addTo(YOUR_RECYCLEVIEW).setOnItemLongClickListener(new RecycleClick.OnItemLongClickListener() {
#Override
public boolean onItemLongClicked(RecyclerView recyclerView, int position, View v) {
// YOUR CODE
return true;
}
});
recyclerview animation has not been tested, the other is normal. I think it has been optimized to the maximum. Interface has other uses, you can temporarily ignore.
public abstract class BaseAdapterRV<VH extends BaseViewHolder> extends RecyclerView.Adapter<VH> implements AdapterInterface {
public final String TAG = getClass().getSimpleName();
protected final Activity mActivity;
protected final LayoutInflater mInflater;
protected ItemClickInterface<?, Integer> mListener;
public BaseAdapterRV(Activity activity) {
mActivity = activity;
mInflater = LayoutInflater.from(mActivity);
}
#Override
public final VH onCreateViewHolder(ViewGroup parent, int viewType) {
return onCreateViewHolder(parent, viewType, mInflater);
}
#Override
public final void onBindViewHolder(VH holder, int position) {
holder.itemView.setTag(R.id.tag_view_click, position);
//创建点击事件
holder.itemView.setOnClickListener(mListener);
holder.itemView.setOnLongClickListener(mListener);
onBindVH(holder, position);
}
///////////////////////////////////////////////////////////////////////////
// 以下是增加的方法
///////////////////////////////////////////////////////////////////////////
/**
* 注意!涉及到notifyItemInserted刷新时立即获取position可能会不正确
* 里面也有onItemLongClick
*/
public void setOnItemClickListener(ItemClickInterface<?, Integer> listener) {
mListener = listener;
notifyDataSetChanged();
}
#NonNull
protected abstract VH onCreateViewHolder(ViewGroup parent, int viewType, LayoutInflater inflater);
protected abstract void onBindVH(VH holder, int position);
}
This is Interface
/**
* OnItemClickListener的接口
* 见子类实现{#link OnItemClickListener}{#link OnItemItemClickListener}
*/
public interface ItemClickInterface<DATA1, DATA2> extends View.OnClickListener, View.OnLongClickListener {
void onItemClick(DATA1 data1, DATA2 data2);
boolean onItemLongClick(DATA1 data1, DATA2 data2);
}
This is an abstract class
public abstract class OnItemClickListener<DATA> implements ItemClickInterface<View, DATA> {
#Override
public void onClick(View v) {
onItemClick(v, (DATA) v.getTag(R.id.tag_view_click));
}
#Override
public boolean onLongClick(View v) {
return onItemLongClick(v, (DATA) v.getTag(R.id.tag_view_click));
}
#Override
public boolean onItemLongClick(View view, DATA data) {
return false;
}
}
You only need it
mAdapter.setOnItemClickListener(new OnItemClickListener<Integer>() {
#Override
public void onItemClick(View view, Integer integer) {
}
#Override
public boolean onItemLongClick(View view, Integer integer) {
return true;
}
});
I found one of the shortest ways using androidx lifecycle mutable live data
Adapter:
private val onItemClickListener = MutableLiveData<YourAdapterItem>()
override fun onBindViewHolder(holder: GifsViewHolder, position: Int) {
holder.itemView.setOnClickListener { onItemClickListener.value = gifs[position] }
}
fun getOnItemClickListener(): MutableLiveData<Gif> {
return onItemClickListener
}
anywhere in MainActivity
yourFancyAdapter.getOnItemClickListener().observe(this, Observer {
println(it)
})

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