Why i can't click my item on recyclerview

Question

I can't click the item on recyclerview, I don't know why, so can somebody help me to clear this problem?

so this in my code in MainActivity, and I call this function in onCreate :

private void showRecyclerList(){
    recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));
    UserAdapter userAdapter = new UserAdapter(this, userModel);
    recyclerView.setAdapter(userAdapter);

    userAdapter.setOnItemClickCallback(new UserAdapter.OnItemClickCallback() {
        @Override
        public void onItemClicked(UserModel data) {
        Intent intent = new Intent(MainActivity.this, UserDetailActivity.class);
        intent.putExtra(UserDetailActivity.EXTRA_DATA, (Parcelable) userModel);
        startActivity(intent);
        }
    });
}

I used the Interface from OnItemClickCallback and I up it on User Adapter, and this is my UserAdapter:

public class UserAdapter extends RecyclerView.Adapter<UserAdapter.ListViewHolder> {

private Context context;
private List<UserModel> userData = new ArrayList<>();

private OnItemClickCallback onItemClickCallback;

public void setOnItemClickCallback(final OnItemClickCallback onItemClickCallback) {
    this.onItemClickCallback = onItemClickCallback;
}

public static final String DATA_EXTRA = "data_extra";


public UserAdapter(Context context, List<UserModel> userData) {
    this.context = context;
    this.userData = userData;
}


@NonNull
@Override
public ListViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
    View view = LayoutInflater.from(context).inflate(R.layout.item_user, parent,false);
    return new ListViewHolder(view);
}

@Override
public void onBindViewHolder(@NonNull ListViewHolder holder, int position) {
    //UserModel user = userData.get(position);

    holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            onItemClickCallback.onItemClicked(userData.get(holder.getAdapterPosition()));
        }
    });

    Glide.with(context)
            .load(userData.get(position).getAvatarUrl())
            .into(holder.imgPhoto);

    holder.tvName.setText(userData.get(position).getLogin());
}

@Override
public int getItemCount() {
    return userData.size();
}

public class ListViewHolder extends RecyclerView.ViewHolder
{
    ImageView imgPhoto;
    TextView tvName;
    public ListViewHolder(View itemView) {
        super(itemView);
        imgPhoto = itemView.findViewById(R.id.iv_avatar);
        tvName = itemView.findViewById(R.id.tv_name);

    }

}

public interface OnItemClickCallback {
    void onItemClicked(UserModel data);
}

and this is my error message :

java.lang.NullPointerException: Attempt to invoke interface method 'void com.dicoding.githubuserwithapi.UserAdapter$OnItemClickCallback.onItemClicked(com.dicoding.githubuserwithapi.model.UserModel)' on a null object reference at com.dicoding.githubuserwithapi.UserAdapter$1.onClick(UserAdapter.java:60) at android.view.View.performClick(View.java:7357) at android.view.View.performClickInternal(View.java:7334) at android.view.View.access$3600(View.java:808) at android.view.View$PerformClick.run(View.java:28200) at android.os.Handler.handleCallback(Handler.java:907) at android.os.Handler.dispatchMessage(Handler.java:99) at android.os.Looper.loop(Looper.java:223) at android.app.ActivityThread.main(ActivityThread.java:7478) at java.lang.reflect.Method.invoke(Native Method) at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:549) at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:941) I/Process: Sending signal. PID: 9602 SIG: 9

I have an error in UserAdapter line 60

holder.itemView.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            **onItemClickCallback.onItemClicked(userData.get(holder.getAdapterPosition()));**
        }
    });

on my UserModel class, there is only the data from the user and I used Parcelable on it.

I think I can't get the position, but I don't know where can I fix it, so can u guys help me with this problem..

Answer 1

When creating LayoutInflater you should use parent.context.

View view = LayoutInflater.from(parent.context).inflate(R.layout.item_user, parent,false);

Why are you calling adapter's getAdapterPosition() if position is already available to you as a parameter of onBindViewHolder()?

onItemClickCallback.onItemClicked(userData.get(position));

When you're defining that click listener you're not using the data you passed to it.

userAdapter.setOnItemClickCallback(new UserAdapter.OnItemClickCallback() {
        @Override
        public void onItemClicked(UserModel data) {
        Intent intent = new Intent(MainActivity.this, UserDetailActivity.class);
        intent.putExtra(UserDetailActivity.EXTRA_DATA, (Parcelable) **userModel**);
        startActivity(intent);
        }
    });