Develop Reference

Android Studio RecyclerView: Why always ( No adapter attached; skipping layout )

I am a student who currently taking mobile application development. Although my app can run but it doesnt show any activity instead of just give me W/RecyclerView: No adapter attached; skipping layout. I dont know how to solve the issue, so I was hoping can get some guidlines from experts.
Here is my code
MainActivity.java
package my.edu.utar.practicalassignment;
import android.app.AlertDialog;
import android.app.ProgressDialog;
import android.graphics.drawable.Drawable;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.EditText;
import android.widget.Spinner;
import android.widget.TextView;
import android.widget.Toast;
import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;
import androidx.appcompat.widget.Toolbar;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import com.google.android.gms.tasks.OnCompleteListener;
import com.google.android.gms.tasks.Task;
import com.google.android.material.floatingactionbutton.FloatingActionButton;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
public class MainActivity extends AppCompatActivity {
private Toolbar tool;
private TextView textView;
private RecyclerView recyclerView;
private Button AddBtn;
RecyclerView.LayoutManager layoutManager;
private FirebaseAuth auth;
private DatabaseReference ref;
private String userID = "";
private ProgressDialog progressDialog;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
tool = findViewById(R.id.toolbar);
setSupportActionBar(tool);
//getSupportActionBar().setTitle("Today's Spending");
textView=findViewById(R.id.totalCashBack);
recyclerView =findViewById(R.id.recycle_view);
// recyclerView =(RecyclerView)findViewById(R.id.recycleView);
// layoutManager = new LinearLayoutManager(this);
// recyclerView.setLayoutManager(layoutManager);
AddBtn = findViewById(R.id.add_new);
auth = FirebaseAuth.getInstance();
userID = auth.getCurrentUser().getUid();
ref = FirebaseDatabase.getInstance().getReference().child("expenses").child(userID);
// if(userID !=null){
// try{
// ref = FirebaseDatabase.getInstance().getReference().child("expenses").child(userID);
//
// }catch (NullPointerException ex){
// ex.printStackTrace();
// }
// }
progressDialog = new ProgressDialog(this);
AddBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
addItem();
}
});
}
private void addItem() {
AlertDialog.Builder alert = new AlertDialog.Builder(this);
LayoutInflater layout = LayoutInflater.from(this);
View view = layout.inflate(R.layout.input_layout, null);
alert.setView(view);
final AlertDialog dialog = alert.create();
dialog.setCancelable(false);
final Spinner spinnerItem = view.findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<>(this, android.R.layout.simple_list_item_1, getResources().getStringArray(R.array.category));
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinnerItem.setAdapter(adapter);
final EditText amount = view.findViewById(R.id.insert_amount);
final EditText notes = view.findViewById(R.id.insert_note);
final Button saveButton = view.findViewById(R.id.add_button);
final Button cancelButton = view.findViewById(R.id.cancel_button);
saveButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
String amountGet = amount.getText().toString();
String notesGet = notes.getText().toString();
String categoryGet = spinnerItem.getSelectedItem().toString();
Drawable icon = getResources().getDrawable(R.drawable.error);
if(amountGet.isEmpty()){
amount.setError("Please enter an amount!!!", icon );
return;
}
if(notesGet.isEmpty()){
notes.setError("Please enter a notes!!!", icon );
return;
}
if(categoryGet.equals("Select a Category")){
Toast.makeText(MainActivity.this, "Please select a valid category", Toast.LENGTH_SHORT).show();
}
else{
progressDialog.setMessage("Had added the information into database");
progressDialog.setCanceledOnTouchOutside(false);
progressDialog.show();
String id = ref.push().getKey();
DateFormat format = new SimpleDateFormat("dd-MM-yyyy");
Calendar calendar = Calendar.getInstance();
String date = format.format(calendar.getTime());
Data inform = new Data(categoryGet, date, id, notesGet, Integer.parseInt(amountGet));
ref.child(id).setValue(inform).addOnCompleteListener(new OnCompleteListener<Void>() {
#Override
public void onComplete(#NonNull Task<Void> task) {
if(task.isSuccessful()){
Toast.makeText(MainActivity.this, "Information added successfully", Toast.LENGTH_SHORT).show();
}else{
Toast.makeText(MainActivity.this, "Fail to add the information", Toast.LENGTH_SHORT).show();
}
progressDialog.dismiss();
}
});
}
dialog.dismiss();
}
});
cancelButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
dialog.dismiss();
}
});
}
}
MainActivity.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#000"
android:orientation="vertical"
tools:context=".MainActivity">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<androidx.appcompat.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="#ffff00"
android:elevation="4dp" />
<TextView
android:id="#+id/totalCashBack"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginTop="5dp"
android:gravity="center"
android:text=" Total Cash Back = RM 0"
android:textColor="#fff"
android:textSize="20sp"
android:textStyle="bold" />
<androidx.coordinatorlayout.widget.CoordinatorLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recycle_view"
android:layout_width="match_parent"
android:layout_height="556dp" />
</androidx.coordinatorlayout.widget.CoordinatorLayout>
</LinearLayout>
<Button
android:id="#+id/add_new"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="bottom|end"
android:layout_margin="16dp"
android:backgroundTint="#ffff00"
android:text="Add"
app:fabSize="normal" />
</LinearLayout>
InputLayout.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:elevation="10dp"
app:cardElevation="10dp"
android:layout_margin="10dp"
android:orientation="vertical"
android:layout_height="match_parent">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:background="#000"
android:layout_margin="10dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:gravity="center">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="What did you had spend on ?"
android:gravity="center"
android:textColor="#fff"
android:textStyle="bold"
android:layout_margin="5dp"
android:textSize="20sp"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical">
<Spinner
android:id="#+id/spinner"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:background="#ffff00"
android:entries="#array/category"/>
<EditText
android:id="#+id/insert_amount"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Please enter a amount:"
android:textColor="#fff"
android:inputType="number"
android:textColorHint="#fff"/>
<EditText
android:id="#+id/insert_note"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:hint="Please enter a note:"
android:textColor="#fff"
android:textColorHint="#fff"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="horizontal">
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1">
<Button
android:id="#+id/cancel_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Cancel"
android:textAllCaps="false"
android:textColor="#000"
android:textStyle="bold"
android:background="#fff"
android:layout_margin="2dp"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1">
<Button
android:id="#+id/add_button"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Add Transaction"
android:textAllCaps="false"
android:textColor="#000"
android:textStyle="bold"
android:background="#ffff00"
android:layout_margin="2dp"/>
</RelativeLayout>
</LinearLayout>
</LinearLayout>
</androidx.cardview.widget.CardView>
strings.xml
<resources>
<string name="app_name">PracticalAssignment</string>
<string-array name="category">
<item>Select a category</item>
<item>Petrol Spend</item>
<item>Groceries Spend</item>
<item>eWallet Transaction</item>
<item>Other Eligible Spend</item>
</string-array>
</resources>

You have to create an adapter class and add with your recycler view.
The basic snippet to set adapter to recycler view is like bellow
YourAdater adapter = YourAdater();
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
recyclerView.setAdapter(adapter);
for more detail that how to create a RecyclerView AdapterClass you can see this or this

xml file doesnt show when app is running for some reason

Hi when i run my application for some reason it doesnt run my xml file in the application theres no error or anything but the xml doesnt show.
What the app looks like when it runs (missing home_items xml): https://gyazo.com/1f701b1790f6688d7242eaa5774a3dae
What the home_items looks like: https://gyazo.com/d697abdcd5a4c3d3b2064729fcaa9274
home_items.xml:
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<de.hdodenhof.circleimageview.CircleImageView
android:id="#+id/profileImage"
android:layout_width="56dp"
android:layout_height="56dp"
android:layout_margin="8dp"
android:src="#drawable/ic_person"
app:civ_border_color="#434343"
app:civ_border_width="1dp" />
<LinearLayout
android:layout_width="match_parent"
android:layout_height="60dp"
android:layout_marginTop="8dp"
android:layout_marginBottom="8dp"
android:layout_toEndOf="#+id/profileImage"
android:gravity="center_vertical"
android:orientation="vertical">
<TextView
android:id="#+id/nameTv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="Username"
android:textColor="#000"
android:textStyle="bold" />
<TextView
android:id="#+id/timeTv"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="2h"
android:textColor="#000" />
</LinearLayout>
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="220dp"
android:layout_below="#+id/profileImage"
android:scaleType="centerCrop" />
<LinearLayout
android:id="#+id/linearLayout"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/imageView"
android:orientation="horizontal">
<ImageButton
android:id="#+id/likeBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:background="#drawable/ic_heart" />
<ImageButton
android:id="#+id/commentBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:background="#drawable/ic_comment" />
<ImageButton
android:id="#+id/shareBtn"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_margin="8dp"
android:background="#drawable/ic_share" />
</LinearLayout>
<TextView
android:id="#+id/descTv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/linearLayout"
android:paddingStart="8dp"
android:paddingEnd="8dp"
android:text="Description"
android:textStyle="bold" />
<TextView
android:id="#+id/likeCountTv"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_below="#+id/descTv"
android:paddingStart="8dp"
android:paddingEnd="8dp"
android:text="100 likes"
android:textStyle="bold" />
</RelativeLayout>
HomeAdapter.java
package com.example.soulforge.adapter;
import android.content.Context;
import android.graphics.Color;
import android.graphics.drawable.ColorDrawable;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageButton;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;
import com.bumptech.glide.Glide;
import com.example.soulforge.R;
import com.example.soulforge.fragments.Home;
import com.example.soulforge.model.HomeModel;
import java.util.List;
import java.util.Random;
import de.hdodenhof.circleimageview.CircleImageView;
public class HomeAdapter extends RecyclerView.Adapter<HomeAdapter.HomeHolder>{
private List<HomeModel> list;
Context context;
public HomeAdapter(List<HomeModel> list, Context context) {
this.list = list;
this.context = context;
}
#NonNull
#Override
public HomeHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.home_items,parent, false);
return new HomeHolder(view);
}
#Override
public void onBindViewHolder(#NonNull HomeHolder holder, int position) {
holder.userNameTv.setText(list.get(position).getUserName());
holder.timeTv.setText(""+list.get(position).getTimestamp());
int count = list.get(position).getLikeCount();
if(count ==0){
holder.likeCountTv.setVisibility(View.INVISIBLE);
}else if (count == 1){
holder.likeCountTv.setText(count + " like");
}else{
holder.likeCountTv.setText(count + " likes");
}
holder.descriptionTv.setText(list.get(position).getDescription());
Random random = new Random();
int color = Color.argb(255, random.nextInt(256), random.nextInt(256), random.nextInt(256));
Glide.with(context.getApplicationContext())
.load(list.get(position).getProfileImage())
.placeholder(R.drawable.ic_person)
.timeout(6500)
.into(holder.profileImage);
Glide.with(context.getApplicationContext())
.load(list.get(position).getImageUrl())
.placeholder(new ColorDrawable(color))
.timeout(7000)
.into(holder.imageView);
}
#Override
public int getItemCount() {
return list.size();
}
static class HomeHolder extends RecyclerView.ViewHolder{
private CircleImageView profileImage;
private TextView userNameTv, timeTv, likeCountTv, descriptionTv;
private ImageView imageView;
private ImageButton likeBtn, commentBtn, shareBtn;
public HomeHolder(#NonNull View itemView) {
super(itemView);
profileImage = itemView.findViewById(R.id.profileImage);
imageView = itemView.findViewById(R.id.imageView);
userNameTv = itemView.findViewById(R.id.nameTv);
timeTv = itemView.findViewById(R.id.timeTv);
likeCountTv = itemView.findViewById(R.id.likeCountTv);
likeBtn = itemView.findViewById(R.id.likeBtn);
commentBtn = itemView.findViewById(R.id.commentBtn);
shareBtn = itemView.findViewById(R.id.shareBtn);
descriptionTv = itemView.findViewById(R.id.descTv);
}
}
}
Hi im wondering whats the issue and why the home_items doesnt show in my application.

build -> clean project
then
build -> Rebuild project
then Run

Go to
File -> Invalidate Caches/ Restart -> Invalidate and restart
It fixes minor xml bugs
If not,
Post more of your adapter code
Updated:
Try adding this to your adapter:
#Override
public int getItemViewType(int position)
{
return position;
}
Updated:
Try this again in adapter:
in your onCreateViewHolder:
return new HomeAdapter.HomeHolder(view);

How do I fix my FirebaseRecyclerAdapter on a fragment?

I am working on this application and I'm trying to show my "expenses" database data in my personal fragment. I have created a recycler view file to replace the default layout. I am struggling to make this work. Can anyone help with the FirebaseRecycler Adapter and the holder class? I am not able to make this work, my fragment display the default layout with no information. I have tried and follow some codes but it is not working.
here is my personal fragment where the recycler view should appear
package uk.brighton.ama75.project;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Adapter;
import android.widget.TextView;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.firebase.ui.database.FirebaseRecyclerOptions;
import com.google.firebase.auth.FirebaseAuth;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.google.firebase.database.Query;
import java.time.chrono.JapaneseDate;
import androidx.annotation.NonNull;
import androidx.annotation.Nullable;
import androidx.fragment.app.Fragment;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
public class personalFragment extends Fragment {
private FirebaseAuth mAuth;
private String currentUserID;
private DatabaseReference databaseReference;
private RecyclerView recyclerView;
private Adapter adapter;
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View myView = inflater.inflate(R.layout.fragment_personal, container, false);
mAuth = FirebaseAuth.getInstance();
currentUserID = mAuth.getCurrentUser().getUid();
databaseReference = FirebaseDatabase.getInstance().getReference().child("Expenses").child(currentUserID);
recyclerView = myView.findViewById(R.id.recycler_expense);
LinearLayoutManager layoutManager = new LinearLayoutManager(getActivity());
layoutManager.setStackFromEnd(true);
layoutManager.setReverseLayout(true);
recyclerView.setHasFixedSize(true);
recyclerView.setLayoutManager(layoutManager);
return myView;
}
#Override
public void onStart() {
super.onStart();
Query query = FirebaseDatabase.getInstance()
.getReference()
.child("expenses")
.limitToLast(5);
FirebaseRecyclerOptions<PersonalExpenses> options =
new FirebaseRecyclerOptions.Builder<PersonalExpenses>()
.setQuery(query, PersonalExpenses.class)
.build();
FirebaseRecyclerAdapter adapter = new FirebaseRecyclerAdapter<PersonalExpenses, MyViewHolder>(options) {
#Override
protected void onBindViewHolder(#NonNull MyViewHolder holder, int position, #NonNull PersonalExpenses model) {
holder.setDate(model.getDate());
holder.setDescription(model.getDescription());
holder.setAmount(model.getAmount());
holder.setType(model.getType());
}
#NonNull
#Override
public MyViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext())
.inflate(R.layout.expense_recycler, parent, false);
return new MyViewHolder(view);
}
};
recyclerView.setAdapter(adapter);
}
#Override
public void onStop() {
super.onStop();
}
public static class MyViewHolder extends RecyclerView.ViewHolder {
private final View mView;
public MyViewHolder(View itemView) {
super(itemView);
mView = itemView;
}
private void setDate(String date) {
TextView mDate = mView.findViewById(R.id.date_income);
mDate.setText(date);
}
private void setType(String type) {
TextView mType = mView.findViewById(R.id.type_txt);
mType.setText(type);
}
private void setDescription(String description) {
TextView mNote = mView.findViewById(R.id.note_txt);
mNote.setText(description);
}
private void setAmount(String amount) {
TextView mAmount = mView.findViewById(R.id.amount_income);
String stramount = String.valueOf(amount);
mAmount.setText(stramount);
}
}
}
This is the expenses recycler view file
<?xml version="1.0" encoding="utf-8"?>
<androidx.cardview.widget.CardView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="#+id/expense_recycler"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:elevation="5dp"
app:cardElevation="5dp">
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="5dp"
android:orientation="horizontal">
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1">
<TextView
android:id="#+id/date_income"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="6 June 2019"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="2">
<TextView
android:id="#+id/type_txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:maxLines="1"
android:text="Type"
android:textAlignment="center"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />
<TextView
android:id="#+id/note_txt"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_below="#+id/type_txt"
android:text="#string/description"
android:textAlignment="center"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="3
">
<TextView
android:id="#+id/amount_income"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="0000"
android:textAlignment="center"
android:textAppearance="?android:textAppearanceSmall"
android:textStyle="bold" />
</RelativeLayout>
</LinearLayout>
</androidx.cardview.widget.CardView>
This is the personal layout
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
xmlns:card_view="http://schemas.android.com/apk/res-auto"
android:orientation="vertical"
android:background="#FFF1F3FC"
android:layout_width="match_parent"
android:layout_height="match_parent">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
app:cardElevation="5dp"
android:elevation="10dp"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="match_parent"
android:orientation="horizontal"
android:layout_height="wrap_content">
<RelativeLayout
android:layout_width="0dp"
android:layout_weight="1"
android:gravity="center"
android:layout_margin="10dp"
android:layout_height="wrap_content"
tools:ignore="Suspicious0dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#android:color/black"
android:id="#+id/expenses"
android:text="expense"/>
</RelativeLayout>
<RelativeLayout
android:layout_width="0dp"
android:layout_weight="3"
android:gravity="center"
android:layout_margin="10dp"
android:layout_height="wrap_content"
tools:ignore="Suspicious0dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/expense_txt"
android:textAppearance="?android:textAppearanceMedium"
android:textColor="#android:color/black"
android:text="000.00"/>
</RelativeLayout>
</LinearLayout>
</androidx.cardview.widget.CardView>
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:id="#+id/recycler_expense"
android:layout_height="match_parent"/>
</LinearLayout>

I believe you are missing these two main code.
Set adapter.startListening() inside onStart()
Set adapter.stopListening() inside onStop()
Make sure to put the code before the scope end of onStart() as you are performing a lot of operations and setting your adapter above.

Setting Up Horizontal RecyclerView

I want to add 10dp padding for my first tile in recycler View.
Just Like in the Book My show app the first App has 10dp padding (assume) then the padding between two tiles (suppose 5dp).
Similarly Last tile also have 10dp (assume) padding in the end
I'm adding my code of the recycler view If anyone wants to add something in it
RecyclerMetroAdapter.java
package com.example.android.indianmetro;
import android.content.Context;
import android.graphics.Bitmap;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import com.bumptech.glide.Glide;
import java.util.ArrayList;
public class RecyclerViewAdapter extends
RecyclerView.Adapter<RecyclerViewAdapter.ViewHolder> {
private static final String TAG = "RecyclerViewAdapter";
private ArrayList<String> mPlaceNames = new ArrayList<>();
private ArrayList<String> mPlaceImageUrl = new ArrayList<>();
private ArrayList<String> mPlaceMetroDistance = new ArrayList<>();
private ArrayList<String> mClosestMetro = new ArrayList<>();
private Context mContext;
public RecyclerViewAdapter(Context context, ArrayList<String> placeNames, ArrayList<String> placeImageUrl,
ArrayList<String> placeMetroDistance, ArrayList<String> closestMetro ) {
mPlaceNames = placeNames;
mPlaceImageUrl = placeImageUrl;
mPlaceMetroDistance = placeMetroDistance;
mClosestMetro = closestMetro;
mContext = context;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup viewGroup, int i) {
View view = LayoutInflater.from(viewGroup.getContext()).inflate(R.layout.horizontal_item, viewGroup, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder viewHolder, int i) {
Log.d(TAG, "onCreateViewHolder: called");
Glide.with(mContext)
.asBitmap()
.load(mPlaceImageUrl.get(i))
.into(viewHolder.placeImage);
viewHolder.placeName.setText(mPlaceNames.get(i));
viewHolder.placeMetroDistance.setText(mPlaceMetroDistance.get(i));
viewHolder.closestMetro.setText(mClosestMetro.get(i));
}
#Override
public int getItemCount() {
if (mPlaceNames.size() < 8){
return mPlaceNames.size();
} else return 8;
}
public class ViewHolder extends RecyclerView.ViewHolder{
ImageView placeImage;
TextView placeName;
TextView placeMetroDistance;
TextView closestMetro;
public ViewHolder(#NonNull View itemView) {
super(itemView);
placeImage = (ImageView) itemView.findViewById(R.id.image);
placeName = itemView.findViewById(R.id.textView);
placeMetroDistance = itemView.findViewById(R.id.textView2);
closestMetro = itemView.findViewById(R.id.placeMetroName);
}
}
}
Code of tiles I'm using inside my RecyclerView
horizontal_item.xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
<android.support.v7.widget.CardView
android:id="#+id/cardView2"
android:layout_width="120dp"
android:layout_height="140dp"
android:layout_marginStart="10dp"
android:layout_marginTop="8dp"
app:cardCornerRadius="10dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">
<ImageView
android:id="#+id/image"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:scaleType="centerCrop"
android:src="#drawable/delhi1" />
</android.support.v7.widget.CardView>
<TextView
android:id="#+id/textView"
android:layout_width="110dp"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="2dp"
android:ellipsize="end"
android:maxLines="1"
android:text="India Gate"
android:textColor="#color/darkHeading"
android:textSize="15sp"
android:textStyle="bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/cardView2" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="10dp"
android:layout_marginTop="36dp"
android:text="2.4 Km Away"
android:textColor="#color/blueAccent"
android:textSize="10sp"
android:textStyle="bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/cardView2" />
<ImageView
android:id="#+id/imageView2"
android:layout_width="10dp"
android:layout_height="10dp"
android:layout_marginStart="10dp"
android:layout_marginTop="24dp"
android:src="#drawable/ic_metro"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/cardView2" />
<TextView
android:id="#+id/placeMetroName"
android:layout_width="90dp"
android:layout_height="wrap_content"
android:layout_marginLeft="25dp"
android:layout_marginStart="25dp"
android:layout_marginTop="20dp"
android:ellipsize="end"
android:maxLines="1"
android:text="Central Secretariat"
android:textColor="#color/subHeading"
android:textSize="12sp"
android:textStyle="bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="#+id/cardView2" />
</android.support.constraint.ConstraintLayout>
Also if some one can suggest that how to make a tile fully visible from left and not allow any tile partially hidden from the left side

I guess you can try to set the padding in onBindViewHolder(),
for the first:
if (i == 0)
viewHolder.placeImage.setPadding(10, 5, 5, 5);
and for the last:
if (i == mPlaceImageUrl.size() - 1)
viewHolder.placeImage.setPadding(5, 5, 10, 5);
Change the numbers to what you like they are left->top->right->bottom padding.

Activities togglebutton when clicking a part of an image

I'm currently trying to make a small application in java, and I have encountered a small problem.
I need to activate a togglebutton when I touch a particular area of the image that I have provided.
I enclose the code of my pages.
main.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center_horizontal"
android:orientation="vertical"
android:padding="4dip" >
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:gravity="center"
android:orientation="horizontal" >
<Button
android:id="#+id/btnPag1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Lights"
tools:ignore="HardcodedText" >
</Button>
<Button
android:id="#+id/btnPag2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Automation"
tools:ignore="HardcodedText" >
</Button>
<Button
android:id="#+id/btnPag3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Garden"
tools:ignore="HardcodedText" />
</LinearLayout>
<android.support.v4.view.ViewPager
android:id="#+id/pager"
android:layout_width="match_parent"
android:layout_height="0px"
android:layout_weight="1" >
</android.support.v4.view.ViewPager>
</LinearLayout>
page1.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:background="#000000"
android:gravity="center_horizontal|center_vertical"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Light 1"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
<ToggleButton
android:id="#+id/toggleButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ToggleButton"
tools:ignore="HardcodedText" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Light 2"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
<ToggleButton
android:id="#+id/toggleButton2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ToggleButton"
tools:ignore="HardcodedText" />
<TextView
android:id="#+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Light 3"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
<ToggleButton
android:id="#+id/toggleButton3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ToggleButton"
tools:ignore="HardcodedText" />
<TextView
android:id="#+id/textView4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Light 4"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
<ToggleButton
android:id="#+id/toggleButton4"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ToggleButton"
tools:ignore="HardcodedText" />
<ImageView
android:id="#+id/imageView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:src="#drawable/casa"
tools:ignore="ContentDescription" />
</LinearLayout>
page2.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#000000"
android:gravity="center_horizontal|center_vertical"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Gate"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
<Button
android:id="#+id/button1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Activates"
tools:ignore="HardcodedText" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
page3.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:background="#000000"
android:gravity="center_horizontal|center_vertical"
android:orientation="vertical" >
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Irrigation"
android:textAppearance="?android:attr/textAppearanceLarge"
tools:ignore="HardcodedText" />
<ToggleButton
android:id="#+id/toggleButton1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="ToggleButton"
tools:ignore="HardcodedText" />
<TextView
android:id="#+id/textView2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text=""
android:textAppearance="?android:attr/textAppearanceLarge" />
</LinearLayout>
MercuryActivity.java
package it.anddev.bradipao.mercury;
// derived from http://thepseudocoder.wordpress.com/2011/10/05/android-page-swiping-using-viewpager/
import java.util.List;
import java.util.Vector;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.support.v4.view.ViewPager;
import android.view.View;
import android.view.View.OnClickListener;
import android.widget.Button;
public class MercuryActivity extends FragmentActivity implements Page1Fragment.OnPageListener {
// list contains fragments to instantiate in the viewpager
List<Fragment> fragments = new Vector<Fragment>();
// page adapter between fragment list and view pager
private PagerAdapter mPagerAdapter;
// view pager
private ViewPager mPager;
// activity data
public String p2text,p3text;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
// creating fragments and adding to list
fragments.add(Fragment.instantiate(this,Page1Fragment.class.getName()));
fragments.add(Fragment.instantiate(this,Page2Fragment.class.getName()));
fragments.add(Fragment.instantiate(this,Page3Fragment.class.getName()));
// creating adapter and linking to view pager
this.mPagerAdapter = new PagerAdapter(super.getSupportFragmentManager(),fragments);
mPager = (ViewPager) super.findViewById(R.id.pager);
mPager.setAdapter(this.mPagerAdapter);
// upper bar button listener, allows direct page access
Button button = (Button)findViewById(R.id.btnPag1);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(0); // go to first page
}
});
button = (Button)findViewById(R.id.btnPag2);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(1); // go to second page
}
});
button = (Button)findViewById(R.id.btnPag3);
button.setOnClickListener(new OnClickListener() {
public void onClick(View v) {
mPager.setCurrentItem(2); // go to third page
}
});
}
// page 1 fragment listener implementation
#Override
public void onPage1(String s) {
// set activity data with received string
p2text = new String(s+" 2");
p3text = new String(s+" 3");
// page 2 fragment update
Page2Fragment f2 = (Page2Fragment) fragments.get(1);
f2.ptext = p2text;
// if page 2 view is already created, update
View v2 = f2.getView();
if (v2!=null) {
}
// page 3 fragment update
Page3Fragment f3 = (Page3Fragment) fragments.get(2);
f3.ptext = p3text;
// if page 3 view is already created, update
View v3 = f3.getView();
if (v3!=null) {
}
}
}
Page1Fragment.java
package it.anddev.bradipao.mercury;
import android.app.Activity;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
public class Page1Fragment extends Fragment {
public String ptext="..PAGE 1..";
// activity listener interface
private OnPageListener pageListener;
public interface OnPageListener {
public void onPage1(String s);
}
// onAttach : set activity listener
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
// if implemented by activity, set listener
if(activity instanceof OnPageListener) {
pageListener = (OnPageListener) activity;
}
// else create local listener (code never executed in this example)
else pageListener = new OnPageListener() {
#Override
public void onPage1(String s) {
Log.d("PAG1","Button event from page 1 : "+s);
}
};
}
// onCreateView :
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
// fragment not when container null
if (container == null) {
return null;
}
// inflate view from layout
View view = (LinearLayout)inflater.inflate(R.layout.page1,container,false);
// update text
return view;
}
// set text helper function
}
Page2Fragment.java
package it.anddev.bradipao.mercury;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.LinearLayout;
public class Page2Fragment extends Fragment {
public String ptext="..PAGE 2..";
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
// fragment not when container null
if (container == null) {
return null;
}
// inflate view from layout
View view = (LinearLayout)inflater.inflate(R.layout.page2,container,false);
// update text
return view;
}
// set text helper function
}
Page3Fragment.java
package it.anddev.bradipao.mercury;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.LinearLayout;
public class Page3Fragment extends Fragment {
Button btnWrite;
public String ptext="..PAGE 3..";
public View onCreateView(LayoutInflater inflater,ViewGroup container,Bundle savedInstanceState) {
// fragment not when container null
if (container == null) {
return null;
}
// inflate view from layout
View view = (LinearLayout)inflater.inflate(R.layout.page3,container,false);
// update text
return view;
}
}
PageAdapter.java
package it.anddev.bradipao.mercury;
import java.util.List;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
public class PagerAdapter extends FragmentPagerAdapter {
// fragments to instantiate in the viewpager
private List<Fragment> fragments;
// constructor
public PagerAdapter(FragmentManager fm,List<Fragment> fragments) {
super(fm);
this.fragments = fragments;
}
// return access to fragment from position, required override
#Override
public Fragment getItem(int position) {
return this.fragments.get(position);
}
// number of fragments in list, required override
#Override
public int getCount() {
return this.fragments.size();
}
}