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Getting duplicated cardviews using SwipeRefresh Layout

So here is my problem, I got an API that gives me the lastest news of many sources. Each one of them goes with a cardview. The problem here is, while I'm using the swipeRefresh, it gets duplicated cardViews with the same news, like if I have 10 news, it duplicates to 20 with the same ones.
Here is my code where I apply the swipeRefresh:
package com.example.newsapp4;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import androidx.swiperefreshlayout.widget.SwipeRefreshLayout;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Toast;
import com.example.newsapp4.Model.Articles;
import com.example.newsapp4.Model.Headlines;
import java.util.ArrayList;
import java.util.List;
import java.util.Locale;
import retrofit2.Call;
import retrofit2.Callback;
import retrofit2.Response;
public class bbcnews extends AppCompatActivity {
Adapter adapter;
Intent intencion;
RecyclerView recyclerView;
public static String source = "My Source";
public static String API_KEY = "My API Key";
SwipeRefreshLayout srl;
List<Articles> articles = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_bbcnews);
srl = findViewById(R.id.swipeRefresh);
srl.setOnRefreshListener(new SwipeRefreshLayout.OnRefreshListener() {
#Override
public void onRefresh() {
retrieveJson(source, API_KEY);
}
});
recyclerView = findViewById(R.id.recyclerView1);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
adapter = new Adapter(bbcnews.this,articles);
recyclerView.setAdapter(adapter);
retrieveJson(source, API_KEY);
}
public void retrieveJson(String source, String apiKey){
srl.setRefreshing(true);
Call<Headlines> call = ApiClient.getInstance().getApi().getHeadlines(source, apiKey);
call.enqueue(new Callback<Headlines>() {
#Override
public void onResponse(Call<Headlines> call, Response<Headlines> response) {
if(response.isSuccessful() && response.body().getArticles() != null){
srl.setRefreshing(false);
articles.clear();
articles = response.body().getArticles();
adapter.setArticles(articles);
}
}
#Override
public void onFailure(Call<Headlines> call, Throwable t) {
srl.setRefreshing(false);
Toast.makeText(bbcnews.this, t.getLocalizedMessage(), Toast.LENGTH_SHORT).show();
}
});
}
public String getCountry(){
Locale locale = Locale.getDefault();
String country = locale.getCountry();
return country.toLowerCase();
}
public void aPerfil(View vista){
intencion = new Intent(this, profile_activity.class);
startActivity(intencion);
}
}
I don't think that I need to put the xml code with the progressbar and the swipeRefresh but here are both:
This one is the Items.xml where I created the cardView:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content"
xmlns:app="http://schemas.android.com/apk/res-auto">
<androidx.cardview.widget.CardView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
app:cardElevation="4dp"
android:id="#+id/cardView"
app:cardCornerRadius="10dp">
<FrameLayout
android:layout_width="match_parent"
android:layout_height="200dp">
<ProgressBar
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:id="#+id/loader"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/image"
android:scaleType="centerCrop"
android:src="#drawable/img"/>
<ImageView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#drawable/gradient" />
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="TITLE"
android:textSize="20dp"
android:padding="10dp"
android:fontFamily="#font/g_bold"
android:textColor="#color/white"
android:id="#+id/tvTitle"/>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_gravity="bottom"
android:orientation="horizontal">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Source"
android:textSize="16dp"
android:padding="10dp"
android:ems="15"
android:fontFamily="#font/g_light"
android:textColor="#color/white"
android:id="#+id/tvSource"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:fontFamily="#font/g_light"
android:gravity="right"
android:text="Date"
android:textColor="#color/white"
android:padding="10dp"
android:textSize="16dp"
android:id="#+id/tvDate"/>
</LinearLayout>
</FrameLayout>
</androidx.cardview.widget.CardView>
</LinearLayout>
And here the one with the swipeRefresh in the recyclerView:
<?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:orientation="vertical"
android:background="#color/white"
tools:context=".bbcnews">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="DINGO BBC NEWS"
android:textColor="#color/black"
android:textSize="20sp"
android:fontFamily="#font/g_bold"
android:background="#color/white"
android:padding="10dp"
android:textAlignment="center"/>
<GridLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_margin="10dp"
android:paddingTop="10dp"
android:paddingBottom="10dp"
android:columnCount="2"
android:paddingLeft="20dp"
android:paddingRight="5dp"
android:background="#drawable/black_background"
android:rowCount="2">
<EditText
android:id="#+id/editTextTextPersonName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:ems="10"
android:hint="Search"
android:textColor="#color/grey"
android:textColorHint="#color/grey"
android:padding="5dp"
android:layout_column="0"
android:background="#drawable/black_background"
android:layout_row="0"
android:layout_columnWeight="1"
android:inputType="textPersonName" />
<Button
android:id="#+id/button2"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingRight="20dp"
android:background="#drawable/black_background"
android:drawableRight="#drawable/ic_baseline_search_24"
android:layout_column="1"
android:layout_row="0"/>
</GridLayout>
<androidx.swiperefreshlayout.widget.SwipeRefreshLayout
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/swipeRefresh">
<androidx.recyclerview.widget.RecyclerView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:layout_marginTop="5dp"
android:id="#+id/recyclerView1"/>
</androidx.swiperefreshlayout.widget.SwipeRefreshLayout>
</LinearLayout>
Also this is my adapter.java code:
package com.example.newsapp4;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ImageView;
import android.widget.TextView;
import androidx.annotation.NonNull;
import androidx.cardview.widget.CardView;
import androidx.recyclerview.widget.RecyclerView;
import com.example.newsapp4.Model.Articles;
import com.squareup.picasso.Picasso;
import java.util.List;
public class Adapter extends RecyclerView.Adapter<Adapter.ViewHolder> {
Context context;
List<Articles> articles;
public Adapter(Context context, List<Articles> articles) {
this.context = context;
this.articles = articles;
}
#NonNull
#Override
public ViewHolder onCreateViewHolder(#NonNull ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.items, parent, false);
return new ViewHolder(view);
}
#Override
public void onBindViewHolder(#NonNull ViewHolder holder, int position) {
final Articles a = articles.get(position);
String imageUrl = a.getUrlToImage();
holder.tvTitle.setText(a.getTitle());
holder.tvSource.setText(a.getSource().getName());
holder.tvDate.setText(a.getPublishedAt());
Picasso.with(context).load(imageUrl).into(holder.imageView);
}
#Override
public int getItemCount() {
return articles.size();
}
public static class ViewHolder extends RecyclerView.ViewHolder {
TextView tvTitle,tvSource,tvDate;
ImageView imageView;
CardView cardView;
public ViewHolder(#NonNull View itemView) {
super(itemView);
tvTitle = itemView.findViewById(R.id.tvTitle);
tvSource = itemView.findViewById(R.id.tvSource);
tvDate = itemView.findViewById(R.id.tvDate);
imageView = itemView.findViewById(R.id.image);
cardView = itemView.findViewById(R.id.cardView);
}
}
public void setArticles(List<Articles> articles) {
this.articles.addAll(articles);
int count = getItemCount();
notifyItemRangeInserted(count, count + articles.size());
}
}
Thanks for your time!

// Clear adapter list before add to list.
public void setArticles(List<Articles> articles) {
if(this.articles!=null && this.articles.size()>0)
this.articles.clear();
this.articles.addAll(articles);
int count = getItemCount();
notifyItemRangeInserted(count, count + articles.size());
}

From what I can understand in your code is on the success of API call after Swipe Refresh which is this section here
articles.clear();
articles = response.body().getArticles();
adapter.setArticles(articles);
You are here clearing the article inside your activity, but the thing is inside your Adapter there is already another list of articles, you are not clearing them.
And then when you make the adapter.setArticles(articles); call, inside the following function, your articles get added to the already existing list of articles and thus, the duplicate list.
public void setArticles(List<Articles> articles) {
this.articles.addAll(articles);
int count = getItemCount();
notifyItemRangeInserted(count, count + articles.size());
}
To fix this you can make the following modifications to your function.
public void setArticles(List<Articles> articles, boolean clearAll) {
if(clearAll){ this.articles.clear(); }
this.articles.addAll(articles);
notifyDataSetChanged();
}
And then modify your function call as follows
adapter.setArticles(articles, true);
That way when the Boolean is true, it will clear the existing list. Also I would suggest you to replace the insert call with data set change call. Else you can make a separate function all together for adding elements and for clearing existing elements.

Image is visible but text is not visible in ListView

I am trying to create a custom layout for list view in android studio. I was able to successfully get image in the in ListView on runtime but wasn't able to print text in the list view . When i run my program in emulator it runs without any error but it doesn't show any text it only shows image from drawables.
MainActivity.java
import androidx.appcompat.app.AppCompatActivity;
import android.os.Bundle;
import android.widget.ListView;
public class MainActivity extends AppCompatActivity {
private final static String[] names={"A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A","A",
"A","A","A","A","A","A","A","A","A","A","A","A","A","A",};
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
ListView ls = findViewById((R.id.customlistview));
ls.setAdapter(new CustomListAdapter(getApplicationContext(),names,R.drawable.za));
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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="match_parent"
android:layout_height="match_parent"
tools:context=".MainActivity">
<ListView
android:id="#+id/customlistview"
android:layout_width="409dp"
android:layout_height="0dp"
android:layout_marginStart="16dp"
android:layout_marginTop="1dp"
android:layout_marginBottom="1dp"
app:layout_constraintBottom_toBottomOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
</androidx.constraintlayout.widget.ConstraintLayout>
CustomListAdapter.java
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;
public class CustomListAdapter extends BaseAdapter {
private final Context context;
private final String[] names;
private final int image;
private final LayoutInflater layoutInflater;
public CustomListAdapter(Context context,String[] names,int image) {
this.context=context;
this.image=image;
this.names=names;
layoutInflater= (LayoutInflater) this.context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}
#Override
public int getCount() {
return names.length;
}
#Override
public Object getItem(int position) {
return position;
}
#Override
public long getItemId(int position) {
return position;
}
#Override
public View getView(int position, View convertView, ViewGroup parent) {
View rootview;
rootview = layoutInflater.inflate(R.layout.list_item_layout, null);
TextView tv= rootview.findViewById(R.id.textView);
ImageView iv=rootview.findViewById(R.id.imageView);
tv.setText(names[position]);
iv.setImageResource(image);
return rootview;
}
}
list_item_layout.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"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal">
<TextView
android:id="#+id/textView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_weight="1"
android:height="70dp"
android:gravity="center"
android:text="TextView"
android:textSize="18sp" />
<ImageView
android:id="#+id/imageView"
android:layout_width="match_parent"
android:layout_height="70dp"
android:layout_weight="2"
app:srcCompat="#mipmap/ic_launcher" />
</LinearLayout>

The issue is in your list_item_layout file. There is an issue with match_parent in your layout try using below code
<?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"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:weightSum="3"
android:orientation="horizontal">
<TextView
android:id="#+id/textView"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_weight="1"
android:height="70dp"
android:gravity="center"
android:text="TextView"
android:textSize="18sp" />
<ImageView
android:id="#+id/imageView"
android:layout_width="0dp"
android:layout_height="70dp"
android:layout_weight="2"
app:srcCompat="#mipmap/ic_launcher" />

The problem was caused by the text colour , changing the colour of textview text in list_item_layout resolved the issue.

Android Studio RecyclerView wont show my data when i add toolbar at my `layout.xml` file

I created a page where it will show the firebase data in a RecyclerView. It work but I decided to put a toolbar at the top of the page to have a back function. After I put the toolbar in my layout file, the RecyclerView is not showing any data anymore. I think that my layout XML file is wrong. Thanks in advance for anyone helping.
Actity file
package com.example.attendanceappvqyfyp;
import androidx.appcompat.app.AlertDialog;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.content.DialogInterface;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.MenuItem;
import android.view.View;
import android.widget.EditText;
import android.widget.TextView;
import android.widget.Toast;
import android.widget.Toolbar;
import com.example.attendanceappvqyfyp.Interface.itemClickListener;
import com.example.attendanceappvqyfyp.Common.Common;
import com.example.attendanceappvqyfyp.Model.LecturerClass;
import com.example.attendanceappvqyfyp.Model.News;
import com.example.attendanceappvqyfyp.Model.Timetable;
import com.firebase.ui.database.FirebaseRecyclerAdapter;
import com.google.firebase.database.DatabaseReference;
import com.google.firebase.database.FirebaseDatabase;
import com.example.attendanceappvqyfyp.Common.Common;
public class LecturerClassList extends AppCompatActivity {
RecyclerView recyclerView;
RecyclerView.LayoutManager layoutManager;
FirebaseDatabase database;
DatabaseReference lecturerclass;
DatabaseReference news;
FirebaseRecyclerAdapter<LecturerClass,LecturerClassViewHolder> adapter;
TextView newscourse, newsclass;
EditText newsdescription;
Toolbar toolbar;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_lecturer_class_list);
//Firebase
database = FirebaseDatabase.getInstance();
lecturerclass = database.getReference("Class");
news = database.getReference("News");
recyclerView = (RecyclerView)findViewById(R.id.recycler_lecturerclass);
recyclerView.setHasFixedSize(true);
layoutManager = new LinearLayoutManager(this);
recyclerView.setLayoutManager(layoutManager);
//Toolbar code
toolbar = findViewById(R.id.toolbar);
toolbar.setTitle("Class List");
toolbar.setNavigationIcon(R.drawable.ic_arrow_back_black_24dp);
loadLecturerClass(Common.currentLecturer.getName());
}
private void loadLecturerClass(String Lecturer) {
adapter = new FirebaseRecyclerAdapter<LecturerClass, LecturerClassViewHolder>(LecturerClass.class, R.layout.lecturerclass_item, LecturerClassViewHolder.class, lecturerclass.orderByChild("lecturer").equalTo(Lecturer)) {
#Override
protected void populateViewHolder(LecturerClassViewHolder lecturerClassViewHolder, LecturerClass lecturerClass, int i) {
lecturerClassViewHolder.lclasstitle.setText("Class :" + adapter.getRef(i).getKey());
lecturerClassViewHolder.ldate.setText("Day :" + lecturerClass.getDay());
lecturerClassViewHolder.ltime.setText("Time :" + lecturerClass.getTime());
lecturerClassViewHolder.lclassroom.setText("Classroom :" + lecturerClass.getClassroom());
lecturerClassViewHolder.lcourse.setText(lecturerClass.getCourse());
lecturerClassViewHolder.setItemClickListener(new itemClickListener() {
#Override
public void onClick(View view, int position, boolean isLongClick) {
//code later
}
});
}
};
recyclerView.setAdapter(adapter);
}
#Override
public boolean onContextItemSelected(MenuItem item) {
if(item.getTitle().equals(Common.News))
{
showNewsDialog(adapter.getRef(item.getOrder()).getKey(),adapter.getItem(item.getOrder()));
}
return super.onContextItemSelected(item);
}
private void showNewsDialog(final String course, final LecturerClass item) {
AlertDialog.Builder alertDialog = new AlertDialog.Builder(LecturerClassList.this);
alertDialog.setTitle("Make Announcement");
alertDialog.setMessage("Make announcement about this class.");
LayoutInflater inflater = this.getLayoutInflater();
View lecturer_make_news = inflater.inflate(R.layout.activity_lecturer_make_news, null);
newscourse = lecturer_make_news.findViewById(R.id.NewsCourse);
newsclass = lecturer_make_news.findViewById(R.id.NewsClass);
newsdescription = lecturer_make_news.findViewById(R.id.NewsDescription);
newscourse.setText("Course: "+item.getCourse());
newsclass.setText("Subject: " + course);
alertDialog.setView(lecturer_make_news);
alertDialog.setPositiveButton("Post", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int i) {
if(newsdescription.getText().toString().isEmpty()){
Toast.makeText(LecturerClassList.this, "Post cancel, description cannot be empty.", Toast.LENGTH_SHORT).show();
}
else {
News lnews = new News(
item.getCourse(),
course,
newsdescription.getText().toString()
);
news.child(String.valueOf(System.currentTimeMillis())).setValue(lnews);
Toast.makeText(LecturerClassList.this, "Announcement post successfully.", Toast.LENGTH_SHORT).show();
finish();
}
}
});
alertDialog.setNegativeButton("Cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();;
}
});
alertDialog.show();
}
}
Activity file for viewholder
package com.example.attendanceappvqyfyp;
import android.view.ContextMenu;
import android.view.View;
import android.widget.TextView;
import com.example.attendanceappvqyfyp.Common.Common;
import androidx.recyclerview.widget.RecyclerView;
import com.example.attendanceappvqyfyp.Interface.itemClickListener;
public class LecturerClassViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnCreateContextMenuListener {
public TextView lclasstitle, ldate, ltime, lclassroom, lcourse;
private itemClickListener itemClickListener;
public LecturerClassViewHolder(View itemView) {
super(itemView);
lclasstitle = (TextView)itemView.findViewById(R.id.lclasstitle);
ldate = (TextView)itemView.findViewById(R.id.ldate);
ltime = (TextView)itemView.findViewById(R.id.ltime);
lclassroom = (TextView)itemView.findViewById(R.id.lclassroom);
lcourse = (TextView)itemView.findViewById(R.id.lcourse);
itemView.setOnCreateContextMenuListener(this);
itemView.setOnClickListener(this);
}
public void setItemClickListener(itemClickListener itemClickListener) {
this.itemClickListener = itemClickListener;
}
#Override
public void onClick(View view) {
itemClickListener.onClick(view, getAdapterPosition(), false);
}
public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {
menu.setHeaderTitle("Select");
menu.add(0,0,getAdapterPosition(), Common.News);
}
}
Layout file for recyclerview
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.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="match_parent"
android:layout_height="match_parent"
tools:context=".LecturerClassList">
<android.widget.Toolbar
android:id="#+id/toolbar"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:background="?attr/colorPrimary"
android:minHeight="?attr/actionBarSize"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:theme="#style/ThemeOverlay.AppCompat.Dark" />
<androidx.recyclerview.widget.RecyclerView
android:id="#+id/recycler_lecturerclass"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:scrollbars="vertical"
app:layout_constraintTop_toBottomOf="#+id/toolbar" />
</androidx.constraintlayout.widget.ConstraintLayout>
Layout file for itemview
<?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:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="160dp"
app:cardElevation="4dp"
android:layout_marginBottom="8dp"
>
<RelativeLayout
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/lclasstitle"
android:layout_width="match_parent"
android:layout_height="40dp"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/ldate"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignBottom="#id/lclasstitle"
android:layout_marginBottom="-40dp"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/ltime"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignBottom="#id/ldate"
android:layout_marginBottom="-40dp"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/lclassroom"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:gravity="center"
android:text=""
android:textColor="#android:color/black"
android:textSize="20sp" />
<TextView
android:id="#+id/lcourse"
android:layout_width="match_parent"
android:layout_height="40dp"
android:layout_alignParentBottom="true"
android:gravity="center"
android:text=""
android:visibility="invisible"
android:textColor="#android:color/black"
android:textSize="20sp" />
</RelativeLayout>
</androidx.cardview.widget.CardView>
Thanks to ZeePee for giving this link Display Back Arrow on Toolbar, although the toolbar didnt work for me, i change it back to actionbar and use the code from the link and it work.

Try adding horizontal constraints for Toolbar and Recycler View. After that you need to specify where do you want your single item widgets in Relative layout

null object reference on set adapter

I know that there are a lot of question like this, but i can't find one that can help me. Please pay no attention at strings that are hard coded or other things like that, i will fix. I don't see anything wrong in adapter class or in the fragments. I use Disco class for fill a place list, the Place class contains all the methods that after i use in the adapter.Can anyone help me please? Thank you.
Class MainActivity
package com.techmind.tourguideapp;
import android.support.design.widget.TabLayout;
import android.support.v4.app.FragmentManager;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentManager manager = getSupportFragmentManager();
ViewPager pager = findViewById(R.id.tourPager);
pager.setAdapter(new FragmentAdapter(manager));
TabLayout tabLayout = (TabLayout) findViewById(R.id.tabs);
tabLayout.setupWithViewPager(pager);
}
}
class Disco
package com.techmind.tourguideapp;
import java.util.ArrayList;
import java.util.List;
/**
* Created by Nahuel on 31.05.2018.
*/
public class Disco {
public static ArrayList<Places> initDiscoList(ArrayList<Places> places) {
places.add(new Places().
setAddress("via a").
setImage(1).
setName("casino").
setPhone("333").
setPrice("20€").
setHour("10:30"));
return places;
}
}
Class DiscoFragment
package com.techmind.tourguideapp;
import android.support.v4.app.Fragment;
import android.location.Location;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ListView;
import java.util.ArrayList;
import java.util.List;
/**
* Created by Nahuel on 31.05.2018.
*/
public class DiscoFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
ArrayList<Places> list = new ArrayList<>();
list = Disco.initDiscoList(list);
PlacesAdapter adapter = new PlacesAdapter(getActivity(), list);
View view = inflater.inflate(R.layout.row_item, container, false);
ListView listView = (ListView) view.findViewById(R.id.list_items);
listView.setAdapter(adapter);
return view;
}
}
Class FragmentAdapter
package com.techmind.tourguideapp;
import android.content.Context;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
/**
* Created by Nahuel on 31.05.2018.
*/
public class FragmentAdapter extends FragmentPagerAdapter {
public FragmentAdapter (FragmentManager fm) {
super(fm);
}
#Override
public Fragment getItem(int position) {
return new DiscoFragment();
}
#Override
public int getCount() {
return 3;
}
public CharSequence getPageTitle(int position) {
return "Gradara";
}
}
Class Places
package com.techmind.tourguideapp;
/**
* Created by Nahuel on 31.05.2018.
*/
public class Places {
private String name;
private String price;
private String phone;
private String Address;
private String hour;
private int image;
private final int NO_IMAGE = -1;
public Places () {
}
public String getHour() {
return hour;
}
public String getName() {
return name;
}
public String getPrice() {
return price;
}
public String getPhone() {
return phone;
}
public String getAddress() {
return Address;
}
public int getImage() {
return image;
}
public Places setName(String name) {
this.name = name;
return this;
}
public Places setHour(String hour) {
this.hour = hour;
return this;
}
public Places setPrice(String price) {
this.price = price;
return this;
}
public Places setPhone(String phone) {
this.phone = phone;
return this;
}
public Places setAddress(String address) {
Address = address;
return this;
}
public Places setImage(int image) {
this.image = image;
return this;
}
}
Class PlaceAdapter
package com.techmind.tourguideapp;
import android.content.Context;
import android.location.Location;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.ArrayAdapter;
import android.widget.ImageView;
import android.widget.TextView;
import java.util.List;
public class PlacesAdapter extends ArrayAdapter<Places> {
public PlacesAdapter(Context context, List<Places> places) {
super(context,-1, places);
}
public View getView (int position, ViewGroup parent, View convertView) {
View listView = convertView;
Places place = getItem(position);
if(listView == null) {
listView = LayoutInflater.from(getContext()).inflate(
R.layout.row_item, parent, false);
}
TextView location = listView.findViewById(R.id.locationName);
location.setText("casino");
TextView hour = listView.findViewById(R.id.txthour);
hour.setText("aaa");
TextView address = listView.findViewById(R.id.address);
address.setText("aaaaa");
TextView price = listView.findViewById(R.id.txtmoney);
price.setText("aaaaa");
TextView phone = listView.findViewById(R.id.phone);
phone.setText("aaaaa");
ImageView img = listView.findViewById(R.id.imgRow);
img.setImageResource(R.drawable.ic_launcher_background);
return listView;
}
}
Activity_Main.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:orientation="vertical"
tools:context="com.techmind.tourguideapp.MainActivity">
<android.support.design.widget.TabLayout
android:id="#+id/tabs"
android:layout_width="match_parent"
android:layout_height="wrap_content"
app:tabMaxWidth="0dp"
/>
<android.support.v4.view.ViewPager
android:id="#+id/tourPager"
android:layout_width="match_parent"
android:layout_height="wrap_content"/>
List_item.xml
</LinearLayout>
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent">
<ListView
android:id="#+id/list_items"
android:layout_width="wrap_content"
android:layout_height="wrap_content">
</ListView>
</LinearLayout>
Row_item.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<ImageView
android:id="#+id/imgRow"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:src="#drawable/gradara" />
<TextView
android:id="#+id/locationName"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:textSize="24sp"
android:textStyle="bold"
android:text=""/>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_weight="0.5">
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp">
<ImageView
android:id="#+id/positionIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:src="#mipmap/position"
android:layout_alignParentStart="true"/>
<TextView
android:id="#+id/txtPosition"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="#+id/positionIcon"
android:layout_marginTop="5dp"
android:text="" />
<TextView
android:id="#+id/address"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignBottom="#+id/positionIcon"
android:layout_toRightOf="#id/positionIcon"
android:text="" />
</RelativeLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp">
<ImageView
android:id="#+id/moneyIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:src="#mipmap/money"
android:layout_alignParentStart="true"/>
<TextView
android:id="#+id/txtmoney"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="#+id/moneyIcon"
android:layout_marginTop="15dp"
android:text="10€ - 20€" />
</LinearLayout>
<RelativeLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="5dp">
<ImageView
android:id="#+id/hourIcon"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:src="#mipmap/hour"
android:layout_alignParentStart="true"/>
<TextView
android:id="#+id/txthour"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_toEndOf="#+id/hourIcon"
android:layout_marginTop="15dp"
android:text="09:30 - 23:00" />
</RelativeLayout>
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="10dp">
<TextView
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Phone:"
android:layout_marginEnd="5dp"
android:textStyle="bold"/>
<TextView
android:id="#+id/phone"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="3334323560"
/>
</LinearLayout>
</LinearLayout>
</LinearLayout>

You said you got a null pointer on set adapter. Are you talking about
this line in file DiscoFragment?
listView.setAdapter(adapter)
if listView is null then the findViewByID didn't find a view. Or maybe something inside adapter is null. It is hard to tell from what you said.

i found the error in
ArrayList<Places> list = new ArrayList<>();
list = Disco.initDiscoList(list);
PlacesAdapter adapter = new PlacesAdapter(getActivity(), list);
View view = inflater.inflate(R.layout.row_item, container, false);
ListView listView = (ListView) view.findViewById(R.id.list_items);
listView.setAdapter(adapter);
return view;
}
When i use the inflate method the first parameter was wrong, i used the layout of the row instead of the listView layout.
Thank you for your answers, next times i will post logs and less useless code :)

How to move to next activtity with bundle the touch event is not working

guys in my project i need to click the item on the list and move to next activity using bundle i need to carry some data also, but i have some issue..
Please help me to move to next activity i can't understand what is the mistake i did,when i click on the item it is not even responding..
here i just use "e_name.setText("hiiii")" for testing purpose its not working.
AT THE END I HAVE MENTIONED MY LAYOUT CODES ALSO.
if possible please send me a link to learn more about custom adapter and list view..
//Main activity.java
package com.prematix.ashok.friday_9;
import android.app.ListActivity;
import android.content.Intent;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.Button;
import android.widget.EditText;
import android.widget.ListView;
import android.widget.Toast;
import java.util.ArrayList;
public class MainActivity extends AppCompatActivity {
EditText e_name, e_desig, e_salary;
Button save;
String itemNames[];
String itemDescriptions[];
ListView itemsListView;
ArrayList<Item> list = new ArrayList<>();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
e_name = (EditText) findViewById(R.id.ed_name);
e_desig = (EditText) findViewById(R.id.ed_desig);
e_salary = (EditText) findViewById(R.id.ed_salary);
save = (Button) findViewById(R.id.save);
itemsListView = (ListView) findViewById(R.id.mylist);
save.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
//create adapter object
CustomListAdapter adapter = new CustomListAdapter(getApplicationContext(), generateItemsList());
//set custom adapter as adapter to our list view
itemsListView.setAdapter(adapter);
}
private ArrayList<Item> generateItemsList() {
itemNames = new String[]{e_name.getText().toString()};
itemDescriptions = new String[]{e_desig.getText().toString()};
for (int i = 0; i < itemNames.length; i++) {
list.add(new Item(itemNames[i], itemDescriptions[i]));
}
return list;
}
});
itemsListView.setOnItemClickListener(new AdapterView.OnItemClickListener(){
#Override
public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {
e_name.setText("hiiiii");
}
});
// ListView itemsListView = (ListView)findViewById(R.id.list_view_items);
}
}
//CustommListAdapter.java
package com.prematix.ashok.friday_9;
import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.TextView;
import java.util.ArrayList;
/**
* Created by ${Nagaveni} on 2017-06-09.
*/
public class CustomListAdapter extends BaseAdapter {
private Context context;
private ArrayList<Item> items;
public CustomListAdapter(Context context,ArrayList<Item> items){
this.context = context;
this.items = items;
}
#Override
public int getCount() {
return items.size();
}
#Override
public Object getItem(int i) {
return items.get(i);
}
#Override
public long getItemId(int i) {
return i;
}
#Override
public View getView(int i, View view, ViewGroup viewGroup) {
if(view == null) {
view = LayoutInflater.from(context).inflate(R.layout.layout_list_view_row_items, viewGroup, false);
}
//get current item to be displayed
Item currentitem = (Item)getItem(i);
//get the text view for item name and item designation
TextView name = (TextView)view.findViewById(R.id.name);
TextView designation = (TextView)view.findViewById(R.id.desig);
TextView salary = (TextView)view.findViewById(R.id.salary);
//sets the text for item name and item designation from the current item object
name.setText(currentitem.getNames());
designation.setText(currentitem.getDesignation());
salary.setText("10,000");
//returns the view for current row
return view;
}
}
//here is my layout code
layout_list_view_items.xml
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="wrap_content">
<LinearLayout
android:layout_width="260dp"
android:layout_marginLeft="8dp"
android:layout_height="wrap_content"
android:orientation="vertical">
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="name"
android:id="#+id/name"
android:textStyle="bold"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="designation"
android:id="#+id/desig"
android:textStyle="bold"/>
<TextView
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:text="salary"
android:id="#+id/salary"
android:textStyle="bold"/>
</LinearLayout>
<LinearLayout
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:orientation="vertical"
android:layout_marginLeft="70dp">
<CheckBox
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:id="#+id/checkBox"
android:layout_weight="1" />
</LinearLayout>
</LinearLayout>
//activity_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:id="#+id/activity_main"
android:orientation="vertical"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:paddingBottom="#dimen/activity_vertical_margin"
android:paddingLeft="#dimen/activity_horizontal_margin"
android:paddingRight="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_vertical_margin"
tools:context="com.prematix.ashok.friday_9.MainActivity">
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="Name"
android:ems="10"
android:id="#+id/ed_name" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="Designation"
android:ems="10"
android:id="#+id/ed_desig" />
<EditText
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:inputType="textPersonName"
android:hint="Salary"
android:ems="10"
android:id="#+id/ed_salary" />
<Button
android:text="Save"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:id="#+id/save" />
<ListView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/mylist"/>
</LinearLayout>