How to build a Horizontal ListView with RecyclerView?

Question

I need to implement a horizontal listview in my Android application. I did a bit of research and came across How can I make a horizontal ListView in Android? and Horizontal

Answer 1

With the release of RecyclerView library, now you can align a list of images bind with text easily. You can use LinearLayoutManager to specify the direction in which you would like to orient your list, either vertical or horizontal as shown below.

You can download a full working demo from this post

Answer 2

recyclerView.setLayoutManager(new LinearLayoutManager(this,LinearLayoutManager.HORIZONTAL,false));

recyclerView.setAdapter(adapter);

Answer 3

 <HorizontalScrollView
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            >
        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:orientation="horizontal"
            android:scrollbars="vertical|horizontal" />
        </HorizontalScrollView>

    import androidx.appcompat.app.AppCompatActivity;
    import android.content.Context;
    import android.content.ContextWrapper;
    import android.graphics.Bitmap;
    import android.graphics.BitmapFactory;
    import android.os.AsyncTask;
    import android.os.Bundle;
    import android.os.Environment;
    import android.view.View;
    import android.widget.ImageView;
    import android.widget.Toast;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.FileNotFoundException;
    import java.io.FileOutputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.net.HttpURLConnection;
    public class MainActivity extends AppCompatActivity
     {
        ImageView mImageView1;
        Bitmap bitmap;
        String mSavedInfo;
        @Override
        protected void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);
            setContentView(R.layout.activity_main);
            mImageView1 = (ImageView) findViewById(R.id.image);
        }
        public Bitmap getBitmapFromURL(String src) {
            try {
                java.net.URL url = new java.net.URL(src);
                HttpURLConnection connection = (HttpURLConnection) url.openConnection();
                connection.setDoInput(true);
                connection.connect();
                InputStream input = connection.getInputStream();
                Bitmap myBitmap = BitmapFactory.decodeStream(input);
                return myBitmap;
            } catch (IOException e) {
                e.printStackTrace();
                return null;
            }
        }
        public void button2(View view) {
            new DownloadImageFromTherad().execute();
        }
        private class DownloadImageFromTherad extends AsyncTask<String, Integer, String> {
            @Override
            protected String doInBackground(String... params) {
                bitmap = getBitmapFromURL("https://cdn.pixabay.com/photo/2016/08/08/09/17/avatar-1577909_960_720.png");
                return null;
            }

            @Override
            protected void onPostExecute(String s) {
                super.onPostExecute(s);
                File sdCardDirectory = Environment.getExternalStorageDirectory();
                File image = new File(sdCardDirectory, "test.png");
                boolean success = false;
                FileOutputStream outStream;
                mSavedInfo = saveToInternalStorage(bitmap);
                if (success) {
                    Toast.makeText(getApplicationContext(), "Image saved with success", Toast.LENGTH_LONG).show();
                } else {
                    Toast.makeText(getApplicationContext(), "Error during image saving" + mSavedInfo, Toast.LENGTH_LONG).show();
                }
            }
        }
        private String saveToInternalStorage(Bitmap bitmapImage) {
            ContextWrapper cw = new ContextWrapper(getApplicationContext());
            // path to /data/data/yourapp/app_data/imageDir
            File directory = cw.getDir("imageDir", Context.MODE_PRIVATE);
            File mypath = new File(directory, "profile.jpg");
            FileOutputStream fos = null;
            try {
                fos = new FileOutputStream(mypath);
                bitmapImage.compress(Bitmap.CompressFormat.PNG, 100, fos);
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    fos.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
            return directory.getAbsolutePath();
        }
        private void loadImageFromStorage(String path) {
            try {
                File f = new File(path, "profile.jpg");
                Bitmap b = BitmapFactory.decodeStream(new FileInputStream(f));
                mImageView1.setImageBitmap(b);
            } catch (FileNotFoundException e) {
                e.printStackTrace();
            }
        }
        public void showImage(View view) {
            loadImageFromStorage(mSavedInfo);
        }
    }

Answer 4

If you wish to use the Horizontal Recycler View to act as a ViewPager then it's possible now with the help of LinearSnapHelper which is added in Support Library version 24.2.0.

Firstly Add RecyclerView to your Activity/Fragment

<android.support.v7.widget.RecyclerView
        android:layout_below="@+id/sign_in_button"
        android:layout_width="match_parent"
        android:orientation="horizontal"
        android:id="@+id/blog_list"
        android:layout_height="match_parent">
    </android.support.v7.widget.RecyclerView>

In my case I have used a CardView inside the RecyclerView

blog_row.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.v7.widget.CardView 

    xmlns:android="http://schemas.android.com/apk/res/android"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        xmlns:app="http://schemas.android.com/apk/res-auto"
        android:layout_margin="15dp"
        android:orientation="vertical">

        <LinearLayout
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:gravity="center"
            android:orientation="vertical">

            <com.android.volley.toolbox.NetworkImageView
                android:id="@+id/imageBlogPost"
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                android:adjustViewBounds="true"
                android:paddingBottom="15dp"
                android:src="@drawable/common_google_signin_btn_text_light_normal" />

            <TextView
                android:id="@+id/TitleTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
               android:layout_marginBottom="20dp"

                android:text="Post Title Here"
                android:textSize="16sp" />

            <TextView
                android:id="@+id/descriptionTextView"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="Post Description Here"
                android:paddingBottom="15dp"
                android:textSize="14sp" />
        </LinearLayout>

    </android.support.v7.widget.CardView>

In your Activity/Fragment

    private RecyclerView mBlogList;




 LinearLayoutManager layoutManager
                    = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);
            mBlogList = (RecyclerView) findViewById(R.id.blog_list);

            mBlogList.setHasFixedSize(true);
            mBlogList.setLayoutManager(layoutManager);

LinearSnapHelper snapHelper = new LinearSnapHelper() {
            @Override
            public int findTargetSnapPosition(RecyclerView.LayoutManager lm, int velocityX, int velocityY) {
                View centerView = findSnapView(lm);
                if (centerView == null)
                    return RecyclerView.NO_POSITION;

                int position = lm.getPosition(centerView);
                int targetPosition = -1;
                if (lm.canScrollHorizontally()) {
                    if (velocityX < 0) {
                        targetPosition = position - 1;
                    } else {
                        targetPosition = position + 1;
                    }
                }

                if (lm.canScrollVertically()) {
                    if (velocityY < 0) {
                        targetPosition = position - 1;
                    } else {
                        targetPosition = position + 1;
                    }
                }

                final int firstItem = 0;
                final int lastItem = lm.getItemCount() - 1;
                targetPosition = Math.min(lastItem, Math.max(targetPosition, firstItem));
                return targetPosition;
            }
        };
        snapHelper.attachToRecyclerView(mBlogList);

Last Step is to set adapter to RecyclerView

mBlogList.setAdapter(firebaseRecyclerAdapter);

Answer 5

Complete example

The only real difference between a vertical RecyclerView and a horizontal one is how you set up the LinearLayoutManager. Here is the code snippet. The full example is below.

LinearLayoutManager horizontalLayoutManagaer = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.HORIZONTAL, false);
recyclerView.setLayoutManager(horizontalLayoutManagaer);

This fuller example is modeled after my vertical RecyclerView answer.

Update Gradle dependencies

Make sure the following dependencies are in your app gradle.build file:

implementation 'com.android.support:appcompat-v7:27.1.1'
implementation 'com.android.support:recyclerview-v7:27.1.1'

You can update the version numbers to whatever is the most current.

Create activity layout

Add the RecyclerView to your xml layout.

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rvAnimals"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

</RelativeLayout>

Create item layout

Each item in our RecyclerView is going to have a single a colored View over a TextView. Create a new layout resource file.

recyclerview_item.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="wrap_content"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:padding="10dp">

    <View
        android:id="@+id/colorView"
        android:layout_width="100dp"
        android:layout_height="100dp"/>

    <TextView
        android:id="@+id/tvAnimalName"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"/>

</LinearLayout>

Create the adapter

The RecyclerView needs an adapter to populate the views in each row (horizontal item) with your data. Create a new java file.

MyRecyclerViewAdapter.java

public class MyRecyclerViewAdapter extends RecyclerView.Adapter<MyRecyclerViewAdapter.ViewHolder> {

    private List<Integer> mViewColors;
    private List<String> mAnimals;
    private LayoutInflater mInflater;
    private ItemClickListener mClickListener;

    // data is passed into the constructor
    MyRecyclerViewAdapter(Context context, List<Integer> colors, List<String> animals) {
        this.mInflater = LayoutInflater.from(context);
        this.mViewColors = colors;
        this.mAnimals = animals;
    }

    // inflates the row layout from xml when needed
    @Override
    @NonNull
    public ViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = mInflater.inflate(R.layout.recyclerview_item, parent, false);
        return new ViewHolder(view);
    }

    // binds the data to the view and textview in each row
    @Override
    public void onBindViewHolder(@NonNull ViewHolder holder, int position) {
        int color = mViewColors.get(position);
        String animal = mAnimals.get(position);
        holder.myView.setBackgroundColor(color);
        holder.myTextView.setText(animal);
    }

    // total number of rows
    @Override
    public int getItemCount() {
        return mAnimals.size();
    }

    // stores and recycles views as they are scrolled off screen
    public class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener {
        View myView;
        TextView myTextView;

        ViewHolder(View itemView) {
            super(itemView);
            myView = itemView.findViewById(R.id.colorView);
            myTextView = itemView.findViewById(R.id.tvAnimalName);
            itemView.setOnClickListener(this);
        }

        @Override
        public void onClick(View view) {
            if (mClickListener != null) mClickListener.onItemClick(view, getAdapterPosition());
        }
    }

    // convenience method for getting data at click position
    public String getItem(int id) {
        return mAnimals.get(id);
    }

    // allows clicks events to be caught
    public void setClickListener(ItemClickListener itemClickListener) {
        this.mClickListener = itemClickListener;
    }

    // parent activity will implement this method to respond to click events
    public interface ItemClickListener {
        void onItemClick(View view, int position);
    }
}

Notes

• Although not strictly necessary, I included the functionality for listening for click events on the items. This was available in the old ListViews and is a common need. You can remove this code if you don't need it.

Initialize RecyclerView in Activity

Add the following code to your main activity.

MainActivity.java

public class MainActivity extends AppCompatActivity implements MyRecyclerViewAdapter.ItemClickListener {

    private MyRecyclerViewAdapter adapter;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        // data to populate the RecyclerView with
        ArrayList<Integer> viewColors = new ArrayList<>();
        viewColors.add(Color.BLUE);
        viewColors.add(Color.YELLOW);
        viewColors.add(Color.MAGENTA);
        viewColors.add(Color.RED);
        viewColors.add(Color.BLACK);

        ArrayList<String> animalNames = new ArrayList<>();
        animalNames.add("Horse");
        animalNames.add("Cow");
        animalNames.add("Camel");
        animalNames.add("Sheep");
        animalNames.add("Goat");

        // set up the RecyclerView
        RecyclerView recyclerView = findViewById(R.id.rvAnimals);
        LinearLayoutManager horizontalLayoutManager
                = new LinearLayoutManager(MainActivity.this, LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(horizontalLayoutManager);
        adapter = new MyRecyclerViewAdapter(this, viewColors, animalNames);
        adapter.setClickListener(this);
        recyclerView.setAdapter(adapter);
    }

    @Override
    public void onItemClick(View view, int position) {
        Toast.makeText(this, "You clicked " + adapter.getItem(position) + " on item position " + position, Toast.LENGTH_SHORT).show();
    }
}

Notes

• Notice that the activity implements the ItemClickListener that we defined in our adapter. This allows us to handle item click events in onItemClick.

Finished

That's it. You should be able to run your project now and get something similar to the image at the top.

Notes

• The colored views in my example could of course be replaced with images in a real project.
• Vertical RecyclerView example

Answer 6

Trying to build a horizontal ListView is taking too much time. I have resolved it in two ways.

1.By using a ViewPager whose adapter extends from PagerAdapter.

2.By using RecyclerView just as above. Need to apply LayoutManager as in the following code:

LinearLayoutManager layoutManager
    = new LinearLayoutManager(this, LinearLayoutManager.HORIZONTAL, false);

RecyclerView myList = (RecyclerView) findViewById(R.id.my_recycler_view);
myList.setLayoutManager(layoutManager);