RecyclerView Widget Example In Android

RecyclerView 

Android L support library include two new widget : CardLayout and RecyclerView.
In this tutorial we will  explain the RecyclerView widget.

• RecyclerView is more flexible than Listview.
• when we have a large amount of data to bind in list we use a ViewHolder in ListView . ViewHolder class hold the reference of UI component for each row item in ListView. In ListView, ViewHolder avoids looking up the UI components all the time the system showsa row in the List. RecyclerView forces us to use the ViewHolder Pattern.
• RecyclerView  is more efficient and flexible than ListView.

RecyclerView Example

NOTE:  Recycler View Widget available in Android L preview SDK.

dependencies {

  compile fileTree(dir: 'libs', include: ['*.jar'])
    compile 'com.android.support:appcompat-v7:22.0.0'
    compile 'com.android.support:recyclerview-v7:+'

}

our project compile with this library i.e. available in dependencies.

RecyclerView Layout is available in main_activity.xml

activity_main.xml


<RelativeLayout 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"  tools:context=".MainActivity">
    <android.support.v7.widget.Toolbar
        android:id="@+id/toolbar"
        android:layout_width="match_parent"
        android:layout_height="56dp"
        android:background="#FF9933">

        <TextView
            android:id="@+id/tool_title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="RecyclerViewDemo"
            android:textColor="#ffffff"
            android:layout_marginLeft="30dp"/>
    </android.support.v7.widget.Toolbar>
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_list"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:layout_below="@id/toolbar"/>

</RelativeLayout>

RecyclerView  Implementation

MainActivity.java


package program.androidheight.recyclerviewdemo;

import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.widget.DefaultItemAnimator;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.Toast;


public class MainActivity extends Activity {
    Context context;
    RecyclerView recyclerView;
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        context= MainActivity.this;
         recyclerView = (RecyclerView)findViewById(R.id.recycler_list);
        RecyclerModal itemsData[] = {new RecyclerModal("Ramesh", "1234567890", R.drawable.ic_launcher),
                new RecyclerModal("suresh", "2222222562", R.drawable.ic_launcher),
                new RecyclerModal("prem", "2344322341", R.drawable.ic_launcher),
                new RecyclerModal("yogesh", "4567765412", R.drawable.ic_launcher),
                new RecyclerModal("niraj", "1234554321", R.drawable.ic_launcher),
        };


        // 2. set layoutManger
        recyclerView.setLayoutManager(new LinearLayoutManager(this));
        // 3. create an adapter
        RecyclerAdapter mAdapter = new RecyclerAdapter(itemsData,context);
        // 4. set adapter
        recyclerView.setAdapter(mAdapter);
        recyclerView.setItemAnimator(new DefaultItemAnimator());


    }
    public boolean onContextItemSelected(MenuItem item) {

        switch (item.getItemId()) {
            case R.id.call:
                Toast.makeText(context,"You have clicked Call" ,Toast.LENGTH_LONG).show();

                break;
            case R.id.msg:
                Toast.makeText(context,"You have clicked SMS",Toast.LENGTH_LONG).show();
                break;
        }
        return super.onContextItemSelected(item);
    }


}

Most Important thing in RecyclerView is Adapter class

Adapter class is responsible to bind the data model to the UI component that renders the information.This adapter must extend a class called RecyclerView.Adapter.

RecyclerAdapter.java

package program.androidheight.recyclerviewdemo;

import android.content.Context;

import android.content.Intent;

import android.support.v7.widget.RecyclerView;

import android.view.ContextMenu;

import android.view.LayoutInflater;

import android.view.MenuItem;

import android.view.View;

import android.view.ViewGroup;

import android.widget.AdapterView;

import android.widget.ImageView;

import android.widget.TextView;

import android.widget.Toast;

/**

 * Created by PRABHU on 22-03-2015.

 */

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

    public  RecyclerModal [] modal;

    private int position;

    static Context context;

    ContextMenu.ContextMenuInfo info;

    public RecyclerAdapter(RecyclerModal [] modal, Context context){

        this.modal = modal;

        this.context =context;

    }

    public RecyclerAdapter(){

    }

    @Override

    public ViewHolder onCreateViewHolder(ViewGroup viewGroup, int parent) {

        View itemLayoutView = LayoutInflater.from(viewGroup.getContext())

                .inflate(R.layout.item_layout,viewGroup, false);

        // create ViewHolder

        ViewHolder viewHolder = new ViewHolder(itemLayoutView);

        //set onClick listener on RecyclerView

        return viewHolder;

    }

    @Override

    public void onBindViewHolder(final ViewHolder viewHolder, int position) {

        //bind the UI in the row Item

        viewHolder.txtViewName.setText(modal[position].getName());

        viewHolder.txtViewNumber.setText(modal[position].getNumber());

        viewHolder.imgViewIcon.setImageResource(modal[position].getImageUrl());

    }

    @Override

    public int getItemCount() {

        return modal.length;

    }

    //ViewHolder is used to hold the reference of each Ui of row Item

    public static class ViewHolder extends RecyclerView.ViewHolder implements View.OnClickListener,View.OnCreateContextMenuListener {

        public TextView txtViewName,txtViewNumber;

        public ImageView imgViewIcon;

        public ViewHolder(View itemLayoutView) {

            super(itemLayoutView);

            txtViewName = (TextView) itemLayoutView.findViewById(R.id.name);

            txtViewNumber = (TextView) itemLayoutView.findViewById(R.id.Number);

            imgViewIcon = (ImageView) itemLayoutView.findViewById(R.id.image);

            //set onclickListener

            itemLayoutView.setOnClickListener(this);

            //set onContextListener

            itemLayoutView.setOnCreateContextMenuListener(this);

        }

        @Override

        public void onClick(View v) {

            Intent intent = new Intent(context,DetailsActivity.class);

            intent.putExtra("name",txtViewName.getText().toString());

            intent.putExtra("number",txtViewNumber.getText().toString());

           context.startActivity(intent);

           Toast.makeText(RecyclerAdapter.context,"you have clicked Row "+getPosition(),Toast.LENGTH_LONG).show();

            }

        @Override

        public void onCreateContextMenu(ContextMenu menu, View v, ContextMenu.ContextMenuInfo menuInfo) {

            new RecyclerAdapter().info = menuInfo;

            menu.setHeaderTitle("Select The Action");

            menu.add(0, R.id.call, 0, "Call");//groupId, itemId, order, title

            menu.add(0, R.id.msg, 0, "SMS");

        }

    }

    }

RecyclerModel.java

package program.androidheight.recyclerviewdemo;

/**

 * Created by PRABHU on 22-03-2015.

 */

public class RecyclerModal {

    private String name;

    private String number;

    private int imageUrl;

    public RecyclerModal(){

    }

    public RecyclerModal( String name,String number, int imageUrl) {

        super();

        this.imageUrl = imageUrl;

        this.name = name;

        this.number=number;

    }

    public String getName() {

        return name;

    }

    public String getNumber() {

        return number;

    }

    public int getImageUrl() {

        return imageUrl;

    }

}

Manifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="program.androidheight.recyclerviewdemo" >

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme" >
        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>

        <activity
            android:name=".DetailsActivity"
            android:label="@string/title_activity_details" >
        </activity>
    </application>

</manifest>

OUTPUT

You can download project from Github.

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