Logo

Android RecyclerView

RecyclerView is a ViewGroup brought to AndroidStudio as successor to ListView and GridView. These are all improvements and are included in the latest v7 support package. It was written to improve the efficiency of ListViews and GridViews while allowing you to create lists using XML layouts with highly definable items.

This improvement is achieved by reusing views that are not visible to the user. For example, if the app user scrolls down to where items 4 and 5 are displayed. Items 1, 2, and 3 are deleted from memory to reduce memory consumption.

Implementation

To create a RecyclerView, you need to configure three subparts that provide the level of control the user needs to select different designs.

  1. Card Layout: The card layout is the XML layout processed for generating list entries by the RecyclerView.
  2. ViewHolder: A Java class that stores a reference to a card layout display that needs to be dynamically modified during program execution, with a list of data retrieved from an online database or otherwise added.
  3. Data Class:It is a Java class that serves as a structure for holding data about all items in the RecyclerView.

RecyclerView’s implementation is as follows:

Item_job.xml

<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="wrap_content"
android:orientation="vertical"
android:visibility="visible">


<androidx.cardview.widget.CardView
android:id="@+id/Card"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_marginStart="16dp"
android:layout_marginTop="8dp"
android:layout_marginEnd="16dp"
android:layout_marginBottom="16dp"
app:cardBackgroundColor="@color/white"
app:cardElevation="10dp"
app:cardMaxElevation="24dp"
app:cardPreventCornerOverlap="true"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.6"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">


<androidx.constraintlayout.widget.ConstraintLayout
android:layout_width="match_parent"
android:layout_height="wrap_content">


<androidx.cardview.widget.CardView
android:id="@+id/viewEducation"
style="@style/CardView"
android:layout_width="50dp"
android:layout_height="50dp"
android:layout_margin="16dp"
android:elevation="25dp"
app:cardCornerRadius="25dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent">


<TextView
android:id="@+id/txtEducationFirstLetter"
style="@style/TextAppearance.AppCompat.Headline"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:gravity="center"
android:text="C"
android:textAllCaps="true" />


</androidx.cardview.widget.CardView>


<ImageButton
android:id="@+id/drop"
android:layout_width="40dp"
android:layout_height="40dp"
android:layout_marginTop="16dp"
android:layout_marginEnd="16dp"
android:background="#FFFFFF"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintTop_toTopOf="parent"
app:srcCompat="@drawable/ic_baseline_arrow_drop_down_24" />


<TextView
android:id="@+id/Name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:text="Name of Job"
android:textColor="#0B0B0B"
android:textSize="22sp"
android:textStyle="bold"
app:layout_constraintEnd_toStartOf="@+id/drop"
app:layout_constraintHorizontal_bias="0.065"
app:layout_constraintStart_toEndOf="@+id/viewEducation"
app:layout_constraintTop_toTopOf="parent" />


<TextView
android:id="@+id/textView3"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:text="xyz"
android:textColor="#0B0A0A"
android:textSize="14sp"
app:layout_constraintStart_toEndOf="@+id/viewEducation"
app:layout_constraintTop_toBottomOf="@+id/Name" />


<TextView
android:id="@+id/location"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginStart="8dp"
android:layout_marginTop="3dp"
android:paddingBottom="10dp"
android:text="@string/location"
android:textColor="#0B0A0A"
app:layout_constraintStart_toEndOf="@+id/viewEducation"
app:layout_constraintTop_toBottomOf="@+id/textView3" />


<androidx.constraintlayout.widget.ConstraintLayout
android:id="@+id/expandableLayout"
android:layout_width="0dp"
android:layout_height="wrap_content"
android:layout_marginTop="8dp"


android:visibility="visible"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@id/location">


<TextView
android:id="@+id/textView5"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/description"
android:textAlignment="viewStart"
android:textColor="#0B0B0B"
android:textSize="16sp"
android:textStyle="bold"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />


<TextView
android:id="@+id/des"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/desc"
android:textColor="#0B0B0B"
android:textSize="14sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView5" />


<TextView
android:id="@+id/textView6"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/skills"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/des" />


<TextView
android:id="@+id/sk"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/sk"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView6" />


<TextView
android:id="@+id/textView7"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/req"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/sk" />


<TextView
android:id="@+id/rk"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/r"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView7" />


<TextView
android:id="@+id/textView8"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/count"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/rk"
tools:layout_editor_absoluteY="26dp" />


<TextView
android:id="@+id/textView9"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/sdate"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView8"
tools:layout_editor_absoluteY="26dp" />


<TextView
android:id="@+id/textView10"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:paddingStart="10dp"
android:paddingEnd="10dp"
android:text="@string/pdate"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView9" />


<TextView
android:id="@+id/textView11"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="@string/sal"
android:textColor="#0B0B0B"
android:textSize="16sp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintHorizontal_bias="0.864"
app:layout_constraintStart_toEndOf="@+id/textView9"
app:layout_constraintTop_toBottomOf="@+id/textView8"
tools:layout_editor_absoluteX="273dp" />


<Button
android:id="@+id/button3"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:backgroundTint="#0EBA15"
android:backgroundTintMode="src_over"
android:text="Apply  Now"
app:cornerRadius="35dp"
app:layout_constraintEnd_toEndOf="parent"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/textView10"
tools:layout_editor_absoluteX="16dp" />


                x
</androidx.constraintlayout.widget.ConstraintLayout>


<TextView
android:id="@+id/loca"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="4dp"
android:paddingBottom="10dp"
android:text="TextView"
app:layout_constraintStart_toEndOf="@+id/location"
app:layout_constraintTop_toBottomOf="@+id/textView3" />
</androidx.constraintlayout.widget.ConstraintLayout>
</androidx.cardview.widget.CardView>
</LinearLayout>

Jobs.java

package com.example.myapplication;


public class Jobs {
private String name;
private String desc;
private String skills;
private String loc;
private boolean expanded;


public Jobs (String name, String desc, String skills, String Location){
this.name = name;
this.desc = desc;
this.skills = skills;
this.loc = Location;
this.expanded = true;
    }
public boolean isExpanded() {
return expanded;
    }
public void setExpanded(boolean expanded) {
this.expanded = expanded;
    }


public String getLocation() {
return loc;
    }


public String getName() {
return name;
    }


public String getDesc() {
return desc;
    }


public String getSkills() {
return skills;
    }


}

Adapter: Adapter is the main code responsible for RecyclerView. This keeps all the important methods handling the implementation of RecylcerView. Here are themethods for a successful implementation:

  • onCreateViewHolder: Handles inflation of card layout with RecyclerView item.
  • onBindViewHolder: It handles the setting of various data and methods related to the click of a specific item of RecyclerView.
  • getItemCount: Returns the size of the RecyclerView.
  • onAttachedToRecyclerView: Attach the adapter to the RecyclerView.

An example of an adapter used in this implementation is:

package com.example.myapplication;


import android.content.Context;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.Button;
import android.widget.ImageButton;
import android.widget.TextView;
import android.widget.Toast;
import androidx.cardview.widget.CardView;
import androidx.constraintlayout.widget.ConstraintLayout;
import androidx.recyclerview.widget.RecyclerView;
import java.util.List;


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


List<Jobs>jobsList;
Context context;


public Adapter(List<Jobs>jobsList)
    {
this.jobsList = jobsList;
    }


@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.item,parent,false);
ViewHolder viewHolder = new ViewHolder(view);
view.setClickable(true);
context = parent.getContext();
return viewHolder;
    }


@Override
public void onBindViewHolder(ViewHolder holder, final int position) {
Jobs job = jobsList.get(position);


        holder.name.setText(job.getName());
        holder.desc.setText(job.getDesc());
        holder.skill.setText(job.getSkills());
        holder.f.setText(""+job.getName().charAt(0));
        holder.loc.setText(job.getLocation());


boolean isExpanded = jobsList.get(position).isExpanded();
        holder.expandable.setVisibility(isExpanded ? View.VISIBLE : View.GONE);


        holder.drop.setImageResource(job.isExpanded() ? R.drawable.ic_baseline_arrow_drop_up_24: R.drawable.ic_baseline_arrow_drop_down_24);


        holder.apply.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
holder.apply.setText("APPLIED");
holder.apply.setBackgroundColor(R.color.teal_700);
            }
        });


    }


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


public class ViewHolder extends RecyclerView.ViewHolder
{
TextView desc, name, skill, f, loc;
ConstraintLayout expandable;
Button apply;
ImageButton drop;
CardView cv;
public ViewHolder(View itemView)
        {
super(itemView);
desc = (TextView)itemView.findViewById(R.id.des);
name = (TextView)itemView.findViewById(R.id.Name);
skill = (TextView)itemView.findViewById(R.id.sk);
apply = itemView.findViewById(R.id.button3);
drop = itemView.findViewById(R.id.drop);
f = itemView.findViewById(R.id.txtEducationFirstLetter);
expandable = itemView.findViewById(R.id.expandableLayout);
cv = itemView.findViewById(R.id.Card);
loc = itemView.findViewById(R.id.loca);
drop.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View view) {
Jobs job = jobsList.get(getAdapterPosition());
job.setExpanded(!job.isExpanded());
                    notifyItemChanged(getAdapterPosition());
                }
            });
        }


    }
}

RecyclerView Implementation in an activity:

package com.example.myapplication;


import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.DefaultItemAnimator;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;
import android.os.Bundle;
import java.util.ArrayList;


public class RecycleActivity extends AppCompatActivity {
RecyclerView recyclerView;
Adapter ListAdapter;
ArrayList<Jobs>jobs ;


public static final String[] Names= {"Cyber Security", "Web Dev", "Android Dev", "Machine Learning"};
public static final String[] Desc = {"Cyber Security is *****************" , "Web development is the ************************", "Android is a powerful operating system that provides support to a variety of different applications on smart devices. These android applications are more user-friendly and easier to operate.", " Machine Learning is *********"};
public static final String[] Skills = {".Net, C#", "Java, Python", "Java, Kotlin", "Python"};
public static final String[] Locations ={"New Delhi", "Bangalore", "Gurugram", "Jaipur"};
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_recycle);
jobs = new ArrayList<Jobs>();
for(int i=0;i<Names.length;i++)
        {
Jobs jb = new Jobs(Names[i], Desc[i], Skills[i], Locations[i]);
jobs.add(jb);
        }
for(int i=0;i<Names.length;i++)
        {
Jobs jb = new Jobs(Names[i], Desc[i], Skills[i], Locations[i]);
jobs.add(jb);
        }
ListAdapter = new Adapter(jobs);


recyclerView = (RecyclerView)findViewById(R.id.Jobs);
recyclerView.setLayoutManager(new LinearLayoutManager(this));
recyclerView.setHasFixedSize(true);
recyclerView.setItemAnimator(new DefaultItemAnimator());
recyclerView.setAdapter(ListAdapter);
    }
}

Recycler View Output-

Android RecyclerView

Related Topics

Android RecyclerView

RecyclerView is a ViewGroup brought to AndroidStudio as successor to ListView and GridView. These are all improvements and are included in the latest v7 support package. It was written to...

8 minutes read.

Android EditText

In Android, EditText is a UI widget utilized to allow the user to input or change the text. While using the EditTextwidget in your Android application, you need to use...

4 minutes read.

Android Broadcast Receivers

Android applications can send or receive broadcast messages from the Android operating system and other Androidapplications, like the publish-subscribe design pattern. When an event of interest happens,these broadcasts are sent. For...

4 minutes read.

Dashboard UI Design in Android

One of the essential components that draw the user’s attentions into the application's operation is the dashboard design. It offers details on the application's general functionality in one location. Imagine...

11 minutes read.

Android ScrollView

A ScrollView is a view group that is used to create vertically scrollable views in an android application. Only a single direct child can be contained by ScrollView. For placing...

5 minutes read.

Creating a Calendar View App in Android

This article demonstrates how to make an Android application that uses CalendarView to display the Calendar. It also provides the option to pick the current date and view the date....

3 minutes read.

How to reduce the size of APK in Android

What exactly is an APK file? The full form of APK is Android Package Kit. It is the Android operating system's application file format. We use Android Studio to generate APK...

7 minutes read.

AdapterViewFlipper in Android with Example

The AdapterViewFlipper class, a subclass of the ViewAnimator class, is what we use to switch from two or multiple views when only one is present at a time. The AdapterViewFlipper...

10 minutes read.

Android Styles and Themes

Android styles allow you to design the appearance (for example, colors, size, and fonts) of Android UI components from XML resource files. With this method, you only need to set...

5 minutes read.

Android Tutorial

This Android tutorial will provide you with all the concepts that will be beneficial for both beginners and advanced-level students or candidates. You can learn this tutorial to begin your...

6 minutes read.

ImageView Widget in Android

What you should already KNOW? You should be familiar with: 1) Creating, building, and running apps in Android Studio 2) Basics of android widgets Explanation: Image View widget is used to insert the image...

2 minutes read.

Top Programming Languages for Android Development

For mobile apps, there are so many programming languages. You would need to spend days simply researching if you had to pick one from a list of 30 coding languages...

8 minutes read.

Jetpack Architecture Components in Android

A collection of software elements, libraries, tools, and instructions is called Android Jetpack. It is available to assist in creating reliable Android applications. Jetpack, which was introduced by Google in...

8 minutes read.

Different Ways to Create aar File in Android Studio

A file called an Android archive file (*.aar) can be created using Android Studio and comprises classes and methods that use related files and classes for Android. The Android library...

4 minutes read.

Difference between android developer and web

From a small business to a big firm, every organization in the world of technology requires a digital market presence and only mobile applications and websites/web applications provide for digital...

4 minutes read.

Android Studio's Layout Editor

The Layout Editor allows you to efficiently create layouts by dragging UI elements from the Palette into the visual design editor instead of manually creating the layout XML file by...

8 minutes read.

Android GridView

Theview group that displays items in a two-dimensional scrolling grid is called GridView. The data isadded into this grid layout from anArray List or database. The adapter class isutilized to...

4 minutes read.

Android Time picker example

How to pick Time from the user in android? Write an android example to pick Time from the user and display the date to the user. Android provides controls for the user...

3 minutes read.

Event Handling in Android

Events are a convenient way to gather data about user interactions with interactive elements of your application. Like a button click or a screen touch. A queue of events on...

3 minutes read.

How to crop Image from Camera and Gallery in Android?

In this tutorial, we'll learn how to crop photos in the Android Gallery and Camera. There is no crop feature in this project, contrary to what was covered in the...

5 minutes read.