RecyclerView (리사이클러뷰)

Source: https://www.edwith.org/boostcourse-android/lecture/20492/

1. 실행 결과 화면

    

2. build.gradle (app)

의존성 추가

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

3. 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:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    android:gravity="center"
    tools:context="com.tistory.qlyh8.practice.MainActivity">
 
    <android.support.v7.widget.RecyclerView
        android:id="@+id/recycler_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
 
</LinearLayout>
 

4. recyclerview_item.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="wrap_content"
    android:layout_margin="10dp"
    android:orientation="vertical"
    android:gravity="center"
    android:background="@android:color/holo_purple"
    tools:context="com.tistory.qlyh8.practice.MainActivity">
   <TextView
       android:id="@+id/text1"
       android:layout_width="wrap_content"
       android:layout_height="wrap_content"
       android:layout_marginRight="10dp"
       android:gravity="center"
       android:textSize="25sp"
       android:textColor="@android:color/white"
       tools:text="Name" />
    <TextView
        android:id="@+id/text2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="20sp"
        android:textColor="@android:color/white"
        tools:text="010-0000-0000"/>
</LinearLayout>
 

5. PersonItem.java

package com.tistory.qlyh8.practice;
 
// 각 아이템을 위한 데이터 클래스
public class PersonItem {
    private String name;
    private String mobile;
 
    PersonItem(String name, String mobile) {
        this.name = name;
        this.mobile = mobile;
    }
 
    public String getName() {
        return name;
    }
 
    public void setName(String name) {
        this.name = name;
    }
 
    public String getMobile() {
        return mobile;
    }
 
    public void setMobile(String mobile) {
        this.mobile = mobile;
    }
}
 

6. RecyclerViewHolder.java

package com.tistory.qlyh8.practice;
 
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.TextView;
 
/*
 * 화면에 보일 때 사용되는 각각의 뷰는 뷰홀더에 담아두게 된다.
 * 뷰홀더 객체가 생성될 때 뷰가 전달되는데, 뷰홀더 객체는 뷰를 담아두고 뷰에 표시될 데이터를 설정한다.
 * 뷰홀더는 재사용된다.
 */
class RecyclerViewHolder extends RecyclerView.ViewHolder {
 
    private TextView textView1, textView2;
    private RecyclerViewAdapter.itemClickListener listener;
 
    RecyclerViewHolder(View itemView) {
        super(itemView);
 
        textView1 = itemView.findViewById(R.id.text1);
        textView2 = itemView.findViewById(R.id.text2);
 
        itemView.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                int position = getAdapterPosition();
                if (listener != null) {
                    listener.onItemClick(RecyclerViewHolder.this, view, position);
                }
            }
        });
    }
 
    // PersonItem 객체를 전달받아 뷰홀더 안에 있는 뷰에 데이터 설정
    void setItem(PersonItem item) {
        textView1.setText(item.getName());
        textView2.setText(item.getMobile());
    }
 
    void setOnItemClickListener(RecyclerViewAdapter.itemClickListener listener) {
        this.listener = listener;
    }
}
 

7. RecyclerViewAdapter.java

package com.tistory.qlyh8.practice;
 
import android.content.Context;
import android.support.annotation.NonNull;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
 
import java.util.ArrayList;
 
 
// 각 아이템을 위한 데이터를 담는 어댑터
public class RecyclerViewAdapter extends RecyclerView.Adapter<RecyclerViewHolder>  {
 
    private Context context;
    private ArrayList<PersonItem> items = new ArrayList<>();
    private itemClickListener listener;
 
    public interface itemClickListener {
        void onItemClick(RecyclerViewHolder holder, View view, int position);
    }
 
    RecyclerViewAdapter(Context context) {
        this.context = context;
    }
 
    @Override
    public int getItemCount() {
        return items.size(); // 어댑터에서 관리하는 아이템의 개수를 반환
    }
 
    @NonNull
    @Override
    public RecyclerViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        // recyclerview_item XML 레이아웃을 이용해 뷰 객체를 만든 후 뷰홀더에 담아 반환
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        View itemView = inflater.inflate(R.layout.recyclerview_item, parent, false);
        return new RecyclerViewHolder(itemView);
    }
 
    @Override
    public void onBindViewHolder(@NonNull RecyclerViewHolder holder, int position) {
        // 뷰홀더에 각 아이템의 데이터를 설정
        PersonItem item = items.get(position);
        holder.setItem(item);
        holder.setOnItemClickListener(listener);
    }
 
    public void addItem(PersonItem item) {
        items.add(item);    // 아이템 추가
    }
 
    public void addItems(ArrayList<PersonItem> items) {
        this.items = items; // 아이템 배열 추가
    }
 
    public PersonItem getItem(int position) {
        return items.get(position); // 아이템 가져오기
    }
 
    public void setOnItemClickListener(itemClickListener listener) {
        this.listener = listener;
    }
}
 

 

8. MainActivity.java

package com.tistory.qlyh8.practice;
 
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.Toast;
 
 
public class MainActivity extends AppCompatActivity {
 
    private RecyclerViewAdapter adapter;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        // RecyclerView 는 껍데기 역할만 한다.
        RecyclerView recyclerView = findViewById(R.id.recycler_view);
 
        // 가로 방향으로 레이아웃 설정
        // reverseLayout: 아이템이 보이는 방향. true 지정시 아래에서 위로 올라감
        LinearLayoutManager layoutManager = new LinearLayoutManager(this,
                LinearLayoutManager.HORIZONTAL, false);
        recyclerView.setLayoutManager(layoutManager);
 
        adapter = new RecyclerViewAdapter(getApplicationContext());
        adapter.addItem(new PersonItem("Amy", "010-1000-1000"));
        adapter.addItem(new PersonItem("John", "010-2000-2000"));
        adapter.addItem(new PersonItem("Tom", "010-3000-3000"));
        recyclerView.setAdapter(adapter);   // 어뎁터 설정
 
        // 아이템 클릭 이벤트 설정
        adapter.setOnItemClickListener(new RecyclerViewAdapter.itemClickListener() {
            @Override
            public void onItemClick(RecyclerViewHolder holder, View view, int position) {
                PersonItem item = adapter.getItem(position);
                Toast.makeText(getApplicationContext(), "이름: "+item.getName(), Toast.LENGTH_SHORT).show();
            }
        });
    }
}

9. 참고

- Create a List with RecyclerView

  https://developer.android.com/guide/topics/ui/layout/recyclerview

- Android UI 멋지게 만들기

  https://academy.realm.io/kr/posts/gotocph-israel-ferrer-camacho-android-ui/

- RecyclerView와 Realm으로 만드는 GridLayout

  https://academy.realm.io/kr/posts/android-recycler-view/

- Android RecyclerView 요약

  https://medium.com/@bansooknam/android-recyclerview-%EC%9A%94%EC%95%BD-aaea4a9c95e7