[JAVA][Android] RecyclerView의 간격을 조정하기

안드로이드 리사이클러뷰는 기본적으로 뷰끼리 붙어있습니다. 간격을 조정해서 띄움으로써 좀 더 데이터의 구분이 쉬워집니다.

 

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=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/monsterRecyclerView"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>

 

list_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="wrap_content"
    android:orientation="horizontal"
    android:layout_marginLeft="10dp"
    android:layout_marginTop="10dp">

    <ImageView
        android:id="@+id/imgMonster"
        android:layout_width="80dp"
        android:layout_height="80dp"
        android:layout_marginRight="30dp" />

    <LinearLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:orientation="vertical"
        android:layout_marginTop="5dp">

        <TextView
            android:id="@+id/txtName"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="sample"
            android:textSize="24sp" />

        <TextView
            android:id="@+id/txtLevel"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:text="Lv. sample"
            android:textSize="24sp" />
    </LinearLayout>

</LinearLayout>

 

MainActivity

import android.os.Bundle;
import androidx.appcompat.app.AppCompatActivity;
import androidx.recyclerview.widget.LinearLayoutManager;
import androidx.recyclerview.widget.RecyclerView;

public class MainActivity extends AppCompatActivity {

    int ITEM_DIVIDER_HEIGHT = 200; // 간격의 높이를 원하는 만큼 설정합니다.

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

        RecyclerView recyclerView = findViewById(R.id.monsterRecyclerView);
        recyclerView.setAdapter(new Adapter());
        recyclerView.setLayoutManager(new LinearLayoutManager(this));

        // RecyclerView에 간격을 설정하는 ItemDecoration을 추가합니다.
        recyclerView.addItemDecoration(new RecyclerDecoration(ITEM_DIVIDER_HEIGHT));
    }
}

 

RecyclerDecoration

import android.graphics.Rect;
import android.view.View;

import androidx.annotation.NonNull;
import androidx.recyclerview.widget.RecyclerView;

public class RecyclerDecoration extends RecyclerView.ItemDecoration{

    private final int divHeight;


    public RecyclerDecoration(int divHeight) {
        this.divHeight = divHeight;
    }

    @Override
    public void getItemOffsets(@NonNull Rect outRect, @NonNull View view, @NonNull RecyclerView parent, @NonNull RecyclerView.State state) {
        super.getItemOffsets(outRect, view, parent, state);
        if (parent.getChildAdapterPosition(view) != parent.getAdapter().getItemCount() - 1)
            outRect.bottom = divHeight;
    }
}

 

DTO

public class DTO {
    private String name;
    private String level;
    private int image;

    public DTO(String name, String level, int image) {
        this.name = name;
        this.level = level;
        this.image = image;
    }

    public String getName() {
        return name;
    }

    public String getLevel() {
        return level;
    }

    public int getImage() {
        return image;
    }
}

 

Adapter

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.recyclerview.widget.RecyclerView;
import java.util.ArrayList;

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

    ArrayList<DTO> items;

    public Adapter() {
        items = new ArrayList<>();
        items.add(new DTO("테스트1", "간격의높이조절해보기1", R.drawable.ic_launcher_background));
        items.add(new DTO("테스트2", "간격의높이조절해보기2", R.drawable.ic_launcher_background));
        items.add(new DTO("테스트3", "간격의높이조절해보기3", R.drawable.ic_launcher_background));

    }

    @NonNull
    @Override
    public MonsterViewHolder onCreateViewHolder(@NonNull ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.list_item, parent, false);
        return new MonsterViewHolder(view);
    }

    @Override
    public void onBindViewHolder(@NonNull MonsterViewHolder holder, int position) {
        DTO currentMonster = items.get(position);
        holder.monsterName.setText(currentMonster.getName());
        holder.monsterLevel.setText(currentMonster.getLevel());
        holder.monsterImage.setImageResource(currentMonster.getImage());
    }

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

    static class MonsterViewHolder extends RecyclerView.ViewHolder {
        TextView monsterName;
        TextView monsterLevel;
        ImageView monsterImage;

        public MonsterViewHolder(@NonNull View itemView) {
            super(itemView);
            monsterName = itemView.findViewById(R.id.txtName);
            monsterLevel = itemView.findViewById(R.id.txtLevel);
            monsterImage = itemView.findViewById(R.id.imgMonster);
        }
    }
}