상하 대괄호([ ]) 모양(로또 용지 번호 모양) 만들기(android)

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
    <!-- @color/lotto 색상의 2dp 사이즈의 테두리가 있는 사각형 -->
    <item>
        <shape android:shape="rectangle">
            <stroke android:width="2dp" android:color="@color/lotto"/>
            <solid android:color="@color/lotto_background"/>
        </shape>
    </item>
    <!-- 위/아래 10dp 떨어진 위치에 배경색 @color/lotto_background 사각형을 덮어줍니다 -->
    <item android:top="10dp" android:bottom="10dp">
        <shape android:shape="rectangle">
            <!-- 포스팅 하면서 보니 아래 stroke 부분은 제거해도 동일하게 동작합니다. -->
            <stroke android:width="2dp" android:color="@color/lotto_background"/>
            <solid android:color="@color/lotto_background"/>
        </shape>
    </item>
</layer-list>

<?xml version="1.0" encoding="utf-8"?>
<layer-list xmlns:android="http://schemas.android.com/apk/res/android">
	<!-- @color/lotto 색상의 2dp 사이즈의 테두리가 있는 사각형 -->
    <item>
        <shape android:shape="rectangle">
            <stroke android:width="2dp" android:color="@color/lotto"/>
            <solid android:color="@color/lotto_background"/>
        </shape>
    </item>
    <!-- 위/아래 10dp 떨어진 위치에 배경색 @color/lotto_background 사각형을 덮어줍니다 -->
    <item android:top="10dp" android:bottom="10dp">
        <shape android:shape="rectangle">
            <stroke android:width="2dp" android:color="@color/lotto_background"/>
            <solid android:color="@color/lotto_background"/>
        </shape>
    </item>
    <!-- 상/하/좌/우 2dp씩 들어간 위치에 @color/black 사각형을 덮어줍니다 -->
    <item android:top="2dp" android:bottom="2dp" android:left="2dp" android:right="2dp">
        <shape android:shape="rectangle">
            <solid android:color="@color/black"/>
        </shape>
    </item>
</layer-list>

<?xml version="1.0" encoding="utf-8"?>
<TextView xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:id="@+id/txt_lotto_number"
    android:layout_width="29dp"
    android:layout_height="45dp"
    android:gravity="center"
    tools:text="1"
    android:background="@drawable/border_lotto_number"
    android:textColor="@color/lotto"
    android:textStyle="bold"
    android:layout_marginBottom="10dp"
    />

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout 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="457dp"
    android:background="@drawable/border_lotto"
    android:layout_marginLeft="16dp"
    android:layout_marginTop="16dp"
    android:layout_marginRight="16dp"
    android:layout_marginBottom="16dp"
    >

    <!-- 게임 회차 및 선택된 번호 표시 부분 축약-->
    <LinearLayout
        android:id="@+id/game_summary"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:orientation="horizontal">
        <!-- 게임 회차 표시 부분 축약 -->
        <TextView
            android:id="@+id/txt_game_number"
            tools:text="1"/>
    </LinearLayout>

    <!-- 여기가 로또 번호 표시 부분. LottoNumberAdapter 코드 참고 -->
    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/view_number_recycler"
        android:layout_width="0dp"
        android:layout_height="0dp"
        app:layoutManager="androidx.recyclerview.widget.GridLayoutManager"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintTop_toBottomOf="@id/game_summary"
        app:layout_constraintBottom_toBottomOf="parent"
        app:spanCount="7"
        android:padding="16dp" />
</androidx.constraintlayout.widget.ConstraintLayout>

package kr.sosone.lotto.adapter

import android.content.Context
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import android.widget.TextView
import androidx.core.content.ContextCompat
import androidx.recyclerview.widget.RecyclerView
import kr.sosone.lotto.R
import kr.sosone.lotto.model.LottoNumber

class LottoNumberAdapter (private val context: Context, private val dataset: List<LottoNumber>)
    : RecyclerView.Adapter<LottoNumberAdapter.ItemViewHolder>()
{
    class ItemViewHolder(private val view: View) : RecyclerView.ViewHolder(view){
        // number_item.xml에 정의된 TextView
        val txtLottoNumber: TextView = view.findViewById(R.id.txt_lotto_number)
    }


    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): ItemViewHolder {
        val adapterLayout = LayoutInflater.from(parent.context)
            .inflate(R.layout.number_item, parent, false)
        return ItemViewHolder(adapterLayout);
    }

    override fun onBindViewHolder(holder: LottoNumberAdapter.ItemViewHolder, position: Int) {
        val item = dataset[position]
        if(item.isPick){
            // 선택된 아이템일 경우 border_lotto_number_selected 배경 및 텍스트 색상 변경
            holder.txtLottoNumber.setBackgroundResource(R.drawable.border_lotto_number_selected)
            holder.txtLottoNumber.setTextColor(ContextCompat.getColor(context, R.color.white))
        }

        holder.txtLottoNumber.text = item.number.toString()
    }

    override fun getItemCount() = dataset.size
}

package kr.sosone.lotto.model

data class LottoNumber(val number: Int, val isPick: Boolean)

class LottoGameAdapter(private val context: Context, private val dataset: List<LottoGame>)
    : RecyclerView.Adapter<LottoGameAdapter.ItemViewHolder>()
{
    class ItemViewHolder(private val view: View) : RecyclerView.ViewHolder(view){
        // 중첩 RecyclerView 처리
        val viewNumberRecycler: RecyclerView = view.findViewById(R.id.view_number_recycler)
    }

    override fun onBindViewHolder(holder: LottoGameAdapter.ItemViewHolder, position: Int) {
        // 중첩 RecyclerView 처리
        holder.viewNumberRecycler.adapter = LottoNumberAdapter(context, item.fullNumbers)
        holder.viewNumberRecycler.setHasFixedSize(true)
    }
}