10. 할 일 리스트 Room 데이터베이스, 리사이클러뷰

10.3 준비하기: 프로젝트, 뷰 바인딩, 라이브러리

10.3.2 뷰 바인딩 설정과 필요 라이브러리 추가

build.gradle

plugins {
    id 'com.android.application'
    id 'org.jetbrains.kotlin.android'
    
    id 'kotlin-kapt'
}

viewBinding {
        enabled = true
    }
    
dependencies {
    def room_version = "2.5.0"

    implementation "androidx.room:room-runtime:$room_version"
    annotationProcessor "androidx.room:room-compiler:$room_version"

    // To use Kotlin annotation processing tool (kapt)
    kapt "androidx.room:room-compiler:$room_version"
    implementation 'androidx.core:core-ktx:1.12.0'
    implementation 'androidx.appcompat:appcompat:1.6.1'
    implementation 'com.google.android.material:material:1.11.0'
    implementation 'androidx.constraintlayout:constraintlayout:2.1.4'
    testImplementation 'junit:junit:4.13.2'
    androidTestImplementation 'androidx.test.ext:junit:1.1.5'
    androidTestImplementation 'androidx.test.espresso:espresso-core:3.5.1'
}

room 데이터베이스 바로가기

10.4 레이아웃 구성하기

AndroidManifest.xml

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

    <application
        android:allowBackup="true"
        android:dataExtractionRules="@xml/data_extraction_rules"
        android:fullBackupContent="@xml/backup_rules"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/Theme.TodoList"
        tools:targetApi="31">
        <activity
            android:name=".AddTodoActivity"
            android:exported="true">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".MainActivity"
            android:exported="true">
        </activity>
    </application>

</manifest>

10.4.1 MainActivity의 레이아웃 작성하기

activity_main.xml

<?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="match_parent"
    tools:context=".MainActivity">

    <androidx.recyclerview.widget.RecyclerView
        android:id="@+id/recycleView"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        app:layout_constraintBottom_toTopOf="@id/btn_add"
        app:layout_constraintTop_toTopOf="parent"
        />
    
    <Button
        android:id="@+id/btn_add"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="할 일 추가하기"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginBottom="20dp"
        android:layout_marginStart="10dp"
        android:layout_marginEnd="10dp"
        />

</androidx.constraintlayout.widget.ConstraintLayout>

10.4.2 AddTodoActivity의 레이아웃 작성하기

strings.xml

<resources>
    <string name="app_name">TodoList</string>
    <string name="add_todo">할 일 추가하기</string>
    <string name="title">제목</string>
    <string name="hint_title">해야 할 일을 입력해주세요.</string>
    <string name="importance">중요도</string>
    <string name="importance_low">낮음</string>
    <string name="importance_middle">중간</string>
    <string name="importance_high">높음</string>
    <string name="completion">완료</string>
</resources>

activity_add_todo.xml

<?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="match_parent"
    tools:context=".AddTodoActivity">

    <TextView
        android:id="@+id/title"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="30dp"
        android:text="@string/title"
        app:layout_constraintBottom_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent" />

    <EditText
        android:id="@+id/edit_title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="8dp"
        android:layout_marginEnd="20dp"
        android:hint="@string/hint_title"
        android:imeOptions="actionDone"
        android:inputType="text"
        android:textSize="14sp"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/title" />

    <TextView
        android:id="@+id/importane"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="30dp"
        android:text="@string/importance"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toBottomOf="@id/edit_title" />

    <RadioGroup
        android:id="@+id/radio_group"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginStart="20dp"
        android:layout_marginTop="8dp"
        app:layout_constraintBottom_toBottomOf="@id/importane">

        <RadioGroup
            android:id="@+id/btn_low"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/importance_low" />

        <RadioGroup
            android:id="@+id/btn_middle"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/importance_middle" />

        <RadioGroup
            android:id="@+id/btn_high"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="@string/importance_high" />
    </RadioGroup>

    <Button
        android:id="@+id/btn_completion"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:layout_marginStart="10dp"
        android:layout_marginEnd="10dp"
        android:layout_marginBottom="20dp"
        android:text="@string/completion"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintStart_toStartOf="parent" />


</androidx.constraintlayout.widget.ConstraintLayout>

10.5 Room으로 데이터베이스 구성하기

10.5.1 엔티티 생성하기

db/ToDoEntity.kt

package com.example.todolist.db

import androidx.room.ColumnInfo
import androidx.room.PrimaryKey
import androidx.room.Entity

@Entity
data class ToDoEntity (
    @PrimaryKey(autoGenerate = true) var id : Int? = null,
    @ColumnInfo(name = "title") val title : String,
    @ColumnInfo(name="importance") val importance : Int
)

10.5.2 데이터 접근 객체(DAO) 생성하기

db/ToDoDao.kt

package com.example.todolist.db

import androidx.room.Dao
import androidx.room.Delete
import androidx.room.Insert
import androidx.room.Query

@Dao
interface ToDoDao {
    @Query("SELECT * FROM ToDoEntity")
    fun getAll() : List<ToDoEntity>

    @Insert
    fun insertTodo(todo : ToDoEntity)

    @Delete
    fun deleteTodo(todo : ToDoEntity)
}

10.5.3 데이터베이스 생성하기

AppDatabase.kt

package com.example.todolist.db

import android.content.Context
import androidx.room.Database
import androidx.room.Room
import androidx.room.RoomDatabase

@Database(entities = arrayOf(ToDoEntity::class), version = 1)
abstract class AppDatabase : RoomDatabase() {
    abstract fun getTodoDao() : ToDoDao

    companion object {
        val databaseName = "db_todo"
        var appDatabase : AppDatabase? = null

        fun getInstance(context : Context) : AppDatabase? {
            if(appDatabase == null) {
                appDatabase = Room.databaseBuilder(context,
                    AppDatabase::class.java,
                    databaseName).build()
            }
            return appDatabase
        }
    }
}

10.6 할 일 추가 기능 구현하기

MainActivity.kt

package com.example.todolist

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.todolist.databinding.ActivityMainBinding

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnAdd.setOnClickListener{
            val intent = Intent(this, AddTodoActivity::class.java)
            startActivity(intent)
        }
    }
}

AddTodoActivity.kt

package com.example.todolist

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.room.Dao
import com.example.todolist.databinding.ActivityAddTodoBinding
import com.example.todolist.db.AppDatabase
import com.example.todolist.db.ToDoDao
import com.example.todolist.db.ToDoEntity

class AddTodoActivity : AppCompatActivity() {
    
    lateinit var binding : ActivityAddTodoBinding
    lateinit var db : AppDatabase
    lateinit var todoDao: ToDoDao
    
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        
        binding = ActivityAddTodoBinding.inflate(layoutInflater)
        setContentView(binding.root)
        
        db = AppDatabase.getInstance(this)!!
        todoDao = db.getTodoDao()
        
        binding.btnCompletion.setOnClickListener {
            insertTodo()
        }
    }
    
    private fun insertTodo() {
        val todoTitle = binding.edtTitle.text.toString()
        var todoImportance = binding.radioGroup.checkedRadioButtonId
        
        when(todoImportance) {
            R.id.btn_high -> {
                todoImportance = 1
            }
            
            R.id.btn_middle -> {
                todoImportance = 2
            }
            
            R.id.btn_low -> {
                todoImportance = 3
            }
            
            else -> {
                todoImportance = -1
            }
        }
        
        if(todoImportance == -1 || todoTitle.isBlank()) {
            Toast.makeText(this, "모든 항목을 채워주세요.",
                Toast.LENGTH_SHORT).show()
        } else {
            Thread {
                todoDao.insertTodo(ToDoEntity(null, todoTitle, todoImportance))
                runOnUiThread {
                    Toast.makeText(this, "추가되었습니다.", 
                        Toast.LENGTH_SHORT).show()
                    finish()
                }
            }.start()
        }
    }
}

View > Tool Windows > App Inspection

10.7 리사이클러뷰로 리스트 구현하기

MainActivity.kt

package com.example.todolist

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import com.example.todolist.databinding.ActivityMainBinding
import com.example.todolist.db.AppDatabase
import com.example.todolist.db.ToDoDao
import com.example.todolist.db.ToDoEntity

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    private lateinit var db : AppDatabase
    private lateinit var todoDao : ToDoDao
    private lateinit var todoList : ArrayList<ToDoEntity>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnAdd.setOnClickListener{
            val intent = Intent(this, AddTodoActivity::class.java)
            startActivity(intent)
        }

        db = AppDatabase.getInstance(this)!!
        todoDao = db.getTodoDao()

        getAllTodoList()
    }

    private fun getAllTodoList() {
        Thread {
            todoList = ArrayList(todoDao.getAll())
            setRecyclerView()
        }.start()
    }
    
    private fun setRecyclerView() {
        
    }
}

10.7.2 리사이클러뷰 어댑터 만들기

item_todo.xml

<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="100dp"
    xmlns:app="http://schemas.android.com/apk/res-auto">
    <TextView
        android:id="@+id/tv_importance"
        android:layout_width="50dp"
        android:layout_height="50dp"
        android:background="@color/yellow"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        android:layout_marginStart="20dp"
        android:text="2"
        android:gravity="center"
        android:textSize="19sp"
        android:textColor="@color/white"
        />

    <TextView
        android:id="@+id/tv_title"
        android:layout_width="0dp"
        android:layout_height="wrap_content"
        android:text="GO TO GYM"
        app:layout_constraintStart_toEndOf="@id/tv_importance"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        android:layout_marginEnd="20dp"
        android:layout_marginStart="10dp"
        />
</androidx.constraintlayout.widget.ConstraintLayout>

colors.xml

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <color name="purple_200">#FFBB86FC</color>
    <color name="purple_500">#FF6200EE</color>
    <color name="purple_700">#FF3700B3</color>
    <color name="teal_200">#FF03DAC5</color>
    <color name="teal_700">#FF018786</color>
    <color name="black">#FF000000</color>
    <color name="white">#FFFFFFFF</color>
    
    <color name="red">#FF3030</color>
    <color name="yellow">#FFC600</color>
    <color name="green">#10A806</color>
</resources>

TodoRecyclerViewAdapter.kt

package com.example.todolist

import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.example.todolist.databinding.ItemTodoBinding
import com.example.todolist.db.ToDoEntity

class TodoRecycleViewAdapter(private val todoList : ArrayList<ToDoEntity>) : RecyclerView.Adapter<TodoRecycleViewAdapter.MyViewHolder>() {
    inner class MyViewHolder(binding : ItemTodoBinding) : RecyclerView.ViewHolder(binding.root) {
        val tv_importance = binding.tvImportance
        val tv_title = binding.tvTitle
        val root = binding.root
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val binding: ItemTodoBinding =
            ItemTodoBinding.inflate(LayoutInflater.from(parent.context), parent, false)
        return MyViewHolder(binding)
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        val todoData = todoList[position]
        when(todoData.importance) {
            1 -> {
                holder.tv_importance.setBackgroundResource(R.color.red)
            }
            2 -> {
                holder.tv_importance.setBackgroundResource(R.color.yellow)
            }
            3 -> {
                holder.tv_importance.setBackgroundResource(R.color.green)
            }
        }

        holder.tv_importance.text = todoData.importance.toString()

        holder.tv_title.text = todoData.title
    }

    override fun getItemCount(): Int {
        return todoList.size
    }
}

10.7.3 MainActivity.kt에서 어댑터 연결하기

MainActivity.kt

package com.example.todolist

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.todolist.databinding.ActivityMainBinding
import com.example.todolist.db.AppDatabase
import com.example.todolist.db.ToDoDao
import com.example.todolist.db.ToDoEntity

class MainActivity : AppCompatActivity() {

    private lateinit var binding: ActivityMainBinding

    private lateinit var db : AppDatabase
    private lateinit var todoDao : ToDoDao
    private lateinit var todoList : ArrayList<ToDoEntity>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnAdd.setOnClickListener{
            val intent = Intent(this, AddTodoActivity::class.java)
            startActivity(intent)
        }

        db = AppDatabase.getInstance(this)!!
        todoDao = db.getTodoDao()

        getAllTodoList()
    }

    private fun getAllTodoList() {
        Thread {
            todoList = ArrayList(todoDao.getAll())
            setRecyclerView()
        }.start()
    }

    private fun setRecyclerView() {
        runOnUiThread {
            adapter = TodoRecyclerViewAdapter(todoList)
            binding.recyclerView.adapter = adapter
            binding.recycleView.layoutManager = LinearLayoutManager(this)
        }
    }
    
    override fun onRestart() {
        super.onRestart()
        getAllTodoList()
    }
}

10.8 할 일 삭제 기능 구현하기

MainActivity.kt

package com.example.todolist

import android.content.DialogInterface
import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.todolist.databinding.ActivityMainBinding
import com.example.todolist.db.AppDatabase
import com.example.todolist.db.ToDoDao
import com.example.todolist.db.ToDoEntity

class MainActivity : AppCompatActivity() , OnItemLongClickListener{

    private lateinit var binding: ActivityMainBinding

    private lateinit var db : AppDatabase
    private lateinit var todoDao : ToDoDao
    private lateinit var todoList : ArrayList<ToDoEntity>
    private lateinit var adapter: TodoRecyclerViewAdapter

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnAdd.setOnClickListener{
            val intent = Intent(this, AddTodoActivity::class.java)
            startActivity(intent)
        }

        // db 인스턴스를 가져오고 DB 작업을 할 수 있는 DAO를 가져옴
        db = AppDatabase.getInstance(this)!!
        todoDao = db.getTodoDao()

        getAllTodoList() // 할 일 리스트 가져오기
    }

    private fun getAllTodoList() {
        Thread{
            todoList = ArrayList(todoDao.getAll())
            setRecyclerView()
        }.start()
    }

    private fun setRecyclerView() {
        // 리사이클러뷰 설정
        runOnUiThread{
            adapter = TodoRecyclerViewAdapter(todoList, this) // 어댑터 객체 할당
            binding.recyclerView.adapter = adapter
            binding.recyclerView.layoutManager = LinearLayoutManager(this)
        }
    }

    override fun onRestart() {
        super.onRestart()
        getAllTodoList()
    }

    override fun onLongClick(position: Int) {
        val builder : AlertDialog.Builder = AlertDialog.Builder(this)
        builder.setTitle("할 일 삭제")
        builder.setMessage("정말 삭제하시겠습니까?")
        builder.setNegativeButton("취소", null)
        builder.setPositiveButton("네",
            object : DialogInterface.OnClickListener{
                override fun onClick(p0 : DialogInterface?, p1: Int) {
                    deleteTodo(position)
                }
            })

        builder.setNeutralButton("수정",
            object : DialogInterface.OnClickListener{
                override fun onClick(p0 : DialogInterface?, p1: Int) {
                    updateTodo(position)
                }
            })

        builder.show()
    }

    private fun updateTodo(position: Int){

    }

    private fun deleteTodo(position: Int){
        Thread {
            todoDao.deleteTodo(todoList[position]) // DB에서 삭제
            todoList.removeAt(position) // 리스트에서 삭제
            runOnUiThread{
                adapter.notifyDataSetChanged()
                Toast.makeText(this, "삭제되었습니다.", Toast.LENGTH_SHORT).show()
            }
        }.start()
    }

}

OnItemLongClickListener.kt

package com.example.todolist

interface OnItemLongClickListener {
    fun onLongClick(position : Int)
}

TodoRecyclerViewAdapter.kt

package com.example.todolist

import android.view.LayoutInflater
import android.view.ViewGroup
import androidx.recyclerview.widget.RecyclerView
import com.example.todolist.databinding.ItemTodoBinding
import com.example.todolist.db.ToDoEntity

class TodoRecycleViewAdapter(private val todoList : ArrayList<ToDoEntity>, private val listener : OnItemLongClickListener) : RecyclerView.Adapter<TodoRecycleViewAdapter.MyViewHolder>() {
    inner class MyViewHolder(binding : ItemTodoBinding) : RecyclerView.ViewHolder(binding.root) {
        val tv_importance = binding.tvImportance
        val tv_title = binding.tvTitle
        val root = binding.root
    }

    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): MyViewHolder {
        val binding: ItemTodoBinding =
            ItemTodoBinding.inflate(LayoutInflater.from(parent.context), parent, false)
        return MyViewHolder(binding)
    }

    override fun onBindViewHolder(holder: MyViewHolder, position: Int) {
        val todoData = todoList[position]
        when(todoData.importance) {
            1 -> {
                holder.tv_importance.setBackgroundResource(R.color.red)
            }
            2 -> {
                holder.tv_importance.setBackgroundResource(R.color.yellow)
            }
            3 -> {
                holder.tv_importance.setBackgroundResource(R.color.green)
            }
        }

        holder.tv_importance.text = todoData.importance.toString()

        holder.tv_title.text = todoData.title

        holder.root.setOnLongClickListener {
            listener.onLongClick(position)
            false
        }
    }

    override fun getItemCount(): Int {
        return todoList.size
    }
}

MainActivity.kt

package com.example.todolist

import android.content.DialogInterface
import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.Toast
import androidx.appcompat.app.AlertDialog
import androidx.recyclerview.widget.LinearLayoutManager
import com.example.todolist.databinding.ActivityMainBinding
import com.example.todolist.db.AppDatabase
import com.example.todolist.db.ToDoDao
import com.example.todolist.db.ToDoEntity

class MainActivity : AppCompatActivity(), OnItemLongClickListener {

    private lateinit var binding: ActivityMainBinding

    private lateinit var db : AppDatabase
    private lateinit var todoDao : ToDoDao
    private lateinit var todoList : ArrayList<ToDoEntity>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityMainBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.btnAdd.setOnClickListener{
            val intent = Intent(this, AddTodoActivity::class.java)
            startActivity(intent)
        }

        db = AppDatabase.getInstance(this)!!
        todoDao = db.getTodoDao()

        getAllTodoList()
    }

    private fun getAllTodoList() {
        Thread {
            todoList = ArrayList(todoDao.getAll())
            setRecyclerView()
        }.start()
    }

    private fun setRecyclerView() {
        runOnUiThread {
            adapter = TodoRecyclerViewAdapter(todoList, this)
            binding.recyclerView.adapter = adapter
            binding.recycleView.layoutManager = LinearLayoutManager(this)
        }
    }

    override fun onRestart() {
        super.onRestart()
        getAllTodoList()
    }

    override fun onLongClick(position: Int) {
        val builder: AlertDialog.Builder = AlertDialog.Builder(this)
        builder.setTitle("할 일 삭제")
        builder.setMessage("정말 삭제하시겠습니까?")
        builder.setNegativeButton("취소", null)
        builder.setPositiveButton("네",
            object : DialogInterface.OnClickListener {
                override fun onClick(p0: DialogInterface?, p1: Int) {
                    deleteTodo(position)
                }
            }
        )
        builder.show()
    }

    private fun deleteTodo(position: Int) {
        Thread {
            todoDao.deleteTodo(todoList[position])
            todoList.removeAt(position)
            runOnUiThread {
                adapter.notifyDataSetChanged()
                Toast.makeText(this, "삭제되었습니다.", Toast.LENGTH_SHORT).show()
            }
        }.start()
    }
}