[Kotlin]Tab Navigator – 1.메인화면(Main Screen)

더 친절한 코틀린 앱프로그래밍 책에 있는 코드 입니다.
This is code from the Friendlier Kotlin App Programming book

이 코드는 뷰바인딩을 사용하지 않았습니다.
This code does not use view binding.

Test : compileSdk = 35 targetSdk = 35

1.Directory & files

2.MainActivity.kt

package com.example.tabex

import android.os.Bundle
import android.widget.Toast
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import com.google.android.material.bottomnavigation.BottomNavigationView

class MainActivity : AppCompatActivity() {

    lateinit var bottom_navigation:BottomNavigationView

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(R.layout.activity_main)
        ViewCompat.setOnApplyWindowInsetsListener(findViewById(R.id.main)) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }
        with(supportFragmentManager.beginTransaction()){
            val fragment1 = Fragment1()
            replace(R.id.container,fragment1)
            commit()
        }
        bottom_navigation = findViewById(R.id.bottom_navigation)

       
        // "bottom_navigation..setOnNavigationItemReselectedListener" was deprecated
        bottom_navigation.setOnItemSelectedListener {
            when(it.itemId){
                R.id.tab1 -> {
                    showToast("첫번쨰 탭 선택됨 First tab selected")
                    with(supportFragmentManager.beginTransaction()) {
                        val fragment1 = Fragment1()
                        replace(R.id.container, fragment1)
                        commit()
                    }
                    return@setOnItemSelectedListener true

                }
                R.id.tab2 -> {
                    showToast("두번째 탭 선택됨 Second tab selected")
                    with(supportFragmentManager.beginTransaction()) {
                        val fragment2 = Fragment2()
                        replace(R.id.container, fragment2)
                        commit()
                    }
                    return@setOnItemSelectedListener true
                }
                R.id.tab3 -> {
                    showToast("세번쨰 탭 선택됨 Third tab selected")
                    with(supportFragmentManager.beginTransaction()) {
                        val fragment3 = Fragment3()
                        replace(R.id.container, fragment3)
                        commit()
                    }
                    return@setOnItemSelectedListener true
                }
            }
            return@setOnItemSelectedListener false
        }
    }

    fun showToast(message:String?){
        Toast.makeText(applicationContext,message,Toast.LENGTH_LONG).show()
    }
}

3.active_main.xml

-xml design

-xml code

<?xml version="1.0" encoding="utf-8"?>
<androidx.drawerlayout.widget.DrawerLayout 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:id="@+id/drawerLayout"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:fitsSystemWindows="true"
    tools:openDrawer="start">
    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <com.google.android.material.appbar.AppBarLayout
            android:id="@+id/appBarLayout"
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <androidx.appcompat.widget.Toolbar
                android:id="@+id/toolbar"
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:layout_marginTop="30dp"
                android:background="?attr/colorPrimary"
                app:popupTheme="@style/AppTheme.PopupOverlay" />

        </com.google.android.material.appbar.AppBarLayout>

        <FrameLayout
            android:id="@+id/container"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior"></FrameLayout>

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

    <com.google.android.material.navigation.NavigationView
        android:id="@+id/navigationView"
        android:layout_width="wrap_content"
        android:layout_height="match_parent"
        android:layout_gravity="start"
        android:fitsSystemWindows="true"
        app:headerLayout="@layout/nav_header"
        app:menu="@menu/nav_menu" />
</androidx.drawerlayout.widget.DrawerLayout>