안드로이드 TabLayout + ViewPager2 + Fragment swipe

https://hyperrookie.tistory.com/741

안드로이드 ViewPager2 + Fragment swape

직전에 했던 코드에 TabLayout을 추가했다.

TabItem의 title용 array가 필요하고 ViewPage2 adapter를 연결한 후에 다음과 같이 처리

TabLayoutMediator(tabLayout, activityMainViewPager2) { tab, position ->
    tab.text = tabTitles[position]
}.attach()

MainActivity.kt

package com.example.myviewpager2fragment

import android.os.Bundle
import android.os.Handler
import android.os.Looper
import android.util.Log
import android.view.View
import android.widget.Toast
import androidx.activity.OnBackPressedCallback
import androidx.activity.enableEdgeToEdge
import androidx.appcompat.app.AppCompatActivity
import androidx.core.view.ViewCompat
import androidx.core.view.WindowInsetsCompat
import androidx.fragment.app.Fragment
import androidx.viewpager2.widget.ViewPager2.OnPageChangeCallback
import com.example.myviewpager2fragment.adapter.PageAdapter
import com.example.myviewpager2fragment.databinding.ActivityMainBinding
import com.example.myviewpager2fragment.fragment.FirstFragment
import com.example.myviewpager2fragment.fragment.SecondFragment
import com.google.android.material.tabs.TabLayoutMediator
import kotlin.system.exitProcess

class MainActivity : AppCompatActivity() {

    private val binding by lazy {
        ActivityMainBinding.inflate(layoutInflater)
    }
    private lateinit var pageAdapter: PageAdapter
    private lateinit var tabTitles: MutableList<String>
    private lateinit var fragmentList: MutableList<Fragment>
    private lateinit var firstFragment: FirstFragment
    private lateinit var secondFragment: SecondFragment
    private var isTerminated: Boolean = false

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        enableEdgeToEdge()
        setContentView(binding.root)
        ViewCompat.setOnApplyWindowInsetsListener(binding.main) { v, insets ->
            val systemBars = insets.getInsets(WindowInsetsCompat.Type.systemBars())
            v.setPadding(systemBars.left, systemBars.top, systemBars.right, systemBars.bottom)
            insets
        }

        this.onBackPressedDispatcher.addCallback(this, object : OnBackPressedCallback(true) {
            override fun handleOnBackPressed() {
                if (binding.activityMainViewPager2.currentItem == 0) {
                    if (!isTerminated) {
                        Toast.makeText(this@MainActivity, "한번 더 클릭하면 종료됩니다", Toast.LENGTH_SHORT)
                            .show()
                    } else {
                        Handler(mainLooper).postDelayed({
                            finishAndRemoveTask()
                            exitProcess(0)
                        }, 100)
                    }
                } else {
                    binding.activityMainViewPager2.currentItem -= 1
                }
            }
        })

        tabTitles = mutableListOf("First", "Second")
        firstFragment = FirstFragment(binding)
        secondFragment = SecondFragment()
        fragmentList = mutableListOf(firstFragment, secondFragment)

        pageAdapter = PageAdapter(this, fragmentList)

        with(binding) {

            activityMainViewPager2.apply {
                adapter = pageAdapter
                registerOnPageChangeCallback(object : OnPageChangeCallback() {
                    override fun onPageSelected(position: Int) {
                        super.onPageSelected(position)
                        activityMainImageButtonBack.visibility =
                            if (position == 0) View.INVISIBLE else View.VISIBLE
                    }
                })
            }

            TabLayoutMediator(tabLayout, activityMainViewPager2) { tab, position ->
                tab.text = tabTitles[position]
            }.attach()

            activityMainImageButtonBack.setOnClickListener {
                if (activityMainViewPager2.currentItem == 1) {
                    activityMainViewPager2.currentItem = 0
                }
            }
        }
    }
}