val getContent = registerForActivityResult(GetContent()) { uri: Uri? ->
    // Handle the returned Uri
    
    // 여기서 갤러리의 이미지 Uri를 어떻게 처리할 지 정할 수 있음
}

override fun onCreate(savedInstanceState: Bundle?) {
    // ...

    val selectButton = findViewById<Button>(R.id.select_button)

    selectButton.setOnClickListener {
        // Pass in the mime type you'd like to allow the user to select
        // as the input
        getContent.launch("image/*")
    }
}

class MainActivity : AppCompatActivity() {
    lateinit var bt_open_camera:Button
    lateinit var iv_photo:ImageView

    private lateinit var resultLauncher: ActivityResultLauncher<Intent>

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        bt_open_camera = findViewById<Button>(R.id.bt_open_camera)
        iv_photo = findViewById<ImageView>(R.id.iv_photo)

        // Activity에서 온 result를 처리하는 Launcher
        // 콜백을 등록하는 것임
        resultLauncher =
            registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
                if (result.resultCode == Activity.RESULT_OK) {
                    handleCameraImage(result.data) // Launcher가 카메라 촬영을 성공적으로 마쳤다는 resultCode를 받았을 경우 실행
                }
            }
        
        // Launcher에 카메라 촬영하는 Intent 보냄
        bt_open_camera.setOnClickListener {
            val cameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
            resultLauncher.launch(cameraIntent)
        }
    }

    private fun handleCameraImage(intent: Intent?) {
        
        // "data"라는 key로 온 이미지 데이터를 받음
        val bitmap = intent?.extras?.get("data") as Bitmap

        // 이미지뷰의 이미지 변경
        iv_photo.setImageBitmap(bitmap)
    }

}

// filepath에 이미지 uri 입력

fun getOrientationOfImage(filepath : String): Int? {
        var exif : ExifInterface? = null
        var result: Int? = null
        try{
            exif = ExifInterface(filepath)
        }catch (e: Exception){
            e.printStackTrace()
            return -1
        }
        val orientation = exif.getAttributeInt(ExifInterface.TAG_ORIENTATION, -1)
        if(orientation != -1){
            result = when(orientation){
                ExifInterface.ORIENTATION_ROTATE_90 -> {90
                    Log.d(TAG, "rotation 90")}
                ExifInterface.ORIENTATION_ROTATE_180 -> {180
                    Log.d(TAG, "rotation 180")}
                ExifInterface.ORIENTATION_ROTATE_270 -> {270
                    Log.d(TAG, "rotation 270")}
                else -> 0
            }
        }
        return result
    }

class ListviewActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_listview)

        val listView = findViewById<ListView>(R.id.listView)

        val item = arrayOf("0번", "1번", "2번", "3번", "4번", "5번", "6번", "7번", "8번", "9번", "10번", "11번", "12번", "13번", "14번", "15번", "16번")
        listView.adapter = ArrayAdapter(this, android.R.layout.simple_list_item_1, item)

        listView.onItemClickListener = AdapterView.OnItemClickListener { parent, view, position, id ->

            // 매개변수로 parent, view, position, id 4개가 주어져야함

           val selectItem = parent.getItemAtPosition(position)
            Toast.makeText(this, selectItem.toString(), Toast.LENGTH_SHORT).show()
        }
    }
}

class Data(val profile:Int, val name:String)    // 이미지뷰, 텍스트뷰 설정을 위한 클래스
                                                // Drawable에서 Int형식으로 이미지를 받을 수 있음

class CustomAdapter (val context: Context, val DataList:ArrayList<Data>) : BaseAdapter(){
    override fun getCount() = DataList.size

    override fun getItem(position: Int) = DataList[position]

    override fun getItemId(position: Int) = 0L // L이 붙어야 long 형식

    override fun getView(position: Int, convertView: View?, parent: ViewGroup?): View {
        val view:View = LayoutInflater.from(context).inflate(R.layout.custom_list, null)   // context는 현재 layout임. 즉 현재 layout 코드를 통해 새로운 layout을 하나 만듬
                                                                                                // 다시말하면 custom_list.xml을 activity_listview.xml에 대입시키기 위해
                                                                                                // 새로운 layout을 만듬
        val profile = view.findViewById<ImageView>(R.id.iv_custom)
        val name = view.findViewById<TextView>(R.id.tv_custom)
        val data = DataList[position]

        profile.setImageResource(data.profile)
        name.text = data.name

        return view
    }

}

class ListviewActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_listview)

        var DataList = arrayListOf(
            Data(R.drawable.youtube_button, "0번"),
            Data(R.drawable.youtube_button_light, "1번"),
            Data(R.drawable.youtube_button, "2번"),
            Data(R.drawable.youtube_button, "3번"),
        )


        val listView = findViewById<ListView>(R.id.listView)

        listView.adapter = CustomAdapter(this, DataList)

                listView.onItemClickListener = AdapterView.OnItemClickListener { parent, view, position, id ->

            // 매개변수로 parent, view, position, id 4개가 주어져야함

           val selectItem = parent.getItemAtPosition(position) as Data
            Toast.makeText(this, selectItem.name, Toast.LENGTH_SHORT).show()
        }
    }
}

class CustomViewHolder(private val binding: CustomListBinding) : RecyclerView.ViewHolder(binding.root){
                // CustomViewHolder 클래스는 custom_list.xml 화면을 View로 만들어서 activity_recycler.xml에 붙이는 역할을 함

    val profile = binding.ivCustom // 뷰에 있는 이미지 뷰
    val name = binding.tvCustom  // 뷰에 있는 텍스트 뷰
}
class CustomAdapter(val DataList:ArrayList<Data>, val context:Context): RecyclerView.Adapter<CustomViewHolder>(){
    override fun onCreateViewHolder(parent: ViewGroup, viewType: Int): CustomViewHolder {   
                                                                                                                           // custom_list가 팽창하는것

        // 뷰 바인딩으로 인해 코드 변경
        // 레이아웃이 parent.context로부터 팽창함
        val binding = CustomListBinding.inflate(LayoutInflater.from(context), parent, false)
        return CustomViewHolder(binding)
    }

    override fun getItemCount() = DataList.size     // 화면에 표시할 뷰 갯수
    override fun onBindViewHolder(holder: CustomViewHolder, position: Int) {
        holder.profile.setImageResource(DataList[position].profile)
        holder.name.text = DataList[position].name

        holder.itemView.setOnClickListener{
            Toast.makeText(context, DataList[position].name, Toast.LENGTH_SHORT).show()
        }
    }
}

// 뷰바인딩 적용
class RecyclerActivity : AppCompatActivity() {
    private lateinit var binding: ActivityRecyclerBinding       // Activity 이름에 걸맞게 타입을 적어줘야 함

    val DataList = arrayListOf(
        Data(R.drawable.youtube_button, "0번"),
        Data(R.drawable.youtube_button, "1번"),
        Data(R.drawable.youtube_button, "2번"),
        Data(R.drawable.youtube_button, "3번"),
        Data(R.drawable.youtube_button, "4번"),
        Data(R.drawable.youtube_button, "5번"),
        Data(R.drawable.youtube_button, "6번"),
        Data(R.drawable.youtube_button, "7번"),
        Data(R.drawable.youtube_button, "8번"),
        Data(R.drawable.youtube_button, "9번"),
        Data(R.drawable.youtube_button, "10번"),
        Data(R.drawable.youtube_button, "11번")
    )

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

        binding.recyclerView.layoutManager = LinearLayoutManager(this)      // 이 코드를 통해 화면상 수직이동이 가능해짐(스크롤뷰 마냥)
        binding.recyclerView.adapter = CustomAdapter(DataList, this)
    }
}

package com.example.android_study

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.appcompat.app.AppCompatActivity
import androidx.fragment.app.Fragment
import com.example.android_study.databinding.ActivityChangeFragmentBinding
import com.example.android_study.databinding.FragmentMyBinding

class ChangeFragmentActivity : AppCompatActivity() {

    private lateinit var binding : ActivityChangeFragmentBinding
    private lateinit var myFragment: MyFragment
    private lateinit var mySecondFragment: MySecondFragment

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

        setContentView(binding.root)

        binding.fragmentChangeBtn1.setOnClickListener {
            myFragment = MyFragment.newInstance("hohohoho", "dfsfs")
            supportFragmentManager.beginTransaction().replace(R.id.activity_change_frame_layout, myFragment).commit()
        }

        binding.fragmentChangeBtn2.setOnClickListener {
            mySecondFragment = MySecondFragment.newInstance("hohohohoasfslkadjf", "Asdfsa")
            supportFragmentManager.beginTransaction().replace(R.id.activity_change_frame_layout, mySecondFragment).commit()
        }
    }
}

package com.example.android_study

import android.os.Bundle
import androidx.fragment.app.Fragment
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import com.example.android_study.databinding.FragmentMyBinding

// TODO: Rename parameter arguments, choose names that match
// the fragment initialization parameters, e.g. ARG_ITEM_NUMBER
private const val ARG_PARAM1 = "param1"
private const val ARG_PARAM2 = "param2"

/**
 * A simple [Fragment] subclass.
 * Use the [MyFragment.newInstance] factory method to
 * create an instance of this fragment.
 */
class MyFragment : Fragment() {
    // TODO: Rename and change types of parameters
    private var param1: String? = null
    private var param2: String? = null

    private var _binding: FragmentMyBinding? = null
    private val binding get() = _binding!!

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        arguments?.let {
            param1 = it.getString(ARG_PARAM1)
            param2 = it.getString(ARG_PARAM2)
        }
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        // Inflate the layout for this fragment

        _binding = FragmentMyBinding.inflate(inflater, container, false)
        return binding.root
//        return inflater.inflate(R.layout.fragment_my, container, false)
    }

    override fun onDestroyView() {
        _binding = null     // Fragment가 없어질 때 _binding을 null 처리함
        super.onDestroyView()
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        binding.textview.text = param1

//        super.onViewCreated(view, savedInstanceState)
    }

    companion object {
        /**
         * Use this factory method to create a new instance of
         * this fragment using the provided parameters.
         *
         * @param param1 Parameter 1.
         * @param param2 Parameter 2.
         * @return A new instance of fragment MyFragment.
         */
        // TODO: Rename and change types and number of parameters
        @JvmStatic
        fun newInstance(param1: String, param2: String) =
            MyFragment().apply {
                arguments = Bundle().apply {
                    putString(ARG_PARAM1, param1)
                    putString(ARG_PARAM2, param2)
                }
            }
    }
}

package com.example.android_study

import androidx.fragment.app.Fragment
import androidx.fragment.app.FragmentActivity
import androidx.viewpager2.adapter.FragmentStateAdapter

class MyPagerAdapter(fa: FragmentActivity) : FragmentStateAdapter(fa){      // 주 생성자의 fa값을 부모의 생성자로 넘김
    private val NUM_PAGES = 3

    override fun getItemCount() = NUM_PAGES

    override fun createFragment(position: Int): Fragment {
        return when(position){
            0 -> {MyFragment.newInstance("Page1", "")}  // 얘네가 아까 Fragment의 두개 param1, param2에 들어가는것
            1 -> {MyFragment.newInstance("Page2", "")}
            else -> {MyFragment.newInstance("Page3", "")}
        }
    }


}

class ViewPagerActivity : AppCompatActivity() {
    private lateinit var binding: ActivityViewpagerBinding
    private val images = listOf(
        R.drawable.idol1,
        R.drawable.idol2,
        R.drawable.idol3,
    )
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        binding = ActivityViewpagerBinding.inflate(layoutInflater)
        setContentView(binding.root)

        binding.viewpager.apply{
            adapter = MyPagerAdapter(context as FragmentActivity)
            setPageTransformer(ZoomOutPageTransformer())
        }

        TabLayoutMediator(binding.tabs, binding.viewpager){ tab, position ->
            tab.text = "Title $position"        // tab에 표시할 텍스트
            tab.setIcon(images[position])
        }.attach()
    }

}

et_pw.setOnEditorActionListener() { v, actionId, event ->
            if(actionId == EditorInfo.IME_ACTION_DONE){
                Login(v)
                true
            } else {
                false
            }
        }