혀가 길지 않은 개발자

[Android] 에뮬레이터 추가

혀가 길지 않은 개발자 — Sun, 12 Dec 2021 13:48:21 +0900

안드로이드 스튜디오에 원하는 기기 에뮬레이터 추가

https://developer.samsung.com/galaxy-emulator-skin/guide.html

[Kotlin] 암호화와 복호화

혀가 길지 않은 개발자 — Sun, 6 Jun 2021 17:48:39 +0900

암호화 (AES256, BLOWFISH)

복호화

Hash 함수를 통과 하기전의 원본 데이터를 메시지(message)라고 부르고, 통과된 이후의 데이터를 다이제스트(digest)라고 부른다.

1. AES/ECB/PKCS5PADDING 방식

키

plaintext

cipher

ciphertext

2. AES/CBC/PKCS5PADDING 방식

키

plaintext

cipher

ciphertext

3. key값의 길이에 따라 AES128, AES192, AES256 으로 구분됨

AES128 : 키값 16bytes

AES192 : 키값 24bytes

AES256 : 키값 32bytes

MainActivity.kt

package com.example.encryptionexample

import android.os.Bundle
import android.util.Base64
import android.util.Log
import androidx.appcompat.app.AppCompatActivity
import javax.crypto.Cipher
import javax.crypto.spec.IvParameterSpec
import javax.crypto.spec.SecretKeySpec

class MainActivity : AppCompatActivity() {

    companion object {
        const val SECRET_KEY = "ABCDEFGH12345678"
        const val SECRET_IV = "1234567812345678"
    }

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

        val encrypted = "안녕하세요!!!".encryptECB()
        val decrypted = encrypted.decryptECB()

        Log.e("", encrypted)
        Log.e("", decrypted)

        val encryptedCBC = "Hello~!!!".encryptCBC()
        val decryptedCBC = encryptedCBC.decryptCBC()

        Log.e("", encryptedCBC)
        Log.e("", decryptedCBC)
    }

    /**
     * ECB 암호화
     */
    private fun String.encryptECB(): String{
        val keySpec = SecretKeySpec(SECRET_KEY.toByteArray(), "AES")    /// 키
        val cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING")     //싸이퍼
        cipher.init(Cipher.ENCRYPT_MODE, keySpec)       // 암호화/복호화 모드
        val ciphertext = cipher.doFinal(this.toByteArray())
        val encodedByte = Base64.encode(ciphertext, Base64.DEFAULT)
        return String(encodedByte)
    }

    /**
     * ECB 복호화
     */
    private fun String.decryptECB(): String {
        val keySpec = SecretKeySpec(SECRET_KEY.toByteArray(), "AES")
        var decodedByte: ByteArray = Base64.decode(this, Base64.DEFAULT)
        val cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING")
        cipher.init(Cipher.DECRYPT_MODE, keySpec)
        val output = cipher.doFinal(decodedByte)

        return String(output)
    }

    /**
     * CBC 암호화
     */
    private fun String.encryptCBC(): String{
        val iv = IvParameterSpec(SECRET_IV.toByteArray())
        val keySpec = SecretKeySpec(SECRET_KEY.toByteArray(), "AES")    /// 키
        val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")     //싸이퍼
        cipher.init(Cipher.ENCRYPT_MODE, keySpec, iv)       // 암호화/복호화 모드
        val crypted = cipher.doFinal(this.toByteArray())
        val encodedByte = Base64.encode(crypted, Base64.DEFAULT)

        return String(encodedByte)
    }

    /**
     * CBC 복호화
     */
    private fun String.decryptCBC(): String {
        var decodedByte: ByteArray = Base64.decode(this, Base64.DEFAULT)
        val iv = IvParameterSpec(SECRET_IV.toByteArray())
        val keySpec = SecretKeySpec(SECRET_KEY.toByteArray(), "AES")
        val cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING")
        cipher.init(Cipher.DECRYPT_MODE, keySpec, iv)
        val output = cipher.doFinal(decodedByte)

        return String(output)
    }

}

실행 결과

참고.

https://developer.android.com/guide/topics/security/cryptography?hl=ko

암호화 | Android 개발자 | Android Developers

Android의 암호화 기능을 알아보세요.

developer.android.com

Encoding ? Enctyption ?

https://stackoverflow.com/questions/4657416/difference-between-encoding-and-encryption

Difference between encoding and encryption

What is the difference between encoding and encryption?

stackoverflow.com

CBC? ECB?

https://m.blog.naver.com/PostView.naver?isHttpsRedirect=true&blogId=jsky10503&logNo=221258926405

블록암호와 운용방식(ECB, CBC, CTR)

블록암호(block cipher)란 기밀성있는 정보를 고정된 크기의 블록단위로 구성하여 암호화 작업을 하는 대칭...

blog.naver.com

http://happinessoncode.com/2019/04/06/java-cipher-algorithm-mode-padding/

Java Cipher - 알고리즘, 운용 모드, 패딩의 이해

자바에서는 대칭키 알고리즘을 사용하여 데이터를 암호화/복호화할 때 javax.crypto.Cipher 클래스를 사용한다. 이 클래스의 인스턴스는 정적 메서드인 Cipher.getInstance()를 호출하여 가져올 수 있는데,

happinessoncode.com

[Kotlin] Lifecycle, LifecycleOwner, LifecycleObserver

혀가 길지 않은 개발자 — Sat, 5 Jun 2021 21:37:33 +0900

Lifecycle

LifecycleOwner

LifecycleObserver

MainActivity.kt

package com.example.lifecycleexample

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.util.Log
import android.widget.Button
import androidx.lifecycle.Lifecycle
import androidx.lifecycle.LifecycleEventObserver

class MainActivity : AppCompatActivity() {

    private val btShow: Button by lazy {
        findViewById(R.id.bt_show)
    }

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

        val bottomLifecycleObserver = LifecycleEventObserver { source, event ->
            when (source.lifecycle.currentState) {
                Lifecycle.State.CREATED -> Log.e("", "MainActivity :: Lifecycle.State.CREATED")
                Lifecycle.State.STARTED -> Log.e("", "MainActivity :: Lifecycle.State.STARTED")
                Lifecycle.State.DESTROYED -> Log.e("", "MainActivity :: Lifecycle.State.DESTROYED")
            }

            when (event) {
                Lifecycle.Event.ON_CREATE -> Log.e("", "MainActivity :: Lifecycle.Event.ON_CREATE")
                Lifecycle.Event.ON_START -> Log.e("", "MainActivity :: Lifecycle.Event.ON_START")
                Lifecycle.Event.ON_RESUME -> Log.e("", "MainActivity :: Lifecycle.Event.ON_RESUME")
                Lifecycle.Event.ON_PAUSE -> Log.e("", "MainActivity :: Lifecycle.Event.ON_PAUSE")
                Lifecycle.Event.ON_STOP -> Log.e("", "MainActivity :: Lifecycle.Event.ON_STOP")
                Lifecycle.Event.ON_DESTROY -> Log.e("", "MainActivity :: Lifecycle.Event.ON_DESTROY")
            }
        }

        btShow.setOnClickListener {
            TestDialog().apply {
                lifecycleObserver = bottomLifecycleObserver
            }.show(supportFragmentManager, "TestDialog")

        }
    }

}

다이얼로그의 생명주기에 반응하여 로그를 출력. (LifecycleObserver)

TestDialog.kt

package com.example.lifecycleexample

import android.os.Bundle
import android.util.Log
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.lifecycle.LifecycleObserver
import com.google.android.material.bottomsheet.BottomSheetDialogFragment

class TestDialog : BottomSheetDialogFragment() {

    lateinit var lifecycleObserver: LifecycleObserver

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        Log.e("", "TestDialog :: onCreate()")
    }

    override fun onCreateView(
        inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?
    ): View? {
        viewLifecycleOwner.lifecycle.addObserver(lifecycleObserver)
        Log.e("", "TestDialog :: onCreateView()")
        return inflater.inflate(R.layout.dialog_test, container, false)
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        Log.e("", "TestDialog :: onViewCreated()")
    }

    override fun onActivityCreated(savedInstanceState: Bundle?) {
        super.onActivityCreated(savedInstanceState)
        Log.e("", "TestDialog :: onActivityCreated()")
    }

    override fun onStart() {
        super.onStart()
        Log.e("", "TestDialog :: onStart()")
    }

    override fun onResume() {
        super.onResume()
        Log.e("", "TestDialog :: onResume()")
    }

    override fun onPause() {
        super.onPause()
        Log.e("", "TestDialog :: onPause()")
    }

    override fun onStop() {
        super.onStop()
        Log.e("", "TestDialog :: onStop()")
    }

    override fun onDestroy() {
        super.onDestroy()
        Log.e("", "TestDialog :: onDestroy()")
    }

}

MainActivity 에서 생선한 lifecycleObserver 를 다이얼로그의 생명주기에 추가한다.

viewLifecycleOwner.lifecycle.addObserver(lifecycleObserver)

실행 결과

다이얼로그 띄웠을 때

다이얼로그 없어졌을 때

[Kotlin] registerForActivityResult

혀가 길지 않은 개발자 — Thu, 27 May 2021 21:01:07 +0900

~~startActivityForResult()~~

~~onActivityResult()~~

registerForResultActivity

ActivityResultLauncher<Intent>

registerForActivityResult

ActivityResultContracts.StartActivityForResult()

ActivityResultLauncher.launch(intent)

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">

    <TextView
        android:id="@+id/tv_main"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="30dp"
        tools:text="Main"
        app:layout_constraintVertical_chainStyle="packed"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintStart_toStartOf="parent"
        app:layout_constraintEnd_toEndOf="parent"
        app:layout_constraintBottom_toTopOf="@+id/bt_main" />

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_main"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="move to SubActivity"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toBottomOf="@+id/tv_main" />

</androidx.constraintlayout.widget.ConstraintLayout>

activity_main.xml

Activity_sub.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"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_sub"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="back"
        android:textAllCaps="false"
        app:layout_constraintBottom_toBottomOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintTop_toTopOf="parent" />

</androidx.constraintlayout.widget.ConstraintLayout>

activity_sub.xml

SubActivity.kt

package com.example.registerforresultactivityexample

import android.content.Intent
import android.os.Bundle
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.AppCompatButton

class SubActivity : AppCompatActivity() {

    private val btSub: AppCompatButton by lazy { findViewById(R.id.bt_sub) }

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

        btSub.setOnClickListener {
            val intent = Intent(this, MainActivity::class.java).apply {
                putExtra("address", "Seoul")
            }
            setResult(RESULT_OK, intent)
            if (!isFinishing) finish()
        }
    }

}

MainActivity.kt

package com.example.registerforresultactivityexample

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.TextView
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.contract.ActivityResultContracts
import androidx.appcompat.widget.AppCompatButton

class MainActivity : AppCompatActivity() {

    private val btMain: AppCompatButton by lazy { findViewById(R.id.bt_main) }
    private val tvMain: TextView by lazy { findViewById(R.id.tv_main) }

    lateinit var activityResultLauncher: ActivityResultLauncher<Intent>

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

        btMain.setOnClickListener {
            activityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
                if (it.resultCode == RESULT_OK) {
                    val address = it.data?.getStringExtra("address") ?: ""
                    tvMain.text = address
                }
            }

            val intent = Intent(this, SubActivity::class.java)
            activityResultLauncher.launch(intent)
        }
    }

}

실행 결과 에러 발생

????????

에러 발생

onResume() 에서 registerForActivityResult() 호출하면 에러가 발생함.

onCreate() 아니면 onStart() 에서 사용해야 함.

MainActivity.kt

package com.example.registerforresultactivityexample

import android.content.Intent
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.widget.TextView
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.contract.ActivityResultContracts
import androidx.appcompat.widget.AppCompatButton

class MainActivity : AppCompatActivity() {

    private val btMain: AppCompatButton by lazy { findViewById(R.id.bt_main) }
    private val tvMain: TextView by lazy { findViewById(R.id.tv_main) }

    lateinit var activityResultLauncher: ActivityResultLauncher<Intent>

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

        activityResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) {
            if (it.resultCode == RESULT_OK) {
                val address = it.data?.getStringExtra("address") ?: ""
                tvMain.text = address
            }
        }

        btMain.setOnClickListener {
            val intent = Intent(this, SubActivity::class.java)
            activityResultLauncher.launch(intent)
        }
    }

}

실행 결과

에러 발생 시 참고.

https://stackoverflow.com/questions/65121235/fatal-error-lifecycleowners-must-call-register-before-they-are-started-on-regist

Fatal error LifecycleOwners must call register before they are STARTED on registerForActivityResult

I have a simple empty activity that checks if permissions need to be requested. When registerForActivityResult is called, it crashes with the error java.lang.IllegalStateException: LifecycleOwner com.

stackoverflow.com

[Kotlin] 위치 권한

혀가 길지 않은 개발자 — Thu, 27 May 2021 04:32:57 +0900

1. 위치 권한 팝업 (2가지) (주의사항)

2. GPS 허용 팝업, 위치 얻기

Manifest.permission.ACCESS_FINE_LOCATION (해당 권한 팝업 허용시 ACCESS_COARSE_LOCATION 권한도 허용됨)

Manifest.permission.ACCESS_COARSE_LOCATION (팝업 허용시 ACCESS_FINE_LOCATION 권한은 허용이 안됨)

ContextCompat.checkSelfPermission()

ActivityResultContracts.RequestPermission()

ActivityResultContracts.RequestMultiplePermissions()

PackageManager.PERMISSION_GRANTED

checkSelfPermission

requestPermissions

~~FusedLocationProviderApi~~

FusedLocationProviderClient

1. 위치 권한 팝업 (2가지) (주의사항)

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/tv_latitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="24dp"
        tools:text="111.12313"/>

    <TextView
        android:id="@+id/tv_longitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="24dp"
        tools:text="122.244231"/>

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_permission_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="권한 요청 첫 번째 방법"
        android:textAllCaps="false" />

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_permission_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="권한 요청 두 번째 방법"
        android:textAllCaps="false" />

</LinearLayout>

activity_main.xml

MainActivity.kt

package com.example.gpsexample

import android.Manifest
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import android.widget.TextView
import android.widget.Toast
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.contract.ActivityResultContracts
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.AppCompatButton
import androidx.core.content.ContextCompat

/**
 * 1. ActivityResultLauncher.launch() 를 이용하여 위치 권한 요청
 * 2. Activity.RequestPermissions() 를 이용하여 위치 권한 요청
 *
 * 주의 사항 : 첫 번째 방법 사용 시 onRequestPermissionsResult() 의 super() 먼저 호출되고
 *          registerForActivityResult 콜백이 실행된 후 다시
 *          onRequestPermissionsResult() super() 하위 코드가 실행된다.
 *          when() 으로 분기 처리 안 하면 위치 권한 응답 처리가 두 번 된다.
 *
 *          두 번째 방법 사용 시엔 onRequestPermissionsResult() 만 실행됨.
 *
 *          즉, 사용자가 시스템 권한 대화상자에 응답하면 onRequestPermissionsResult() 실행됨.
 */
class MainActivity : AppCompatActivity() {

    companion object {
        const val REQUEST_CODE_PERMISSIONS = 1001
    }

    private val permissions = arrayOf(
        Manifest.permission.ACCESS_FINE_LOCATION,
        Manifest.permission.ACCESS_COARSE_LOCATION
    )

    private val tvLatitude: TextView by lazy { findViewById(R.id.tv_latitude) }
    private val tvLongitude: TextView by lazy { findViewById(R.id.tv_longitude) }
    private val btPermission1: AppCompatButton by lazy { findViewById(R.id.bt_permission_1) }
    private val btPermission2: AppCompatButton by lazy { findViewById(R.id.bt_permission_2) }

    private lateinit var activityResultLauncher: ActivityResultLauncher<Array<String>>

    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        activityResultLauncher = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) {
            if (it.all { permission -> permission.value == true }) {

            } else {
                Toast.makeText(this, "권한 거부", Toast.LENGTH_SHORT).show()
            }
        }

        setOnClick()
    }

    /**
     * 버튼 클릭 이벤트
     */
    @RequiresApi(Build.VERSION_CODES.M)
    private fun setOnClick() {

        // 권한 요청 첫 번째 방법
        btPermission1.setOnClickListener {
            if (checkPermission(permissions)) {
                activityResultLauncher.launch(permissions)
            }
        }

        // 권한 요청 두 번째 방법
        btPermission2.setOnClickListener {
            if (!checkPermission(permissions)) {
                requestPermissions(permissions, REQUEST_CODE_PERMISSIONS)
            }
        }
    }

    /**
     * 권한 체크
     */
    private fun checkPermission(permissions: Array<String>): Boolean {
        return permissions.all {
            ContextCompat.checkSelfPermission(this, it) == PackageManager.PERMISSION_GRANTED
        }
    }

    /**
     * 권한 요청 결과
     */
    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        when (requestCode) {
            REQUEST_CODE_PERMISSIONS -> {
                if (grantResults.all { it == PackageManager.PERMISSION_GRANTED }) {

                } else {
                    Toast.makeText(this, "권한 거부", Toast.LENGTH_SHORT).show()
                }
            }
        }
    }
}

Activity.RequestPermissions() 사용시 @RequiresApi(Build.VERSION_CODES.M) 필요

즉, ActivityResultLauncher 사용 추천

주의사항 : 둘 다 onRequestPermissionResult 호출됨. (when 분기처리 한 이유)

실행 결과

2. GPS 허용 팝업, 위치 얻기

LocationRequest

LocationSettingRequest

FusedLocationProviderClient

LocationCallback()

ActivityResultContracts.StartIntentSenderForResult()

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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"
    android:orientation="vertical"
    android:gravity="center"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/tv_latitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="24dp"
        tools:text="111.12313"/>

    <TextView
        android:id="@+id/tv_longitude"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:textSize="24dp"
        tools:text="122.244231"/>

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_permission_1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginTop="20dp"
        android:text="권한 요청 첫 번째 방법"
        android:textAllCaps="false" />

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_permission_2"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="권한 요청 두 번째 방법"
        android:textAllCaps="false" />

    <androidx.appcompat.widget.AppCompatButton
        android:id="@+id/bt_location"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="위치 얻기"
        android:textAllCaps="false" />

</LinearLayout>

activity_main.xml

MainActivity.kt

package com.example.gpsexample

import android.Manifest
import android.annotation.SuppressLint
import android.content.Intent
import android.content.IntentSender
import android.content.pm.PackageManager
import android.os.Build
import android.os.Bundle
import android.os.Looper
import android.widget.TextView
import android.widget.Toast
import androidx.activity.result.ActivityResultLauncher
import androidx.activity.result.IntentSenderRequest
import androidx.activity.result.contract.ActivityResultContracts
import androidx.annotation.RequiresApi
import androidx.appcompat.app.AppCompatActivity
import androidx.appcompat.widget.AppCompatButton
import androidx.core.content.ContextCompat
import com.google.android.gms.common.api.ResolvableApiException
import com.google.android.gms.location.*

/**
 * 1. ActivityResultLauncher.launch() 를 이용하여 위치 권한 요청
 * 2. Activity.RequestPermissions() 를 이용하여 위치 권한 요청
 *
 * 주의 사항 : 첫 번째 방법 사용 시 onRequestPermissionsResult() 의 super() 먼저 호출되고
 *          registerForActivityResult 콜백이 실행된 후 다시
 *          onRequestPermissionsResult() super() 하위 코드가 실행된다.
 *          when() 으로 분기 처리 안 하면 위치 권한 응답 처리가 두 번 된다.
 *
 *          두 번째 방법 사용 시엔 onRequestPermissionsResult() 만 실행됨.
 *
 *          즉, 사용자가 시스템 권한 대화상자에 응답하면 onRequestPermissionsResult() 실행됨.
 */
class MainActivity : AppCompatActivity() {

    companion object {
        const val REQUEST_CODE_PERMISSIONS = 1001
    }

    private val permissions = arrayOf(
        Manifest.permission.ACCESS_FINE_LOCATION,
        Manifest.permission.ACCESS_COARSE_LOCATION
    )

    private val tvLatitude: TextView by lazy { findViewById(R.id.tv_latitude) }
    private val tvLongitude: TextView by lazy { findViewById(R.id.tv_longitude) }
    private val btPermission1: AppCompatButton by lazy { findViewById(R.id.bt_permission_1) }
    private val btPermission2: AppCompatButton by lazy { findViewById(R.id.bt_permission_2) }
    private val btLocation: AppCompatButton by lazy { findViewById(R.id.bt_location) }

    private lateinit var permissionResultLauncher: ActivityResultLauncher<Array<String>>
    private lateinit var resolutionResultLauncher: ActivityResultLauncher<IntentSenderRequest>

    private val locationRequest = LocationRequest.create().apply {
        priority = LocationRequest.PRIORITY_HIGH_ACCURACY
        interval = 10000
        fastestInterval = 5000
        numUpdates = 10
    }

    private val builder = LocationSettingsRequest.Builder()
        .addLocationRequest(locationRequest)
        .setAlwaysShow(true)

    private lateinit var fusedLocationClient: FusedLocationProviderClient

    private val locationCallback = object : LocationCallback() {
        override fun onLocationResult(p0: LocationResult) {
            super.onLocationResult(p0)
            tvLatitude.text = p0.lastLocation.latitude.toString()
            tvLongitude.text = p0.lastLocation.longitude.toString()
        }

        override fun onLocationAvailability(p0: LocationAvailability) {
            super.onLocationAvailability(p0)
        }
    }

    @SuppressLint("VisibleForTests")
    @RequiresApi(Build.VERSION_CODES.M)
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)

        fusedLocationClient = FusedLocationProviderClient(this)

        permissionResultLauncher = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) {
            if (it.all { permission -> permission.value == true }) {
                getLocation()
            } else {
                Toast.makeText(this, "권한 거부", Toast.LENGTH_SHORT).show()
            }
        }

        resolutionResultLauncher = registerForActivityResult(ActivityResultContracts.StartIntentSenderForResult()) {
            if (it.resultCode == RESULT_OK) {
                getLocation()
            }
        }

        setOnClick()
    }

    override fun onPause() {
        super.onPause()
        fusedLocationClient.removeLocationUpdates(locationCallback)
    }

    /**
     * 버튼 클릭 이벤트
     */
    @RequiresApi(Build.VERSION_CODES.M)
    private fun setOnClick() {
        // 권한 요청 첫 번째 방법
        btPermission1.setOnClickListener {
            if (!checkPermission(permissions)) {
                permissionResultLauncher.launch(permissions)
            } else {
                Toast.makeText(this, "이미 권한이 있습니다.", Toast.LENGTH_SHORT).show()
            }
        }

        // 권한 요청 두 번째 방법
        btPermission2.setOnClickListener {
            if (!checkPermission(permissions)) {
                requestPermissions(permissions, REQUEST_CODE_PERMISSIONS)
            } else {
                Toast.makeText(this, "이미 권한이 있습니다.", Toast.LENGTH_SHORT).show()
            }
        }

        // 위치 얻기
        btLocation.setOnClickListener {
            getLocation()
        }
    }

    /**
     * 권한 체크
     */
    private fun checkPermission(permissions: Array<String>): Boolean {
        return permissions.all {
            ContextCompat.checkSelfPermission(this, it) == PackageManager.PERMISSION_GRANTED
        }
    }

    /**
     * 위치 얻기
     */
    private fun getLocation() {
        if (checkPermission(permissions)) {
            LocationServices.getSettingsClient(this@MainActivity).checkLocationSettings(builder.build()).run {
                addOnSuccessListener { response ->
                    // All location settings are satisfied. The client can initialize
                    // location requests here.
                    // ...
                    fusedLocationClient.requestLocationUpdates(locationRequest, locationCallback, Looper.getMainLooper())
                }

                addOnFailureListener { exception ->
                    if (exception is ResolvableApiException) {
                        // Location settings are not satisfied, but this can be fixed
                        // by showing the user a dialog.
                        try {
                            // Show the dialog by calling startResolutionForResult(),
                            // and check the result in onActivityResult().
                            val intentSenderRequest = IntentSenderRequest.Builder(exception.resolution).build()
                            resolutionResultLauncher.launch(intentSenderRequest)
                        } catch (sendEx: IntentSender.SendIntentException) {
                            // Ignore the error.
                        }
                    }
                }
            }
        } else {
            permissionResultLauncher.launch(permissions)
        }
    }

    /**
     * 권한 요청 결과
     */
    override fun onRequestPermissionsResult(
        requestCode: Int,
        permissions: Array<out String>,
        grantResults: IntArray
    ) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        when (requestCode) {
            REQUEST_CODE_PERMISSIONS -> {
                if (grantResults.all { it == PackageManager.PERMISSION_GRANTED }) {

                } else {
                    Toast.makeText(this, "권한 거부", Toast.LENGTH_SHORT).show()
                }
            }
        }
    }
}

시스템 위치 OFF 상태

실행 결과

위치 사용 ON 상태

참고.

https://developer.android.com/training/location/change-location-settings?hl=ko (위치 요청 다이얼로그)

위치 설정 변경 | Android 개발자 | Android Developers

앱에서 위치를 요청하거나 권한 업데이트를 수신해야 한다면 기기는 GPS 또는 Wi-Fi 검색과 같은 적절한 시스템 설정을 사용해야 합니다. 앱은 서비스(예: 기기의 GPS)를 직접 사용 설정하기보다는

developer.android.com

https://developer.android.com/training/location/request-updates?hl=ko#stop-updates

위치 업데이트 요청 | Android 개발자 | Android Developers

위치 정보를 적절하게 사용하면 앱 사용자에게 도움이 될 수 있습니다. 예를 들어 사용자가 걷거나 운전하는 동안 길을 찾아주는 앱 또는 애셋의 위치를 추적하는 앱은 일정한 간격으로 기기의

developer.android.com

https://stackoverflow.com/questions/65158308/deprecated-onactivityresult-in-androidx (startResolutionForResult 응답 처리)

deprecated OnActivityResult() in androidx

OnActivityResult() is deprecated in androidx. I took reference from below links https://developer.android.com/training/basics/intents/result https://developer.android.com/jetpack/androidx/releases/

stackoverflow.com

[Kotlin] View

혀가 길지 않은 개발자 — Tue, 25 May 2021 23:34:37 +0900

Widget

Layout

requestLayout()

invalidate()

Button

EditText

TextView

LinearLayout

Toolbar

ViewGroup

View

View Lifecycle

참고.

https://www.charlezz.com/?p=29013

Android에서 View의 생명주기 | 찰스의 안드로이드

https://proandroiddev.com/the-life-cycle-of-a-view-in-android-6a2c4665b95e을 번역한 내용입니다. 안드로이드 앱을 실행할 때 우리가 가장 먼저 스크린에서 볼 수 있는 것이 View라고 말할 수 있다. View 클래스는 사

www.charlezz.com

[Kotlin] dp와 px

혀가 길지 않은 개발자 — Tue, 25 May 2021 20:54:32 +0900

dp와 px 지긋지긋하다.

px : 화면을 구성하는 최소 단위 (px = dp * dpi / 160)

DPI : 1인치에 들어가는 px을 나타내는 단위 (Dot Per Inch) (100dpi = 1인치에 100px)

dp : 픽셀 독립 단위 (dp = px * 160 / dpi)

ldpi : 120dpi
mdpi : 160dpi (기본) (1dp = 1px)
hdpi : 240dpi
xhdpi : 320dpi
xxhdpi : 480dpi
xxxhdpi : 640dpi

hdpi

dpi : 240

ImageView 사이즈 : 400px / 400px

TextView 사이즈 : 100px

440dpi

dpi : 440

ImageView 사이즈 : 400px / 400px

TextView 사이즈 : 100px

이래서 dp를 사용하는 게 좋다. dp로 설정했을 때 차이를 보자.

hdpi

dpi : 240

ImageView 사이즈 : 200dp / 200dp

TextView 사이즈 : 40dp

440dpi

dpi : 440

ImageView 사이즈 : 200dp / 200dp

TextView 사이즈 : 40dp

이래서 dp를 사용하는 게 좋다. 비율이 맞다.

dp 와 px 간 변환

Resources.getSystem().displayMetrics.density (dpi / 160)

dp <-> px 둘 다 가능

TypedValue.applyDimension(TypedValue.COMPLEX_UNIT_DIP, dp, resources.displayMetrics).roundToInt()

얘는 dp To px 만 가능.

[Kotlin] CoordinatorLayout

혀가 길지 않은 개발자 — Mon, 24 May 2021 11:17:16 +0900

CoordinatorLayout

AppBarLayout

MaterialToolbar

app:layout_scrollFlags

app:layout_behavior="@string/appbar_scrolling_view_behavior"

fragment_plant_detail.xml

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

    <androidx.coordinatorlayout.widget.CoordinatorLayout
        android:id="@+id/cnl_"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:fitsSystemWindows="true">

        <com.google.android.material.appbar.AppBarLayout
            android:layout_width="match_parent"
            android:layout_height="wrap_content">

            <com.google.android.material.appbar.MaterialToolbar
                android:layout_width="match_parent"
                android:layout_height="wrap_content"
                app:layout_scrollFlags="scroll|enterAlways"
                app:title="@string/app_name" />

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

        <androidx.core.widget.NestedScrollView
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            app:layout_behavior="@string/appbar_scrolling_view_behavior">

            <LinearLayout
                android:layout_width="match_parent"
                android:layout_height="match_parent"
                android:orientation="vertical">

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="800dp"
                    android:gravity="center"
                    android:text="1"
                    android:textSize="30sp" />

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="800dp"
                    android:gravity="center"
                    android:text="2"
                    android:textSize="30sp" />

                <TextView
                    android:layout_width="match_parent"
                    android:layout_height="800dp"
                    android:gravity="center"
                    android:text="3"
                    android:textSize="30sp" />

            </LinearLayout>

        </androidx.core.widget.NestedScrollView>

    </androidx.coordinatorlayout.widget.CoordinatorLayout>

</layout>

fragment_plant_detail.xml

app:layout_scrollFlags 의 종류

app:layout_scrollFlags="scroll|enterAlways" (스크롤 내리면 툴바 노출, 스크롤 올리면 툴바 사라짐)

"enterAlways" 속성

app:layout_scrollFlags="scroll|enterAlwaysCollapsed" (스크롤 최상단까지 내리면 툴바 노출, 스크롤 올리면 툴바 사라짐)

"enterAlwaysCollapsed" 속성

app:layout_scrollFlags="scroll|exitUntilCollapsed" (반응 없음. CollapsingToolbarLayout 사용할 때 쓰임)

"exitUntilCollapsed" 속성

app:layout_scrollFlags="scroll|snap" ("enterAlwaysCollapsed"와 동일한 효과. CollapsingToolbarLayout 사용할 때 쓰임)

"exitUntilCollapsed" 속성

[Kotlin] CollapsingToolbarLayout

혀가 길지 않은 개발자 — Mon, 24 May 2021 00:27:18 +0900

CollapsingToolbarLayout

Collapsing? 붕괴

CoordinatorLayout

AppBarLayout

MaterialToolbar

NestedScrollView

FloatingActionButton

android:layout_height="?attr/actionBarSize"

fitsSystemWindows

app:contentInsetStart

[Kotlin] Navigation

혀가 길지 않은 개발자 — Sun, 23 May 2021 23:09:29 +0900

프레그먼트 간 이동을 관리

FragmentContainerView

nav_host

androidx.navigation.fragment.NavHostFragment

defaultNavHost

navGraph

build.gradle (Project)

buildscript {
    dependencies {
    	// safeArgs
        classpath "android.arch.navigation:navigation-safe-args-gradle-plugin:1.0.0"
    }
}

build.gradle (Module:app)

plugins {
    id 'dagger.hilt.android.plugin'             // hilt
    id 'androidx.navigation.safeargs.kotlin'	// safeArgs
}

dependencies {
    implementation 'androidx.navigation:navigation-fragment-ktx:2.3.5'
    implementation 'androidx.navigation:navigation-ui-ktx:2.3.5'
}

activity_garden.xml

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

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/nav_host"
        android:name="androidx.navigation.fragment.NavHostFragment"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        app:defaultNavHost="true"
        app:navGraph="@navigation/nav_garden" />

</layout>

GardenActivity.kt

package com.example.sunflowerexample

import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import androidx.databinding.DataBindingUtil.setContentView
import com.example.sunflowerexample.databinding.ActivityGardenBinding
import dagger.hilt.android.AndroidEntryPoint

@AndroidEntryPoint
class GardenActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView<ActivityGardenBinding>(this, R.layout.activity_garden)
    }
}

HomeViewPagerFragment.kt (xml에 버튼 하나 있음)

package com.example.sunflowerexample

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.navigation.fragment.findNavController
import com.example.sunflowerexample.databinding.FragmentViewPagerBinding
import dagger.hilt.android.AndroidEntryPoint

@AndroidEntryPoint
class HomeViewPagerFragment : Fragment() {

    lateinit var binding: FragmentViewPagerBinding

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        binding = FragmentViewPagerBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.btViewPager.setOnClickListener {
            findNavController().navigate(HomeViewPagerFragmentDirections.actionViewPagerFragmentToPlantDetailFragment("plantId"))
        }
    }
}

PlantDetailFragment.kt (xml에 버튼 하나 있음)

package com.example.sunflowerexample

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import androidx.navigation.fragment.findNavController
import com.example.sunflowerexample.databinding.FragmentPlantDetailBinding
import dagger.hilt.android.AndroidEntryPoint

@AndroidEntryPoint
class PlantDetailFragment : Fragment() {

    lateinit var binding: FragmentPlantDetailBinding

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View {
        binding = FragmentPlantDetailBinding.inflate(inflater, container, false)
        return binding.root
    }

    override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        binding.btPlantDetail.setOnClickListener {
            findNavController().navigate(PlantDetailFragmentDirections.actionPlantDetailFragmentToGalleryFragment("plantName"))
        }
    }
}

GalleryFragment.kt (xml에 버튼 하나 있음)

package com.example.sunflowerexample

import android.os.Bundle
import android.view.LayoutInflater
import android.view.View
import android.view.ViewGroup
import androidx.fragment.app.Fragment
import com.example.sunflowerexample.databinding.FragmentGalleryBinding
import dagger.hilt.android.AndroidEntryPoint

@AndroidEntryPoint
class GalleryFragment : Fragment()  {

    override fun onCreateView(
        inflater: LayoutInflater,
        container: ViewGroup?,
        savedInstanceState: Bundle?
    ): View? {
        val binding = FragmentGalleryBinding.inflate(inflater, container, false)
        return binding.root
    }

}

nav_garden.xml

nav_garden.xml 생성 절차 1

nav_garden 생성 절차 2

<?xml version="1.0" encoding="utf-8"?>
<navigation 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/nav_garden"
    app:startDestination="@id/view_pager_fragment">

    <fragment
        android:id="@+id/view_pager_fragment"
        android:name="com.example.sunflowerexample.HomeViewPagerFragment"
        tools:layout="@layout/fragment_view_pager">

        <action
            android:id="@+id/action_view_pager_fragment_to_plant_detail_fragment"
            app:destination="@+id/plant_detail_fragment" />
    </fragment>


    <fragment
        android:id="@+id/plant_detail_fragment"
        android:name="com.example.sunflowerexample.PlantDetailFragment"
        android:label="@string/plant_details_title"
        tools:layout="@layout/fragment_gallery">

        <action
            android:id="@+id/action_plant_detail_fragment_to_gallery_fragment"
            app:destination="@+id/gallery_fragment" />

        <argument
            android:name="plantId"
            app:argType="string" />
    </fragment>

    <fragment
        android:id="@+id/gallery_fragment"
        android:name="com.example.sunflowerexample.GalleryFragment"
        android:label="@string/plant_details_title"
        tools:layout="@layout/fragment_gallery">

        <argument
            android:name="plantName"
            app:argType="string" />
    </fragment>

</navigation>

실행 결과

프레그먼트가 바뀌는데 밋밋하다?

애니메이션 추가 ㄱㄱ

애니메이션 생성 절차 1

애니메이션 생성 절차 2

anim.xml (/res/values)

<?xml version="1.0" encoding="utf-8"?>
<resources>
    <integer name="slide">200</integer>
</resources>

slide_in_left.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate android:fromXDelta="-100%" android:toXDelta="0%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="@integer/slide" />
</set>

slide_out_left.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate android:fromXDelta="0%" android:toXDelta="-100%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="@integer/slide" />
</set>

slide_in_right.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate android:fromXDelta="100%" android:toXDelta="0%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="@integer/slide" />
</set>

slide_in_right.xml

<?xml version="1.0" encoding="utf-8"?>
<set xmlns:android="http://schemas.android.com/apk/res/android">
    <translate android:fromXDelta="100%" android:toXDelta="0%"
        android:fromYDelta="0%" android:toYDelta="0%"
        android:duration="@integer/slide" />
</set>

duration : 실행 시간

fromXDelta : 시작 X축 값 (0% = 처음 자리)

toXDelta : 끝 X축 값 (100% = 오른쪽으로 100%만큼 이동) (-100% = 왼쪽으로 100%만큼 이동)

fromYDelta : 시작 Y축 값 (0% = 처음 자리)

toYDelta : 끝 Y축 값 (200% = 아래쪽으로 200%만큼 이동) (-200% = 위쪽으로 200%만큼 이동)

nav_garden.xml

<?xml version="1.0" encoding="utf-8"?>
<navigation 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/nav_garden"
    app:startDestination="@id/view_pager_fragment">

    <fragment
        android:id="@+id/view_pager_fragment"
        android:name="com.example.sunflowerexample.HomeViewPagerFragment"
        tools:layout="@layout/fragment_view_pager">

        <action
            android:id="@+id/action_view_pager_fragment_to_plant_detail_fragment"
            app:destination="@+id/plant_detail_fragment"
            app:exitAnim="@anim/slide_out_left"
            app:enterAnim="@anim/slide_in_right"
            app:popEnterAnim="@anim/slide_in_left"
            app:popExitAnim="@anim/slide_out_right" />
    </fragment>


    <fragment
        android:id="@+id/plant_detail_fragment"
        android:name="com.example.sunflowerexample.PlantDetailFragment"
        android:label="@string/plant_details_title"
        tools:layout="@layout/fragment_gallery">

        <action
            android:id="@+id/action_plant_detail_fragment_to_gallery_fragment"
            app:destination="@+id/gallery_fragment"
            app:enterAnim="@anim/slide_in_right"
            app:exitAnim="@anim/slide_out_left"
            app:popEnterAnim="@anim/slide_in_left"
            app:popExitAnim="@anim/slide_out_right" />

        <argument
            android:name="plantId"
            app:argType="string" />
    </fragment>

    <fragment
        android:id="@+id/gallery_fragment"
        android:name="com.example.sunflowerexample.GalleryFragment"
        android:label="@string/plant_details_title"
        tools:layout="@layout/fragment_gallery">

        <argument
            android:name="plantName"
            app:argType="string" />
    </fragment>

</navigation>

app:enterAnim : A -> B로 Action할 때 들어오는 UI 대상의 Animation(B의 Animation)

app:exitAnim : A -> B로 Action할 때 나가는 UI 대상의 Animation(A의 Animation)

app:popEnterAnim : B -> A로 Pop할 때 들어오는 UI 대상의 Animation(A의 Animation)

app:popExitAnim : B -> A로 Pop할 때 나가는 UI 대상의 Animation(B의 Animation)

실행 결과

참고.

https://github.com/android/sunflower

android/sunflower

A gardening app illustrating Android development best practices with Android Jetpack. - android/sunflower

github.com