labs-mobile-applications/app/src/main/java/com/example/myapplication/MainActivity.kt

package com.example.myapplication

import android.Manifest
import android.content.pm.PackageManager
import android.graphics.Bitmap
import android.os.Bundle
import android.widget.Button
import android.widget.ImageView
import android.widget.Toast
import androidx.activity.ComponentActivity
import androidx.activity.result.contract.ActivityResultContracts
import androidx.core.content.ContextCompat

class MainActivity : ComponentActivity() {

    private lateinit var btnCamera: Button
    private lateinit var imageView: ImageView

    // Новый контракт
    private val takePicturePreview = registerForActivityResult(
        ActivityResultContracts.TakePicturePreview()
    ) { bitmap: Bitmap? ->
        if (bitmap != null) {
            imageView.setImageBitmap(bitmap)
        } else {
            Toast.makeText(this, "Фото не получено", Toast.LENGTH_SHORT).show()
        }
    }

    // Запрос разрешения на камеру
    private val requestCameraPermission = registerForActivityResult(
        ActivityResultContracts.RequestPermission()
    ) { granted ->
        if (granted) {
            takePicturePreview.launch(null)
        } else {
            Toast.makeText(this, "Разрешение на камеру не выдано", Toast.LENGTH_SHORT).show()
        }
    }

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

        btnCamera = findViewById(R.id.btnCamera)
        imageView = findViewById(R.id.imageView)

        btnCamera.setOnClickListener {
            if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA)
                == PackageManager.PERMISSION_GRANTED
            ) {
                takePicturePreview.launch(null)
            } else {
                requestCameraPermission.launch(Manifest.permission.CAMERA)
            }
        }
    }
}