write this in kivy instead:

package com.example.camera_scale

import android.Manifest
import android.content.Intent
import android.content.pm.PackageManager
import android.os.Bundle
import android.provider.MediaStore
import android.view.KeyEvent
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.activity.result.contract.ActivityResultContracts
import androidx.activity.result.ActivityResultLauncher
import androidx.compose.foundation.layout.fillMaxSize
import androidx.compose.material3.MaterialTheme
import androidx.compose.material3.Surface
import androidx.compose.material3.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.Modifier
import androidx.compose.ui.tooling.preview.Preview
import androidx.core.content.ContextCompat
import com.example.camera_scale.ui.theme.Camera_scaleTheme

class MainActivity : ComponentActivity() {
    private val CAMERA_PERMISSION_REQUEST_CODE = 1
    private lateinit var cameraResultLauncher: ActivityResultLauncher<Intent>

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

        cameraResultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()) { result ->
            if (result.resultCode == RESULT_OK && result.data != null) {
                //TODO: Handle the captured image and send it to the server
            }
        }

        setContent {
            Camera_scaleTheme {
                // A surface container using the ‘background’ color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) {
                    Greeting("Android")
                }
            }
        }
    }

    private fun handleVolumeKeys(event: KeyEvent): Boolean {
        return when (event.keyCode) {
            KeyEvent.KEYCODE_VOLUME_UP, KeyEvent.KEYCODE_VOLUME_DOWN -> {
                if (event.action == KeyEvent.ACTION_DOWN) {
                    takePhotoIfPermissionGranted()
                }
                true
            }
            else -> false
        }
    }

    override fun onKeyDown(keyCode: Int, event: KeyEvent): Boolean {
        if (handleVolumeKeys(event)) {
            return true
        }
        return super.onKeyDown(keyCode, event)
    }

    private fun takePhotoIfPermissionGranted() {
        if (ContextCompat.checkSelfPermission(this, Manifest.permission.CAMERA) == PackageManager.PERMISSION_GRANTED) {
            capturePhoto()
        } else {
            requestCameraPermission()
        }
    }

    private fun requestCameraPermission() {
        requestPermissions(arrayOf(Manifest.permission.CAMERA), CAMERA_PERMISSION_REQUEST_CODE)
    }

    private fun capturePhoto() {
        val callCameraIntent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
        if (callCameraIntent.resolveActivity(packageManager) != null) {
            cameraResultLauncher.launch(callCameraIntent)
        }
    }

    override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<out String>, grantResults: IntArray) {
        super.onRequestPermissionsResult(requestCode, permissions, grantResults)
        if (requestCode == CAMERA_PERMISSION_REQUEST_CODE) {
            if ((grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED)) {
                capturePhoto()
            } else {
                // Handle the user’s denial of permission
            }
        }
    }
}

@Composable
fun Greeting(name: String) {
    Text(text = "Hello $name!")
}

@Preview(showBackground = true)
@Composable
fun GreetingPreview() {
    Camera_scaleTheme {
        Greeting("Android")
    }
}