Android Compose Jetpack

camera.kt

package io.github.onliniak.qr_scanner

import android.os.Bundle
import android.util.Log
import androidx.activity.ComponentActivity
import androidx.activity.compose.rememberLauncherForActivityResult
import androidx.activity.compose.setContent
import androidx.activity.result.contract.ActivityResultContracts
import androidx.activity.result.launch
import androidx.compose.material.Button
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.tooling.preview.Preview
import com.google.mlkit.vision.barcode.Barcode
import com.google.mlkit.vision.barcode.BarcodeScannerOptions
import com.google.mlkit.vision.barcode.BarcodeScanning
import com.google.mlkit.vision.common.InputImage
import io.github.onliniak.qr_scanner.ui.theme.QR_ScannerTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            QR_ScannerTheme {
                // A surface container using the 'background' color from the theme
                Surface(color = MaterialTheme.colors.background) {
                    Greeting()
                }
            }
        }
    }
}

@Composable
fun Greeting() {
    //https://developer.android.com/reference/kotlin/androidx/activity/compose/package-summary#rememberlauncherforactivityresult
    val launcher = rememberLauncherForActivityResult(ActivityResultContracts.TakePicturePreview()) {
        val options = BarcodeScannerOptions.Builder()
            .setBarcodeFormats(
                Barcode.FORMAT_QR_CODE,
                Barcode.FORMAT_AZTEC)
            .build()
        val scanner = BarcodeScanning.getClient(options)
        scanner.process(InputImage.fromBitmap(it, 0))
            .addOnSuccessListener { barcodes ->
                for (barcode in barcodes) {
                    val bounds = barcode.boundingBox
                    val corners = barcode.cornerPoints

                    val rawValue = barcode.rawValue

                    Log.i("bounds", bounds.toString())
                    Log.i("corners", corners.toString())
                    Log.i("rawValue", rawValue)

                    // See API reference for complete list of supported types
//                when (barcode.valueType) {
//                    Barcode.TYPE_WIFI -> {
//                        val ssid = barcode.wifi!!.ssid
//                        val password = barcode.wifi!!.password
//                        val type = barcode.wifi!!.encryptionType
//                    }
//                    Barcode.TYPE_URL -> {
//                        val title = barcode.url!!.title
//                        val url = barcode.url!!.url
//                    }
//                }
                }
            }
            .addOnFailureListener { e ->
                Log.w("problem", e.toString())
            }
    }

    Button(onClick = { launcher.launch() }) {
        Text(text = "Take a picture")
    }
}

openCVcamera.kt

// Na chwilę obecną OpenCV to najgorsza biblioteka. 
// Radzi sobie jedynie z tekstem.

package io.github.onliniak.qr_scanner

import android.os.Bundle
// import android.util.Log
import androidx.activity.ComponentActivity
import androidx.activity.compose.rememberLauncherForActivityResult
import androidx.activity.compose.setContent
import androidx.activity.result.contract.ActivityResultContracts
import androidx.activity.result.launch
import androidx.compose.foundation.layout.Column
import androidx.compose.material.Button
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.*
import androidx.compose.ui.tooling.preview.Preview
import io.github.onliniak.qr_scanner.ui.theme.QR_ScannerTheme
import org.opencv.android.OpenCVLoader
import org.opencv.android.Utils
import org.opencv.core.Mat
import org.opencv.objdetect.QRCodeDetector

data class CounterState(val counter: String = "")

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        OpenCVLoader.initDebug()
        setContent {
            QR_ScannerTheme {
                // A surface container using the 'background' color from the theme
                Surface(color = MaterialTheme.colors.background) {
                    Greeting()
                }
            }
        }
    }
}

@Composable
fun Greeting() {
    var counterState by remember { mutableStateOf(CounterState()) }
    // Start camera app (for example Google Camera or whatever)
    val launcher = rememberLauncherForActivityResult(ActivityResultContracts.TakePicturePreview()){bitmap ->
        // We need picture in specific "OpenCV Mat" format
        // Convert android's bitmap to OpenCV Mat
        // Output as mat variable
        val mat = Mat()
        Utils.bitmapToMat(bitmap, mat)
        // Decoded string
        val photo = QRCodeDetector().detectAndDecode(mat)

        counterState = counterState.copy(counter = photo)
    }
    Column {
        Button(onClick = { launcher.launch() }) {
            Text(text = "Take a picture")
        }

        Text(text = "QR: " + counterState.counter)
    }
}

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    QR_ScannerTheme {
        Greeting()
    }
}

original.kt

package io.github.onliniak.qr_scanner

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.Composable
import androidx.compose.ui.tooling.preview.Preview
import io.github.onliniak.qr_scanner.ui.theme.QR_ScannerTheme

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            QR_ScannerTheme {
                // A surface container using the 'background' color from the theme
                Surface(color = MaterialTheme.colors.background) {
                    Greeting("Android")
                }
            }
        }
    }
}

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

@Preview(showBackground = true)
@Composable
fun DefaultPreview() {
    QR_ScannerTheme {
        Greeting("Android")
    }
}

state.kt

package io.github.onliniak.qr_scanner

import android.os.Bundle
import androidx.activity.ComponentActivity
import androidx.activity.compose.setContent
import androidx.compose.material.MaterialTheme
import androidx.compose.material.Surface
import androidx.compose.material.Text
import androidx.compose.runtime.*
import androidx.compose.runtime.Composable
import androidx.compose.ui.tooling.preview.Preview
import io.github.onliniak.qr_scanner.ui.theme.QR_ScannerTheme

// https://github.com/vinaygaba/Learn-Jetpack-Compose-By-Example/blob/master/app/src/main/java/com/example/jetpackcompose/state/StateActivity.kt
data class CounterState(val counter: Int = 0)

class MainActivity : ComponentActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContent {
            QR_ScannerTheme {
                // A surface container using the 'background' color from the theme
                Surface(color = MaterialTheme.colors.background) {
                    Greeting()
                }
            }
        }
    }
}

@Composable
fun Greeting() {
  var counterState by remember { mutableStateOf(CounterState()) }
        Button(
            onClick = {
                counterState = counterState.copy(counter = counterState.counter + 1)
            }) {
            Text(text = "Counter value is ${counterState.counter}")
        }