UsefulCodebase.tk

  //runtime permission check for location
  fun checkPermission(): Boolean{
        return ActivityCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED
    }
    
    //request permission
     fun requestPermission(){
        ActivityCompat.requestPermissions(this,
            arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
            locationPermissionCode)
    }

//Camerax demo with analysis
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.Manifest
import android.content.pm.PackageManager
import android.net.Uri
import android.util.Log
import android.view.View
import android.widget.Toast
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import java.util.concurrent.Executors
import androidx.camera.core.*
import androidx.camera.lifecycle.ProcessCameraProvider
import kotlinx.android.synthetic.main.activity_main.*
import java.io.File
import java.nio.ByteBuffer
import java.text.SimpleDateFormat
import java.util.*
import java.util.concurrent.ExecutorService
typealias LumaListener = (luma: Double) -> Unit
class MainActivity : AppCompatActivity() {
private var imageCapture: ImageCapture? = null

private lateinit var outputDirectory: File
private lateinit var cameraExecutor: ExecutorService

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

    // Request camera permissions
    if (allPermissionsGranted()) {
        startCamera()

    } else {
        ActivityCompat.requestPermissions(
                this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
    }

    // Set up the listener for take photo button
    camera_capture_button.setOnClickListener { takePhoto() }

    outputDirectory = getOutputDirectory()

    cameraExecutor = Executors.newSingleThreadExecutor()

}

private fun takePhoto() {

    image.visibility = View.GONE
    viewFinder.visibility = View.VISIBLE
    println("take photo")
    // Get a stable reference of the modifiable image capture use case
    println("image capture $imageCapture")
    val imageCapture = imageCapture ?: return

    // Create time-stamped output file to hold the image
    val photoFile = File(
            outputDirectory,
            SimpleDateFormat(FILENAME_FORMAT, Locale.US
            ).format(System.currentTimeMillis()) + ".jpg")

    println("File $photoFile")

    // Create output options object which contains file + metadata
    val outputOptions = ImageCapture.OutputFileOptions.Builder(photoFile).build()
    println("output $outputOptions")

    // Set up image capture listener, which is triggered after photo has
    // been taken
    imageCapture.takePicture(
            outputOptions, ContextCompat.getMainExecutor(this), object : ImageCapture.OnImageSavedCallback {
        override fun onError(exc: ImageCaptureException) {
            println("Error ${exc.message}")
            Log.e(TAG, "Photo capture failed: ${exc.message}", exc)
        }

        override fun onImageSaved(output: ImageCapture.OutputFileResults) {
            val savedUri = Uri.fromFile(photoFile)
            viewFinder.visibility = View.GONE
            image.visibility = View.VISIBLE
            image.setImageURI(savedUri)

             val msg = "Photo capture succeeded: $savedUri"
            println("message $msg")
            Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
            Log.d(TAG, msg)
        }
    })


}

private fun startCamera() {
    val cameraProviderFuture = ProcessCameraProvider.getInstance(this)

    cameraProviderFuture.addListener(Runnable {
        // Used to bind the lifecycle of cameras to the lifecycle owner
        val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()

        // Preview
        val preview = Preview.Builder()
                .build()
                .also {
                    it.setSurfaceProvider(viewFinder.createSurfaceProvider())
                }

        imageCapture = ImageCapture.Builder()
                .build()

        val imageAnalyzer = ImageAnalysis.Builder()
                .build()
                .also {
                    it.setAnalyzer(cameraExecutor, LuminosityAnalyzer { luma ->
                        Log.d(TAG, "Average luminosity: $luma")
                    })
                }

        // Select back camera as a default
        val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

        try {
            // Unbind use cases before rebinding
            cameraProvider.unbindAll()

            // Bind use cases to camera
            cameraProvider.bindToLifecycle(
                    this, cameraSelector, preview, imageCapture, imageAnalyzer)

        } catch(exc: Exception) {
            Log.e(TAG, "Use case binding failed", exc)
        }

    }, ContextCompat.getMainExecutor(this))
}

private fun allPermissionsGranted() = REQUIRED_PERMISSIONS.all {
    ContextCompat.checkSelfPermission(
            baseContext, it) == PackageManager.PERMISSION_GRANTED
}

private fun getOutputDirectory(): File {
    val mediaDir = externalMediaDirs.firstOrNull()?.let {
        File(it, resources.getString(R.string.enrolment_id)).apply { mkdirs() } }
    return if (mediaDir != null && mediaDir.exists())
        mediaDir else filesDir
}

override fun onDestroy() {
    super.onDestroy()
    cameraExecutor.shutdown()
}


override fun onRequestPermissionsResult(
        requestCode: Int, permissions: Array<String>, grantResults:
        IntArray) {
    if (requestCode == REQUEST_CODE_PERMISSIONS) {
        if (allPermissionsGranted()) {
            startCamera()
        } else {
            Toast.makeText(this,
                    "Permissions not granted by the user.",
                    Toast.LENGTH_SHORT).show()
            finish()
        }
    }
}


companion object {
    private const val TAG = "form_capture"
   // private const val FILENAME_FORMAT = "yyyy-MM-dd-HH-mm-ss-SSS"
    private const val FILENAME_FORMAT = "ddMMyyyy"
    private const val ENROLMENT_ID = "123443444"
    private const val REQUEST_CODE_PERMISSIONS = 10
    private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA)
}

private class LuminosityAnalyzer(private val listener: LumaListener) : ImageAnalysis.Analyzer {

    private fun ByteBuffer.toByteArray(): ByteArray {
        rewind()    // Rewind the buffer to zero
        val data = ByteArray(remaining())
        get(data)   // Copy the buffer into a byte array
        return data // Return the byte array
    }

    override fun analyze(image: ImageProxy) {

        val buffer = image.planes[0].buffer
        val data = buffer.toByteArray()
        val pixels = data.map { it.toInt() and 0xFF }
        val luma = pixels.average()

        listener(luma)

        image.close()
    }
}

}

###CameraxApp demo without analysis
import androidx.appcompat.app.AppCompatActivity
import android.os.Bundle
import android.Manifest
import android.content.pm.PackageManager
import android.net.Uri
import android.util.Log
import android.view.View
import android.widget.Toast
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import java.util.concurrent.Executors
import androidx.camera.core.*
import androidx.camera.lifecycle.ProcessCameraProvider
import kotlinx.android.synthetic.main.activity_main.*
import java.io.File
import java.nio.ByteBuffer
import java.text.SimpleDateFormat
import java.util.*
import java.util.concurrent.ExecutorService
typealias LumaListener = (luma: Double) -> Unit

class MainActivity : AppCompatActivity() {
private var imageCapture: ImageCapture? = null

private lateinit var outputDirectory: File
private lateinit var cameraExecutor: ExecutorService

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

    // Request camera permissions
    if (allPermissionsGranted()) {
        startCamera()

    } else {
        ActivityCompat.requestPermissions(
                this, REQUIRED_PERMISSIONS, REQUEST_CODE_PERMISSIONS)
    }

    // Set up the listener for take photo button
    camera_capture_button.setOnClickListener { takePhoto() }

    outputDirectory = getOutputDirectory()

    cameraExecutor = Executors.newSingleThreadExecutor()

}

private fun takePhoto() {

    image.visibility = View.GONE
    viewFinder.visibility = View.VISIBLE
    println("take photo")
    // Get a stable reference of the modifiable image capture use case
    println("image capture $imageCapture")
    val imageCapture = imageCapture ?: return

    // Create time-stamped output file to hold the image
    val photoFile = File(
            outputDirectory,
            SimpleDateFormat(FILENAME_FORMAT, Locale.US
            ).format(System.currentTimeMillis()) + ".jpg")

    println("File $photoFile")

    // Create output options object which contains file + metadata
    val outputOptions = ImageCapture.OutputFileOptions.Builder(photoFile).build()
    println("output $outputOptions")

    // Set up image capture listener, which is triggered after photo has
    // been taken
    imageCapture.takePicture(
            outputOptions, ContextCompat.getMainExecutor(this), object : ImageCapture.OnImageSavedCallback {
        override fun onError(exc: ImageCaptureException) {
            println("Error ${exc.message}")
            Log.e(TAG, "Photo capture failed: ${exc.message}", exc)
        }

        override fun onImageSaved(output: ImageCapture.OutputFileResults) {
            val savedUri = Uri.fromFile(photoFile)
            viewFinder.visibility = View.GONE
            image.visibility = View.VISIBLE
            image.setImageURI(savedUri)

             val msg = "Photo capture succeeded: $savedUri"
            println("message $msg")
            Toast.makeText(baseContext, msg, Toast.LENGTH_SHORT).show()
            Log.d(TAG, msg)
        }
    })


}

private fun startCamera() {
    val cameraProviderFuture = ProcessCameraProvider.getInstance(this)

    cameraProviderFuture.addListener(Runnable {
        // Used to bind the lifecycle of cameras to the lifecycle owner
        val cameraProvider: ProcessCameraProvider = cameraProviderFuture.get()

        // Preview
        val preview = Preview.Builder()
                .build()
                .also {
                    it.setSurfaceProvider(viewFinder.createSurfaceProvider())
                }

        imageCapture = ImageCapture.Builder()
                .build()

// val imageAnalyzer = ImageAnalysis.Builder()
// .build()
// .also {
// it.setAnalyzer(cameraExecutor, LuminosityAnalyzer { luma ->
// Log.d(TAG, "Average luminosity: $luma")
// })
// }

        // Select back camera as a default
        val cameraSelector = CameraSelector.DEFAULT_BACK_CAMERA

        try {
            // Unbind use cases before rebinding
            cameraProvider.unbindAll()

            // Bind use cases to camera
            cameraProvider.bindToLifecycle(
                    this, cameraSelector, preview, imageCapture)

        } catch(exc: Exception) {
            Log.e(TAG, "Use case binding failed", exc)
        }

    }, ContextCompat.getMainExecutor(this))
}

private fun allPermissionsGranted() = REQUIRED_PERMISSIONS.all {
    ContextCompat.checkSelfPermission(
            baseContext, it) == PackageManager.PERMISSION_GRANTED
}

private fun getOutputDirectory(): File {
    val mediaDir = externalMediaDirs.firstOrNull()?.let {
        File(it, resources.getString(R.string.enrolment_id)).apply { mkdirs() } }
    return if (mediaDir != null && mediaDir.exists())
        mediaDir else filesDir
}

override fun onDestroy() {
    super.onDestroy()
    cameraExecutor.shutdown()
}


override fun onRequestPermissionsResult(
        requestCode: Int, permissions: Array<String>, grantResults:
        IntArray) {
    if (requestCode == REQUEST_CODE_PERMISSIONS) {
        if (allPermissionsGranted()) {
            startCamera()
        } else {
            Toast.makeText(this,
                    "Permissions not granted by the user.",
                    Toast.LENGTH_SHORT).show()
            finish()
        }
    }
}


companion object {
    private const val TAG = "form_capture"
   // private const val FILENAME_FORMAT = "yyyy-MM-dd-HH-mm-ss-SSS"
    private const val FILENAME_FORMAT = "ddMMyyyy"
    private const val ENROLMENT_ID = "123443444"
    private const val REQUEST_CODE_PERMISSIONS = 10
    private val REQUIRED_PERMISSIONS = arrayOf(Manifest.permission.CAMERA)
}

private class LuminosityAnalyzer(private val listener: LumaListener) : ImageAnalysis.Analyzer {

    private fun ByteBuffer.toByteArray(): ByteArray {
        rewind()    // Rewind the buffer to zero
        val data = ByteArray(remaining())
        get(data)   // Copy the buffer into a byte array
        return data // Return the byte array
    }

    override fun analyze(image: ImageProxy) {

        val buffer = image.planes[0].buffer
        val data = buffer.toByteArray()
        val pixels = data.map { it.toInt() and 0xFF }
        val luma = pixels.average()

        listener(luma)

        image.close()
    }
}

}

fun Context.deleteSharePreference(key: String) {
val settings: SharedPreferences = getDefaultSharedPreferences(this)
settings.edit().remove(key).apply()
}