permission runtime management

Permissions.kt

import android.Manifest

object Permissions {

    const val CAMERA = Manifest.permission.CAMERA
    const val READ_EXTERNAL_STORAGE = Manifest.permission.READ_EXTERNAL_STORAGE
    const val WRITE_EXTERNAL_STORAGE = Manifest.permission.WRITE_EXTERNAL_STORAGE
}

PermissionsManager.kt

interface PermissionsManager {

    fun requestPermission(permission: String, requestCode: Int)

    fun isPermissionGranted(permission: String): Boolean

    fun showPermissionDeniedSnackbar(permission: String)

    fun showPermissionDeniedDialog(permission: String, negativeButtonAction: () -> Unit)
}

PermissionsServiceImpl.kt

import android.app.Activity
import android.content.pm.PackageManager
import androidx.appcompat.app.AlertDialog
import androidx.core.app.ActivityCompat
import androidx.core.content.ContextCompat
import com.google.android.material.snackbar.Snackbar

class PermissionsServiceImpl(private val activity: Activity) : PermissionsManager {
 
    override fun requestPermission(permission: String, requestCode: Int) {
        ActivityCompat.requestPermissions(activity, arrayOf(permission), requestCode)
    }

    override fun isPermissionGranted(permission: String): Boolean {
        return ContextCompat.checkSelfPermission(activity, permission) == PackageManager.PERMISSION_GRANTED
    }

    override fun showPermissionDeniedSnackbar(permission: String) {
        Snackbar.make(activity.findViewById(android.R.id.content),
                      "Permission Denied: $permission",
                      Snackbar.LENGTH_SHORT)
                .show()
    }

    override fun showPermissionDeniedDialog(permission: String, negativeButtonAction: () -> Unit) {
        AlertDialog.Builder(activity)
                .setTitle("Permission Needed")
                .setMessage("The app needs $permission permission to function.")
                .setCancelable(false)
                .setPositiveButton("Grant Access") { _, _ ->
                    val PERMISSION_REQUEST_CODE = 0
                    requestPermission(permission, PERMISSION_REQUEST_CODE)
                }
                .setNegativeButton("Do not Allow") { _, _ ->
                    negativeButtonAction.invoke()
                }
                .show()
    }
}