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how to get permission result in kotlin

I am trying to use a camera on my android. the user will be prompt for the permission of the camera. previously I used startActivityForResult and onRequestPermissionRequest for them. recently I found out that they are deprecated, so I'm trying out with registerForActivity. I managed to change to startActivity but I'm stuck at the permission request. I am wondering do I have to create another permissionlauncher or can I do the permission inside my resultlauncher.
companion object{
private const val CAMERA_PERMISSION_CODE = 1
private const val CAMERA_REQUEST_CODE = 2
}
val checkpermission = Manifest.permission.CAMERA
var resultLauncher = registerForActivityResult(ActivityResultContracts.StartActivityForResult()){ result ->
if (result.resultCode == Activity.RESULT_OK) {
val data: Intent? = result.data
val DP: Bitmap = data!!.extras!!.get("data") as Bitmap
val image = findViewById<ImageView>(R.id.imageButtonVerifyPhoto)
image.setImageBitmap(DP)
}
}
val permissionLauncher = registerForActivityResult(ActivityResultContracts.RequestPermission()){
isGranted ->
if(isGranted){
val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
resultLauncher.launch((intent))
Toast.makeText(this,"Permission is tested", Toast.LENGTH_SHORT).show()
}else{
Toast.makeText(this,"Permission is denied",Toast.LENGTH_SHORT).show()
}
}
var cameraButton = findViewById<Button>(R.id.buttonRetakePhoto) // can change later
cameraButton.setOnClickListener {
if(ContextCompat.checkSelfPermission(
this,
checkpermission
) == PackageManager.PERMISSION_GRANTED
){
val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
resultLauncher.launch(intent)
}else{
permissionLauncher.launch(checkpermission)
}
}
}
below is my previous code for the onRequestPermission
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<out String>,
grantResults: IntArray
) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if(requestCode == CAMERA_REQUEST_CODE){
if(grantResults.isNotEmpty()&& grantResults[0] == PackageManager.PERMISSION_GRANTED){
val intent = Intent(MediaStore.ACTION_IMAGE_CAPTURE)
startActivityForResult(intent, CAMERA_REQUEST_CODE)
}else{
Toast.makeText(this,"Permission is denied",Toast.LENGTH_SHORT).show()
}
}
}

Requesting runtime permissions is just a little more simplified
private val requestPermission =
registerForActivityResult(ActivityResultContracts.RequestPermission()) { isGranted ->
// do something
}
Now we can call this to get any type of permission you want
cameraButton.setOnClickListener {
if (ContextCompat.checkSelfPermission(
this,
Manifest.permission.CAMERA
) != PackageManager.PERMISSION_GRANTED
) {
// Pass any permission you want while launching
requestPermission.launch(Manifest.permission.CAMERA)
}
}
Make sure to add in build.gradle
implementation 'androidx.fragment:fragment-ktx:1.2.0' // or later
implementation 'androidx.activity:activity-ktx:1.3.0' // or later
If you want to understand how all this works check here

Latest soluton in 2022: (no more request code)
Create Helper Extension Functions (for use in Fragment):
fun Fragment.requestPermissions(request: ActivityResultLauncher<Array<String>>, permissions: Array<String>) = request.launch(permissions)
fun Fragment.isAllPermissionsGranted(permissions: Array<String>) = permissions.all {
ContextCompat.checkSelfPermission(requireContext(), it) == PackageManager.PERMISSION_GRANTED
}
Request Permissions in Fragment:
class FirstFragment : Fragment() {
companion object {
private val PERMISSIONS = arrayOf(Manifest.permission.ACCESS_FINE_LOCATION, Manifest.permission.ACCESS_BACKGROUND_LOCATION)
}
private lateinit var binding: FragmentFirstBinding
private lateinit var permissionsRequest: ActivityResultLauncher<Array<String>>
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_first, container, false)
permissionsRequest = getPermissionsRequest()
binding.grantButton.setOnClickListener {
requestPermissions(permissionsRequest, PERMISSIONS) //extension function
}
return binding.root
}
private fun getPermissionsRequest() = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) {
if (isAllPermissionsGranted(PERMISSIONS)) { //extension function
//do your stuff
} else {
//do your stuff
}
}
}

You could try Aaper, it allows to request for permissions using annotations like so:
Fist, add the permission to your manifest:
<uses-permission android:name="android.permission.CAMERA" />
Then, annotate a method that needs to use the camera:
#EnsurePermissions(permissions = [Manifest.permission.CAMERA])
fun takePhoto() {
Toast.makeText(this, "Camera permission granted", Toast.LENGTH_SHORT).show()
}
That's it, when you call the takePhoto method, it'll check for the camera permission, and if it's not available it will launch a permission request dialog. If the user approves it, then it will proceed to run takePhotos body.
Disclaimer, I'm the creator of Aaper

Is there some way to override a function of superclass either from extension functions or from interfaces in kotlin?

In android to do some tasks we require the user to grant related permissions. Complete process of checking and requesting permission involves 3 steps: checking permission, requesting permission and checking result. If the permission is denied, then don't need to run that task. So to simplify this, I wrote the following interface and extension function in ActivityExtensions.kt
private val permissionTaskSource = HashMap<Int, TaskCompletionSource<Boolean>>()
interface PermissionHandler {
#RequiresApi(Build.VERSION_CODES.M)
fun Activity.permissionRequest(requestCode: Int, vararg permissions: String): Task<Boolean> {
requestPermissions(permissions, requestCode)
val tcs = TaskCompletionSource<Boolean>()
permissionTaskSource[requestCode] = tcs
return tcs.task
}
fun permissionResult(requestCode: Int, grantResults: IntArray) {
permissionTaskSource[requestCode]!!.setResult(grantResults.all { it == PERMISSION_GRANTED })
permissionTaskSource.remove(requestCode)
}
}
suspend fun <T> T.requiresPermission(vararg permissions: String): Unit? where T : Activity, T : PermissionHandler {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M)
return Unit // If version lower than M then no need of runtime permissions.
if (permissions.all { ContextCompat.checkSelfPermission(this, it) == PERMISSION_GRANTED })
return Unit // If already all permissions granted, then no need to ask again.
val granted = permissionRequest(System.currentTimeMillis().toInt(), *permissions).await()
if (granted)
return Unit // Permission granted now
return null // Permission denied now
}
Whenever required some permissions to do a task in an activity or fragment, I can use this line:
private suspend fun someTask() {
requiresPermission(/* list of required permissions */) ?: run{ /*permission denied. handle properly*/ return }
// Inside fragment this has to be called with requiresActivity() receiver.
...
}
This whole thing is working fine.. but in every activity/fragment I have to write these 4 lines of code.
override fun onRequestPermissionsResult(
requestCode: Int, permissions: Array<out String>, grantResults: IntArray
) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
permissionResult(requestCode, grantResults)
}
Is there some way I can move these codes also to ActivityExtensions.kt file to make it much neater and avoid repetitive code?

Why doesn't camerax sample project put constant inside a class?

The Code A is from camerax sample project.
PERMISSIONS_REQUEST_CODE is a constant, I think it would be put inside a class, just like Code B.
I think Code B can reduce the couple and more clear
Is the Code A better Code B?
Code A
private const val PERMISSIONS_REQUEST_CODE = 10
private val PERMISSIONS_REQUIRED = arrayOf(Manifest.permission.CAMERA)
class PermissionsFragment : Fragment() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (!hasPermissions(requireContext())) {
// Request camera-related permissions
requestPermissions(PERMISSIONS_REQUIRED, PERMISSIONS_REQUEST_CODE)
} else {
// If permissions have already been granted, proceed
Navigation.findNavController(requireActivity(), R.id.fragment_container).navigate(
PermissionsFragmentDirections.actionPermissionsToCamera())
}
}
override fun onRequestPermissionsResult(
requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if (requestCode == PERMISSIONS_REQUEST_CODE) {
if (PackageManager.PERMISSION_GRANTED == grantResults.firstOrNull()) {
// Take the user to the success fragment when permission is granted
Toast.makeText(context, "Permission request granted", Toast.LENGTH_LONG).show()
Navigation.findNavController(requireActivity(), R.id.fragment_container).navigate(
PermissionsFragmentDirections.actionPermissionsToCamera())
} else {
Toast.makeText(context, "Permission request denied", Toast.LENGTH_LONG).show()
}
}
}
...
}
Code B
private val PERMISSIONS_REQUIRED = arrayOf(Manifest.permission.CAMERA)
class PermissionsFragment : Fragment() {
private val PERMISSIONS_REQUEST_CODE = 10
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (!hasPermissions(requireContext())) {
// Request camera-related permissions
requestPermissions(PERMISSIONS_REQUIRED, PERMISSIONS_REQUEST_CODE)
} else {
// If permissions have already been granted, proceed
Navigation.findNavController(requireActivity(), R.id.fragment_container).navigate(
PermissionsFragmentDirections.actionPermissionsToCamera())
}
}
override fun onRequestPermissionsResult(
requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if (requestCode == PERMISSIONS_REQUEST_CODE) {
if (PackageManager.PERMISSION_GRANTED == grantResults.firstOrNull()) {
// Take the user to the success fragment when permission is granted
Toast.makeText(context, "Permission request granted", Toast.LENGTH_LONG).show()
Navigation.findNavController(requireActivity(), R.id.fragment_container).navigate(
PermissionsFragmentDirections.actionPermissionsToCamera())
} else {
Toast.makeText(context, "Permission request denied", Toast.LENGTH_LONG).show()
}
}
}
...
}

By adding request code as compile-time constant, it can be accessed without keeping an instance of the class(like static modifier in Java).
Properties the value of which is known at compile time can be marked as compile time constants using the const modifier. Such properties need to fulfil the following requirements:
Top-level, or member of an object declaration or a companion object.
Initialized with a value of type String or a primitive type
No custom getter
Such properties can be used in annotations
The code sample makes a fragment with sole responsibility of handling Camera permission. While onActivityResult() is handled inside fragment, there might be a scenario later on when you want to do some work in Parent Activity based on the result, like for example removing this fragment when the request is complete. In order to do that, you would need access to this request code in Activity. By adding request code as compile-time constant, it can be accessed without keeping an instance of the fragment.
Other than that, there is no merit/demerit in either approaches since you will only making one instance of this fragment throughout your app anyway.

Another option would be to put the constant inside a companion object. This will allow you to make the PERMISSIONS_REQUEST_CODE constant AND statically accessible without the need to have an instant of PermissionsFragment.
Like this:
class PermissionsFragment : Fragment() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
if (!hasPermissions(requireContext())) {
// Request camera-related permissions
requestPermissions(PERMISSIONS_REQUIRED, PERMISSIONS_REQUEST_CODE)
} else {
// If permissions have already been granted, proceed
Navigation.findNavController(requireActivity(), R.id.fragment_container).navigate(
PermissionsFragmentDirections.actionPermissionsToCamera())
}
}
override fun onRequestPermissionsResult(
requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults)
if (requestCode == PERMISSIONS_REQUEST_CODE) {
if (PackageManager.PERMISSION_GRANTED == grantResults.firstOrNull()) {
// Take the user to the success fragment when permission is granted
Toast.makeText(context, "Permission request granted", Toast.LENGTH_LONG).show()
Navigation.findNavController(requireActivity(), R.id.fragment_container).navigate(
PermissionsFragmentDirections.actionPermissionsToCamera())
} else {
Toast.makeText(context, "Permission request denied", Toast.LENGTH_LONG).show()
}
}
}
companion object {
private const val PERMISSIONS_REQUEST_CODE = 10
}
}
Outside of PermissionsFragment you would be able to access it by writing PermissionsFragment.PERMISSIONS_REQUEST_CODE if you remove the private visibility modifier.

ActivityCompat onRequestPermissionsResult() not Called

I'm trying to write a small class to handle permission checking. Only problem is that onRequestPermissionsResult() never gets called:
class PermissionHelper(val activity: Activity) : ActivityCompat.OnRequestPermissionsResultCallback{
interface OnPermissionRequested {
fun onPermissionResponse(isPermissionGranted: Boolean)
}
private var listener: OnPermissionRequested? = null
fun isPermissionGranted(permission: String) : Boolean {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
return activity.applicationContext.checkSelfPermission(permission) == PackageManager.PERMISSION_GRANTED
}
return true
}
fun requestPermission(permissions: Array<String>,
requestCode: Int,
listener: OnPermissionRequested) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
this.listener = listener
activity.requestPermissions(permissions, requestCode)
}
}
override fun onRequestPermissionsResult(requestCode: Int,
permissions: Array<out String>,
grantResults: IntArray) {
val isPermissionGranted = grantResults.isNotEmpty() &&
grantResults[0] == PackageManager.PERMISSION_GRANTED
listener?.onPermissionResponse(isPermissionGranted)
}
companion object {
const val PERMISSIONS_REQUEST_READ_CALENDAR = 200
const val PERMISSIONS_REQUEST_WRITE_CALENDAR = 201
const val PERMISSIONS_REQUEST_CALENDAR = 101
const val PERMISSIONS_REQUEST_LOCATION = 102
const val READ_CALENDAR = Manifest.permission.READ_CALENDAR
const val WRITE_CALENDAR = Manifest.permission.WRITE_CALENDAR
const val ACCESS_FINE_LOCATION = Manifest.permission.ACCESS_FINE_LOCATION
}
}
The system dialog to request the permission pops up, but the response is never handled. (i.e. the break point inside onRequestPermissionsResult() is never hit). Nothing is null, and all values are correct.
Thanks for any help.

onRequestPermissionsResult will be called on your Activity. There is nothing in this code that is going to call the onRequestPermissionsResult of your PermissionHelper.
You need this in your activity
override fun onRequestPermissionsResult(requestCode: Int,
permissions: Array<out String>,
grantResults: IntArray) {
helper.onRequestPermissionsResult(requestCode, permissions, grantResults)
}

My suggestion is use this library for handle permissions:
https://github.com/Karumi/Dexter
If you don't want to use Dexter library, I suggest use ActivityCompat.requestPermissions() instead of activity.requestPermissions()
You can find more info in this answer:
https://stackoverflow.com/a/56761238/5661680

Kotlin - Internet and location permissions problem

Ι am writing an android application that uses both location and internet connection permissions and I am running it on my tablet. As you can see, I have included both in the manifest file. The problem is that when OnConnected() function is called the below if in the MainActivity.kt evaluates to true and I can't proceed further in the function. So can you give me some hint to provide some more code if it is not relevant
AndroidManifest.xml :
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
MainActivity.kt
override fun onConnected(p0: Bundle?) {
if(ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_FINE_LOCATION) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(this,Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED)
{
return;
}
//some code
}

You have to understand the logic behind permissions in Android. Just adding the permissions in the manifest, doesn't mean that the user has authorized the application to do what those permissions enable.
If your if condition evaluates to true, since those permissions are not granted, you have to ask the user for those permissions.
Android has a some good documentation on how to this.
I highly suggest you go over that.

From Android 6.0 onwards needs to request permission the best way is to do a permissionManager Class to Handle that and then check in your Activity if the user has accepted the permissions:
class PermissionManager private constructor() {
fun checkPermission(
activity: Activity,
permissionRequests: Array<String>?,
requestCode: Int
): Boolean {
permissionRequests?.let {
it.firstOrNull {
ContextCompat.checkSelfPermission(
activity,
it
) != PackageManager.PERMISSION_GRANTED
}?.apply {
ActivityCompat.requestPermissions(
activity,
permissionRequests,
requestCode
)
return false
}
}
return true
}
companion object {
val instance by lazy { PermissionManager() }
const val CAMERA_PERMISSION = 1
}
}
Then in your activity check the permission Result:
class MainActivity : AppCompatActivity() {
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_ar)
//If the user has the permission accepted the next times
if (PermissionManager.instance.checkPermission(
this, arrayOf(
Manifest.permission.CAMERA
), PermissionManager.CAMERA_PERMISSION
)
) {
initLogic()
}
}
override fun onRequestPermissionsResult(
requestCode: Int,
permissions: Array<out String>,
grantResults: IntArray
) {
when (requestCode) {
PermissionManager.CAMERA_PERMISSION -> {
if (grantResults.isNotEmpty() && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
initLogic()
} else {
return
}
}
}
}
}