Code works outside of lambda expression, but not from within - android

I have the follow code:
override fun onCreate(savedInstanceState: Bundle?) {
...
fab_action.setOnClickListener(actionSetMyLocationEnable) //passing my lambda
}
private val actionSetMyLocationEnable: (View) -> Unit = { it as FloatingActionButton
it.isSelected = !it.isSelected
setMyLocationEnable(it.isSelected) //this call work fine
}
private fun setMyLocationEnable(enable: Boolean) {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(
this,
arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
PERMISSION_REQUEST_ACCESS_FINE_LOCATION)
return //and this return work nice too
}
mMap.isMyLocationEnabled = enable
}
But, when I apply it as follows:
private val actionSetMyLocationEnable: (View) -> Unit = { it as FloatingActionButton
it.isSelected = !it.isSelected
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(
this,
arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
PERMISSION_REQUEST_ACCESS_FINE_LOCATION)
return //error 1
}
mMap.isMyLocationEnabled = it.isSelected //error 2
}
I'm facing these two errors:
error 1.
'return' is not allowed here
error 2.
Call requires permission which may be rejected by user: code should
explicitly check to see if permission is available (with
checkPermission) or explicitly handle a potential SecurityException
I know what each error means, but
My question is: why does my code work outside of the lambda expression and does not work when inside? And how do I solve this?
UPDATED
The #Rene Ferrari's solution solve the error 1. Thanks a lot #Rene Ferrari

Based of mTak answer my solution is the following:
private val actionSetMyLocationEnable: (View) -> Unit = returnHere#{ it as FloatingActionButton
it.isSelected = !it.isSelected
if (ContextCompat.checkSelfPermission(this, Manifest.permission.ACCESS_FINE_LOCATION)
!= PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(
this,
arrayOf(Manifest.permission.ACCESS_FINE_LOCATION),
PERMISSION_REQUEST_ACCESS_FINE_LOCATION)
return#returnHere //error 1
}
mMap.isMyLocationEnabled = it.isSelected //error 2
}
You can basically define a label to which you want to return. This label can be named anything except keywords ofcourse. In this example I named it returnHere

Related

HealthConnect Permission Handling: What is the difference between the two else{...} segments?

Im trying to implement permission handling for healthconnect. This is done in the funciton checkPermissionAndRun (strongly inspired by the documentation), however I'm not sure what the difference between the two else{...} code segments is.Both check if the permission is given already, but why do we need 2 of those? Furthermore, is it alright if I call the checkpermissionandrun function once in the oncreate, or should i do this also when interacting with HealthConnect?
class MainActivity : AppCompatActivity() {
// build a set of permissions for required data types
val PERMISSIONS =
setOf(
HealthPermission.createReadPermission(HeartRateRecord::class),
HealthPermission.createWritePermission(HeartRateRecord::class),
HealthPermission.createReadPermission(StepsRecord::class),
HealthPermission.createWritePermission(StepsRecord::class)
)
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
val hcManager = HealthConnectManager(this)
checkPermissionsAndRun(hcManager.healthConnectClient, PERMISSIONS)
}
private fun checkPermissionsAndRun(client: HealthConnectClient, PERMISSIONS: Set<HealthPermission>) {
val requestPermissionActivityContract = PermissionController.createRequestPermissionResultContract()
val requestPermissions =
registerForActivityResult(requestPermissionActivityContract) { granted ->
if (granted.containsAll(PERMISSIONS)) {
//Permission granted text 1
Toast.makeText(applicationContext, "permissions granted 1", Toast.LENGTH_SHORT).show()
} else {
// Lack of required permissions, But what is different to the coroutine else below?
}
}
lifecycleScope.launch {
val granted = client.permissionController.getGrantedPermissions(PERMISSIONS)
if (granted.containsAll(PERMISSIONS)) {
//Permission Granted text 2
Toast.makeText(applicationContext, "permissions granted 2", Toast.LENGTH_SHORT).show()
} else {
//lack of required permissions
requestPermissions.launch(PERMISSIONS)
}
}
}
}
Thank you in advance

Location permission issue Android 13

Location permission is directly going to isAnyPermissionPermanentlyDenied on Android 13. It is not asking permission to user. Even if I grant the permission in settings also, it is going to isAnyPermissionPermanentlyDenied.
val permissions = ArrayList<String>()
permissions.add(Manifest.permission.ACCESS_FINE_LOCATION)
Dexter.withActivity(this).withPermissions(permissions)
.withListener(object : MultiplePermissionsListener {
override fun onPermissionsChecked(report: MultiplePermissionsReport) {
when {
report.areAllPermissionsGranted() -> {
checkAppUpdate()
}
report.isAnyPermissionPermanentlyDenied -> {
startActivity(
Intent(
Settings.ACTION_APPLICATION_DETAILS_SETTINGS,
Uri.parse("package:" + BuildConfig.APPLICATION_ID)
)
)
}
else -> {
checkPermission()
}
}
}
override fun onPermissionRationaleShouldBeShown(
permissions: List<PermissionRequest>,
token: PermissionToken
) {
token.continuePermissionRequest()
}
}).onSameThread().check()
First ask for COARSE location permission.
And only when the user allowed that ask for FINE.
At first, Dexter is not under active maintenance anymore and I would not recommend to use it when you work on Android 13. The new way is also way more straight forward
Example:
private val permissionList = arrayOf(
Manifest.permission.READ_CONTACTS,
Manifest.permission.WRITE_CONTACTS,
Manifest.permission.CALL_PHONE
)
private val activityResultLauncher =
registerForActivityResult(RequestMultiplePermissions()) { permissions ->
if (!permissions.values.contains(false)) {
// contactsProvider.addMockContactList()
permissionState.value = true
Log.d(TAG, "activityResultLauncher")
}
}
private fun checkPermissions() {
val hasPermission = permissionList.all {
checkSelfPermission(it) == PackageManager.PERMISSION_GRANTED
}
Log.d(TAG, "checkPermissions")
if (!hasPermission) {
activityResultLauncher.launch(permissionList)
} else {
getContactList()
permissionState.value = true
}
}
And second, for getting location information you need two permissions: ACCESS_COARSE_LOCATION and ACCESS_FINE_LOCATION. Since fine location depends on coarse location, it will get instantly revoked everytime.

Making network call to receive image and show it when location access has been granted

i'm wanting to make a network call when location access has been granted. so i'm using LaunchedEffect(key1 = location.value){...} to decide when to make that network call to recompose, but facing some issues.
upon initial launch user is greeted with the location request (either precise or coarse). during this, the Toast.makeText(context, "Allow location access in order to see image", Toast.LENGTH_SHORT).show() get's called twice and shows up twice. when the user selects an option from the location request dialog, i would assume location.value would end up changing and viewModel.getImage(location.value!!) get's called. debugging through this, that all happens, but the image doesn't end up showing. i got it to work sometimes by force closing the app, then opening it again, then the image shows up. any insights? here is the location code in that same file:
val locationLiveData = LocationLiveData(context)
val location = locationLiveData.observeAsState()
val requestSinglePermissionLauncher = rememberLauncherForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) {
when {
it.getOrDefault(Manifest.permission.ACCESS_FINE_LOCATION, false) -> {
locationLiveData.startLocationUpdates()
}
it.getOrDefault(Manifest.permission.ACCESS_COARSE_LOCATION, false) -> {
locationLiveData.startLocationUpdates()
} else -> {
Toast.makeText(context, "Allow location access", Toast.LENGTH_SHORT).show()
}
}
}
if (ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) == PermissionChecker.PERMISSION_GRANTED ||
ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) == PermissionChecker.PERMISSION_GRANTED) {
locationLiveData.startLocationUpdates()
} else {
// true so we execute once not again when we compose or so
LaunchedEffect(key1 = true) {
requestSinglePermissionLauncher.launch(arrayOf(
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION))
}
}
EDIT 2
LocationLiveData
class LocationLiveData(var context: Context): LiveData<LocationDetails>() {
// used to get last known location
private val fusedLocationClient = LocationServices.getFusedLocationProviderClient(context)
// We have at least 1 observer or 1 component looking at us
// here we can get the last known location of the device
override fun onActive() {
super.onActive()
if (ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_FINE_LOCATION
) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_COARSE_LOCATION
) != PackageManager.PERMISSION_GRANTED
) {
return
}
fusedLocationClient.lastLocation.addOnSuccessListener {
setLocationData(it)
}
}
// no one is looking at this live data anymore
override fun onInactive() {
super.onInactive()
fusedLocationClient.removeLocationUpdates(locationCallback)
}
internal fun startLocationUpdates() {
if (ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_FINE_LOCATION
) != PackageManager.PERMISSION_GRANTED && ActivityCompat.checkSelfPermission(
context,
Manifest.permission.ACCESS_COARSE_LOCATION
) != PackageManager.PERMISSION_GRANTED
) {
return
}
fusedLocationClient.requestLocationUpdates(locationRequest, locationCallback, Looper.getMainLooper())
}
private fun setLocationData(location: Location) {
value = LocationDetails(longitude = location.longitude.toString(), latitude = location.latitude.toString())
}
private val locationCallback = object : LocationCallback() {
override fun onLocationResult(p0: LocationResult) {
super.onLocationResult(p0)
for (location in p0.locations) {
setLocationData(location)
}
}
}
companion object {
private const val ONE_MINUTE: Long = 60_000
val locationRequest: LocationRequest = LocationRequest.create().apply {
interval = ONE_MINUTE
fastestInterval = ONE_MINUTE / 4
priority = Priority.PRIORITY_HIGH_ACCURACY
}
}
}
COMPOSABLE
#RequiresApi(Build.VERSION_CODES.N)
#Composable
fun HomeScreen(viewModel: HomeScreenViewModel = hiltViewModel(), navigateToAuthScreen: () -> Unit, navigateToAddImage: () -> Unit){
var text by remember { mutableStateOf(TextFieldValue("")) }
val context = LocalContext.current
val locationLiveData = remember { LocationLiveData(context) }
val location = locationLiveData.observeAsState()
val requestSinglePermissionLauncher = rememberLauncherForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) {
when {
it.getOrDefault(Manifest.permission.ACCESS_FINE_LOCATION, false) -> {
locationLiveData.startLocationUpdates()
}
it.getOrDefault(Manifest.permission.ACCESS_COARSE_LOCATION, false) -> {
locationLiveData.startLocationUpdates()
}
}
}
if (ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_FINE_LOCATION) == PermissionChecker.PERMISSION_GRANTED ||
ContextCompat.checkSelfPermission(context, Manifest.permission.ACCESS_COARSE_LOCATION) == PermissionChecker.PERMISSION_GRANTED) {
locationLiveData.startLocationUpdates()
} else {
// true so we execute once not again when we compose or so
LaunchedEffect(key1 = true) {
requestSinglePermissionLauncher.launch(arrayOf(
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION))
}
}
Scaffold( topBar = {
HomeScreenTopBar()
},
floatingActionButton = {
FloatingActionButton(onClick = {
if (location.value != null) {
navigateToAddImageScreen()
} else {
Toast.makeText(context, "allow location access to add image", Toast.LENGTH_SHORT).show()
}
},
backgroundColor = MaterialTheme.colors.primary
) {
Icon(
imageVector = Icons.Default.Add,
contentDescription = "Save note"
)
}
}) {innerPadding ->
Column(modifier = Modifier
.fillMaxSize()
.padding(innerPadding)) {
LaunchedEffect(key1 = location.value) {
if (location.value != null) {
viewModel.getListings(location.value!!)
} else {
Toast.makeText(context, "Allow location access in order to see image", Toast.LENGTH_SHORT).show()
}
}
}
This line
val locationLiveData = LocationLiveData(context)
creates a new LocationLiveData instance on every recomposition.
You have to remember the same instance of LocationLiveData across recompositions, if you want it to hold any state or view state.
Change it to
// remember LocationLiveData across recompositions
// this does not survive configuration changes, nor other short Activity restarts
val locationLiveData = remember { LocationLiveData(context) }
As also mentioned in the code comment above, now locationLiveData will survive re-compositions, but it will still get reset on:
every configuration change (examples include but are not limited to:
orientation change, light/dark mode change, language change...)
every short Activity restart, caused by the system in some cases
also application death (but that is somewhat expected)
To solve 1. and 2. you can use rememberSaveable that can save primitive and other Parcelable types automatically (in your case you can also implement the Saver interface), to solve 3. you have to save the state to any of the persistent storage options and then restore as needed.
To learn more about working with state in Compose see the documentation section on Managing State. This is fundamental information to be able to work with state in Compose and trigger recompositions efficiently. It also covers the fundamentals of state hoisting. If you prefer a coding tutorial here is the code lab for State in Jetpack Compose.
An introduction to handling the state as the complexity increases is in the video from Google about Using Jetpack Compose's automatic state observation.

onRequestPermissionsResult Deprecated [duplicate]

I tried to implement request permissions for writing and reading from storage. Everything worked good but today Android showed me that the method onRequestPermissionsResult(...) is deprecated. There are so many questions about this topic in StackOverflow, but unfortunately, they are outdated.
I called the methods below in a fragment.
It was suggested simply to call:
requestPermissions(new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE},
StorageKeys.STORAGE_PERMISSION_CODE)
instead of my approach:
ActivityCompat.requestPermissions(getActivity(),
new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE},
StorageKeys.STORAGE_PERMISSION_CODE))
But both of them show that onRequestPermissionsResult(...) is deprecated.
Here is my onRequestPermissionsResult(...)-method:
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions,
#NonNull int[] grantResults) {
if (requestCode == StorageKeys.STORAGE_PERMISSION_CODE) {
if (grantResults.length > 0
&& grantResults[0] == PackageManager.PERMISSION_GRANTED) {
exportBibTex.createBibFile();
exportBibTex.writeBibFile(exportBibTex
.getBibDataLibrary(libraryModel, bookDao, noteDao));
Toast.makeText(getContext(),
getString(R.string.exported_file_stored_in) + '\n'
+ File.separator + StorageKeys.DOWNLOAD_FOLDER + File.separator + fileName
+ StorageKeys.BIB_FILE_TYPE, Toast.LENGTH_LONG).show();
} else {
Toast.makeText(getContext(), R.string.storage_permission_denied,
Toast.LENGTH_SHORT).show();
}
}
}
Here is a simple alert dialog, in which I call the onRequestPermissionsResult(...):
private void showRequestPermissionDialog() {
AlertDialog.Builder reqAlertDialog = new AlertDialog.Builder(getContext());
reqAlertDialog.setTitle(R.string.storage_permission_needed);
reqAlertDialog.setMessage(R.string.storage_permission_alert_msg);
reqAlertDialog.setPositiveButton(R.string.ok,
(dialog, which) -> ActivityCompat.requestPermissions(getActivity(),
new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE},
StorageKeys.STORAGE_PERMISSION_CODE));
reqAlertDialog.setNegativeButton(R.string.cancel,
(dialog, which) -> dialog.dismiss());
reqAlertDialog.create().show();
}
Is there any alternative for onRequestPermissionsResult(...), that I can use?
The onRequestPermissionsResult() method is deprecated in androidx.fragment.app.Fragment.
So you may use registerForActivityResult() method instead of onRequestPermissionsResult().
You can refer this URL.
Following is Kotlin code, but you can refer it:
val requestPermissionLauncher = registerForActivityResult(
ActivityResultContracts.RequestPermission()
) { isGranted ->
if (isGranted) {
// PERMISSION GRANTED
} else {
// PERMISSION NOT GRANTED
}
}
// Ex. Launching ACCESS_FINE_LOCATION permission.
private fun startLocationPermissionRequest() {
requestPermissionLauncher.launch(Manifest.permission.ACCESS_FINE_LOCATION)
}
I added java code from following URL.
How to get a permission request in new ActivityResult API (1.3.0-alpha05)?
private ActivityResultLauncher<String> requestPermissionLauncher = registerForActivityResult(
new ActivityResultContracts.RequestPermission(),
new ActivityResultCallback<Boolean>() {
#Override
public void onActivityResult(Boolean result) {
if (result) {
// PERMISSION GRANTED
} else {
// PERMISSION NOT GRANTED
}
}
}
);
// Ex. Launch the permission window -- this is in onCreateView()
floatingActionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
requestPermissionLauncher.launch(Manifest.permission.ACCESS_FINE_LOCATION);
}
});
You can also request multiple permissions:
val requestMultiplePermissions = registerForActivityResult(
ActivityResultContracts.RequestMultiplePermissions()
) { permissions ->
permissions.entries.forEach {
Log.d("DEBUG", "${it.key} = ${it.value}")
}
}
requestMultiplePermissions.launch(
arrayOf(
Manifest.permission.READ_CONTACTS,
Manifest.permission.ACCESS_FINE_LOCATION
)
)
A simple way in Kotlin
import android.Manifest
import android.content.Context
import android.content.pm.PackageManager
import android.os.Build
import androidx.activity.result.contract.ActivityResultContracts
import androidx.core.app.ActivityCompat
import androidx.fragment.app.Fragment
class MyFragment : Fragment() {
companion object {
val TAG: String = MyFragment::class.java.simpleName
var PERMISSIONS = arrayOf(
Manifest.permission.CAMERA,
Manifest.permission.READ_EXTERNAL_STORAGE,
Manifest.permission.WRITE_EXTERNAL_STORAGE
)
}
private val permReqLauncher =
registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
val granted = permissions.entries.all {
it.value == true
}
if (granted) {
displayCameraFragment()
}
}
private fun takePhoto() {
if (Build.VERSION.SDK_INT < Build.VERSION_CODES.M) {
displayCameraFragment()
return
}
activity?.let {
if (hasPermissions(activity as Context, PERMISSIONS)) {
displayCameraFragment()
} else {
permReqLauncher.launch(
PERMISSIONS
)
}
}
}
// util method
private fun hasPermissions(context: Context, permissions: Array<String>): Boolean = permissions.all {
ActivityCompat.checkSelfPermission(context, it) == PackageManager.PERMISSION_GRANTED
}
private fun displayCameraFragment() {
// open camera fragment
}
}
Alternative registerForActivityResult
Example use:
private fun permissionSetup() {
val permission = ContextCompat.checkSelfPermission(
requireContext(), Manifest.permission.READ_CONTACTS)
if (permission != PackageManager.PERMISSION_GRANTED) {
permissionsResultCallback.launch(Manifest.permission.READ_CONTACTS)
} else {
println("Permission isGranted")
}
}
private val permissionsResultCallback = registerForActivityResult(
ActivityResultContracts.RequestPermission()){
when (it) {
true -> { println("Permission has been granted by user") }
false -> {
Toast.makeText(requireContext(), "Permission denied", Toast.LENGTH_SHORT).show()
dialog.dismiss()
}
}
}
Register the permissions callback in your activity or fragment. which handle user permission
Example-Storage permission
private final ActivityResultLauncher<String> requestPermissionLauncher = registerForActivityResult(
new ActivityResultContracts.RequestPermission(),
result -> {
if (result) {
//Permission granted
} else {
//permission denied
if (ActivityCompat.shouldShowRequestPermissionRationale(activity, WRITE_EXTERNAL_STORAGE)) {
//show permission snackbar
} else {
//display error dialog
}
}
});
Ask for the permission.The registered ActivityResultCallback gets the result of this request.
if (checkSelfPermission(activity, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PermissionChecker.PERMISSION_GRANTED) {
requestPermissionLauncher.launch(Manifest.permission.WRITE_EXTERNAL_STORAGE);
} else {
//Permission already granted
}
This works for me - (kotlin):
private fun checkPermissions() {
if (mContext?.let {
ContextCompat.checkSelfPermission(
it,
READ_EXTERNAL_STORAGE
)
} != PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "Request Permissions")
requestMultiplePermissions.launch(
arrayOf(READ_EXTERNAL_STORAGE, WRITE_EXTERNAL_STORAGE))
} else {
Log.d(TAG, "Permission Already Granted")
}
}
private val requestMultiplePermissions =
registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
permissions.entries.forEach {
Log.d(TAG, "${it.key} = ${it.value}")
}
if (permissions[READ_EXTERNAL_STORAGE] == true && permissions[WRITE_EXTERNAL_STORAGE] == true) {
Log.d(TAG, "Permission granted")
} else {
Log.d(TAG, "Permission not granted")
}
}
Most of the answers address the OP requirement. But I have found few things that are missing so I thought to provide a complete example (in Koltin)
class ProfileFragment : Fragment(){
private lateinit var permissionRequest : ActivityResultLauncher<Array<String>>
companion object {
val LOCATION_PERMISSIONS = arrayOf(
Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION
)
}
private fun getGpsLocation() {
if(activity != null){
permissionRequest.launch(LOCATION_PERMISSIONS)
}
}
override fun onViewCreated(view: View, savedInstanceState: Bundle?) {
super.onViewCreated(view, savedInstanceState)
binding.locBtn.setOnClickListener { getGpsLocation() }
}
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
registerPermissionRequest()
}
override fun onCreateView(inflater: LayoutInflater, container: ViewGroup?, savedInstanceState: Bundle?): View {
binding = DataBindingUtil.inflate(inflater, R.layout.fragment_profile, container, false)
return binding.root
}
private fun registerPermissionRequest(){
var permissionCount = 0
permissionRequest = registerForActivityResult(ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
permissions.entries.forEach {
if(it.value){
permissionCount++
}
}
if(permissionCount == 2){
getMyLocation()
}
}
}
}
The things that are missing are
A)Fragments must call registerForActivityResult() before they are created (i.e. initialization, onAttach(), or onCreate()). Other wise it won't work and the app would crash.
Error:
java.lang.IllegalStateException: Fragment ProfileFragment{bf12414} (210ad5a1-3286-4586-a48f-deac1d8e3eef
id=0x7f09008b) is attempting to registerForActivityResult after being
created. Fragments must call registerForActivityResult() before they
are created (i.e. initialization, onAttach(), or onCreate()).
B) It is recommended to request permission when it is really needed. In my example when user clicks on Button with id locBtn, permission dialog is shown rather than showing when activity/fragment is created.
Please refer to the official documentation: https://developer.android.com/training/permissions/requesting
Review the following, which can be found in the documentation.
// Register the permissions callback, which handles the user's response to the
// system permissions dialog. Save the return value, an instance of
// ActivityResultLauncher. You can use either a val, as shown in this snippet,
// or a lateinit var in your onAttach() or onCreate() method.
val requestPermissionLauncher =
registerForActivityResult(RequestPermission()
) { isGranted: Boolean ->
if (isGranted) {
// Permission is granted. Continue the action or workflow in your
// app.
} else {
// Explain to the user that the feature is unavailable because the
// features requires a permission that the user has denied. At the
// same time, respect the user's decision. Don't link to system
// settings in an effort to convince the user to change their
// decision.
}
}
After which, launch the request
when {
ContextCompat.checkSelfPermission(
CONTEXT,
Manifest.permission.REQUESTED_PERMISSION
) == PackageManager.PERMISSION_GRANTED -> {
// You can use the API that requires the permission.
}
//Is not needed for it to work, but is a good practice as it plays a role
//in letting user know why the permission is needed.
shouldShowRequestPermissionRationale(...) -> {
// In an educational UI, explain to the user why your app requires this
// permission for a specific feature to behave as expected. In this UI,
// include a "cancel" or "no thanks" button that allows the user to
// continue using your app without granting the permission.
showInContextUI(...)
}
else -> {
// You can directly ask for the permission.
// The registered ActivityResultCallback gets the result of this request.
requestPermissionLauncher.launch(
Manifest.permission.REQUESTED_PERMISSION)
}
}
Suppose we need to take some permissions like audio and camera. Then we can put it on a variable of array.
private val REQUESTED_PERMISSIONS =
arrayOf(Manifest.permission.RECORD_AUDIO, Manifest.permission.CAMERA)
This registerForActivityResult invoke when we launch with multiple permission array.
private val requestMultiplePermissions = registerForActivityResult(
ActivityResultContracts.RequestMultiplePermissions()
) { permissions ->
permissions.entries.forEach {
Log.d("DEBUG", "${it.key} = ${it.value}")
if (!it.value){
return#registerForActivityResult
}
}
init()
}
Now we make a function to check permission is already granted or not.
private fun checkSelfPermission(): Boolean {
return !(ContextCompat.checkSelfPermission(
requireContext(),
REQUESTED_PERMISSIONS[0]
) != PackageManager.PERMISSION_GRANTED ||
ContextCompat.checkSelfPermission(
requireContext(),
REQUESTED_PERMISSIONS[1]
) != PackageManager.PERMISSION_GRANTED)
}
Now we check permission is granted or not from onCreate method. If permission is not granted then we invoke requestMultiplePermissions.launch(REQUESTED_PERMISSIONS) like
super.onCreate(savedInstanceState)
if (!checkSelfPermission()) {
requestMultiplePermissions.launch(REQUESTED_PERMISSIONS)
}
}
You can use some external library for permission handling to reduce some boilerplate code. I use Dexter library. Rx Permissions is also good choice if you are using RxJava2.
Try this in in your pubspec.yamal under flutter section:
plugin:
androidPackage: com.ly.permission
pluginClass: PermissionPlugin
It works with me.

"Unexpected tokens" error in function call

I'm having some trouble with Kotlin syntax, it requires a semicolon inside a function call (?!).
I was simply attempting to convert the code from AltBeacon website, the one used to get coarse location permissions. Here's what I've come up with on a rush:
class MainActivity : AppCompatActivity() {
val TAG = "MAIN_ACTIVITY"
val PERMISSION_REQUEST_COARSE_LOCATION = 1
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
setContentView(R.layout.activity_main)
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
if (checkSelfPermission(Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED){
val builder = AlertDialog.Builder(this)
builder.setTitle("This app needs location access")
builder.setMessage("Please grant location access so this app can detect beacons.")
builder.setPositiveButton(android.R.string.ok, null)
builder.setOnDismissListener {
val permissions = arrayOf(Manifest.permission.ACCESS_COARSE_LOCATION)
requestPermissions(permissions, PERMISSION_REQUEST_COARSE_LOCATION)
}
builder.show()
}
}
}
override fun onRequestPermissionsResult(requestCode: Int, permissions: Array<String>, grantResults: IntArray) {
when (requestCode) {
PERMISSION_REQUEST_COARSE_LOCATION-> {
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Log.d(TAG, "coarse location permission granted")
} else {
val builder = AlertDialog.Builder(this)
builder.setTitle("Functionality limited")
builder.setMessage("Since location access has not been granted, this app will not be able to discover beacons when in the background.");
builder.setPositiveButton(android.R.string.ok, null)
builder.setOnDismissListener { }
builder.show()
}
}
}
}
}
Compiler has issues with this line:
requestPermissions(permissions, PERMISSION_REQUEST_COARSE_LOCATION)
Unexpected tokens (use ';' to separate expressions on the same line)
Everything is ok with kotlin syntax here.
The problem is that you have a strange invisible symbol at the end of that line. I pasted that code in notepad++ and saw this:
So just delete it and compilation will succeed.

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