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How to handle the Usb Permission Dialog Event on android when using the "device filter" solution?

I'm trying to handle the event when a user presses "ok" or "cancel" on the automatic permission dialog presented when I connect a "known" USB device to the android phone.
I'm using the android.usb.host library and can send and receive between the android phone and the device. Futhermore do I handle the "USB_DEVICE_ATTACHED" and "USB_DEVICE_DETACHED" using a BroadcastReceiver without any problems.
I want to enable a sort of "autoconnect" feature and therefore I need to know when the user has pressed "ok" in the automatically displayed permission dialog, but I can't find anything online at all. All I find is "bypass dialog", but this is not what I want or need.
When I connect the usb device to the android phone, a permission dialog is automatically displayed because I use the "device_filter.xml" solution from androids documentation which can be seen here Android Usb Docs.
This is how I handle the USB_DEVICE_ATTATCHED and USB_DEVICE_DETACHED events:
public NativeUsbService(ReactApplicationContext reactContext) {
...
// register device attached/detached event listeners
IntentFilter filter = new IntentFilter();
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
reactContext.registerReceiver(usbReceiver, filter);
...
}
And then the Broadcast Receiver:
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if(device != null){
usbDevice = device;
} else {
Log.d(TAG, "onReceive: DEVICE WAS ATTACHED AND WAS NULL :(");
}
}
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
Log.d(TAG, "onReceive: Device was detached!");
if(connection != null) {
connection.releaseInterface(usbDeviceInterface);
connection.close();
}
connection = null;
usbDevice = null;
endpointIn = null;
endpointOut = null;
}
}
};
I have tried multiple different approaches, but nothing has worked.
I have tried getting the user response in from the intent, like with a manual permission request like below:
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if(device != null){
usbDevice = device;
// THIS DOES NOT WORK ↓↓↓
if(intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
// The code never gets here...
}
} else {
Log.d(TAG, "onReceive: DEVICE WAS ATTACHED AND WAS NULL :(");
sendEvent("onDeviceAttached", false);
}
}
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
if(connection != null) {
connection.releaseInterface(usbDeviceInterface);
connection.close();
}
connection = null;
usbDevice = null;
endpointIn = null;
endpointOut = null;
}
}
};
I have also tried by adding a usb permission listener to the broadcast receiver by first adding the action name to my class variables:
private static final String ACTION_USB_PERMISSION = "com.android.example.USB_PERMISSION";
Then adding the action to my intent filter like so:
public NativeUsbService(ReactApplicationContext reactContext) {
// register device attached/detached event listeners
IntentFilter filter = new IntentFilter();
filter.addAction(UsbManager.ACTION_USB_DEVICE_ATTACHED);
filter.addAction(UsbManager.ACTION_USB_DEVICE_DETACHED);
filter.addAction(ACTION_USB_PERMISSION); // added action to my intent filter
reactContext.registerReceiver(usbReceiver, filter);
}
And finally reacting to the action like so:
private final BroadcastReceiver usbReceiver = new BroadcastReceiver() {
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (action.equals(UsbManager.ACTION_USB_DEVICE_ATTACHED)) {
synchronized (this) {
UsbDevice device = (UsbDevice) intent.getParcelableExtra(UsbManager.EXTRA_DEVICE);
if(device != null){
usbDevice = device;
}
}
} else if (action.equals(UsbManager.ACTION_USB_DEVICE_DETACHED)) {
Log.d(TAG, "onReceive: Device was detached!");
if(connection != null) {
connection.releaseInterface(usbDeviceInterface);
connection.close();
}
connection = null;
usbDevice = null;
endpointIn = null;
endpointOut = null;
sendEvent("onDeviceDetached", true);
}
else if (action.equals(ACTION_USB_PERMISSION)) {
Log.d(TAG, "onReceive: ACTION_USB_PERMISSION");
if(intent.getBooleanExtra(UsbManager.EXTRA_PERMISSION_GRANTED, false)) {
Log.d(TAG, "onReceive: EXTRA_PERMISSION_GRANTED = true");
} else Log.d(TAG, "onReceive: EXTRA_PERMISSION_GRANTED = false");
}
}
};
Please make me aware of any missing information.
Any help is greatly appreciated.

Answering my own question in case someone else is facing the same issue.
I though about manually requesting the permission again, after permission was granted, since it is possible to handle this manual permission request when user presses an option in the dialog. I discarded this idea, not because it wouldn't work, but because I saw it as unecessary for the user to also have to press another dialog after the initial (automatic dialog).
I must add that I have not implemented this solution, so I do not know with certainty that it would prompt the user again, but I have had trouble with the manual permission request previously. If you want to try this approach the method belongs to the UsbManager class and is invoke like so usbManger.requestPermission(usbDevice).
I ended up with a solution where I start a thread which runs a loop calling usbManager.hasPermission(usbDevice) until it has permission and then emits an event (emitting this event is my use case, implement it how you like).
The solution can be seen here:
import android.hardware.usb.UsbDevice;
import android.hardware.usb.UsbDeviceConnection;
import android.hardware.usb.UsbManager;
import com.facebook.react.bridge.ReactApplicationContext;
...
private static volatile boolean permissionThreadShouldStop = false;
private static Thread activePermissionThread = null;
...
public static void usbPermissionEventEmitter(ReactApplicationContext reactContext, UsbManager usbManager, UsbDevice usbDevice) {
if((activePermissionThread != null && activePermissionThread.isAlive())) {
activePermissionThread.interrupt();
}
permissionThreadShouldStop = false;
activePermissionThread = new Thread(new Runnable() {
#Override
public void run() {
while (!usbManager.hasPermission(usbDevice) && !permissionThreadShouldStop) {
try {
Thread.sleep(30);
} catch (InterruptedException e) {
e.printStackTrace();
break;
}
}
if(usbManager.hasPermission(usbDevice)) {
sendEvent(reactContext, "onUsbPermissionGranted", true);
}
}
});
activePermissionThread.start();
}
The ReactApplicationContext can be swapped with the normal android context. But this is for a react native module, so I use the reactContext.
I hope this will be helpful for someone, because i'm honestly really surpriced how scarse the android documentation is in regards to implementing Usb functionality using the android.hardware.usb library.
Also in general when searching for information online, I have often found myself lost since there is very little information on this subject.

Unable to scan or discover BT and BLE devices in android

I am a complete novice in Java and Android. I am trying to create a test app to listen for BLE and BT devices nearby. I have another device where I wrote some logic to broadcast its BLE beacons. I verified it using a playstore app. Now I am trying to write my own app on Android.
I have been reading the Android developer pages for guidance. I have literally followed every step of the following pages
https://developer.android.com/guide/topics/connectivity/bluetooth/setup
https://developer.android.com/guide/topics/connectivity/bluetooth/permissions
https://developer.android.com/guide/topics/connectivity/bluetooth/find-bluetooth-devices
https://developer.android.com/guide/topics/connectivity/bluetooth/find-ble-devices
Also, Note that I have used BARE MINIMUM CODE from the Android Developers page So here is what I have done.
1. First off I have added my permissions under AndroidManifest
Note1 : I am deploying this app to My phone running Android 11
Note2 : All this code is written inside MainActivity. I have not created any other activity class
<uses-permission android:name="android.permission.BLUETOOTH" android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" android:maxSdkVersion="30" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
<uses-permission android:name="android.permission.BLUETOOTH_ADVERTISE" />
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
2. Next I check if my BT is enabled.
if (bluetoothAdapter == null) {
blefinder.append("\nDEVICE DOES NOT SUPPORT BLUETOOTH");
}
else {
blefinder.append("\nDEVICE SUPPORTS BLUETOOTH");
}
I get the success message that BT is of course enabled
3. Next I check if my device supports BLE
if (!getPackageManager().hasSystemFeature(PackageManager.FEATURE_BLUETOOTH_LE)) {
blefinder.append("\nBLE NOT SUPPORTED ON THIS DEVICE : ");
finish();
}
else{
blefinder.append("\nBLE IS SUPPORTED ON THIS DEVICE : ");
}
I get the message that BLE is supported
4. Next I list my already paired/bonded devices
For this I call ListPairedAndBondedDevices(); in onCreate() itself right after the above steps. Function Definition Below.
private void ListPairedAndBondedDevices(){
#SuppressLint("MissingPermission") Set<BluetoothDevice> pairedDevices = bluetoothAdapter.getBondedDevices();
if (pairedDevices.size() > 0) {
// There are paired devices. Get the name and address of each paired device.
blefinder.append("\nPAIRED/BONDED DEVICES");
for (BluetoothDevice device : pairedDevices) {
blefinder.append("\n" + device.getName() + " | " + device.getAddress());
}
}
}
This also works like a charm and prints out my paired devices. The next 2 parts is where I face the problem.
5. The Problem Step | Part 1:
Here I register a Broadcast receiver to discover all BT devices in the vicinity. I've unbonded my BT headphones and kept it in pairing mode to verify this.
ListPairedAndBondedDevices(); // From previous code snippet
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); // New code statement
registerReceiver(BTReceiver, filter);// New code statement
Broadcast Receiver implementation
private final BroadcastReceiver BTReceiver = new BroadcastReceiver() {
#SuppressLint("MissingPermission")
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if (BluetoothDevice.ACTION_FOUND.equals(action)) {
// Discovery has found a device. Get the BluetoothDevice
// object and its info from the Intent.
BluetoothDevice device = intent.getParcelableExtra(BluetoothDevice.EXTRA_DEVICE);
blefinder.append("\n" + device.getName() + " | " + device.getAddress());
}
}
};
So This part didn't Work :(
If you see above, I am registering the BTReceiver in onCreate right after listing the already paired devices (by calling ListPairedAndBondedDevices()).
When I ran the debugger, this broadcast receiver never gets called.
6. The Problem Step | Part 2:
Right after this I try to scan for BLE Devices as well by callin scanLeDevice()
ListPairedAndBondedDevices(); // From previous snippet
IntentFilter filter = new IntentFilter(BluetoothDevice.ACTION_FOUND); // From previous snippet
registerReceiver(BTReceiver, filter);// From previous snippet
scanLeDevice(); // ---------------->>> CALLING THIS FUNCTION TO SCAN FOR BLE DEVICES
Implementation of scanLeDevice()
private void scanLeDevice() {
if (!scanning) {
// Stops scanning after a predefined scan period.
handler.postDelayed(new Runnable() {
#Override
public void run() {
scanning = false;
bluetoothLeScanner.stopScan(leScanCallback);
blefinder.append("\nSTOPPING BLE SCAN... TIMEOUT REACHED");
}
}, SCAN_PERIOD);
scanning = true;
bluetoothLeScanner.startScan(leScanCallback);
} else {
scanning = false;
bluetoothLeScanner.stopScan(leScanCallback);
blefinder.append("\nSTOPPING BLE SCAN");
}
}
Unfortunately this also fails. The debugger tells me that this part of the code is getting called.
And after 30 seconds of SCAN_PERIOD (The TIMEOUT that I've set), I get the message that the scanning has stopped (STOPPING BLE SCAN)
Now I have implemented the leScanCallback as well (i.e the Device Scan Callback)
private ScanCallback leScanCallback =
new ScanCallback() {
#Override
public void onScanResult(int callbackType, ScanResult result) {
super.onScanResult(callbackType, result);
blefinder.append("SOMETHING GOT SCANNED?");
blefinder.append("\n"+result.getDevice().toString());
// leDeviceListAdapter.addDevice(result.getDevice());
// leDeviceListAdapter.notifyDataSetChanged();
}
};
Notice that I am not using a ListAdapter since I have no idea about that concept. Hence for starters I am just trying to dump the results in a TextView represented by blefinder . This blefinder prints all the other texts so there is nothing wrong with that TextView variable. When I ran using the, debugger, it is not entering into the leScanCallback piece of code definition at all, even after 30 seconds, after scanLeDevice() function is executed.
I am a little lost here. Is there something I may be missing or doing wrong. It is supposed to be a simple, list the ble/bt devices around my vicinity.
I am happy to share any further information if I have missed. Just let me know in the comments.

Assuming you've done with the permissions that I've mentioned in the comments, we can implement a clean bluetooth LE scanner object and then use it in the UI.
First we implement a result consumer interface in order to deliver the results to the consumers which call the BleScanner.scan() method.
public interface ScanResultConsumer {
public void onDeviceFound(BluetoothDevice device, byte[] scanRecord, int rssi);
public void onScanningStarted();
public void onScanningStopped();
}
Now we need to implement the scanner object that manages the scanning events:
public class BleScanner {
private static final String TAG = BleScanner.class.getSimpleName();
private BluetoothLeScanner leScanner = null;
private BluetoothAdapter bleAdapter = null;
private Handler uiHandler = new Handler(Looper.getMainLooper);
private ScanResultConsumer scanResultConsumer;
private boolean scanning = false;
private final ArrayList<BluetoothDevice> foundDeviceList = new ArrayList<>();
public BleScanner(Context context) {
final BluetoothManager bluetoothManager = (BluetoothManager)
context.getSystemService(Context.BLUETOOTH_SERVICE);
bleAdapter = bluetoothManager.getAdapter();
if(bleAdapter == null) {
Log.d(TAG, "No bluetooth hardware.");
}
else if(!bleAdapter.isEnabled()){
Log.d(TAG, "Blutooth is off.");
}
}
public void scan(ScanResultConsumer scanResultConsumer, long scanTime){
foundDeviceList.clear();
if (scanning){
Log.d(TAG, "Already scanning.");
return;
}
Log.d(TAG, "Scanning...");
if(leScanner == null){
leScanner = bleAdapter.getBluetoothLeScanner();
}
if(scanTimeMs > 0) {
uiHandler.postDelayed(()-> {
if (scanning) {
Log.d(TAG, "Scanning is stopping.");
if(leScanner != null)
leScanner.stopScan(scanCallBack);
else
Log.d(TAG,"Scanner null");
setScanning(false);
}
}, scanTimeMs);
}
this.scanResultConsumer = scanResultConsumer;
leScanner.startScan(scanCallBack);
setScanning(true);
}
private final ScanCallback scanCallBack = new ScanCallback() {
#Override
public void onScanResult(int callbackType, ScanResult result) {
super.onScanResult(callbackType, result);
if (!scanning){
return;
}
if(foundDeviceList.contains(result.getDevice())) {
// This device has already been found
return;
}
// New device found, add it to the list in order to prevent duplications
foundDeviceList.add(result.getDevice());
if(scanResultConsumer != null) {
uiHandler.post(() -> {
scanResultConsumer.onDeviceFound(result.getDevice(),
result.getScanRecord().getBytes(), result.getRssi());
});
}
}
};
public boolean isScanning(){
return scanning;
}
void setScanning(boolean scanning){
this.scanning = scanning;
uiHandler.post(() -> {
if(scanResultConsumer == null) return;
if(!scanning){
scanResultConsumer.onScanningStopped();
// Nullify the consumer in order to prevent UI crashes
scanResultConsumer = null;
} else{
scanResultConsumer.onScanningStarted();
}
});
}
}
Finally we can use this clean implementation in anywhere we need. But do note that a context must be provided in order to create a BleScanner object.
public class MainActivity extends AppCompatActivity {
private BleScanner bleScanner;
private Button buttonScan
// Other codes...
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
// Other codes...
bleScanner = new BleScanner(getApplicationContext());
// Other codes...
// For example if you want to start scanning on a button press
// Let's say you have a button called buttonScan and initiated it
buttonScan = findViewById(R.id.scan_button);
buttonScan.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
bleScanner.scan(new ScanResultConsumer {
#Override
public void onDeviceFound(BluetoothDevice device, byte[] scanRecord, int rssi) {
// TODO Here you have a newly found device, do something.
}
#Override
q public void onScanningStarted() {
// TODO Scanning has just started, you may want to make some UI changes.
}
#Override
public void onScanningStopped() {
// TODO Scanning has just stopped, you may want to make some UI changes.
}
});
}
});
}
}
Note: I written this code in a plain editor not in Android Studio. So there may be some errors, let me know if any.

First you should check if your app was granted the location permission(s) in the Settings app > Apps <your_app> > permissions. Some permissions (like ACCESS_*_LOCATION and BLUETOOTH_ADMIN) need to be requested at runtime and granted by the user through a popup. Normally you should get a SecurityException or a logcat warning when trying to execute code requiring permissions which your app doesn't have, but it's not uncommon for android to skip over error handling.
Consider using this method to start the scan in order check its result code for potential additional info about what is (not) going on.
You might also get some clues by logging all actions received in BTReceiver.onReceive(), not just action found.
Lastly check if the location settings on your device to ensure that bluetooth scanning is turned on (Settings app > location > wifi and bluetooth scanning )

What is this Error when Debug android app?

I got this error when I tried to debug my app
java.lang.NoSuchMethodError: No virtual method requestPermissions([Ljava/lang/String;I)V in class Lcom/cscodetech/townclap/activity/LoginActivity; or its super classes (declaration of 'com.zestar.myclip.activity.LoginActivity' appears in /data/app/com.zestar.myclip-1/base.apk:classes2.dex)
at com.zestar.myclip.activity.LoginActivity.onCreate(LoginActivity.java:92)
The logcat pointed to this line of code
requestPermissions(new String[]{Manifest.permission.CALL_PHONE, Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 1);
What is wrong with that line
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_login);
ButterKnife.bind(this);
FirebaseApp.initializeApp(this);
requestPermissions(new String[]{Manifest.permission.CALL_PHONE, Manifest.permission.ACCESS_COARSE_LOCATION, Manifest.permission.ACCESS_FINE_LOCATION}, 1);
custPrograssbar = new CustPrograssbar();
sessionManager = new SessionManager(LoginActivity.this);
atCode.setOnFocusChangeListener((view, b) -> {
if (!b) {
// on focus off
String str = atCode.getText().toString();
ListAdapter listAdapter = atCode.getAdapter();
for (int i = 0; i < listAdapter.getCount(); i++) {
String temp = listAdapter.getItem(i).toString();
if (str.compareTo(temp) == 0) {
return;
}
}
atCode.setText("");
}
});
getCodelist();
}

as requestPermissions like #TylerV said, try using this way instead
as instructed in
Documentation for how to request app permissions | Android Developers
this should be the right way to request permissions in fragments which goes as this:
You first initialize this variable in fragment/activity which specifies what should happen if the permissions were granted or not:
private ActivityResultLauncher requestPermissionLauncher =
registerForActivityResult(new ActivityResultContracts.RequestMultiplePermissions(), result -> { {
//result is a map(string permission,boolean granted or not)
//to check if all permissions were granted or not
if(result.containsValue(false)){
// 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.
Toast.makeText(getContext(), "Can't continue without the required permissions", Toast.LENGTH_LONG).show();
}
else {
//continue your work flow
}
});
Then when you need to request for a permission you call launch on the object you declared with an array holding the permission you're requesting :
if (ActivityCompat.checkSelfPermission(getContext(),
Manifest.permission.CALL_PHONE) != PackageManager.PERMISSION_GRANTED ||
ActivityCompat.checkSelfPermission(getContext(),
Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.PERMISSION_GRANTED ||
ActivityCompat.checkSelfPermission(getContext(),
Manifest.permission.ACCESS_COARSE_LOCATION) != PackageManager.ACCESS_FINE_LOCATION) {
requestPermissionLauncher.launch(new String[]{Manifest.permission.CALL_PHONE,
Manifest.permission.ACCESS_COARSE_LOCATION,
Manifest.permission.ACCESS_FINE_LOCATION});
} else // continue your work

Please provide your logs when exception occurs. Maybe error is because of android version. You must check if android version is bigger than Api level 26 (Marshmallow):
if(Build.VERSION.SDK_INT >= Build.VERSION_CODES.M){
requestPermissions(INITIAL_PERMS, INITIAL_REQUEST);
}

How to get a permission request in new ActivityResult API (1.3.0-alpha05)?

so, I tried to get a permission with the new registerForActivityResult() method and ask for with button click with .launch() and it doesn´t seem to be opening any window to ask for it.
I´m always getting false in registerForActivityResult().
// Permission to get photo from gallery, gets permission and produce boolean
private ActivityResultLauncher<String> mPermissionResult = registerForActivityResult(
new ActivityResultContracts.RequestPermission(),
new ActivityResultCallback<Boolean>() {
#Override
public void onActivityResult(Boolean result) {
if(result) {
Log.e(TAG, "onActivityResult: PERMISSION GRANTED");
} else {
Log.e(TAG, "onActivityResult: PERMISSION DENIED");
}
}
});
// Launch the permission window -- this is in onCreateView()
floatingActionButton.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
mPermissionResult.launch(Manifest.permission.ACCESS_BACKGROUND_LOCATION);
}
});
This is my LOG always: onActivityResult: PERMISSION DENIED

UPDATE
This answer works, but I found a better solution for permission requests with no open holes here.
From docs:
In your Activity/Fragment, create this field:
// Register the permissions callback, which handles the user's response to the
// system permissions dialog. Save the return value, an instance of
// ActivityResultLauncher, as an instance variable.
private ActivityResultLauncher<String> requestPermissionLauncher =
registerForActivityResult(new RequestPermission(), isGranted -> {
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.
}
});
Somewhere in the same Activity/Fragment:
if (ContextCompat.checkSelfPermission(
context, Manifest.permission.ACCESS_BACKGROUND_LOCATION) ==
PackageManager.PERMISSION_GRANTED) {
performAction(...);
} else if (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.ACCESS_BACKGROUND_LOCATION);
}
If you are getting unreasonable "Permission denied" all the time, maybe you did not declare it in your manifest.xml?

Looking at Update to androidx.fragment:fragment:1.3.0-alpha08: registerForActivityResult not allowed after onCreate anymore. How to use after onCreate?,
private lateinit var checkLocationPermission: ActivityResultLauncher<Array<String>>
// Initialize checkLocationPermission in onAttach or onCreate.
override fun onCreate(savedInstanceState: Bundle?) {
super.onCreate(savedInstanceState)
checkLocationPermission = registerForActivityResult(
ActivityResultContracts.RequestMultiplePermissions()) { permissions ->
if (permissions[Manifest.permission.ACCESS_FINE_LOCATION] == true ||
permissions[Manifest.permission.ACCESS_COARSE_LOCATION] == true) {
initUserLocation()
} else {
// Permission was denied. Display an error message.
}
}
}
fun showMap() {
if (ActivityCompat.checkSelfPermission(requireContext(),
Manifest.permission.ACCESS_FINE_LOCATION) == PackageManager.PERMISSION_GRANTED ||
ActivityCompat.checkSelfPermission(requireContext(),
Manifest.permission.ACCESS_COARSE_LOCATION) == PackageManager.PERMISSION_GRANTED) {
initUserLocation()
} else {
checkLocationPermission.launch(arrayOf(Manifest.permission.ACCESS_FINE_LOCATION,
Manifest.permission.ACCESS_COARSE_LOCATION))
}
}
private fun initUserLocation() {
googleMap?.isMyLocationEnabled = true
}

No such file or Directory only in Android 6.0

Below code is working fine on pre-Marshmallow devices but not in Marshmallow.
These are the permissions in Manifest
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE"/>
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
Here is the code
public void saveImageToSDCard(Bitmap bitmap) {
File myDir = new File(
Environment
.getExternalStoragePublicDirectory(Environment.DIRECTORY_PICTURES),
pref.getGalleryName());
myDir.mkdirs();
Random generator = new Random();
int n = 10000;
n = generator.nextInt(n);
String fname = "Wallpaper-" + n + ".jpg";
File file = new File(myDir, fname);
if (file.exists())
file.delete();
try {
FileOutputStream out = new FileOutputStream(file);
bitmap.compress(Bitmap.CompressFormat.JPEG, 90, out);
out.flush();
out.close();
Uri uri = getImageContentUri(_context,file);
Log.d(TAG, "Wallpaper saved to: " + file.getAbsolutePath());
} catch (Exception e) {
e.printStackTrace();
}
}
And the same code works when I manually allow the storage permission
Here is the solution given by Nitesh Pareek.
private boolean hasPermissions(Context context, String[] permissions) {
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) {
for (String permission : permissions) {
if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
return false;
}
}
}
return true;
}
String[] PERMISSIONS = new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE};
if (!hasPermissions(this, PERMISSIONS)) {
ActivityCompat.requestPermissions(this, PERMISSIONS, 11);
return;
}

Beginning in Android 6.0 (API level 23), users grant permissions to apps while the app is running, not when they install the app.
This is why it works in pre-lolipop versions, and doesn't on API 23. Permissions in Android Manifest alone are not enough, you need to add them at runtime as well. Refer here for more details.

give read write permissions on run time for marshmallow or newer version.
Do like below:-
String[] PERMISSIONS = new String[]{ Manifest.permission.WRITE_EXTERNAL_STORAGE};
if (!hasPermissions(this, PERMISSIONS)) {
ActivityCompat.requestPermissions(this, PERMISSIONS, 11);
return;
}
private boolean hasPermissions(Context context, String... permissions) {
if (android.os.Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && context != null && permissions != null) {
for (String permission : permissions) {
if (ActivityCompat.checkSelfPermission(context, permission) != PackageManager.PERMISSION_GRANTED) {
return false;
}
}
}
return true;
}

You need to take application permissions at runtime instead of taking when install/update as convention
Beginning in Android 6.0 (API level 23), users grant permissions to
apps while the app is running, not when they install the app. This
approach streamlines the app install process, since the user does not
need to grant permissions when they install or update the app
For more help: Requesting Permissions at Run Time
By focusing on the documentation and after doing some google searches, finally I have compiled the code below to handle runtime permissions efficiently
To make it work, you need to follow the instructions below:
Call this method to check if storage permission is granted by user?
If not, then you need to request for it
public static boolean isStoragePermissionGranted(Activity activity) {
boolean flag = false;
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
flag = activity.checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED;
}
return flag;
}
Call this method to request storage permission
public static void requestStoragePermission(Activity activity) {
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (isStoragePermissionGranted(activity)) {
return;
}
// Fire off an async request to actually get the permission
// This will show the standard permission request dialog UI
activity.requestPermissions(new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE},
REQUEST_CODE_STORAGE_PERMISSION);
}
}
Implement this method in your activity to handle response of permission callback
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
switch (requestCode) {
case REQUEST_CODE_STORAGE_PERMISSION:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M) {
if (grantResults.length > 0) {
if (grantResults[0] == PackageManager.PERMISSION_DENIED) {
boolean shouldShowRationale = shouldShowRequestPermissionRationale(permissions[0]);
if (!shouldShowRationale) {
// user denied flagging NEVER ASK AGAIN, you can either enable some fall back,
// disable features of your app or open another dialog explaining again the permission and directing to
// the app setting
dialogReasonStoragePermissionToSettings(this);
} else if (Manifest.permission.WRITE_EXTERNAL_STORAGE.equals(permissions[0])) {
// user denied WITHOUT never ask again, this is a good place to explain the user
// why you need the permission and ask if he want to accept it (the rationale)
dialogReasonStoragePermission(this);
}
} /*else {
// Do on permission granted work here
}*/
}
}
break;
}
}
public static void dialogReasonStoragePermission(final Activity activity) {
AlertDialog.Builder builder = new AlertDialog.Builder(activity);
builder.setMessage(activity.getString(R.string.reason_storage_permission));
builder.setCancelable(false);
builder.setPositiveButton("Retry", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
requestStoragePermission(activity);
}
});
builder.setNegativeButton("Dismiss", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.show();
}
public static void dialogReasonStoragePermissionToSettings(final Activity activity) {
AlertDialog.Builder builder = new AlertDialog.Builder(activity);
builder.setMessage(activity.getString(R.string.reason_storage_permission));
builder.setCancelable(false);
builder.setPositiveButton("Go to Settings", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
goToAppDetailsForPermissionSettings(activity);
}
});
builder.setNegativeButton("Dismiss", new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int id) {
dialog.dismiss();
}
});
AlertDialog dialog = builder.create();
dialog.show();
}
private static final int REQUEST_CODE_APP_DETAILS_PERMISSION_SETTING = 3995;
private static void goToAppDetailsForPermissionSettings(Activity activity) {
Intent intent = new Intent(Settings.ACTION_APPLICATION_DETAILS_SETTINGS);
Uri uri = Uri.fromParts("package", activity.getPackageName(), null);
intent.setData(uri);
activity.startActivityForResult(intent, REQUEST_CODE_APP_DETAILS_PERMISSION_SETTING);
}

I am not providing you direct code for this but here is a reason API level 23 introduce a new Permission structure for more security below is a short but wast description of thing, in documentation here
Beginning in Android 6.0 (API level 23), users grant permissions to apps while the app is running, not when they install the app. This approach streamlines the app install process, since the user does not need to grant permissions when they install or update the app. It also gives the user more control over the app's functionality; for example, a user could choose to give a camera app access to the camera but not to the device location. The user can revoke the permissions at any time, by going to the app's Settings screen.
Code is good just you have to put something additional and that is Runtime Permissions for storage.
Read this blog to know everything from deep inside about Runtime Permissions gave me a clear picture about it, hope it helps you too.
Thanks