Develop Reference

BLUETOOTH_CONNECT permission

I have a problem, I try to activate Bluetooth but first I check for BLUETOOTH_CONNECT runtime permission (required by the BluetoothAdapter.enable()). Every time I request the permission is denied without displaying any dialog box, I tryed to request another permission and it works fine (displays dialog box with options - allow or denie) . I tryed to reinstall the app and clear its cache memory, i also checked for the app permissions allowed but i couldnt find Bluetooth. I also have the permissions in the Manifest.
public void enableordisableBT() {
if (MyBluetoothAdapter == null) {
Log.d(TAG,"Bluetooth not supported");
} else if (!MyBluetoothAdapter.isEnabled()) {
Log.d(TAG,"Bluetooth is currently not enabled");
if (ContextCompat.checkSelfPermission(MainActivity.this,Manifest.permission.BLUETOOTH_CONNECT) == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(MainActivity.this, "You have already granted this permission!", Toast.LENGTH_SHORT).show();
MyBluetoothAdapter.enable();
IntentFilter BTIntent = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBroadcastReceiver1, BTIntent);
}
else
{
requestConnectPermission();
}
} else if (MyBluetoothAdapter.isEnabled()) {
MyBluetoothAdapter.disable();
IntentFilter BTIntent = new IntentFilter(BluetoothAdapter.ACTION_STATE_CHANGED);
registerReceiver(mBroadcastReceiver1, BTIntent);
}
}
private void requestConnectPermission() {
if (ActivityCompat.shouldShowRequestPermissionRationale(this, Manifest.permission.BLUETOOTH_CONNECT)) {
new AlertDialog.Builder(this)
.setTitle("Permission needed")
.setMessage("This permission is needed because of this and that")
.setPositiveButton("ok", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
ActivityCompat.requestPermissions(MainActivity.this,
new String[]{Manifest.permission.BLUETOOTH_CONNECT}, CONNECTION_REQUEST_CODE);
}
})
.setNegativeButton("cancel", new DialogInterface.OnClickListener() {
#Override
public void onClick(DialogInterface dialog, int which) {
dialog.dismiss();
}
})
.create().show();
} else {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.BLUETOOTH_CONNECT}, CONNECTION_REQUEST_CODE);
Log.d(TAG," permisiune in curs de cerere ");
}
}
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
switch (requestCode) {
case CONNECTION_REQUEST_CODE:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(MainActivity.this, "Permission Granted,access to connection available", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(MainActivity.this, "Permission Denied, access to connection unavailable, app requires BLUETOOTH_CONNECT permission in order to operate", Toast.LENGTH_LONG).show();
}
break;
case SCAN_REQUEST_CODE:
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
Toast.makeText(MainActivity.this, "Permission Granted,access to scan available", Toast.LENGTH_LONG).show();
} else {
Toast.makeText(MainActivity.this, "Permission Denied, access to scan unavailable, app requires BLUETOOTH_SCAN permission in order to operate", Toast.LENGTH_LONG).show();
}
break;
}
}

No Activity found to handle Intent { act=android.intent.action.CALL dat=tel0710000001 }

When I run the app there is an Fatal exception error,
android.content.ActivityNotFoundException: No Activity found to handle Intent { act=android.intent.action.CALL dat=tel0710000001 }
Error message
private static final int REQUEST_CALL = 1;
private TextView callText;
private AppCompatButton callTo;
callTo.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
CallButton();[enter image description here][1]
}
});
}
private void CallButton() {
String number = callText.getText().toString();
if (number.trim().length()>0){
if(ContextCompat.checkSelfPermission(MyProfileActivity.this, Manifest.permission.CALL_PHONE )!= PackageManager.PERMISSION_GRANTED){
ActivityCompat.requestPermissions(MyProfileActivity.this,new String[]{Manifest.permission.CALL_PHONE},REQUEST_CALL);
}
else {
String dial = "tel" + number;
startActivity(new Intent(Intent.ACTION_CALL, Uri.parse(dial)));
}
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == REQUEST_CALL) {
if (grantResults.length > 0) {
if (grantResults.length > 0 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
CallButton();
}
} else {
Toast.makeText(this, "Permission Denied", Toast.LENGTH_SHORT).show();
}
}
}
AndroidManifest
<uses-permission android:name="android.permission.ACCESS_COARSE_LOCATION"/>
<uses-permission android:name="android.permission.ACCESS_FINE_LOCATION"/>
<uses-permission android:name="android.permission.CALL_PHONE"/>

try add this in your manifest.xml :
<uses-permission android:name="android.permission.CALL_PHONE" />
But, in the Reference, this permission is classified who "Protection level: dangerous", I recommend use this:
Kotlin:
val i = Intent(Intent.ACTION_DIAL)
i.data = Uri.parse("tel:$phone")
startActivity(i)
Java:
Intent i =new Intent(Intent.ACTION_CALL);
i.setData(Uri("tel:"+phone));
startActivity(i);

java.io.FileNotFoundException: /storage/emulated/0/Notes/fact50Result.txt: open failed ENOENT (No such file or directory)

I am trying to export the results of a factorial calculation in a txt file.
I found this code that looked quite straight forward from this article here.
However I'm getting the error on the title. What am I doing wrong?
I have typed this into the manifest:
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
And this is my code related to saving:
public void save(View v) {
if(numOnRAM!=-1) {
EditText text = (EditText) findViewById(R.id.resultTextBox);
String data = text.getText().toString();
generateNoteOnSD(this,"fact"+numOnRAM+"Results.txt", data);
}
}
public void generateNoteOnSD(Context context, String sFileName, String sBody) {
try {
File root = new File(Environment.getExternalStorageDirectory(), "Notes");
if (!root.exists()) {
root.mkdirs();
}
File gpxfile = new File(root, sFileName);
FileWriter writer = new FileWriter(gpxfile);
writer.append(sBody);
writer.flush();
writer.close();
Toast.makeText(context, "File "+sFileName+" saving success!", Toast.LENGTH_LONG).show();
} catch (IOException e) {
e.printStackTrace();
Toast.makeText(context, e.toString(), Toast.LENGTH_LONG).show();//After adding this
//toast message did I realise the error thar occurs.
}
}

As discussed in the comments, you need to request permissions at runtime to allow your app to write to external storage. You can check if your app has the permission already by using checkSelfPermission(). For example:
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) == PackageManager.PERMISSION_GRANTED) {
// Do the file write
} else {
// Request permission from the user
ActivityCompat.requestPermissions(this,
new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 0);
...
}
In order to handle this permission request, you'll also need to implement onRequestPermissionsResult() from OnRequestPermissionsResultCallback, for example:
#Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case 0:
// Re-attempt file write
}
}
Read the documentation for full information.

I think you have to request permission on runtime. Please check the code below:
final private int REQUEST_CODE_ASK_PERMISSIONS = 123;
private void requestPermission() {
if (ContextCompat.checkSelfPermission(this, Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED ) {
ActivityCompat
.requestPermissions(MainActivity.this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, REQUEST_CODE_ASK_PERMISSIONS);
}
}
#Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case REQUEST_CODE_ASK_PERMISSIONS:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission Granted
Toast.makeText(MainActivity.this, "Permission Granted", Toast.LENGTH_SHORT)
.show();
} else {
// Permission Denied
Toast.makeText(MainActivity.this, "Permission Denied", Toast.LENGTH_SHORT)
.show();
}
break;
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}

For anyone having the same issue, you can remove the android:MaxSdkVersion attribute from the merged manifest as follows.
<uses-permission
android:name="android.permission.WRITE_EXTERNAL_STORAGE"
tools:remove="android:maxSdkVersion" />

After accept permission how to open a activity?

I trying to do a simple functionality. After the user accept permission for camera i need to open a new activity, but how do this?
This is a code. I check the permission and the request it. On my else if i open a new activity.
#RequiresApi(api = Build.VERSION_CODES.M)
#OnClick(R.id.scanButton)
void scanZxing(View view) {
if(getActivity().checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED){
Toast.makeText(context, "We need permissions to acces your CAMERA!", Toast.LENGTH_SHORT).show();
((MainActivity) context).checkCameraPermission();
} else if (view.getId() == R.id.scanButton) {
Intent intent = new Intent(getActivity(), ScanBarcodeActvity.class);
startActivityForResult(intent, 0);
}
}
#TargetApi(23)
public void checkCameraPermission(){
if(Build.VERSION.SDK_INT < Build.VERSION_CODES.M){
return;
}
if (this.checkSelfPermission(Manifest.permission.CAMERA) != PackageManager.PERMISSION_GRANTED) {
requestPermissions(new String[] {Manifest.permission.CAMERA}, REQUEST_CODE_CAMERA);
}
}
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[]
grantResults) {
switch (requestCode) {
case REQUEST_CODE_CAMERA:
if(grantResults[0] == PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "Thanks for your permission", LENGTH_SHORT).show();
} else {
Toast.makeText(this, "We need your permission to open camera",
LENGTH_SHORT).show();
}
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
break;
}
}

You can check the permission request result in your activities onRequestPermissionsResult methodm and if user granted the permission then open the activity
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[] grantResults) {
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
if (requestCode == REQUEST_CODE_CAMERA &&
grantResults[0] == PackageManager.PERMISSION_GRANTED) {
//permisssion was granted
} else {
//permisssion was not granted
}
}

I am supposing you want to open ScanBarcodeActvity.
you can do it in following way
public void openScanBarCodeAcitvity() {
Intent intent = new Intent(getActivity(), ScanBarcodeActvity.class);
startActivityForResult(intent, 0);
}
Call above method at following place in addition to scanZxing() method
#Override
public void onRequestPermissionsResult(int requestCode, #NonNull String[] permissions, #NonNull int[]
grantResults) {
switch (requestCode) {
case REQUEST_CODE_CAMERA:
if(grantResults[0] == PackageManager.PERMISSION_GRANTED){
Toast.makeText(this, "Thanks for your permission", LENGTH_SHORT).show();
//permission granted, open activity
openScanBarCodeAcitvity();
} else {
Toast.makeText(this, "We need your permission to open camera",
LENGTH_SHORT).show();
}
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
break;
}
}

Displaying a TextView depending on whether Android permission is disabled?

I'm trying to display a TextView which appears visible only when a particular Android permission, i.e. WRITE_EXTERNAL_STORAGE, is not enabled. The idea is to explain to the user why they need to enable it in case they've disabled it the first time, and then have them click the TextView to launch the permission request again. The following is not working for me. How can I accomplish this? I have this in my onCreate() method:
if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.M && (checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE) != PackageManager.PERMISSION_GRANTED)) {
ActivityCompat.requestPermissions(this, new String[]{Manifest.permission.WRITE_EXTERNAL_STORAGE}, 1);
} else {
if (NetworkHelper.isOnline(this)) {
new AppendParseData().execute();
}
}
TextView checkFilePermission = (TextView) findViewById(R.id.checkFilePermission);
if (!checkSelfPermission(Manifest.permission.WRITE_EXTERNAL_STORAGE)) {
checkFilePermission.setVisibility(View.VISIBLE);
}

try this way when you request for permission(I have used READ_CONTACTS permission you can use WRITE_EXTERNAL_STORAGE instead)
if (ActivityCompat.checkSelfPermission(MainActivity.this, Manifest.permission.READ_PHONE_STATE)
!= PackageManager.PERMISSION_GRANTED) {
requestContactsPermissions1();
} else {
setTextVisablity(false);
checkSimCard();
}
in onRequestPermissionsResult
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case REQUEST_CODE_ASK_PERMISSIONS:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission Granted
readContacts();
setTextVisablity(false);
} else {
// Permission Denied
setTextVisablity(true);
Toast.makeText(MainActivity.this, "READ_CONTACTS Denied", Toast.LENGTH_SHORT)
.show();
}
break;
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}
in the end setTextVisablity method
public void setTextVisablity(boolean isShow) {
if (isShow) {
tv.setVisibility(View.VISIBLE);
} else {
tv.setVisibility(View.GONE);
}
}

Use this code:-
int hasWriteContactsPermission = ContextCompat.checkSelfPermission(this,Manifest.permission.WRITE_EXTERNAL_STORAGE);
if (hasWriteContactsPermission != PackageManager.PERMISSION_GRANTED) {
ActivityCompat.requestPermissions(this,new String[] {Manifest.permission.WRITE_EXTERNAL_STORAGE},1);
return;
}
else{
//Permission already granted show textview here
}
#Override
public void onRequestPermissionsResult(int requestCode, String[] permissions, int[] grantResults) {
switch (requestCode) {
case 1:
if (grantResults[0] == PackageManager.PERMISSION_GRANTED) {
// Permission Granted
Toast.makeText(MainActivity.this, " PERMISSION_GRANTED", Toast.LENGTH_SHORT)
.show();
} else {
// Permission Denied
Toast.makeText(MainActivity.this, " Denied", Toast.LENGTH_SHORT)
.show();
}
break;
default:
super.onRequestPermissionsResult(requestCode, permissions, grantResults);
}
}