Develop Reference

Android NFC enableReaderMode stopped working; needed to delete and reinstall app?

We have an app utilizing NFC and recently migrated from enableForegroundDispatch to enableReaderMode. Since then, we have been receiving bug reports where the user intermittently has trouble scanning tags.
I was troubleshooting remotely with a customer today who was unable to scan any tags (the app was working through yesterday). Sometimes they would receive an "NFC read error. Try again" message.
When we had them install the older version of our app which uses enableForegroundDispatch, NFC scans worked as intended. Scanning using the NFC Tools app was also working during this time, as was scanning with no app open. We tried rebooting the device and also toggling NFC on / off with no luck. It was just our app.
After much debugging, what appears to have resolved it was to fully delete our app from the device and then reinstall it. The device is a Google Pixel 2 running Android 11.
I have read countless threads about enableReaderMode and am also aware of this bug affecting kiosk apps in Android 11 (but our app isn't a kiosk). I also read about how there is a bug where Android might think our app is not in the foreground.
Is there any credence to the theory that deleting our app (vs. updating the same installed package with different builds) is what resolved this, and if so then what exactly is happening that is causing this?
Edit: I just found the threads about "NFC service dead" and am guessing this is what happened.

I have read the public code for NFC service, I cannot remember it having anything that would be affected differently by update vs uninstall/install other than possibly the Manifest(PackageManager?) permission to use NFC.
I have not looked in to details about how an app update updates the Manifest permissions, but guess an update might not update the permissions if it thinks they are not changed whereas remove/install would probably delete the whole entry and re-add it thus if there was corruption in the permission list a remove/install would likely fix it.
Also if the NFC Service is dead then other App's would not scan as well. I do seem to remember there is something in there to restart the NFC service if it had died.

Application gets restarted if the camera permission is changed

I've implemented a short Flutter App which is requesting and checking the camera permission which works as expected. But, when manually changing the camera permission from the app settings, for both Android and iOS, it will restart my app. I need to mention that I've added in AndroidManifest.xml and Info.plist the required keys for camera. One interesting thing is that for the location the behaviour is fine and the app does not get restarted.
For permissions I'm using the permission_handler flutter library.
I don't know if is a flutter issue or a general mobile known behaviour but if someone knows more please let me know. If someone need some code example I can also provide this. Thank you.

It doesn't get 'restarted', it gets killed. Meaning, it will run from app launch the next time. This is because some permission settings cannot be changed while the App is running. This is by design.

How to set GET_APP_OPS_STATS without rooting?

i am working on an app using the App Ops Manager. I want to get access to the Logs and analyze which app used which resource. The app works fine for the moment, since a wanted to deplay a Demo version. I have the following problem:
I started the App from Android Studio all the time and granted the Permission "GET_APP_OPS_STATS" manually by using adb.exe. Now ive wrote it down in the AndroidManifest.xml by simply using
<uses-permission android:name="android.permission.GET_APP_OPS_STATS" />
This permission doesnt work in the app and I dont get asked to set it manually (like the one for accessing the storage). I think this could be caused by the permission itself, which could be a system permission.
Are there any solutions, how i can use the App Ops Logs without rooting my device od using third party software? Maybe there is another permission i have to set or some code that sets /asks for the permission.
Best regards,
Marvin

Android Call Blocker Code for Android 3.0 and above

I googled for an example source code for blocking calls and came across this EXAMPLE, But later I came to know that Google has updated their policy and
android.permission.MODIFY_PHONE_STATE
is an system level permission from android version 2.3, I have very important module placed on blocking a specific call.
How do I get a system level permission?
Please let me know if there is any way I can do this in my application. Its very important for the product and cannot be released without this functionality.
Please Help!
Thanks in advance

At least as of Android 5.0, MODIFY_PHONE_STATE has the following definition:
<permission android:name="android.permission.MODIFY_PHONE_STATE"
android:permissionGroup="android.permission-group.PHONE_CALLS"
android:protectionLevel="signature|system"
android:label="#string/permlab_modifyPhoneState"
android:description="#string/permdesc_modifyPhoneState" />
Your app can only hold this permission and use it to modify the phone state if it is signed by the firmware's signing key (the "your own custom ROM" scenario from Marcin's comment) or if your app is installed on the system partition. The latter can be accomplished by having your app pre-installed on the device (or having a rooted device user move your app to the system partition, as I understand it).

Android permissions: Phone Calls: read phone state and identity

My android app has nothing to do with phone calls, but I'm seeing that when I install a debug build on my test device it requires "Phone Calls: read phone state and identity" permissions. (I make no mention of this in AndroidManifest.xml).
I'd like to have the minimum possible permissions, and wondered if anyone knew how to get rid of this? I commented out the part where I was logging some stuff from Build.MODEL, Build.VERSION.*, etc. I also commented out the part where I was detecting the landscape/portrait orientation thinking that that might be the "phone state". But neither of those seemed to remove that permission required.
I found this bug report: http://code.google.com/p/android/issues/detail?id=4101 but it's marked working-as-intended with a note about permissions being correct from the market but not otherwise. Is this other people's experience? (I'd hate to have to publish to the market just to test that out.) Otherwise, does anyone know if there's an API I can avoid calling that will make it so my app doesn't need this permission?
Thanks!

(Answering my own question in case anyone else runs into this problem and searches for it.)
Digging around in PackageParser.java in the android source, I found out that the system will automatically assign
android.permission.WRITE_EXTERNAL_STORAGE and
android.permission.READ_PHONE_STATE
to any app that declares a targetSdk version of less than 4 (donut). There must be a compatibility reason for this, maybe apps targeting older versions could assume they had these permissions without declaring them explicitly. So, if you don't want these permissions added to your app implicitly, add a section like the following in AndroidManifest.xml
<uses-sdk android:minSdkVersion="4" android:targetSdkVersion="4" />
That is all.
Have fun, -Mike

Android 1.6 changelog: http://developer.android.com/sdk/android-1.6.html#api
WRITE_EXTERNAL_STORAGE: Allows an
application to write to external
storage. Applications using API Level
3 and lower will be implicitly granted
this permission (and this will be
visible to the user); Applications
using API Level 4 or higher must
explicitly request this permission.
But that is only one of them. For some reason the official change log is missing the info about READ_PHONE_STATE. The full story is cleared up here: http://blogs.zdnet.com/Burnette/?p=1369&page=3
New permissions. 1.6 programs must
explicitly request the
WRITE_EXTERNAL_STORAGE permission to
be able to modify the contents of the
SD card, and they must explicitly
request the READ_PHONE_STATE
permission to be able to be able to
retrieve phone state info. Apps
targeting earlier versions will always
request these permissions implicitly.
So as you can see, there is no way to publish an app targeted at 1.5 or earlier without requesting those permissions when installed on phones running 1.6 or higher.