Android Tutorial Runtime Permissions (Android 6.0+ Permissions)

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Erel

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If the targetSdkVersion is lower than 23 then the standard permissions system will be used on all devices including Android 6+, however soon all Google Play apps will need to set the targetSdkVersion to 26+.

B4A v6.0 adds support for runtime permissions. The nice thing about runtime permissions is that the user is not asked for any permission when they install your application from Google Play. Instead they will be asked to approve "dangerous" permissions at runtime.

Luckily most permissions are not considered dangerous. You can see the list of permissions that are considered dangerous here: https://developer.android.com/guide/topics/permissions/overview.html#permission-groups

Requesting permissions at runtime

Example:
B4X:
Sub Process_Globals
   Private rp As RuntimePermissions
End Sub

Sub Globals
   Private gmap As GoogleMap
   Private MapFragment1 As MapFragment
End Sub

Sub Activity_Create(FirstTime As Boolean)
   Activity.LoadLayout("1")
End Sub

Sub MapFragment1_Ready
   gmap = MapFragment1.GetMap
   rp.CheckAndRequest(rp.PERMISSION_ACCESS_FINE_LOCATION)
End Sub

Sub Activity_PermissionResult (Permission As String, Result As Boolean)
   If Permission = rp.PERMISSION_ACCESS_FINE_LOCATION Then
     gmap.MyLocationEnabled = Result
   End If
End Sub
RuntimePermissions.CheckAndRequest is the key method.

The method (simplified) logic:
B4X:
If <user has already approved> Or <older device> Then
Activity_PermissionResult (Permission, True)
Else
ShowDialog
Activity_PermissionsResult (Permission, Dialog result)
End If
CheckAndRequest is not a blocking method. The program flow will continue and only later Activity_PermissionsResult will be raised.

upload_2016-6-8_14-48-39.png


The CheckAndRequest method can only be called from an Activity.
There is another method named Check that only tests whether the permission has already been approved or not. This method can be called from any module.
It might be tempting to first test whether there is a permission and only if there is no permission call CheckAndRequest. However it will just make the program flow more complicated as you will need to deal with all cases anyway.
As a general rule, you shouldn't call RuntimePermissions.Check from an Activity. It will be simpler to always call CheckAndRequest.

Listing the permissions

Not many are aware to the fact that you can see the project permissions by clicking on the List Permissions button that is inside the Logs tab:



The dangerous permissions are marked with * (in B4A v6+).
You don't need to ask for non-dangerous permissions.

READ_EXTERNAL_STORAGE / WRITE_EXTERNAL_STORAGE

This is the most common dangerous permission. It is added automatically when you use File.DirDefaultExternal or File.DirRootExternal.
However there is a simple workaround for this.

1. Use RuntimePermissions.GetSafeDirDefaultExternal("") instead of File.DirDefaultExternal. The parameter passed is an optional subfolder that will be created under the default folder.

2. Add this code to the manifest editor:
B4X:
AddManifestText(
<uses-permission
  android:name="android.permission.WRITE_EXTERNAL_STORAGE"
  android:maxSdkVersion="19" />
)
The explanation for this is that GetSafeDirDefaultExternal doesn't require any permission on Android 4.4+ (API 19) and requires the WRITE_EXTERNAL_STORAGE on older versions. The code above adds the permission to older devices.

You only need to deal with WRITE_EXTERNAL_STORAGE at runtime if you need access to a folder other than the app's default external folder.

Notes & tips:

- You can only request permissions that were declared in the manifest file (this is usually taken care by the compiler).
- Testing the permissions can be confusing as the user only needs to give permissions once. The solution is to uninstall the app from the device. Click on Ctrl + P (clean project) in the IDE and run again.
- The user actually approves groups of permissions. So if the user has approved the read contacts permission they will not be asked to approve the write contacts permission.
- Once you've uploaded your app to Google Play with targetSdkVersion set to 23 you cannot downgrade the target version back.
- Some Android 4.4 (API 19) devices do not allow access to RuntimePermissions.GetSafeDirDefaultExternal without explicit permission although they should. It it therefore recommended to set android:maxSdkVersion to 19 in the version based permission. It was previously set to 18.
 
Last edited:

ilan

Expert
Licensed User
hi @Erel, once the user has accepted the permission will he be asked again when the next time the app will perform the same task?

thanx


ok no need to answer have seen this now

B4X:
If <user has already approved> Or <older device> Then
Activity_PermissionResult (Permission, True)
Else
ShowDialog
Activity_PermissionsResult (Permission, Dialog result)
End If
 

scrat

Active Member
Licensed User
Hello,

is it possible to request multiple permissions at once ?
Check and CheckAndRequest accept string, is it possible tp pass an array or a list ?

Thanks
 

Erel

Administrator
Staff member
Licensed User
You can call CheckAndRequest multiple times. The permissions are always presented separately to the user.
 

ilan

Expert
Licensed User
hi

i dont understand how to implement it in my app

i want to request all dangerous at the first start (because i use some via service and dont want to ask them when the service is running in background)

how can i do it?
 

ilan

Expert
Licensed User
ok just found out that when i check "RuntimePermission" and try to build the app i get an error something with Admob lib...

B4A version: 6.00
Parsing code. (0.23s)
Compiling code. (0.24s)
Compiling layouts code. (0.01s)
Organizing libraries. (0.67s)
Generating R file. (0.47s)
Compiling generated Java code. Error
B4A line: 341
Activity.AddView(adview1, 0dip, 100%y - height, 1
javac 1.8.0_91
src\net\vladi\callrec\screen.java:847: error: cannot access AdView
mostCurrent._activity.AddView((android.view.View)(mostCurrent._adview1.getObject()),anywheresoftware.b4a.keywords.Common.DipToCurrent((int) (0)),(int) (anywheresoftware.b4a.keywords.Common.PerYToCurrent((float) (100),mostCurrent.activityBA)-_height),anywheresoftware.b4a.keywords.Common.PerXToCurrent((float) (100),mostCurrent.activityBA),_height);
^
class file for com.google.android.gms.ads.AdView not found
when i uncheck again runtime permission it works so there is a conflict between both libs.
 

Cebuvi

Active Member
Licensed User
Hello Erel,

I'm trying to manage permissions in app´s and I started with the example of this tutorial.
I do not get it to work and I do not understand where the problem is.
I attached the zip program to see if you can help me find the solution.
Thank you.

Cesar
 

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FabioG

Active Member
Licensed User
Hi,

when I add the "Runtime Permissions" library an error (see image attacched) telling me not to find android-support-v4.jar
the file is added to the external libraries folder

some advice ?
 

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AndOrNot

Well-Known Member
Licensed User
Hi,

when I add the "Runtime Permissions" library an error (see image attacched) telling me not to find android-support-v4.jar
the file is added to the external libraries folder

some advice ?
Have you copy android-support-v4.jar into b4a libraries from sdk?
 

susu

Well-Known Member
Licensed User
How can I request for permission SYSTEM_ALERT_WINDOW (Draw over other apps) ? It's not exist in RuntimePermissions.

Some thing like this code:
B4X:
public static void requestSystemAlertPermission(Activity context, Fragment fragment, int requestCode) {
    if (VERSION.SDK_INT < VERSION_CODES.M)
        return;
    final String packageName = context == null ? fragment.getActivity().getPackageName() : context.getPackageName();
    final Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION, Uri.parse("package:" + packageName));
    if (fragment != null)
        fragment.startActivityForResult(intent, requestCode);
    else
        context.startActivityForResult(intent, requestCode);
}

Then, in the onActivityResult, you can check if the permission is given or not, as such:

@TargetApi(VERSION_CODES.M)
public static boolean isSystemAlertPermissionGranted(Context context) {
    final boolean result = VERSION.SDK_INT < VERSION_CODES.M || Settings.canDrawOverlays(context);
    return result;
}
Link: http://stackoverflow.com/questions/33172390/how-to-handle-system-alert-window-permission-not-being-auto-granted-on-some-pre/33895409#33895409
 

susu

Well-Known Member
Licensed User
If set targetSdkVersion to 23 and not accepted permission "Draw on top", my app crash with error:
android.view.WindowManager$BadTokenException: Unable to add window android.view.ViewRootImpl$W@eed4eed -- permission denied for this window type

I want to check if permission "Draw on top" is not accepted, it will call "Draw over other apps" setting like image below.

 
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