Android Question NotificationListerner on Android 4

Azam Memon · Apr 3, 2020

Hi,

I have an optional feature in my app to listen to Notifications, I have used NotificationListener for that, which should be enabled only on API >=19 by the user and this option won't appear on API < 19. But when I run my app on android 4 (API < 19), I am getting an error, which is same on NotificationListner example code, the same error appears in my app. However, the app has no access to listen to notifications from notification listener settings of Android OS.

Code:

java.lang.RuntimeException: Unable to create service b4a.notificationlistener.starter: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at android.app.ActivityThread.handleCreateService(ActivityThread.java:2263)
    at android.app.ActivityThread.access$1600(ActivityThread.java:123)
    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1201)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:4424)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
    at b4a.notificationlistener.starter.onCreate(starter.java:39)
    at android.app.ActivityThread.handleCreateService(ActivityThread.java:2253)
    ... 10 more
Caused by: java.lang.reflect.InvocationTargetException
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at b4a.notificationlistener.starter.onCreate(starter.java:37)
    ... 11 more
Caused by: java.lang.NoClassDefFoundError: b4a.notificationlistener.notificationservice
    at b4a.notificationlistener.main.initializeProcessGlobals(main.java:419)
    ... 14 more

Is there any workaround to disable loading process_globals of notificationListener on API < 19? The process_globals of each service and activity are loaded on app launch. I am using minSDK version of 11 and target Sdk as 29.

MarcoRome · Apr 3, 2020

NotificationListener library (NotificationListenerService)

The NotificationListener library allows you to access the device notifications. With this library you can listen to new notifications and removed notifications. You can also clear existing notifications. There are some steps that you need to follow in order to use this feature: - Make sure...

www.b4x.com

This is a new feature which is only available on Android 4.3+ (api 18+)

Azam Memon · Apr 3, 2020

How can I disable it on older versions of Android (API < 18)? This feature produces an error on older versions of android even when not used.

MarcoRome · Apr 3, 2020

B4X:

Sub Process_Globals
   Private listener As NotificationListener
End Sub
Sub Service_Create
    Dim sdkversion As Int
    Dim jo As JavaObject
    sdkversion = jo.InitializeStatic("android.os.Build$VERSION").GetField("SDK_INT")
    If sdkversion > 18 Then
       listener.Initialize("listener")
   ...........
End Sub

Azam Memon · Apr 3, 2020

MarcoRome said:

B4X:

Sub Process_Globals
   Private listener As NotificationListener
End Sub
Sub Service_Create
    Dim sdkversion As Int
    Dim jo As JavaObject
    sdkversion = jo.InitializeStatic("android.os.Build$VERSION").GetField("SDK_INT")
    If sdkversion > 18 Then
       listener.Initialize("listener")
   ...........
End Sub

The problem is the "NotificationListener" service is not being executed. If you check my error log (post #1), the app crashes when main activity loads process_globals of all services and activities (also process_gloabals of notification service) and this crashes the app. I have even added a condition to not initialize NotificationListener as:

B4X:

Sub Process_Globals
    Dim p As Phone
    If p.SdkVersion > 18 Then
        Dim listener As NotificationListener
    End If
End Sub

I am not starting NotificationService with any code in any module but even then the app crashes at start, even the main activity is not being displayed.

MarcoRome · Apr 3, 2020

Error:

.....
Caused by: java.lang.RuntimeException: java.lang.reflect.InvocationTargetException
at b4a.notificationlistener.starter.onCreate(starter.java:39)

Do you tried this way ?

B4X:

Sub Service_Create
    Dim sdkversion As Int
    Dim jo As JavaObject
    sdkversion = jo.InitializeStatic("android.os.Build$VERSION").GetField("SDK_INT")
    If sdkversion > 18 Then
       listener.Initialize("listener")
   ...........
End Sub

Azam Memon · Apr 3, 2020

MarcoRome said:

Do you tried this way ?

B4X:

Sub Service_Create
Dim sdkversion As Int
Dim jo As JavaObject
sdkversion = jo.InitializeStatic("android.os.Build$VERSION").GetField("SDK_INT")
If sdkversion > 18 Then
listener.Initialize("listener")
...........
End Sub

I have tried same using phone.sdkVersion:

B4X:

If p.SdkVersion > 18 Then
    listener.Initialize("listener")
End If

and using your suggested code as well:

B4X:

Dim sdkversion As Int
Dim jo As JavaObject
sdkversion = jo.InitializeStatic("android.os.Build$VERSION").GetField("SDK_INT")
    

If sdkversion > 18 Then
    listener.Initialize("listener")
End If

But result is same.

Issue is somewhere here:

Azam Memon said:
at b4a.notificationlistener.main.initializeProcessGlobals(main.java:419)

In java code of main.java line 419 (See attachment):

B4X:

notificationservice._process_globals();

is being called and this causes the error. I don't want to call this line when API < 19. But these process_globals of each activity and service are automatically called during the app launch.

OliverA · Apr 3, 2020

Try

Code:

Sub Process_Globals
   Private listenerObject As Object
End Sub

Sub Service_Create
    Dim p As Phone
    If p.SdkVersion > 18 Then
        Dim listener As NotificationListener
       listener.Initialize("listener")
       listenerObject = listener
    End If
   ...........
End Sub

Then anywhere that you need to access listener you can do

Code:

    Dim p As Phone
    If p.SdkVersion > 18 Then
        Dim listener As NotificationListener
       listener = listenerObject
       'do you stuff with the listener object as usual
    End If

Note: Untested.

Azam Memon · Apr 3, 2020

OliverA said:
Note: Untested.

same error, there might be the issue is in

B4X:

#Extends: anywheresoftware.b4a.objects.NotificationListenerWrapper

which is loaded when process_globals is called as it extends a class.

Azam Memon · Apr 3, 2020

Azam Memon said:
B4X:
#Extends: anywheresoftware.b4a.objects.NotificationListenerWrapper

Yes, the issue is in NotificationListenerWrapper when I comment it, the code works. So now I have to stop loading this NotificationListenerWrapper on API < 19. Any workaround?

OliverA · Apr 3, 2020

Unless there is a trick that can be done in the NotificationListener source (available in this thread: https://www.b4x.com/android/forum/threads/example-of-extends-in-service.74880/#content), you can use compiler directives to generate two different versions from the same source.

Azam Memon · Apr 4, 2020

OliverA said:
you can use compiler directives to generate two different versions from the same source

Can you guide me, how compiler directives can be used to call two different versions?

Erel · Apr 5, 2020

Best way to check version is with Phone.SdkVersion.

As I see it, it is a waste of time to target Android 4.3- devices: https://developer.android.com/about/dashboards/index.html

If you do insist then create two projects and share the modules between them,

Azam Memon · Apr 10, 2020

Azam Memon said:
at b4a.notificationlistener.main.initializeProcessGlobals(main.java:419)

To solve this issue in main.java, I had tried to change line 419 from:

Code:

notificationservice._process_globals();

to:

B4X:

if(android.os.Build.VERSION.SDK_INT >= 18) {  notificationservice._process_globals(); }

using CustomBuildAction as:

B4X:

#CustomBuildAction: 2, C:\Users\Azam Rafique\Downloads\Compressed\NotificationListenerB4A\NotificationListener\Objects\replac.bat, "notificationservice._process_globals();" "if(android.os.Build.VERSION.SDK_INT >= 18) {  notificationservice._process_globals(); }" "src/b4a/notificationlistener" "\main.java"

Where replac.bat contains script to find and replace string in given file.

Now, I am getting another error in Activity.loadLayout line:

Code:

main_activity_create (java line: 342)
java.lang.NoClassDefFoundError: b4a/notificationlistener/notificationservice
    at java.lang.Class.getDeclaredFields(Native Method)
    at java.lang.Class.getDeclaredFields(Class.java:647)
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayoutHelper(LayoutBuilder.java:368)
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayoutHelper(LayoutBuilder.java:453)
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(LayoutBuilder.java:148)
    at anywheresoftware.b4a.objects.ActivityWrapper.LoadLayout(ActivityWrapper.java:209)
    at b4a.notificationlistener.main._activity_create(main.java:342)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:196)
    at b4a.notificationlistener.main.afterFirstLayout(main.java:104)
    at b4a.notificationlistener.main.access$000(main.java:17)
    at b4a.notificationlistener.main$WaitForLayout.run(main.java:82)
    at android.os.Handler.handleCallback(Handler.java:605)
    at android.os.Handler.dispatchMessage(Handler.java:92)
    at android.os.Looper.loop(Looper.java:137)
    at android.app.ActivityThread.main(ActivityThread.java:4424)
    at java.lang.reflect.Method.invokeNative(Native Method)
    at java.lang.reflect.Method.invoke(Method.java:511)
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
    at dalvik.system.NativeStart.main(Native Method)
Caused by: java.lang.ClassNotFoundException: b4a.notificationlistener.notificationservice
    at dalvik.system.BaseDexClassLoader.findClass(BaseDexClassLoader.java:61)
    at java.lang.ClassLoader.loadClass(ClassLoader.java:501)

In file main.java line 342 is:

Code:

mostCurrent._activity.LoadLayout("1",mostCurrent.activityBA);

If I am commenting Activity.loadLayout line, then it works fine but doesn't show layout. Same issue on my actual working project, issue in that project is also in line activity.loadlayout.

Does anyone have a solution to this issue or any trick, please?

Android Question NotificationListerner on Android 4

Azam Memon

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MarcoRome

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NotificationListener library (NotificationListenerService)

Azam Memon

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