Android Question how to remove System alert window ?

[peacemaker]

Created here: https://www.b4x.com/android/forum/threads/kiosk-mode-variant.77113
?

 

[Erel]

Try this:
Change the Java method to return Object and return the RelativeLayout object.

You can then reference the view with:

Dim v As View = jo.RunMethod("lockScreen", Null)

You can call v.RemoveView to remove it. My guess is that you will encounter other issues, but it worth a try.

 

[peacemaker]

v.RemoveView gives error
java.lang.RuntimeException: Object should first be initialized (View).

If to make v as Object, and later make it = Null - no error, and no help

 

[Erel]

Try:

Dim ctxt As JavaObject
ctxt.InitializeContext
Dim windowManager As JavaObject = ctxt.RunMethod("getSystemService", Array("window"))
windowManager.RunMethod("removeView", Array (v))

 

[peacemaker]

No, the same error. Sample project attached.

 

[JordiCP]

You didn't change the java method return object, so it returns nothing

Change the Java method to return Object and return the RelativeLayout object.

 

[peacemaker]

Oh, indeed !
Now it's OK

If to add a TextView and Button to enter unlocking password - it would be finally useful code.

upd: but it locks the device under Android 4.2, partially locks under Android 4.4, but does not under Android 5.0

 

[JordiCP]

For most android devices below 6.0, the permission will be automatically granted as you have declared SYSTEM_ALERT_WINDOW in your manifest. However for some (Xiaomi and others) devices, this will not be the case. In this case you need to manually add permission to this app. Also, for 6.0 and above, you can add this (or also grant permission manually) Which 5.0 device are you using?<--(EDIT) Ok, I have just seen in your signature that it is a Xiaomi

Code invoquing the lockscreen should only be made after Activity_Resume if the conditions are met.

  If p.SdkVersion>=23 Then
     jo.RunMethod("requestSpecialPermissionIfNeeded",Null)
   End If

and on Activity_Resume

  If p.SdkVersion>=23 Then
     Dim gotPermission As Boolean  = J.RunMethod("getSpecialPermissionValue",Null)
     if not(gotPermission) then Activity.Finish
   End If

   'proceed with locking. and make sure it is only made once.

and add this inline Java code

#if JAVA
import android.content.Intent;
import android.provider.Settings;
import android.net.Uri;

public static int OVERLAY_PERMISSION_REQ_CODE = 1234;

public void requestSpecialPermissionIfNeeded() {
  if (!Settings.canDrawOverlays(this)) {
  Intent intent = new Intent(Settings.ACTION_MANAGE_OVERLAY_PERMISSION,
  Uri.parse("package:" + getPackageName()));
  startActivityForResult(intent, OVERLAY_PERMISSION_REQ_CODE);
  }
}

public boolean getSpecialPermissionValue(){
     return(Settings.canDrawOverlays(this));
}

 

[peacemaker]

Thanks, but ... your code is for Android 6+. And if even 4.4 ... 5.0 are not locked well (notification area is pulled as usual) - no use to talk about 6+

 

[JordiCP]

Yes, I see it is more complicated than expected. There are a lot of stackoverflow posts about this and it does not seem simple...sorry I can't help