Android Question Immersive mode causes a crash in debug mode

[LucaMs]

I "set" immersive mode for the Main; from here I start another Activity and Activity_WindowFocusChanged causes a crash if I start the app in debug mode (see the test project attached).

Spoiler: Error Msg

Copying updated assets files (1)
*** Service (starter) Create ***
** Service (starter) Start **
** Activity (main) Create, isFirst = true **
** Activity (main) Resume **
** Activity (main) Pause, UserClosed = false **
Error occurred on line: 44 (Main)
java.lang.NullPointerException
at b4a.example.main._activity_windowfocuschanged(main.java:427)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:735)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:357)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:260)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at b4a.example.main.onWindowFocusChanged(main.java:185)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onWindowFocusChanged(PhoneWindow.java:2678)
at android.view.View.dispatchWindowFocusChanged(View.java:8018)
at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:968)
at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:3289)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:149)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610)
at dalvik.system.NativeStart.main(Native Method)

Tested only on an Android 4.4.2.

 

[LucaMs]

In the test project attached to the first post, it seems you can solve by changing Sleep(300) to Sleep(100):

Sub Activity_WindowFocusChanged(HasFocus As Boolean)
    If HasFocus Then
        Try
            Dim jo As JavaObject = Activity
            Sleep(100)
            jo.RunMethod("setSystemUiVisibility", Array As Object(5894)) '3846 - non-sticky
        Catch
            Log(LastException)
        End Try
    End If
End Sub

but in other projects this change does not solve.

 

[Deleted member 103]

Did you read that from Erel?

he code was updated with a small change.

The Log(LastException) line was commented. The Activity_WindowFocusChanged event can fire after the activity was paused and this line can cause an untrapped exception to be raised.

I tried it with the tip of Erel and it works.

 

[LucaMs]

Did you read that from Erel?


I tried it with the tip of Erel and it works.

I had read that quickly and I had assumed that the code had been "fixed".

My project crashes even commenting that line.

 

[LucaMs]

My project crashes even commenting that line.

... but commenting that line and setting again Sleep to 300 it's ok

 

[LucaMs]

No, it crashes... randomly

 

[Erel]

Can you post the logs after you commented the relevant line?

 

[LucaMs]

Sometimes the error happens when I write nothing in the Catch part; so I write a Sleep there but... sometimes Sleep(100) is not enough, I have to increase the time, sometimes it is the opposite, I have to decrease this value.

Going by trial:
sometimes it can be solved by "cleaning" the project (CTRL+P), other times stopping the project using the device settings.

Can you post the logs after you commented the relevant line?

Spoiler: Error msg

** Activity (main) Pause, UserClosed = false **
Error occurred on line: 393 (Main)
java.lang.NullPointerException
at mbnt.MyProjName.it.main._activity_windowfocuschanged(main.java:695)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.shell.Shell.runMethod(Shell.java:735)
at anywheresoftware.b4a.shell.Shell.raiseEventImpl(Shell.java:357)
at anywheresoftware.b4a.shell.Shell.raiseEvent(Shell.java:260)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at anywheresoftware.b4a.ShellBA.raiseEvent2(ShellBA.java:144)
at mbnt.MyProjName.it.main.onWindowFocusChanged(main.java:185)
at com.android.internal.policy.impl.PhoneWindow$DecorView.onWindowFocusChanged(PhoneWindow.java:2678)
at android.view.View.dispatchWindowFocusChanged(View.java:8018)
at android.view.ViewGroup.dispatchWindowFocusChanged(ViewGroup.java:968)
at android.view.ViewRootImpl$ViewRootHandler.handleMessage(ViewRootImpl.java:3289)
at android.os.Handler.dispatchMessage(Handler.java:102)
at android.os.Looper.loop(Looper.java:149)
at android.app.ActivityThread.main(ActivityThread.java:5257)
at java.lang.reflect.Method.invokeNative(Native Method)
at java.lang.reflect.Method.invoke(Method.java:515)
at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:794)
at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:610)
at dalvik.system.NativeStart.main(Native Method)

 

[LucaMs]

To solve THIS TIME (previous post):

tried both, cleaning and stopping the project, without success.

I added sleep (100) and this solved (then I received the same error in another Activity, resolved in the same way).

 

[LucaMs]

Well, MAYBE I found something "useful" (for Erel ).

Catch block empty. Start B4A, open the project, run and you get the error.
Change the Sleep command (it does not matter how many ms) inside the Activity_FocusChanged event routine and you no more get the error (in the same "b4a session").

Save the project changed, open and start it again... and again you get the error.