Android Question Why can't I LoadLayout in class?

RB Smissaert · Oct 25, 2024

I have a progressbar class which is running from a B4XPage.
The progressbar class has a layout, which needs to be loaded.
When I load the layout first from the B4XPage and then make calls to the progressbar class there is no problem and all runs fine.
As this progress bar in various places in the project I thought I could do the loading of the layout in the progressbar class instead
and save some lines of code.
When I do this however I run into this error:

B4X:

b4xprogressbar$ResumableSub_Load_Layoutresume (java line: 648)
java.lang.RuntimeException: java.lang.NullPointerException: Attempt to read from field 'java.lang.Object anywheresoftware.b4a.BA.eventsTarget' on a null object reference in method 'anywheresoftware.b4a.keywords.LayoutBuilder$LayoutValuesAndMap anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(java.lang.String, anywheresoftware.b4a.BA, boolean, android.view.ViewGroup, java.util.LinkedHashMap)'
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(LayoutBuilder.java:155)
    at anywheresoftware.b4a.objects.PanelWrapper.LoadLayout(PanelWrapper.java:134)
    at anywheresoftware.b4a.objects.B4XViewWrapper.LoadLayout(B4XViewWrapper.java:329)
    at b4a.exampleljjll.b4xprogressbar$ResumableSub_Load_Layout.resume(b4xprogressbar.java:648)
    at b4a.exampleljjll.b4xprogressbar._load_layout(b4xprogressbar.java:625)
    at b4a.exampleljjll.b4xprogressbar$ResumableSub_Show.resume(b4xprogressbar.java:840)
    at b4a.exampleljjll.b4xprogressbar._show(b4xprogressbar.java:800)
    at b4a.exampleljjll.p_map$ResumableSub_LogMissingTilesInPolygon.resume(p_map.java:7526)
    at b4a.exampleljjll.p_map._logmissingtilesinpolygon(p_map.java:6880)
    at b4a.exampleljjll.p_map$ResumableSub_ShowAreaTiles.resume(p_map.java:13288)
    at b4a.exampleljjll.p_map._showareatiles(p_map.java:13223)
    at b4a.exampleljjll.p_map$ResumableSub_PatientsInAreaDialog.resume(p_map.java:8523)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:275)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:215)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:201)
    at anywheresoftware.b4a.keywords.Common$15.run(Common.java:1804)
    at android.os.Handler.handleCallback(Handler.java:958)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:230)
    at android.os.Looper.loop(Looper.java:319)
    at android.app.ActivityThread.main(ActivityThread.java:9063)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:588)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1103)
Caused by: java.lang.NullPointerException: Attempt to read from field 'java.lang.Object anywheresoftware.b4a.BA.eventsTarget' on a null object reference in method 'anywheresoftware.b4a.keywords.LayoutBuilder$LayoutValuesAndMap anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(java.lang.String, anywheresoftware.b4a.BA, boolean, android.view.ViewGroup, java.util.LinkedHashMap)'
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(LayoutBuilder.java:133)
    ... 23 more
Starter, LogError, strErrorMsg: java.lang.RuntimeException: java.lang.NullPointerException: Attempt to read from field 'java.lang.Object anywheresoftware.b4a.BA.eventsTarget' on a null object reference in method 'anywheresoftware.b4a.keywords.LayoutBuilder$LayoutValuesAndMap anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(java.lang.String, anywheresoftware.b4a.BA, boolean, android.view.ViewGroup, java.util.LinkedHashMap)'

This is the code in the B4XPage:

B4X:

        'Root.LoadLayout("ProgressBar")  'With this (and not loading the layout in clsProgressBar) it runs all fine
        Dim rs As ResumableSub = clsProgressBar.Show(Root, iMaxTilesToCheck, False, 1, "Find missing tiles", "", "/", " done")
        Wait For (rs) Complete (bDone As Boolean)

And this the relevant code in the progressbar class:

B4X:

Sub Load_Layout(vParent As B4XView) As ResumableSub
    
'    Log("vParent.Tag: " & vParent.Tag)
    
    vParent.LoadLayout("ProgressBar")
    
    Return True
    
End Sub

Public Sub Show(Parent As B4XView, _
                iMax As Int, _
                bAnimateValues As Boolean, _
                iProgressPosition As Int, _
                strTitle As String, _
                strDone As String, _
                strValuesSeparator As String, _
                strToDo As String) As ResumableSub
                
'    Parent.LoadLayout("ProgressBar")
                
'    Log("Show")
'    Log("Parent.Tag: " & Parent.Tag)

    Dim rs As ResumableSub = Load_Layout(Parent)
    Wait For (rs) Complete (bDone As Boolean)

I made ResumableSubs in case there was a timing issue, but to no avail.

Thanks for any insight in this problem.

RBS

RB Smissaert · Oct 25, 2024

RB Smissaert said:

I have a progressbar class which is running from a B4XPage.
The progressbar class has a layout, which needs to be loaded.
When I load the layout first from the B4XPage and then make calls to the progressbar class there is no problem and all runs fine.
As this progress bar in various places in the project I thought I could do the loading of the layout in the progressbar class instead
and save some lines of code.
When I do this however I run into this error:

B4X:

b4xprogressbar$ResumableSub_Load_Layoutresume (java line: 648)
java.lang.RuntimeException: java.lang.NullPointerException: Attempt to read from field 'java.lang.Object anywheresoftware.b4a.BA.eventsTarget' on a null object reference in method 'anywheresoftware.b4a.keywords.LayoutBuilder$LayoutValuesAndMap anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(java.lang.String, anywheresoftware.b4a.BA, boolean, android.view.ViewGroup, java.util.LinkedHashMap)'
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(LayoutBuilder.java:155)
    at anywheresoftware.b4a.objects.PanelWrapper.LoadLayout(PanelWrapper.java:134)
    at anywheresoftware.b4a.objects.B4XViewWrapper.LoadLayout(B4XViewWrapper.java:329)
    at b4a.exampleljjll.b4xprogressbar$ResumableSub_Load_Layout.resume(b4xprogressbar.java:648)
    at b4a.exampleljjll.b4xprogressbar._load_layout(b4xprogressbar.java:625)
    at b4a.exampleljjll.b4xprogressbar$ResumableSub_Show.resume(b4xprogressbar.java:840)
    at b4a.exampleljjll.b4xprogressbar._show(b4xprogressbar.java:800)
    at b4a.exampleljjll.p_map$ResumableSub_LogMissingTilesInPolygon.resume(p_map.java:7526)
    at b4a.exampleljjll.p_map._logmissingtilesinpolygon(p_map.java:6880)
    at b4a.exampleljjll.p_map$ResumableSub_ShowAreaTiles.resume(p_map.java:13288)
    at b4a.exampleljjll.p_map._showareatiles(p_map.java:13223)
    at b4a.exampleljjll.p_map$ResumableSub_PatientsInAreaDialog.resume(p_map.java:8523)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:275)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:215)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:201)
    at anywheresoftware.b4a.keywords.Common$15.run(Common.java:1804)
    at android.os.Handler.handleCallback(Handler.java:958)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:230)
    at android.os.Looper.loop(Looper.java:319)
    at android.app.ActivityThread.main(ActivityThread.java:9063)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:588)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1103)
Caused by: java.lang.NullPointerException: Attempt to read from field 'java.lang.Object anywheresoftware.b4a.BA.eventsTarget' on a null object reference in method 'anywheresoftware.b4a.keywords.LayoutBuilder$LayoutValuesAndMap anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(java.lang.String, anywheresoftware.b4a.BA, boolean, android.view.ViewGroup, java.util.LinkedHashMap)'
    at anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(LayoutBuilder.java:133)
    ... 23 more
Starter, LogError, strErrorMsg: java.lang.RuntimeException: java.lang.NullPointerException: Attempt to read from field 'java.lang.Object anywheresoftware.b4a.BA.eventsTarget' on a null object reference in method 'anywheresoftware.b4a.keywords.LayoutBuilder$LayoutValuesAndMap anywheresoftware.b4a.keywords.LayoutBuilder.loadLayout(java.lang.String, anywheresoftware.b4a.BA, boolean, android.view.ViewGroup, java.util.LinkedHashMap)'

This is the code in the B4XPage:

B4X:

        'Root.LoadLayout("ProgressBar")  'With this (and not loading the layout in clsProgressBar) it runs all fine
        Dim rs As ResumableSub = clsProgressBar.Show(Root, iMaxTilesToCheck, False, 1, "Find missing tiles", "", "/", " done")
        Wait For (rs) Complete (bDone As Boolean)

And this the relevant code in the progressbar class:

B4X:

Sub Load_Layout(vParent As B4XView) As ResumableSub
   
'    Log("vParent.Tag: " & vParent.Tag)
   
    vParent.LoadLayout("ProgressBar")
   
    Return True
   
End Sub

Public Sub Show(Parent As B4XView, _
                iMax As Int, _
                bAnimateValues As Boolean, _
                iProgressPosition As Int, _
                strTitle As String, _
                strDone As String, _
                strValuesSeparator As String, _
                strToDo As String) As ResumableSub
               
'    Parent.LoadLayout("ProgressBar")
               
'    Log("Show")
'    Log("Parent.Tag: " & Parent.Tag)

    Dim rs As ResumableSub = Load_Layout(Parent)
    Wait For (rs) Complete (bDone As Boolean)

I made ResumableSubs in case there was a timing issue, but to no avail.

Thanks for any insight in this problem.

RBS

Now for some reason I can't run this anymore, even with loading the layout in the B4XPage.
The error I get is this:

B4X:

DesignerCreateView
Base_Resize
DrawValue
Show 1
Parent.Tag: 22
b4xprogressbar_show (java line: 821)
java.lang.RuntimeException: Object should first be initialized (Panel).
Did you forget to call Activity.LoadLayout?
    at anywheresoftware.b4a.AbsObjectWrapper.getObject(AbsObjectWrapper.java:67)
    at anywheresoftware.b4a.objects.ViewWrapper.setVisible(ViewWrapper.java:271)
    at b4a.exampleljjll.b4xprogressbar._show(b4xprogressbar.java:821)
    at b4a.exampleljjll.p_map$ResumableSub_LogMissingTilesInPolygon.resume(p_map.java:7571)
    at b4a.exampleljjll.p_map._logmissingtilesinpolygon(p_map.java:6926)
    at b4a.exampleljjll.p_map$ResumableSub_ShowAreaTiles.resume(p_map.java:13324)
    at b4a.exampleljjll.p_map._showareatiles(p_map.java:13259)
    at b4a.exampleljjll.p_map$ResumableSub_PatientsInAreaDialog.resume(p_map.java:8559)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:275)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:215)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:201)
    at anywheresoftware.b4a.keywords.Common$15.run(Common.java:1804)
    at android.os.Handler.handleCallback(Handler.java:958)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:230)
    at android.os.Looper.loop(Looper.java:319)
    at android.app.ActivityThread.main(ActivityThread.java:9063)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:588)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1103)
Starter, LogError, strErrorMsg: java.lang.RuntimeException: Object should first be initialized (Panel).
Did you forget to call Activity.LoadLayout?

No idea why this now causes an error and before was running fine.
The above panel that was not initialized is a panel in the layout holding the custom view B4XProgressBar1 and also 2 normal labels.

Maybe all the code that refers to the views on that panel (and that panel itself) should be in the B4XPage and loading the layout should then
be done in the B4XPage. Problem with that though is that this progressbar is used in several B4XPages, so it would lead to code duplication.
All in all a bit of a mess, but I will get this sorted.

RBS

William Lancee · Oct 25, 2024

When you load a layout in class 'X', the context for all the layout related events will be that class.
As well, the object tree of views with root node "Root" will be in future instances of that class.

Re-using the loaded views in another class is not an option.
That being said, all objects (including those views) can be accessed from anywhere in the project if...
1. You make them public.
Or...
2. Have a Public method that accesses the private object in the instance of that "X'.

But, for example, if make a view say a different color, you won't see it until the instance of that class that holds the view is shown.

Of course, you can simply load the same layout in multiple classes. Just put the preparations of views in a Sub and call it after the LoadLayout.
Then you won't need to replicate the bulky part of the code.

klaus · Oct 25, 2024

You might make a small project showing the problem.
With a few code snippets it is difficult do give concrete advice, at least for me.

RB Smissaert · Oct 25, 2024

William Lancee said:
When you load a layout in class 'X', the context for all the layout related events will be that class.
As well, the object tree of views with root node "Root" will be in future instances of that class.

Re-using the loaded views in another class is not an option.
That being said, all objects (including those views) can be accessed from anywhere in the project if...
1. You make them public.
Or...
2. Have a Public method that accesses the private object in the instance of that "X'.

But, for example, if make a view say a different color, you won't see it until the instance of that class that holds the view is shown.

Of course, you can simply load the same layout in multiple classes. Just put the preparations of views in a Sub and call it after the LoadLayout.
Then you won't need to replicate the bulky part of the code.

> Of course, you can simply load the same layout in multiple classes. Just put the preparations of views in a Sub and call it after the LoadLayout.

That is what I had done before and it worked all fine, and still no idea why exactly that now gives errors.
I think loading the layout in the B4XPages is the simplest solution.
Will post some more code later.

RBS

RB Smissaert · Oct 25, 2024

klaus said:
You might make a small project showing the problem.
With a few code snippets it is difficult do give concrete advice, at least for me.

Will post some more code later.

RBS

RB Smissaert · Oct 25, 2024

William Lancee said:
When you load a layout in class 'X', the context for all the layout related events will be that class.
As well, the object tree of views with root node "Root" will be in future instances of that class.

Re-using the loaded views in another class is not an option.
That being said, all objects (including those views) can be accessed from anywhere in the project if...
1. You make them public.
Or...
2. Have a Public method that accesses the private object in the instance of that "X'.

But, for example, if make a view say a different color, you won't see it until the instance of that class that holds the view is shown.

Of course, you can simply load the same layout in multiple classes. Just put the preparations of views in a Sub and call it after the LoadLayout.
Then you won't need to replicate the bulky part of the code.

I am just thinking the simplest way to solve all this is avoid having the custom view.
This is for a simple progressbar and I am sure I can make that without a custom view.

RBS

RB Smissaert · Oct 25, 2024

RB Smissaert said:

Now for some reason I can't run this anymore, even with loading the layout in the B4XPage.
The error I get is this:

B4X:

DesignerCreateView
Base_Resize
DrawValue
Show 1
Parent.Tag: 22
b4xprogressbar_show (java line: 821)
java.lang.RuntimeException: Object should first be initialized (Panel).
Did you forget to call Activity.LoadLayout?
    at anywheresoftware.b4a.AbsObjectWrapper.getObject(AbsObjectWrapper.java:67)
    at anywheresoftware.b4a.objects.ViewWrapper.setVisible(ViewWrapper.java:271)
    at b4a.exampleljjll.b4xprogressbar._show(b4xprogressbar.java:821)
    at b4a.exampleljjll.p_map$ResumableSub_LogMissingTilesInPolygon.resume(p_map.java:7571)
    at b4a.exampleljjll.p_map._logmissingtilesinpolygon(p_map.java:6926)
    at b4a.exampleljjll.p_map$ResumableSub_ShowAreaTiles.resume(p_map.java:13324)
    at b4a.exampleljjll.p_map._showareatiles(p_map.java:13259)
    at b4a.exampleljjll.p_map$ResumableSub_PatientsInAreaDialog.resume(p_map.java:8559)
    at anywheresoftware.b4a.BA.checkAndRunWaitForEvent(BA.java:275)
    at anywheresoftware.b4a.BA.raiseEvent2(BA.java:215)
    at anywheresoftware.b4a.BA.raiseEvent(BA.java:201)
    at anywheresoftware.b4a.keywords.Common$15.run(Common.java:1804)
    at android.os.Handler.handleCallback(Handler.java:958)
    at android.os.Handler.dispatchMessage(Handler.java:99)
    at android.os.Looper.loopOnce(Looper.java:230)
    at android.os.Looper.loop(Looper.java:319)
    at android.app.ActivityThread.main(ActivityThread.java:9063)
    at java.lang.reflect.Method.invoke(Native Method)
    at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:588)
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1103)
Starter, LogError, strErrorMsg: java.lang.RuntimeException: Object should first be initialized (Panel).
Did you forget to call Activity.LoadLayout?

No idea why this now causes an error and before was running fine.
The above panel that was not initialized is a panel in the layout holding the custom view B4XProgressBar1 and also 2 normal labels.

Maybe all the code that refers to the views on that panel (and that panel itself) should be in the B4XPage and loading the layout should then
be done in the B4XPage. Problem with that though is that this progressbar is used in several B4XPages, so it would lead to code duplication.
All in all a bit of a mess, but I will get this sorted.

RBS

Have solved this now, with the layout loaded from the B4XPage (as I had it before).
I think the errors I experienced with that was caused by Initializing the progressbar class in the B4XPage in the one particular B4XPage,
that is the page I was testing this with.

RBS

LucaMs · Saturday at 2:06 AM

RB Smissaert said:
I am just thinking the simplest way to solve all this is avoid having the custom view.

Take a custom view created by Erel and look at the source code

(Obviously one that loads a layout; you can verify this by opening the B4XLib (zip file) and checking that there is a Files folder with a layout inside).

RB Smissaert · Saturday at 2:08 AM

LucaMs said:
Take a custom view created by Erel and look at the source code

(Obviously one that loads a layout; you can verify this by opening the B4XLib (zip file) and checking that there is a Files folder with a layout inside).

Thanks, will do that.

RBS

LucaMs · Saturday at 2:09 AM

RB Smissaert said:
Thanks, will do that.

RBS

Try BCToast.b4xlib

RB Smissaert · Saturday at 2:09 AM

LucaMs said:
Try BCToast.b4xlib

Will do.

Android Question Why can't I LoadLayout in class?

RB Smissaert

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RB Smissaert

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William Lancee

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klaus

Expert

RB Smissaert

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RB Smissaert

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RB Smissaert

Well-Known Member

RB Smissaert

Well-Known Member

LucaMs

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RB Smissaert

Well-Known Member

LucaMs

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RB Smissaert

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