Java Question Access B4A Views from Java and vice versa

[bloxa69]

Hi everybody,
I am trying to access B4A Views from my library and/or my library's views from B4A. It includes adding / modifying the views.
I've searched the forum but couldn't find a sample if any. I would guess it can be done with Reflection library, but I'm getting lost in it.

 

[thedesolatesoul]

You can just pass the views to the library where they will be unwrapped and in a slightly different form.

Warning: pseudojava

void modifyB4AView(anywheresoftware.b4a.button btnb4a){
  android.widget.Button javabtn;
  javabtn = btnb4a.getObject();
  btnb4a.setObject(javabtn);
}

Its actually simpler than this, but to give you an idea.

 

[bloxa69]

hey, thanks man, looks like a way to go, will try ASAP.

how about B4A Panel, what kind of view is that in Java? ViewGroup?

 

[thedesolatesoul]

Yes, that is a ViewGroup if I remember correctly.

 

[bloxa69]

Yes, that is a ViewGroup if I remember correctly.

I've tried it and it works great, here is the working sample code for those who's struggling with the same thing:

        public void modifyB4Panel(BA pBA, PanelWrapper panelB4A, int left, int right, int width, int height){
            ViewGroup javaPanel;
            javaPanel = panelB4A.getObject();
            ImageView imageView = new ImageView(pBA.activity);
            imageView.setBackgroundDrawable(GetApplicationDrawable("nehe_android"));
            imageView.setBackgroundColor(Colors.Red);
            RelativeLayout.LayoutParams imgParams = new RelativeLayout.LayoutParams(LayoutParams.WRAP_CONTENT, LayoutParams.WRAP_CONTENT);
            imgParams.width = width;
            imgParams.height = height;
            imgParams.leftMargin = left;     
            imgParams.rightMargin = right;     
            imageView.setLayoutParams(imgParams);
            imageView.offsetLeftAndRight(200);
               
            javaPanel.addView(imageView);
            panelB4A.setObject(javaPanel);
        }

Now:
I'm trying to modify B4A view (Panel) from withing Java code by using the panel name and not passing the Panel object from B4A;
as a first step I am trying to find my Panel, and it can find the panel ID but then I guess it cannot access that B4A Panel, it shows me the Panel ID in the log, but when I tried to check the Panel's size, it gives null pointer error.

int id = pBA.activity.getResources().getIdentifier(PanelName, "id", pBA.context.getPackageName());
      Common.Log("id found: "+id);
//this line gives null pointer error
       ViewGroup container = (ViewGroup)pBA.activity.findViewById(id);
       Common.Log("container found - width: "+container.getWidth());

I guess I should use anywheresoftware.b4a.objects.PanelWrapper instead of ViewGroup but it looks like it doesn't have findViewById method.
When I use PanelWrapper instead of ViewGroup it says "cannot cast from View to PanelWrapper".