Razvan question

---SOLVED---
the problem was I was passing the Application context,
instead of the activity context.
--- Original question ---
How to programmatically add ImageView to -ROOT- default layout?
(Without creating a new one)

Explanation : When starting a new project, you get the a default XML.

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Hello World!" />

</RelativeLayout>

To create a new ImageView I use
    ImageView imageView = new ImageView(context);
    imageView.setImageResource(R.drawable.somePicture);
    imageView.setLayoutParams(new RelativeLayout.LayoutParams(
    RelativeLayout.LayoutParams.WRAP_CONTENT,
    RelativeLayout.LayoutParams.WRAP_CONTENT));

Now.. in order to apply it to the Layout, i.e.

    someLayout.addView(imageView);

I need to create that layout, and set it as

    someActivity.setContentView(someLayout);

Problem is - I DO NOT want to create a NEW layout.
In the GUI editor, I can just drag the imageView to the default layout.
So, how can I programmatically access that default layout, and than use the addView on it?

P.S. -
Tried naming the layout and accessing with R.id,
Tried "getWindow().getDecorView().getRootView();"
I really feel like I'm missing something very basic in my understanding, but, what ?