TextInputLayout not showing when View added programmatically

Question

I noticed some strange behaviour of TextInputLayout:

When I add the following to my layout:

Answer 1

I use this ((FrameLayout) findViewById(R.id.framePreview)).addView(preview); with no issues at all, maybe its the view type? should this

ViewGroup root = (ViewGroup) findViewById(R.id.root);
root.addView(v);

not be this

LinearLayout root = (LinearLayout) findViewById(R.id.root);
root.addView(v);