Android - CheckBox onDraw keep Alpha and Transparency

I have a LinearLayout with couple views inside plus a CheckBox. When I do change the alpha of root view, all child will change the color transparency of themselves.

What I am trying to do: Extend CheckBox view so it ignores all changes on Alpha and color transparency, set from the parent.

When I call:

root.setAlpha(0.5f);

I want all the child to dim, but not my custom CheckBox.

How can I achieve this extending CheckBox?