Android Custom Layout - onDraw() never gets called
By default, onDraw() isn't called for ViewGroup objects. Instead, you can override dispatchDraw().
Alternatively, you can enable ViewGroup drawing by calling setWillNotDraw(false) in your TableView constructor.
EDIT:
For #2:- Initialize it in the constructor, then just call rect.set() in your onLayout() method.
For #3:- Yes, as far as I'm aware the super call will handle it, you shouldn't have to handle that unless you need to customize the way the children are drawn.