bear in mind though, that paintOverChildren will paint over all child components.
do you have a component with a kidney shape drawn in paint()? and i presume your child components are placed in that. if you want stuff to come from behind, then you’ll really want to actually place them behind. you don’t have to do that by putting the components into the kidney component’s parent - you could just fiddle with your component structure a bit…
Make a clear component to act as the container (the one your kidney is currently drawn in)
Make another component with your kidney shape drawn in
Have the new kidney shape as a child component in your main one, positioned behind the other children
This means you can place the other children behind the kidney ‘layer’ when necessary, keeping them in the same parent as the others.