Paint gradients rectangles on #onDraw: method

> Well, I´m continue working on a Grid widget.
>
> My old grid was very slow in load data. I changed the old mechanism of
> columns and rows ( each row was a panel with cells in tableLayout  ) by
> #onDraw: mechanism, painting the cells and contents of it. Now is incredible
> much more faster. I believe than another people with more knowledge could do
> more fast too.
>
> Now my next problem is implement the "styles" of widget. I need paint
> gradient rectangles, for color of rows , alternate rows, cells etc. Is
> possible do that with #onDraw: mechanism? exists some previous example?
>
> Many thanks for the answer; regards.
>