Creating a shadow around a canvas drawn shape?

Question

What steps are required to create a shape e.g. rectangle with a shadow from scratch using a Canvas?

Adding a shadow layer to the paint used to draw the rectangle yielded

Answer 1

1. create. a Path, add some elements to it

2. set BlurMaskFilter to a Paint

3. draw a path with dx, dy shadow offset

4. unset mask filter

5. draw a path again with no. offset