paint method
Paints the thumb onto the given canvas in the given rectangle.
Consider using radius and extension when deciding how large a rectangle to use for the thumb.
Implementation
void paint(Canvas canvas, Rect rect) {
final rrect = RRect.fromRectAndRadius(
rect,
Radius.circular(rect.shortestSide / 2.0),
);
for (final shadow in shadows) {
canvas.drawRRect(rrect.shift(shadow.offset), shadow.toPaint());
}
canvas
..drawRRect(
rrect.deflate(1.8),
Paint()..color = _kThumbBorderColor,
)
..drawRRect(rrect.deflate(2.3), Paint()..color = color);
}