paint method
Draw itself and its children, according to the calculated
box.offset
Implementation
@override
void paint(Context context) {
super.paint(context);
final resolvedPadding = padding.resolve(Directionality.of(context));
if (child != null) {
final mat = Matrix4.identity();
mat.translate(
box!.x + resolvedPadding.left, box!.y + resolvedPadding.bottom);
context.canvas
..saveContext()
..setTransform(mat);
child!.paint(context);
context.canvas.restoreContext();
}
}