No logic in createRenderObject() #155853
Description
Considering the test class from #155699:
class ThemedCard extends SingleChildRenderObjectWidget {
const ThemedCard({super.key}) : super(child: const SizedBox.expand());
@override
RenderPhysicalShape createRenderObject(BuildContext context) {
final CardThemeData cardTheme = CardTheme.of(context).data;
return RenderPhysicalShape(
clipper: ShapeBorderClipper(shape: cardTheme.shape ?? const RoundedRectangleBorder()),
clipBehavior: cardTheme.clipBehavior ?? Clip.antiAlias,
color: cardTheme.color ?? Colors.white,
elevation: cardTheme.elevation ?? 0.0,
shadowColor: cardTheme.shadowColor ?? Colors.black,
);
}
@override
void updateRenderObject(BuildContext context, RenderPhysicalShape renderObject) {
final CardThemeData cardTheme = CardTheme.of(context).data;
renderObject
..clipper = ShapeBorderClipper(shape: cardTheme.shape ?? const RoundedRectangleBorder())
..clipBehavior = cardTheme.clipBehavior ?? Clip.antiAlias
..color = cardTheme.color ?? Colors.white
..elevation = cardTheme.elevation ?? 0.0
..shadowColor = cardTheme.shadowColor ?? Colors.black;
}
}It's pretty great having the ability to hook up a RenderObjectWidget straight to an InheritedWidget, but having a single source of truth would help to mitigate future bugs.
Proposal: make RenderObject constructor arguments optional
class ThemedCard extends PhysicalShape {
const MyWidget({super.key});
@override
void updateRenderObject(BuildContext context, RenderPhysicalShape renderObject) {
// single source of truth!
}
}I should probably reiterate that this isn't strictly necessary for us to do, but it'd still be wonderful.