Assign same BoxDecoration value to all Containers in the widget tree

Is it possible to have decoration (padding, margin, etc.) fields to be set to an application wide default value for all Container widgets?

I know we could create one instance of BoxDecoration, EdgeInstets, etc., store in a variable and assign only that variable in all Containers like this:

Container(
  margin: _margin,
  padding: _padding,
  decoration: _boxDecoration
)

But this is not what i mean. I mean even without assigning any value. I've tried to extend Container like class MyContainer extends Container { ... } and set the desired default values in the constructor but it didn't work.

Solution 1: jbarat

You shouldn't extend the Container. You should extend the StatelessWidget. Flutter is more about composing than inheritance.

You should have something like this:

class MyContainer extends StatelessWidget{
  final EdgeInsets _globalPadding = EdgeInsets.all(4);
  final Widget child;

  MyContainer({Key key, this.child}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      padding: _globalPadding,
      child: child,
    );
  }
}

Then you can use MyContainer in the place of any Container.