Is there a way to make a flutter widget to disobey scaffold padding?

Question

My app screen has a lot of containers and according to the UX design, they're all supposed to be padded within the scaffold. Now there's one container that has the task of displaying error messages. I want just this container to occupy full width ie. not be padded.

Answer 1

Use the widget Stack as the root widget and put your scaffold inside. The container bellow will be displayed over the scaffold if it exists.

Stack(
  children: <Widget>[
    Scaffold(
          body:...
    ),  
    Container(
      constraints: BoxConstraints.expand(),
      decoration: BoxDecoration(
        color: Colors.red
      ),
    ),
  ],
),