part of widgets; class Box extends Component { static Style _style = new Style(''' display: flex; flex-direction: column; border-radius: 4px; border: 1px solid gray; margin: 10px;''' ); static Style _titleStyle = new Style(''' flex: 1; text-align: center; font-size: 10px; padding: 8px 8px 4px 8px;''' ); static Style _contentStyle = new Style(''' flex: 1; padding: 4px 8px 8px 8px;''' ); String title; List children; Box({String key, this.title, this.children }) : super(key: key); Node render() { return new Container( style: _style, children: [ new Container( key: 'Title', style: _titleStyle, children: [new Text(title)] ), new Container( key: 'Content', style: _contentStyle, children: children ), ] ); } }