I want to create the following layout: 
It's a Container, containing a Row, children:
The size of the square Container should be the height of the parent Container (its width = its height). the Column with the 3 Text widgets should expand to the rest of the parent Container.
Is it possible in Flutter? if so, how?
Based on "The Anonymous Koder"'s answer, this is the way to do it:
return IntrinsicHeight( child: Row( children: [ AspectRatio( aspectRatio: 1.0, child: Container( decoration: BoxDecoration( color: Colors.red, ), ), ), Expanded( child: Column( crossAxisAlignment: CrossAxisAlignment.start, children: [ Text( 'line 1 bla bla bla bla bla bla bla bla bla bla bla bla', overflow: TextOverflow.ellipsis, ), Text( 'line 2 bla bla bla bla bla bla bla bla', overflow: TextOverflow.ellipsis, ), Text( 'line 3', overflow: TextOverflow.ellipsis, ), ], ), ), ], ), ); Try creating a custom widget:
class BoxWidget extends StatelessWidget { BoxWidget(/*...*/); Widget build(_) { return Row( children: [ AspectRatio( aspectRatio: 1, child: Container( decoration: BoxDecoration( color: Colors.red, ), ), ), Column( children: [ Text(widget.text1, style: style), Text(widget.text2, style: style), Text(widget.text3, style: style), ], ), ], ); } } 
Yes this is possible, first create a container then it’s child should be a row, then the children of the row should be another container which will act as the square, and then the column which will have 3 text widget as its children. Also I will advice you to wrap the container acting as the square and the column in expanded widgets both separately in the expanded widget wrapping the column set the flex to 3 and for the container expanded widget set flex to 2.
Yes, It's possible. The trick here is to use LayoutBuilder which returns the size that parents can allow. Here, I used maxHeight as height and as well as the width of Red Square Container and Column takes rest of the width.
Container( width: 500, //parent size height: 100, //parent size child: LayoutBuilder( builder: (context, size) { return Row( children: [ Container( color: Colors.red, height: size.maxHeight, width: size.maxHeight ), Expanded( child: Column( children: [ Expanded( child: Container(color: Colors.yellow), ), Expanded( child: Container(color: Colors.blue), ), Expanded( child: Container(color: Colors.green), ), ] ), ), ], ); }), ), 
