Row mainAxisAlignment not working with FittedBox - flutter

Question

Row mainAxisAlignment is not working after wrapping with FittedBox
Please explain me why this is happening.
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text(widget.title),
),
body: Container(
height: 20,
child: FittedBox(
fit: BoxFit.fill,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [
Text('THis is the thing'),
Text('THis is another thing'),
],
),
),
)
);
}
Expected
Output

Answer 1

If you really want to use Row inside FittedBox with effect of mainAxisAllignment.spaceBetween or any, you have to manually set spaceBetween using SizedBox with width as per spacing. Also set fit property to BoxFit.fitHeight .
Container(
height: 20,
child: FittedBox(
alignment: Alignment.center,
fit: BoxFit.fitHeight,
child: Row(
mainAxisSize: MainAxisSize.min,
children: [
Text('THis is the thing',style: TextStyle(fontSize: 20),),
SizedBox(width: 300,),
Text('THis is another thing',style: TextStyle(fontSize: 20,),),
],
),
),
)
Note: Set allignment property to specify positioning. for MainAxisAllignment.start and MainAxisAllignment.start.
Eg: Alignment.topLeft to get MainAxisAllignment.start effect.

Answer 2

To answer your question,
Row mainAxisAlignment is not working after wrapping with FittedBox
Please explain me why this is happening.
Container always fills the entire width of the screen size. If it has child, then it will wraps up itself to match the width of its child.
Another interesting widget FittedBox will fits its children based on the size of the children within itself by scaling based on available space.
Solution
To achieve the expected result, you can force set the width of Container widget to double.infinity
Snippet
body: Container(
height: 20,
width: double.infinity,
child: FittedBox(
fit: BoxFit.fill,
alignment: Alignment.center,
child: Row(
mainAxisAlignment: MainAxisAlignment.spaceEvenly,
children: [Text('THis is the ROW'), Text('THis is another ')],
),
),
)
NOTE : If texts are small it will be enlarged to occupy the rest of the space because it is inside the FittedBox and vice-versa.