Set equal size to all children in Row

Question

I have a Row that has 2 children like this:

 ----------------------
| wide child1 | child2 |
 ----------------------

Is there any way to make each cell be equal in size, so that each cell's width would be equal to the width of the widest cell? Like this:

 --------------------------
| wide child1 |   child2   |
 --------------------------

So the whole Row would take biggestCellWidth * numOfChildren in width.

I couldn't achieve this behavior with built-in widgets and tried to implement MultiChildLayoutDelegate but it also doesn't work since I can't measure children.

Upd:

// in build function
Container(
            height: 48,
            child: Material(
              clipBehavior: Clip.antiAlias,
              borderRadius: BorderRadius.circular(16),
              color: Theme.of(context).colorScheme.primary,
              child: Row(
                mainAxisSize: MainAxisSize.min,
                mainAxisAlignment: MainAxisAlignment.spaceBetween,
                crossAxisAlignment: CrossAxisAlignment.stretch,
                children: <Widget>[
                  // this widgets should be equal in width
                  _buildButton(
                    text: "Review",
                    onTap: _onReviewTap,
                  ),
                  _buildButton(
                    text: "Buy",
                    onTap: _onBuyTap,
                  ),
                ],
              ),
            ),
          );

 Widget _buildButton({
    @required String text,
    @required Function onTap,
    @required EdgeInsets padding,
  }) {
    return InkWell(
      onTap: onTap,
      child: Center(
        child: Text(
          text,
          style: TextStyle(
            color: Theme.of(context).colorScheme.onPrimary,
          ),
        ),
      ),
    );
  }

Answer 1

You mentioned that all your children are Text widget. We can render texts to learn their size (reference), choose maximum width and do layout with MultiChildLayoutDelegate. It's a bit hacky, but will work:

class _HomePageState extends State<HomePage> {
  @override
  Widget build(BuildContext context) {
    final texts = [
      Text('loooooooooooong text'),
      Text('short one'),
      Text('one more'),
    ];
    final children = <Widget>[
      for (int i = 0; i < texts.length; i++) 
        LayoutId(
          id: '$_kLayoutKey$i',
          child: Container(
            color: Color.fromARGB(255, Random().nextInt(255), Random().nextInt(255), Random().nextInt(255)),
            child: texts[i],
          ),
        ),
    ];

    return Scaffold(
      appBar: AppBar(),
      body: SafeArea(
        child: CustomMultiChildLayout(
          delegate: _CircularLayoutDelegate(texts, 14),
          children: children,
        )
      ),
    );
  }
}

const String _kLayoutKey = 'test';

class _CircularLayoutDelegate extends MultiChildLayoutDelegate {
  _CircularLayoutDelegate(this.texts, this.fontSize);

  final double fontSize;
  final List<Text> texts;

  double _calcTextWidth(BoxConstraints constraints, Text textWidget) {
    RenderParagraph renderParagraph = RenderParagraph(
      TextSpan(
        text: textWidget.data,
        style: TextStyle(
          fontSize: fontSize,
        ),
      ),
      textDirection: TextDirection.ltr,
      maxLines: 1,
    );
    renderParagraph.layout(constraints);
    return renderParagraph.getMinIntrinsicWidth(fontSize).ceilToDouble();
  }

  @override
  void performLayout(Size size) {
    final textSizes = [
      for (final text in texts) 
        _calcTextWidth(BoxConstraints.loose(size), text),
    ];

    final maxWidth = textSizes.fold<double>(0, (p, v) {
      final textWidth = v;
      return textWidth > p ? textWidth : p;
    });

    final textConstraint = BoxConstraints(
      maxWidth: maxWidth,
      minWidth: maxWidth,
      maxHeight: size.height,
    );

    for (int i = 0; i < texts.length; i++) {
      final String childId = '$_kLayoutKey$i';

      if (hasChild(childId)) {
        layoutChild('$_kLayoutKey$i', textConstraint);

        positionChild(
          childId,
          Offset(maxWidth * i, 0),
        );
      }}
  }

  @override
  bool shouldRelayout(_CircularLayoutDelegate oldDelegate) => oldDelegate.texts != texts;
}