clipbox.dart

// https://gist.github.com/HansMuller/dab66f5d34225ad8499ad285e69b6160

// The goal here is for the 'ClipBoxDemo' text widget to appear to scroll upwards
// and be clipped by its Container, as the height of its Container is reduced.

import 'package:flutter/material.dart';

class ClipBoxDemo extends StatelessWidget {
  const ClipBoxDemo({ super.key });

  static const double titleHeight = 52;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Container(
        color: Colors.green.withOpacity(0.1),
        padding: const EdgeInsets.all(100),
        alignment: Alignment.center,
        child: Container(
          color: Colors.green.withOpacity(0.1),
          constraints: const BoxConstraints(maxHeight: titleHeight),
          // The child's height shrinks from 52 to 0 as its window height is reduced.
          child:const  ClipRect(
            clipBehavior: Clip.hardEdge,
            child: OverflowBox(
              minHeight: titleHeight,
              maxHeight: titleHeight,
              alignment: Alignment.bottomLeft,
              child: Text('ClipBoxDemo', style: TextStyle(fontSize: 44)),
            ),
          ),
        ),
      ),
    );
  }
}

void main() {
  runApp(const MaterialApp(home: ClipBoxDemo()));
}