Collapsible

class Demo extends StatefulWidget {
  const Demo({super.key});
 
  @override
  State<Demo> createState() => _DemoState();
}
 
class _DemoState extends State<Demo> with SingleTickerProviderStateMixin {
  late final AnimationController _controller;
  late final Animation<double> _animation;
  bool _expanded = false;
 
  @override
  void initState() {
    super.initState();
    _controller = AnimationController(duration: const Duration(milliseconds: 300), vsync: this);
    _animation = CurvedAnimation(parent: _controller, curve: Curves.easeInOut);
  }
 
  @override
  void dispose() {
    _controller.dispose();
    super.dispose();
  }
 
  void _toggle() {
    setState(() {
      _expanded = !_expanded;
    });
    _controller.toggle();
  }
 
  @override
  Widget build(BuildContext context) => Column(
    mainAxisSize: MainAxisSize.min,
    crossAxisAlignment: CrossAxisAlignment.start,
    children: [
      FButton(onPress: _toggle, child: Text(_expanded ? 'Collapse' : 'Expand')),
      const SizedBox(height: 16),
      AnimatedBuilder(
        animation: _animation,
        builder:
            (context, child) => FCollapsible(
              value: _animation.value,
              child: FCard(
                title: const Text('Lorem ipsum'),
                child: const Text(
                  'Sed ut perspiciatis unde omnis iste natus error sit voluptatem '
                  'accusantium doloremque laudantium, totam rem aperiam, eaque ipsa '
                  'quae ab illo inventore veritatis et quasi architecto beatae vitae '
                  'dicta sunt explicabo.',
                ),
              ),
            ),
      ),
    ],
  );
}