How to make floating widget flutter?

Question

I want to make a floating widget but not floating all the time, when the widget is pulled up from the floating navigation bar it will appear like the picture in the middle

How to make a widget like this middle image?

Answer 1

this sample code of flutter for using showBottomSheet:

import 'package:flutter/material.dart';

void main() => runApp(const MyApp());

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

  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: _title,
      home: Scaffold(
        appBar: AppBar(title: const Text(_title)),
        body: const MyStatelessWidget(),
      ),
    );
  }
}

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

  @override
  Widget build(BuildContext context) {
    return Center(
      child: ElevatedButton(
        child: const Text('showBottomSheet'),
        onPressed: () {
          Scaffold.of(context).showBottomSheet<void>(
            (BuildContext context) {
              return Container(
                height: 200,
                color: Colors.amber,
                child: Center(
                  child: Column(
                    mainAxisAlignment: MainAxisAlignment.center,
                    mainAxisSize: MainAxisSize.min,
                    children: <Widget>[
                      const Text('BottomSheet'),
                      ElevatedButton(
                        child: const Text('Close BottomSheet'),
                        onPressed: () {
                          Navigator.pop(context);
                        },
                      ),
                    ],
                  ),
                ),
              );
            },
          );
        },
      ),
    );
  }
}

Answer 2

You can also try using sliding_up_panel to get the same functionality. It is pretty straight forward to implement and offers plenty customization features as well:

@override
Widget build(BuildContext context) {
  return Scaffold(
    appBar: AppBar(
      title: Text("SlidingUpPanelExample"),
    ),
    body: Stack(
      children: <Widget>[
        Center(child: Text("This is the Widget behind the sliding panel"),),

        SlidingUpPanel(
          panel: Center(child: Text("This is the sliding Widget"),),
        )
      ],
    )
  );
} 

Try the Stack variant so that it doesn't hinder too much with your current code.