search.dart

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'package:rive/rive.dart';

class Search extends StatefulWidget {
  @override
  _SearchState createState() => _SearchState();
}

class _SearchState extends State<Search> {
  final riveFileName = 'assets/search.riv';
  Artboard _artboard;

  @override
  void initState() {
    _loadRiveFile();
    super.initState();
  }

  // loads a Rive file
  void _loadRiveFile() async {
    final bytes = await rootBundle.load(riveFileName);
    final file = RiveFile();

    if (file.import(bytes)) {
      // Select an animation by its name
      setState(() => _artboard = file.mainArtboard
        ..addController(
          SimpleAnimation('search_animation'),
        ));
    }
  }

  @override
  Widget build(BuildContext context) {
    var screensize = MediaQuery.of(context).size;
    return Scaffold(
      body: SafeArea(
        child: Column(
          children: [
            Container(
              height: 400,
              width: 350,
              child: _artboard != null
                  ? Rive(
                artboard: _artboard,
                fit: BoxFit.cover,
              )
                  : Container(),
            ),
          ],
        ),
      ),
    );
  }
}