Hero Widget transitionOnUserGestures bug.

main.dart

import 'package:flutter/cupertino.dart';
import 'package:flutter/material.dart';
import 'package:cached_network_image/cached_network_image.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return CupertinoApp(
      title: 'Flutter Demo',
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      child: CupertinoScrollbar(
        child: CustomScrollView(
          slivers: <Widget>[
            CupertinoSliverNavigationBar(
              largeTitle: Text("Hero"),
            ),
            SliverList(
              delegate: SliverChildBuilderDelegate((context, num) {
                return Row(
                  children: <Widget>[
                    GestureDetector(
                      onTap: () {
                        print("object");
                        Navigator.of(context)
                            .push(CupertinoPageRoute(builder: (context) {
                          return PageTwo();
                        }));
                      },
                      child: Hero(
                        tag: "hero1",
                        transitionOnUserGestures: true,
                        child: ClipPath(
                          clipper: RightSlantClipper(),
                          child: Container(
                            color: Colors.green,
                            width: 80.0,
                            child: CachedNetworkImage(
                              imageUrl:
                                  "https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSMwv2FT4pkFYxy6H1BuRK0W-DiNTmm0jwXTyJpjNzbXdUvDttB",
                              alignment: Alignment(0.2, -0.7),
                              fit: BoxFit.none,
                            ),
                          ),
                        ),
                      ),
                    ),
                    Text("Flutter'n")
                  ],
                );
              }, childCount: 1),
            )
          ],
        ),
      ),
    );
  }
}

class RightSlantClipper extends CustomClipper<Path> {
  @override
  getClip(Size size) {
    var path = Path();
    path.lineTo(0.0, size.height);
    path.lineTo(size.width, size.height);
    path.lineTo(size.width - 20, 0.0);
    path.close();
    return path;
  }

  @override
  bool shouldReclip(CustomClipper oldClipper) => true;
}

class PageTwo extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return CupertinoPageScaffold(
      child: CupertinoScrollbar(
        child: CustomScrollView(
          slivers: <Widget>[
            CupertinoSliverNavigationBar(
              largeTitle: Text("page 2"),
            ),
            SliverFillRemaining(
              child: Hero(
                transitionOnUserGestures: true,
                tag: "hero1",
                child: CachedNetworkImage(
                    imageUrl:
                        "https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcSMwv2FT4pkFYxy6H1BuRK0W-DiNTmm0jwXTyJpjNzbXdUvDttB"),
              ),
            )
          ],
        ),
      ),
    );
  }
}