Flip page effect using Flutter and flip_widget library - flutter

Question

I am working on a flutter app, and what I am trying to implement is a flip effect using this plugin Flip Widget.
The plugin works fine for the right to left (next page) drag effect but I can't make the same effect work from left to right (previous page), I have tried different values for the tilt and percentage value (negative and positive) and nothing worked so far. Here is the code
import 'package:flutter/material.dart';
import 'dart:async';
import 'package:flutter/services.dart';
import 'package:flip_widget/flip_widget.dart';
import 'dart:math' as math;
void main() {
runApp(MyApp());
}
class MyApp extends StatefulWidget {
#override
_MyAppState createState() => _MyAppState();
}
const double _MinNumber = 0.008;
double _clampMin(double v) {
if (v < _MinNumber && v > -_MinNumber) {
if (v >= 0) {
v = _MinNumber;
} else {
v = -_MinNumber;
}
}
return v;
}
class _MyAppState extends State<MyApp> {
GlobalKey<FlipWidgetState> _flipKey = GlobalKey();
Offset _oldPosition = Offset.zero;
bool _visible = true;
#override
void initState() {
super.initState();
}
#override
Widget build(BuildContext context) {
Size size = Size(256, 256);
return MaterialApp(
home: Scaffold(
appBar: AppBar(
title: const Text('Plugin example app'),
),
body: Column(
mainAxisSize: MainAxisSize.min,
children: [
Visibility(
child: Container(
width: size.width,
height: size.height,
child: GestureDetector(
child: FlipWidget(
key: _flipKey,
textureSize: size * 2,
child: Container(
color: Colors.blue,
child: Center(
child: Text("hello"),
),
),
),
onHorizontalDragStart: (details) {
_oldPosition = details.globalPosition;
_flipKey.currentState?.startFlip();
},
onHorizontalDragUpdate: (details) {
Offset off = details.globalPosition - _oldPosition;
double tilt = 1/_clampMin((-off.dy + 20) / 100);
double percent = math.max(0, -off.dx / size.width * 1.4);
percent = percent - percent / 2 * (1-1/tilt);
_flipKey.currentState?.flip(percent, tilt);
},
onHorizontalDragEnd: (details) {
_flipKey.currentState?.stopFlip();
},
onHorizontalDragCancel: () {
_flipKey.currentState?.stopFlip();
},
),
),
visible: _visible,
),
TextButton(
onPressed: () {
setState(() {
_visible = !_visible;
});
},
child: Text("Toggle")
)
],
),
),
);
}
}

Answer 1

The library developer responded to this Github issue and provided an excellent example code for this feature.
https://github.com/gsioteam/flip_widget/issues/2
Thanks for the great work #gsioteam