flutter design Curves layout as single widget - flutter

Question

Here solved question about design this layout.
I have a problem to using that, because of this curve on right of screen is not widget and when I want to have some other widgets in green side, I can't, because designed curve is not widget its clipped from green layout.
Suppose I want to have this curve on right of screen and some widget in below of that.
Source code
import 'package:flutter/material.dart';
void main() {
runApp(MaterialApp(home: Scaffold(body: Test())));
}
class Test extends StatefulWidget {
#override
_TestState createState() => _TestState();
}
class _TestState extends State<Test> {
double _height = 0.0;
double _width = 0.0;
double _rightPadding = 2.0;
double _btnSize = 25.0;
double _btnY = 0.0;
#override
Widget build(BuildContext context) {
if (_height == 0.0)
setState(() {
_height = MediaQuery.of(context).size.height;
_width = MediaQuery.of(context).size.width;
_btnY = _height / 3 * 2;
});
return _height == 0.0
? Container()
: Stack(
children: <Widget>[
Container(
color: Colors.white,
),
CustomPaint(
size: Size(_width - _rightPadding, _height),
painter: CurvedPainter(_btnSize, _btnY),
),
],
);
}
}
class CurvedPainter extends CustomPainter {
CurvedPainter(this.btnSize, this.btnY);
final double btnSize;
final double btnY;
#override
void paint(Canvas canvas, Size size) {
Path path = Path();
path.moveTo(0.0, 0.0);
path.lineTo(size.width, 0.0);
path.lineTo(size.width, btnY - btnSize * 2);
path.cubicTo(size.width, btnY - btnSize * 0.3, size.width - btnSize * 0.95, btnY - btnSize * 0.9, size.width - btnSize, btnY);
path.cubicTo(size.width - btnSize * 0.95, btnY + btnSize * 0.9, size.width, btnY + btnSize * 0.3, size.width, btnY + btnSize * 2);
path.lineTo(size.width, size.height);
path.lineTo(0.0, size.height);
path.lineTo(0.0, 0.0);
canvas.drawPath(
path,
Paint()
..color = Colors.transparent
..style = PaintingStyle.fill);
}
#override
bool shouldRepaint(CurvedPainter oldDelegate) => oldDelegate.btnY != btnY;
}
I want to use right curve as an widget on top of all widgets, without having green side, you suppose green side is as ListView.

Answer 1

It seems that you need something like this given in the image below.
Update: Dragging control added
import 'dart:math' as math;
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
debugShowCheckedModeBanner: false,
title: 'Flutter Demo',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: Scaffold(
body: Test(),
),
);
}
}
class Test extends StatefulWidget {
#override
_TestState createState() => _TestState();
}
enum dragType { vertical, horizontal }
class _TestState extends State<Test> {
final double _btnSize = 48.0;
final double _rightPadding = 0;
double _extraOffcet = 0;
double _btnY;
double _currentX;
double _currentY;
double _height;
double _width;
bool _isHorizontalActive = true;
bool _isVerticalActive = true;
#override
void initState() {
WidgetsBinding.instance.addPostFrameCallback(_afterLayout);
super.initState();
}
_afterLayout(_) {
_height = MediaQuery.of(context).size.height;
_width = MediaQuery.of(context).size.width;
_btnY = _height / 2;
setState(() {});
}
_onDrag(details) {
_updateCoordinates(
details.globalPosition.dx,
details.globalPosition.dy,
);
}
_updateCoordinates(double x, double y) {
setState(() {
if (_isHorizontalActive) {
_updateX(x);
}
if (_isVerticalActive) {
_updateY(y);
}
});
}
_updateX(x) {
var dx = _currentX - x;
_currentX = x;
_extraOffcet = _extraOffcet + dx;
_extraOffcet = math.max(_extraOffcet, _rightPadding);
_extraOffcet = math.min(_extraOffcet, _width - _btnSize);
}
_updateY(y) {
var dy = _currentY - y;
_currentY = y;
_btnY = _btnY - dy;
_btnY = math.max(_btnY, _btnSize);
_btnY = math.min(_btnY, _height - _btnSize);
}
_listItem(String text, double height) {
return Container(
height: height,
child: Text(text, style: TextStyle(fontSize: 20.0)),
);
}
#override
Widget build(BuildContext context) {
return _height == null
? Container()
: Stack(
children: <Widget>[
Container(
padding: EdgeInsets.only(right: 30),
color: Colors.blue,
height: double.infinity,
width: double.infinity,
child: Column(mainAxisAlignment: MainAxisAlignment.center, children: [
_buildSwitch(type: dragType.vertical),
_buildSwitch(type: dragType.horizontal),
...List.generate(
4,
(index) => _listItem('inside', 80),
),
]),
),
Positioned(
right: _extraOffcet + _rightPadding,
child: CustomPaint(
size: Size(_btnSize, _height),
painter: CurvedPainter(_btnSize, _btnY),
),
),
Positioned(
top: _btnY - _btnSize / 2 + 5,
right: _extraOffcet + _rightPadding + 5,
child: GestureDetector(
onPanDown: (details) {
_currentX = details.globalPosition.dx;
_currentY = details.globalPosition.dy;
},
onPanStart: _onDrag,
onPanUpdate: _onDrag,
child: Material(
type: MaterialType.circle,
color: Colors.white,
elevation: 8.0,
child: Container(
width: _btnSize - 10,
height: _btnSize - 10,
child: Icon(Icons.add),
),
),
),
),
Positioned(
top: 0,
left: _width - _extraOffcet,
child: Container(
color: Colors.white,
child: Column(
mainAxisAlignment: MainAxisAlignment.center,
crossAxisAlignment: CrossAxisAlignment.start,
children: List.generate(8, (index) => _listItem('from right', 20)),
),
height: _height,
width: _width,
),
),
],
);
}
SwitchListTile _buildSwitch({dragType type}) {
Function onChange;
String titleText, sutitleText;
bool value;
if (type == dragType.horizontal) {
value = _isHorizontalActive;
titleText = 'Horizontal dragging';
onChange = (newValue) => setState(() => _isHorizontalActive = newValue);
} else {
value = _isVerticalActive;
titleText = 'Vertical dragging';
onChange = (newValue) => setState(() => _isVerticalActive = newValue);
}
sutitleText = value ? 'active' : 'disabled';
return SwitchListTile(
value: value,
onChanged: onChange,
title: Text(titleText),
subtitle: Text(sutitleText),
);
}
}
class CurvedPainter extends CustomPainter {
CurvedPainter(this.btnSize, this.btnY);
final double btnSize;
final double btnY;
#override
void paint(Canvas canvas, Size size) {
var halfBtnSize = btnSize / 2;
var xMax = size.width;
var yMax = size.height;
var path = Path()
..moveTo(halfBtnSize, yMax)
..lineTo(halfBtnSize, btnY + halfBtnSize * 2)
..cubicTo(halfBtnSize, btnY + halfBtnSize, 0, btnY + halfBtnSize, 0, btnY)
..cubicTo(0, btnY - halfBtnSize, halfBtnSize, btnY - halfBtnSize, halfBtnSize,
btnY - halfBtnSize * 2)
..lineTo(halfBtnSize, 0)
..lineTo(xMax, 0)
..lineTo(xMax, yMax);
canvas.drawPath(
path,
Paint()
..color = Colors.white
..style = PaintingStyle.fill);
}
#override
bool shouldRepaint(CurvedPainter oldDelegate) => oldDelegate.btnY != btnY;
}