Draw lines with flutter - dart

Question

Is there any way to display skew borders at the top and bottom?
I came up with the solution below by using two images (top_layout and bottom_layout.png). Is there any other way to make those color bars with shadows without using static images?
return Container(
color: const Color.fromARGB(255, 236, 0, 140),
child: Container(
padding: const EdgeInsets.all(8.0),
child: Container(
color: Colors.white,
margin:
EdgeInsets.only(top: 60.0, bottom: 20.0, left: 15.0, right: 15.0),
child: Stack(
children: <Widget>[
Positioned.fill(
child: Image.asset(
"assets/imgs/top_layout.png",
fit: BoxFit.fitWidth,
alignment: Alignment.topCenter,
),
),
Positioned.fill(
child: Image.asset(
"assets/imgs/xbottom_layout.png",
fit: BoxFit.fitWidth,
alignment: Alignment.bottomLeft,
),
),
],
),
),
),
);
}

Answer 1

How do draw lines in Flutter using the CustomPaint widget
To paint in Flutter you use the CustomPaint widget. The CustomPaint widget takes a CustomPainter object as a parameter. In that class you have to override the paint method, which gives you a canvas that you can paint on. Here is the code to draw the line in the image above.
#override
void paint(Canvas canvas, Size size) {
final p1 = Offset(50, 50);
final p2 = Offset(250, 150);
final paint = Paint()
..color = Colors.black
..strokeWidth = 4;
canvas.drawLine(p1, p2, paint);
}
Notes:
The drawLine method draws a line connecting the two points you give it.
An Offset is a pair of (dx, dy) doubles, offset from the top left corner of the CustomPaint widget.
Another option
You could do something similar with the drawPoints method using the PointMode.polygon option.
#override
void paint(Canvas canvas, Size size) {
final pointMode = ui.PointMode.polygon;
final points = [
Offset(50, 100),
Offset(150, 75),
Offset(250, 250),
Offset(130, 200),
Offset(270, 100),
];
final paint = Paint()
..color = Colors.black
..strokeWidth = 4
..strokeCap = StrokeCap.round;
canvas.drawPoints(pointMode, points, paint);
}
Context
Here is the main.dart code so that you can see it in context.
import 'dart:ui' as ui;
import 'package:flutter/material.dart';
void main() => runApp(MyApp());
class MyApp extends StatelessWidget {
#override
Widget build(BuildContext context) {
return MaterialApp(
home: Scaffold(
body: HomeWidget(),
),
);
}
}
class HomeWidget extends StatelessWidget {
#override
Widget build(BuildContext context) {
return Center(
child: CustomPaint( // <-- CustomPaint widget
size: Size(300, 300),
painter: MyPainter(),
),
);
}
}
class MyPainter extends CustomPainter { // <-- CustomPainter class
#override
void paint(Canvas canvas, Size size) {
// <-- Insert your painting code here.
}
#override
bool shouldRepaint(CustomPainter old) {
return false;
}
}
See also
See this article for my fuller answer.

Answer 2

In this case, you would like to use Custom Painter widget instead. You can draw the shape based on coordinates.
Refer this tutorial for more info.
Drawing Custom Shapes in Flutter using CustomPainter