Non-nullable instance field 'painter' must be initialized in Flutter

Question

I am trying to figure out what is causing this error in the code. It seems like the painter side is causing issues. Been trying to figure this out for some time. I'd love any hints or tips on this. This seems like a change with Flutter 3.0 that took place I suppose.

BubbleIndicatorPainter({this.dxTarget = 125.0, this.dxEntry = 25.0, this.radius = 21.0,
this.dy = 25.0, required this.pageController}) : super(repaint: pageController) {
painter = Paint()
    ..color = CustomTheme.white
    ..style = PaintingStyle.fill;


}




Paint painter;
  final double dxTarget;
  final double dxEntry;
  final double radius;
  final double dy;

Answer 1

You can use late that you will assign data before reading it

late Paint painter;

Or you can make it nullable

 Paint? painter;

More about null-safety

Answer 2

Use

late Paint painter;  Here late assures you will initiate the painter later in the program.

Or

Paint? painter;   Here you are saying painter can be null to the dart compiler

This is error caused because of the dart null safety