paint method

@override void paint(PaintingContext context, Offset center, { required Animation<double> activationAnimation, required Animation<double> enableAnimation, required bool isDiscrete, required TextPainter labelPainter, required RenderBox parentBox, required AnnotatedSliderThemeData sliderTheme, required TextDirection textDirection, required double value, required double textScaleFactor, required Size sizeWithOverflow, })

Implementation

@override
void paint(
  PaintingContext context,
  Offset center, {
  required Animation<double> activationAnimation,
  required Animation<double> enableAnimation,
  required bool isDiscrete,
  required TextPainter labelPainter,
  required RenderBox parentBox,
  required AnnotatedSliderThemeData sliderTheme,
  required TextDirection textDirection,
  required double value,
  required double textScaleFactor,
  required Size sizeWithOverflow,
}) {
  assert(sliderTheme.disabledThumbColor != null);
  assert(sliderTheme.thumbColor != null);

  final Canvas canvas = context.canvas;
  final Tween<double> radiusTween = Tween<double>(
    begin: _disabledThumbRadius,
    end: enabledThumbRadius,
  );
  final ColorTween colorTween = ColorTween(
    begin: sliderTheme.disabledThumbColor,
    end: sliderTheme.thumbColor,
  );

  final Color color = colorTween.evaluate(enableAnimation)!;
  final double radius = radiusTween.evaluate(enableAnimation);

  final Tween<double> elevationTween = Tween<double>(
    begin: elevation,
    end: pressedElevation,
  );

  final double evaluatedElevation = elevationTween.evaluate(
    activationAnimation,
  );
  final Path path =
      Path()..addArc(
        Rect.fromCenter(
          center: center,
          width: 2 * radius,
          height: 2 * radius,
        ),
        0,
        math.pi * 2,
      );

  bool paintShadows = true;
  assert(() {
    if (debugDisableShadows) {
      _debugDrawShadow(canvas, path, evaluatedElevation);
      paintShadows = false;
    }
    return true;
  }());

  if (paintShadows) {
    canvas.drawShadow(path, Colors.black, evaluatedElevation, true);
  }

  canvas.drawCircle(center, radius, Paint()..color = color);
}