toImage method

Implementation

Future<ui.Image?> toImage() async {
  if (isEmpty) return null;

  final recorder = ui.PictureRecorder();
  final canvas = Canvas(recorder);
  final size = Size(double.infinity, widget.height);

  // Draw background
  canvas.drawRect(
    Rect.fromLTWH(0, 0, size.width, size.height),
    Paint()..color = widget.backgroundColor,
  );

  // Draw strokes
  final paint = Paint()
    ..color = widget.penColor
    ..strokeWidth = widget.penWidth
    ..strokeCap = StrokeCap.round
    ..strokeJoin = StrokeJoin.round
    ..style = PaintingStyle.stroke;

  for (final stroke in _strokes) {
    if (stroke.length < 2) continue;
    final path = Path()..moveTo(stroke.first.dx, stroke.first.dy);
    for (var i = 1; i < stroke.length; i++) {
      path.lineTo(stroke[i].dx, stroke[i].dy);
    }
    canvas.drawPath(path, paint);
  }

  final picture = recorder.endRecording();
  return picture.toImage(400, widget.height.toInt());
}