createRoundedMarkerIcon function

Future<BitmapDescriptor> createRoundedMarkerIcon(String title, { required TextStyle textStyle, Color backgroundColor = Colors.blueAccent, })

Implementation

Future<BitmapDescriptor> createRoundedMarkerIcon(String title, {required TextStyle textStyle, Color backgroundColor = Colors.blueAccent}) async {
  TextSpan span = TextSpan(
    style: textStyle,
    text: title,
  );
  TextPainter painter = TextPainter(
    text: span,
    textAlign: TextAlign.center,
    textDirection: ui.TextDirection.ltr,
  );
  painter.text = TextSpan(
    text: title.toString(),
    style: textStyle,
  );
  painter.layout();

  int textWidth = painter.width.toInt();
  int textHeight = painter.height.toInt();

  ui.PictureRecorder pictureRecorder = ui.PictureRecorder();
  Canvas canvas = Canvas(pictureRecorder);

  RRect roundedRect = RRect.fromLTRBAndCorners(
    0,
    0,
    textWidth + 40,
    textHeight + 20,
    bottomLeft: const Radius.circular(10),
    bottomRight: const Radius.circular(10),
    topLeft: const Radius.circular(10),
    topRight: const Radius.circular(10),
  );

  Paint rectPaint = Paint()..color = backgroundColor;
  canvas.drawRRect(roundedRect, rectPaint);

  Path arrowPath = Path();
  arrowPath.moveTo((textWidth + 40) / 2 - 15, textHeight + 20);
  arrowPath.lineTo((textWidth + 40) / 2, textHeight + 40);
  arrowPath.lineTo((textWidth + 40) / 2 + 15, textHeight + 20);
  arrowPath.close();

  Paint arrowPaint = Paint()..color = backgroundColor;
  canvas.drawPath(arrowPath, arrowPaint);

  painter.paint(canvas, const Offset(20.0, 10.0));

  ui.Picture p = pictureRecorder.endRecording();
  ByteData? pngBytes = await (await p.toImage((textWidth + 40), (textHeight + 50))).toByteData(format: ui.ImageByteFormat.png);
  Uint8List data = Uint8List.view(pngBytes!.buffer);

  return BitmapDescriptor.fromBytes(data);
}