generateReceipt method

Implementation

Future<GeneratePrinter?> generateReceipt(GlobalKey globalKey) async {
  try {
    RenderRepaintBoundary boundary = globalKey.currentContext!.findRenderObject() as RenderRepaintBoundary;

    // Get the original image
    ui.Image originalImage = await boundary.toImage(pixelRatio: 3.0);

    // Calculate dimensions maintaining aspect ratio
    double scale = 380.0 / originalImage.width;
    int targetWidth = 380;
    int targetHeight = (originalImage.height * scale).round();

    // Create recorder and canvas
    final recorder = ui.PictureRecorder();
    final canvas = Canvas(recorder);

    // Draw the scaled image
    canvas.drawImageRect(
      originalImage,
      Rect.fromLTWH(0, 0, originalImage.width.toDouble(), originalImage.height.toDouble()),
      Rect.fromLTWH(0, 0, targetWidth.toDouble(), targetHeight.toDouble()),
      Paint(),
    );

    // Convert to image
    final picture = recorder.endRecording();
    final resizedImage = await picture.toImage(targetWidth, targetHeight);

    ByteData? byteData = await resizedImage.toByteData(format: ui.ImageByteFormat.png);

    if (byteData != null) {
      Uint8List pngBytes = byteData.buffer.asUint8List();
      String base64String = base64Encode(pngBytes);
      return GeneratePrinter(
        pngBytes: pngBytes,
        base64String: base64String,
        printerBytes: pngBytes,
        byteBuffer: byteData.buffer,
      );
    }

    throw Exception('Failed to convert receipt to base64');
  } catch (e) {
    return null;
  }
}