printCode128Barcode static method

Future<bool> printCode128Barcode({ required String barcodeData, String displayText = "", String leftText = "", double height = 38, bool displayValue = true, int textSize = 24, double leftTextWidth = 200, double leftTextPosition = 155, int printerWidth = 576, })

Print a Code 128 barcode with custom parameters.

Creates and prints a customized Code 128 barcode, which can include additional text formatting and positioning options.

• barcodeData: Content to encode in the barcode
• displayText: Text to display under the barcode (defaults to barcodeData)
• leftText: Text to display to the left of the barcode
• height: Barcode height in dots
• displayValue: Whether to show the human-readable text
• textSize: Size of the human-readable text
• leftTextWidth: Width allocated for the left text
• leftTextPosition: X position for the left text
• printerWidth: Printer width in dots

Returns true if printing was successful.

Implementation

static Future<bool> printCode128Barcode({
  required String barcodeData,
  String displayText = "",
  String leftText = "",
  double height = 38,
  bool displayValue = true,
  int textSize = 24,
  double leftTextWidth = 200,
  double leftTextPosition = 155,
  int printerWidth = 576, // Default printer width
}) async {
  try {
    final directory = await getTemporaryDirectory();
    final tempPath =
        '${directory.path}/barcode_${DateTime.now().millisecondsSinceEpoch}.png';

    final recorder = PictureRecorder();
    final canvas = Canvas(recorder);

    double totalHeight = height + (displayValue ? textSize * 1.2 : 0);

    // Create white background
    canvas.drawRect(
      Rect.fromLTWH(0, 0, printerWidth.toDouble(), totalHeight),
      Paint()..color = Colors.white,
    );

    // Draw left text if provided
    if (leftText.isNotEmpty) {
      // Use normal font weight for softer appearance
      final textPainter = TextPainter(
        text: TextSpan(
            text: leftText,
            style: TextStyle(
              color: Colors.black,
              fontSize: textSize.toDouble(),
              fontWeight: FontWeight.w300, // Softer appearance
              fontFamily: 'Siemreap', // Use the standard font
            )),
        textDirection: TextDirection.ltr,
        textAlign: TextAlign.left,
      );
      textPainter.layout(maxWidth: leftTextWidth);
      textPainter.paint(canvas, Offset(leftTextPosition, 0));
    }

    // Generate barcode pattern
    final List<int> encodedData = BarcodeGenerator.encodeCode128(barcodeData);
    final List<String> patterns =
        BarcodeGenerator.generateCode128Patterns(encodedData);
    final String fullPattern = patterns.join();

    // Use minimum bar width for barcode
    final double barMinWidth = 2;

    // Calculate optimal barcode dimensions
    final double barcodeWidth = fullPattern.length * barMinWidth;
    final startX = (printerWidth - barcodeWidth) / 2; // Center the barcode
    double currentX = startX;

    // Draw barcode bars with fixed width
    for (int i = 0; i < fullPattern.length; i++) {
      if (fullPattern[i] == '1') {
        canvas.drawRect(
          Rect.fromLTWH(currentX, 2, barMinWidth, height - 2),
          Paint()..color = Colors.black,
        );
      }
      currentX += barMinWidth;
    }

    // Draw text under barcode if requested
    if (displayValue) {
      // Use normal font weight for softer appearance
      final textPainter = TextPainter(
        text: TextSpan(
          text: displayText.isEmpty ? barcodeData : displayText,
          style: TextStyle(
            color: Colors.black,
            fontSize: textSize.toDouble(),
            fontWeight: FontWeight.normal,
            letterSpacing: 0.4, // Reduced spacing
          ),
        ),
        textAlign: TextAlign.center,
        textDirection: TextDirection.ltr,
      );

      textPainter.layout(maxWidth: printerWidth.toDouble());
      textPainter.paint(
        canvas,
        Offset((printerWidth - textPainter.width) / 2, height + 2),
      );
    }

    final picture = recorder.endRecording();
    final img = await picture.toImage(
      printerWidth,
      totalHeight.ceil(),
    );
    final byteData = await img.toByteData(format: ImageByteFormat.png);
    final buffer = byteData!.buffer.asUint8List();

    // Save to temp file
    await File(tempPath).writeAsBytes(buffer);

    // Print the image
    return await PrinterCore.printImage(
      tempPath,
      width: printerWidth,
      alignment: TextFormatter.convertAlignment(Alignment.center),
    );
  } catch (e) {
    print("Error creating barcode: $e");
    return false;
  }
}