Add SVG combine for barcodes (#114)

* Fix test command in Makefile

* Added example how to combine 2 SVG into 1

Author: Denis-Averin

snippets/generate/svg/Combine.cs

@@ -0,0 +1,152 @@
+using Aspose.BarCode.Cloud.Sdk.Api;
+using Aspose.BarCode.Cloud.Sdk.Model;
+
+using System;
+using System.Globalization;
+using System.IO;
+using System.Text;
+using System.Threading.Tasks;
+using System.Xml.Linq;
+
+namespace GenerateSnippets;
+
+/// <summary>
+/// Demonstrates generating two SVG barcodes via Aspose.BarCode Cloud and combining
+/// them into a single SVG containing both codes side-by-side.
+/// </summary>
+internal static class Program
+{
+    private static readonly Encoding Utf8NoBom = new UTF8Encoding(encoderShouldEmitUTF8Identifier: false);
+    private const double BarcodeSpacing = 20d;
+
+    private static Configuration MakeConfiguration()
+    {
+        var config = new Configuration();
+
+        string? envToken = Environment.GetEnvironmentVariable("TEST_CONFIGURATION_ACCESS_TOKEN");
+        if (string.IsNullOrEmpty(envToken))
+        {
+            config.ClientId = "Client Id from https://dashboard.aspose.cloud/applications";
+            config.ClientSecret = "Client Secret from https://dashboard.aspose.cloud/applications";
+        }
+        else
+        {
+            config.JwtToken = envToken;
+        }
+
+        return config;
+    }
+
+    public static async Task Main(string[] args)
+    {
+        string fileName = Path.GetFullPath(Path.Join("Tests", "test_data", "combined.svg"));
+
+        GenerateApi generateApi = new GenerateApi(MakeConfiguration());
+
+        Task<string> eanTask = GenerateSvgAsync(generateApi,
+            barcodeType: EncodeBarcodeType.EAN13,
+            data: "5901234123457");
+
+        Task<string> qrTask = GenerateSvgAsync(generateApi,
+            barcodeType: EncodeBarcodeType.QR,
+            data: "https://products.aspose.cloud/barcode/");
+
+        await Task.WhenAll(eanTask, qrTask);
+
+        string combinedSvg = CombineSvg(eanTask.Result, qrTask.Result);
+
+        await File.WriteAllTextAsync(fileName, combinedSvg, Utf8NoBom);
+
+        Console.WriteLine($"File '{fileName}' generated.");
+    }
+
+    private static async Task<string> GenerateSvgAsync(GenerateApi api, EncodeBarcodeType barcodeType, string data)
+    {
+        await using Stream generated = await api.GenerateAsync(
+            barcodeType: barcodeType,
+            data: data,
+            imageFormat: BarcodeImageFormat.Svg);
+
+        using var reader = new StreamReader(generated, Utf8NoBom, detectEncodingFromByteOrderMarks: true);
+        return await reader.ReadToEndAsync();
+    }
+
+    private static string CombineSvg(string eanSvg, string qrSvg)
+    {
+        XDocument eanDoc = XDocument.Parse(eanSvg);
+        XDocument qrDoc = XDocument.Parse(qrSvg);
+
+        double eanWidth = ParseLength(eanDoc.Root?.Attribute("width"));
+        double eanHeight = ParseLength(eanDoc.Root?.Attribute("height"));
+        double qrWidth = ParseLength(qrDoc.Root?.Attribute("width"));
+        double qrHeight = ParseLength(qrDoc.Root?.Attribute("height"));
+
+        double combinedWidth = eanWidth + BarcodeSpacing + qrWidth;
+        double combinedHeight = Math.Max(eanHeight, qrHeight);
+
+        XNamespace svgNamespace = eanDoc.Root?.Name.Namespace ?? "http://www.w3.org/2000/svg";
+        var combinedRoot = new XElement(svgNamespace + "svg",
+            new XAttribute("xmlns", svgNamespace.NamespaceName),
+            new XAttribute(XNamespace.Xmlns + "xlink", "http://www.w3.org/1999/xlink"),
+            new XAttribute("width", ToInvariantLength(combinedWidth)),
+            new XAttribute("height", ToInvariantLength(combinedHeight)),
+            new XAttribute("viewBox", $"0 0 {ToInvariantLength(combinedWidth)} {ToInvariantLength(combinedHeight)}"));
+
+        double eanOffsetY = Math.Max(0, (combinedHeight - eanHeight) / 2);
+        double qrOffsetY = Math.Max(0, (combinedHeight - qrHeight) / 2);
+
+        combinedRoot.Add(CreateNestedSvg(eanDoc, 0, eanOffsetY, "EAN13"));
+        combinedRoot.Add(CreateNestedSvg(qrDoc, eanWidth + BarcodeSpacing, qrOffsetY, "QR"));
+
+        return combinedRoot.ToString(SaveOptions.OmitDuplicateNamespaces);
+    }
+
+    private static XElement CreateNestedSvg(XDocument source, double offsetX, double offsetY, string label)
+    {
+        if (source.Root == null)
+        {
+            throw new InvalidOperationException("SVG document does not have a root element.");
+        }
+
+        var nested = new XElement(source.Root);
+        nested.SetAttributeValue("x", ToInvariantLength(offsetX));
+        nested.SetAttributeValue("y", ToInvariantLength(offsetY));
+        nested.SetAttributeValue("data-barcode", label);
+        return nested;
+    }
+
+    private static double ParseLength(XAttribute? attribute, double fallback = 100d)
+    {
+        return ParseLength(attribute?.Value, fallback);
+    }
+
+    private static double ParseLength(string? rawValue, double fallback = 100d)
+    {
+        if (string.IsNullOrWhiteSpace(rawValue))
+        {
+            return fallback;
+        }
+
+        var buffer = new StringBuilder();
+        foreach (char c in rawValue)
+        {
+            if (char.IsDigit(c) || c == '.' || c == '-')
+            {
+                buffer.Append(c);
+            }
+            else if (buffer.Length > 0)
+            {
+                break;
+            }
+        }
+
+        return double.TryParse(buffer.ToString(), NumberStyles.Float, CultureInfo.InvariantCulture, out double parsed)
+            ? parsed
+            : fallback;
+    }
+
+    private static string ToInvariantLength(double value)
+    {
+        return value.ToString("0.##", CultureInfo.InvariantCulture);
+    }
+}