Officially enable SVG web viewer

QuickLook.Plugin/QuickLook.Plugin.ImageViewer/SvgMetaProvider.cs

@@ -0,0 +1,75 @@
+using System;
+using System.Diagnostics;
+using System.IO;
+using System.Text.RegularExpressions;
+using System.Windows;
+using System.Xml.Linq;
+
+namespace QuickLook.Plugin.ImageViewer;
+
+public class SvgMetaProvider(string path)
+{
+    private readonly string _path = path;
+    private Size _size = Size.Empty;
+
+    public Size GetSize()
+    {
+        if (_size != Size.Empty)
+        {
+            return _size;
+        }
+
+        if (!File.Exists(_path))
+        {
+            return _size;
+        }
+        try
+        {
+            var svgContent = File.ReadAllText(_path);
+            var svg = XElement.Parse(svgContent);
+            XNamespace ns = svg.Name.Namespace;
+
+            string widthAttr = svg.Attribute("width")?.Value;
+            string heightAttr = svg.Attribute("height")?.Value;
+
+            float? width = TryParseSvgLength(widthAttr);
+            float? height = TryParseSvgLength(heightAttr);
+
+            if (width.HasValue && height.HasValue)
+            {
+                _size = new Size { Width = width.Value, Height = height.Value };
+            }
+
+            string viewBoxAttr = svg.Attribute("viewBox")?.Value;
+            if (!string.IsNullOrEmpty(viewBoxAttr))
+            {
+                var parts = viewBoxAttr.Split([' ', ','], StringSplitOptions.RemoveEmptyEntries);
+                if (parts.Length == 4 &&
+                    float.TryParse(parts[2], out float vbWidth) &&
+                    float.TryParse(parts[3], out float vbHeight))
+                {
+                    _size = new Size { Width = vbWidth, Height = vbHeight };
+                }
+            }
+        }
+        catch (Exception e)
+        {
+            Debug.WriteLine(e);
+        }
+
+        return _size;
+    }
+
+    private static float? TryParseSvgLength(string input)
+    {
+        if (string.IsNullOrEmpty(input))
+            return null;
+
+        var match = Regex.Match(input.Trim(), @"^([\d.]+)(px|pt|mm|cm|in|em|ex|%)?$", RegexOptions.IgnoreCase);
+        if (match.Success && float.TryParse(match.Groups[1].Value, out float value))
+        {
+            return value;
+        }
+        return null;
+    }
+}