fix: issue-372, issue-227, issue-406

lib/core/utils/inline_svg_css.dart

@@ -0,0 +1,61 @@
+/// flutter_svg / vector_graphics ignore `<style>` blocks.
+/// Paths then get the SVG default fill (black), so badges look like a black blob.
+/// This inlines class rules from `<style>` as attributes before parsing.
+String inlineSvgCss(String svg) {
+  final styleBlockPattern = RegExp(
+    r'<style[^>]*>(?:<!\[CDATA\[)?([\s\S]*?)(?:\]\]>)?</style>',
+    caseSensitive: false,
+  );
+
+  final classProps = <String, Map<String, String>>{};
+  for (final match in styleBlockPattern.allMatches(svg)) {
+    final css = match.group(1) ?? '';
+    final rulePattern = RegExp(r'\.([A-Za-z0-9_-]+)\s*\{([^}]*)\}');
+    for (final rule in rulePattern.allMatches(css)) {
+      final className = rule.group(1)!;
+      final body = rule.group(2)!;
+      final props = classProps.putIfAbsent(className, () => <String, String>{});
+      for (final declaration in body.split(';')) {
+        final colon = declaration.indexOf(':');
+        if (colon <= 0) {
+          continue;
+        }
+        final key = declaration.substring(0, colon).trim();
+        final value = declaration.substring(colon + 1).trim();
+        if (key.isNotEmpty && value.isNotEmpty) {
+          props[key] = value;
+        }
+      }
+    }
+  }
+
+  var result = svg.replaceAll(styleBlockPattern, '');
+  if (classProps.isEmpty) {
+    return result;
+  }
+
+  result = result.replaceAllMapped(RegExp(r'''\sclass=(["'])([^"']+)\1'''), (
+    Match match,
+  ) {
+    final classes = match
+        .group(2)!
+        .split(RegExp(r'\s+'))
+        .where((name) => name.isNotEmpty);
+    final attrs = <String, String>{};
+    for (final className in classes) {
+      final props = classProps[className];
+      if (props != null) {
+        attrs.addAll(props);
+      }
+    }
+    if (attrs.isEmpty) {
+      return match.group(0)!;
+    }
+    final attrString = attrs.entries
+        .map((entry) => '${entry.key}="${entry.value}"')
+        .join(' ');
+    return ' $attrString';
+  });
+
+  return result;
+}