fix: fix text decoration regressions (#1448)

Author: a1rwulf

lib/src/builtins/interactive_element_builtin.dart

@@ -30,6 +30,7 @@ class InteractiveElementBuiltIn extends HtmlExtension {
       style: Style(
         color: Colors.blue,
         textDecoration: TextDecoration.underline,
+        textDecorationColor: Colors.blue,
       ),
       node: context.node,
       elementId: context.id,

lib/src/builtins/styled_element_builtin.dart

@@ -414,9 +414,17 @@ class StyledElementBuiltIn extends HtmlExtension {
         continue monospace;
       underline:
       case "u":
-        styledElement.style = Style(
-          textDecoration: TextDecoration.underline,
-        );
+        for (var child in styledElement.children) {
+          if (child.attributes.containsKey("style")) {
+            final newStyle = inlineCssToStyle(child.attributes["style"], null);
+            if (newStyle != null) {
+              styledElement.style = styledElement.style
+                  .merge(Style(textDecorationColor: newStyle.color));
+            }
+          }
+        }
+        styledElement.style = styledElement.style
+            .merge(Style(textDecoration: TextDecoration.underline));
         break;
       case "var":
         continue italics;

lib/src/css_parser.dart

@@ -292,7 +292,7 @@ Style declarationsToStyle(Map<String, List<css.Expression>> declarations) {
           style.border = newBorder;
           break;
         case 'color':
-          style.color =
+          style.color = style.textDecorationColor =
               ExpressionMapping.expressionToColor(value.first) ?? style.color;
           break;
         case 'direction':

lib/src/style.dart

@@ -404,6 +404,10 @@ class Style {
         child.textDecoration ?? TextDecoration.none,
         textDecoration ?? TextDecoration.none,
       ]),
+      textDecorationColor: child.textDecorationColor ?? textDecorationColor,
+      textDecorationThickness:
+          child.textDecorationThickness ?? textDecorationThickness,
+      textDecorationStyle: child.textDecorationStyle ?? textDecorationStyle,
       textShadow: child.textShadow ?? textShadow,
       whiteSpace: child.whiteSpace ?? whiteSpace,
       wordSpacing: child.wordSpacing ?? wordSpacing,