add support for stereotype annotations for class diagrams

packages/mermaid/src/diagrams/class/shapeUtil.ts

@@ -45,6 +45,36 @@ export async function textHelper<T extends SVGGraphicsElement>(
 
   labelGroup = shapeSvg.insert('g').attr('class', 'label-group text');
   await addText(labelGroup, node, 0, ['font-weight: bolder']);
+  // Determine styling based on annotations
+  let labelStyles = ['font-weight: bolder']; // Default bold style
+  let labelClass = 'classTitle';
+
+  if (node.annotations && node.annotations.length > 0) {
+    const annotation = node.annotations[0].toLowerCase();
+    switch (annotation) {
+      case 'abstract':
+        labelClass = 'classTitle abstract';
+        labelStyles = [];
+        break;
+      case 'enumeration':
+        labelClass = 'classTitle enumeration';
+        labelStyles = [];
+        break;
+      case 'interface':
+        labelClass = 'classTitle interface';
+        labelStyles = [];
+        break;
+      default:
+        labelClass = 'classTitle';
+        labelStyles = ['font-weight: bolder'];
+        break;
+    }
+  }
+
+  // Apply the CSS class to the label group
+  labelGroup.attr('class', `label-group text ${labelClass}`);
+
+  await addText(labelGroup, node, 0, labelStyles);
   const labelGroupBBox = labelGroup.node()!.getBBox();
   labelGroupHeight = labelGroupBBox.height;
 

packages/mermaid/src/diagrams/class/styles.js

@@ -148,6 +148,18 @@ g.classGroup line {
   stroke: ${options.lineColor} !important;
   stroke-width: 1;
 }
+  
+  .classTitle.abstract {
+  font-style: italic;
+  font-weight: normal;
+}
+.classTitle.enumeration {
+  text-decoration: underline;
+  font-weight: normal;
+}
+.classTitle.interface {
+  font-weight: bold;
+}
 
 .edgeTerminals {
   font-size: 11px;