Implement support for stamp annotations

src/core/annotation.js

@@ -99,6 +99,9 @@ class AnnotationFactory {
       case 'StrikeOut':
         return new StrikeOutAnnotation(parameters);
 
+      case 'Stamp':
+        return new StampAnnotation(parameters);
+
       case 'FileAttachment':
         return new FileAttachmentAnnotation(parameters);
 
@@ -946,6 +949,15 @@ class StrikeOutAnnotation extends Annotation {
   }
 }
 
+class StampAnnotation extends Annotation {
+  constructor(parameters) {
+    super(parameters);
+
+    this.data.annotationType = AnnotationType.STAMP;
+    this._preparePopup(parameters.dict);
+  }
+}
+
 class FileAttachmentAnnotation extends Annotation {
   constructor(parameters) {
     super(parameters);

src/display/annotation_layer.js

@@ -92,6 +92,9 @@ class AnnotationElementFactory {
       case AnnotationType.STRIKEOUT:
         return new StrikeOutAnnotationElement(parameters);
 
+      case AnnotationType.STAMP:
+        return new StampAnnotationElement(parameters);
+
       case AnnotationType.FILEATTACHMENT:
         return new FileAttachmentAnnotationElement(parameters);
 
@@ -1004,6 +1007,30 @@ class StrikeOutAnnotationElement extends AnnotationElement {
   }
 }
 
+class StampAnnotationElement extends AnnotationElement {
+  constructor(parameters) {
+    let isRenderable = !!(parameters.data.hasPopup ||
+                          parameters.data.title || parameters.data.contents);
+    super(parameters, isRenderable, /* ignoreBorder = */ true);
+  }
+
+  /**
+   * Render the stamp annotation's HTML element in the empty container.
+   *
+   * @public
+   * @memberof StampAnnotationElement
+   * @returns {HTMLSectionElement}
+   */
+  render() {
+    this.container.className = 'stampAnnotation';
+
+    if (!this.data.hasPopup) {
+      this._createPopup(this.container, null, this.data);
+    }
+    return this.container;
+  }
+}
+
 class FileAttachmentAnnotationElement extends AnnotationElement {
   constructor(parameters) {
     super(parameters, /* isRenderable = */ true);