Implement support for Popup annotations

Most code for Popup annotations is already present for Text annotations.
This patch extracts the popup creation logic from the Text annotation
code so it can be reused for Popup annotations.

Not only does this add support for Popup annotations, the Text
annotation code is also considerably easier. If a `Popup` entry is
available for a Text annotation, it will not be more than an image. The
popup will be handled by the Popup annotation. However, it is also
possible for Text annotations to not have a separate Popup annotation,
in which case the Text annotation handles the popup creation itself.

src/core/annotation.js

@@ -52,8 +52,6 @@ var ColorSpace = coreColorSpace.ColorSpace;
 var ObjectLoader = coreObj.ObjectLoader;
 var OperatorList = coreEvaluator.OperatorList;
 
-var DEFAULT_ICON_SIZE = 22; // px
-
 /**
  * @class
  * @alias AnnotationFactory
@@ -95,6 +93,9 @@ AnnotationFactory.prototype = /** @lends AnnotationFactory.prototype */ {
         }
         return new WidgetAnnotation(parameters);
 
+      case 'Popup':
+        return new PopupAnnotation(parameters);
+
       default:
         warn('Unimplemented annotation type "' + subtype + '", ' +
              'falling back to base annotation');
@@ -160,7 +161,7 @@ var Annotation = (function AnnotationClosure() {
 
     // Expose public properties using a data object.
     this.data = {};
-    this.data.id = params.ref.num;
+    this.data.id = params.ref.toString();
     this.data.subtype = dict.get('Subtype').name;
     this.data.annotationFlags = this.flags;
     this.data.rect = this.rectangle;
@@ -639,29 +640,29 @@ var TextWidgetAnnotation = (function TextWidgetAnnotationClosure() {
 })();
 
 var TextAnnotation = (function TextAnnotationClosure() {
-  function TextAnnotation(params) {
-    Annotation.call(this, params);
+  var DEFAULT_ICON_SIZE = 22; // px
 
-    var dict = params.dict;
-    var data = this.data;
+  function TextAnnotation(parameters) {
+    Annotation.call(this, parameters);
 
-    var content = dict.get('Contents');
-    var title = dict.get('T');
-    data.annotationType = AnnotationType.TEXT;
-    data.content = stringToPDFString(content || '');
-    data.title = stringToPDFString(title || '');
-    data.hasHtml = true;
+    this.data.annotationType = AnnotationType.TEXT;
+    this.data.hasHtml = true;
 
-    if (data.hasAppearance) {
-      data.name = 'NoIcon';
+    var dict = parameters.dict;
+    if (this.data.hasAppearance) {
+      this.data.name = 'NoIcon';
     } else {
-      data.rect[1] = data.rect[3] - DEFAULT_ICON_SIZE;
-      data.rect[2] = data.rect[0] + DEFAULT_ICON_SIZE;
-      data.name = dict.has('Name') ? dict.get('Name').name : 'Note';
+      this.data.rect[1] = this.data.rect[3] - DEFAULT_ICON_SIZE;
+      this.data.rect[2] = this.data.rect[0] + DEFAULT_ICON_SIZE;
+      this.data.name = dict.has('Name') ? dict.get('Name').name : 'Note';
     }
 
-    if (dict.has('C')) {
-      data.hasBgColor = true;
+    this.data.popup = !!dict.get('Popup');
+    if (!this.data.popup) {
+      // There is no associated Popup annotation, so the Text annotation
+      // must create its own popup.
+      this.data.title = stringToPDFString(dict.get('T') || '');
+      this.data.contents = stringToPDFString(dict.get('Contents') || '');
     }
   }
 
@@ -746,6 +747,33 @@ var LinkAnnotation = (function LinkAnnotationClosure() {
   return LinkAnnotation;
 })();
 
+var PopupAnnotation = (function PopupAnnotationClosure() {
+  function PopupAnnotation(parameters) {
+    Annotation.call(this, parameters);
+
+    this.data.annotationType = AnnotationType.POPUP;
+
+    var dict = parameters.dict;
+    var parentItem = dict.get('Parent');
+    if (!parentItem) {
+      warn('Popup annotation has a missing or invalid parent annotation.');
+      return;
+    }
+
+    this.data.parentId = dict.getRaw('Parent').toString();
+    this.data.title = stringToPDFString(parentItem.get('T') || '');
+    this.data.contents = stringToPDFString(parentItem.get('Contents') || '');
+    this.setColor(parentItem.get('C'));
+    this.data.color = this.color;
+
+    this.data.hasHtml = (this.data.title && this.data.contents);
+  }
+
+  Util.inherit(PopupAnnotation, Annotation, {});
+
+  return PopupAnnotation;
+})();
+
 exports.Annotation = Annotation;
 exports.AnnotationBorderStyle = AnnotationBorderStyle;
 exports.AnnotationFactory = AnnotationFactory;