Implement support for Popup annotations

We already had most code ready for supporting Popup annotations, but it
was only available for Text annotations. This patch implements the
separation between Text (or any other annotation type for that matter)
and Popup annotations. According to the specification they are two very
separate entities and should thus be implemented that way.

The main reason for this change is because Popup annotations are used
with many other annotation types too. In order to support those, we
first need to have proper support for Popup annotations. With this patch
in place, implementing other annotation types will be much easier.

A consequence of this patch is that the Text annotation code is greatly
simplified. Essentially, a Text annotation is only a container with an
image. The Popup annotation takes care of the rest.

Finally, this change allows for a small bit of refactoring. We no longer
need a separate wrapper as the Popup annotation has its own container,
which acts as the wrapper. This means we can also remove the strange
sanity check that belonged with it.

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');
@@ -639,29 +640,21 @@ 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';
-    }
-
-    if (dict.has('C')) {
-      data.hasBgColor = true;
+      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';
     }
   }
 
@@ -746,6 +739,37 @@ 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;
+    if (!dict.has('Parent')) {
+      warn('Popup annotations without a parent annotation are not supported.');
+      return;
+    }
+
+    var parentItem = dict.get('Parent');
+    if (!parentItem) {
+      warn('Popup annotation has an invalid parent annotation.');
+      return;
+    }
+    this.data.parentId = dict.map.Parent.num;
+    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;