Annotations: move operator list addition logic to src/core/document.js

Ideally, the `Annotation` class should not have anything to do with the
page's operator list. How annotations are added to the page's operator
list is logic that belongs in `src/core/document.js` instead where the
operator list is constructed.

Moreover, some comments have been added to clarify the intent of the
code.

src/core/annotation.js

@@ -451,25 +451,6 @@ var Annotation = (function AnnotationClosure() {
     }
   };
 
-  Annotation.appendToOperatorList = function Annotation_appendToOperatorList(
-      annotations, opList, partialEvaluator, task, intent, renderForms) {
-    var annotationPromises = [];
-    for (var i = 0, n = annotations.length; i < n; ++i) {
-      if ((intent === 'display' && annotations[i].viewable) ||
-          (intent === 'print' && annotations[i].printable)) {
-        annotationPromises.push(
-          annotations[i].getOperatorList(partialEvaluator, task, renderForms));
-      }
-    }
-    return Promise.all(annotationPromises).then(function(operatorLists) {
-      opList.addOp(OPS.beginAnnotations, []);
-      for (var i = 0, n = operatorLists.length; i < n; ++i) {
-        opList.addOpList(operatorLists[i]);
-      }
-      opList.addOp(OPS.endAnnotations, []);
-    });
-  };
-
   return Annotation;
 })();
 

src/core/document.js

@@ -35,6 +35,7 @@
 }(this, function (exports, sharedUtil, corePrimitives, coreStream, coreObj,
                   coreParser, coreCrypto, coreEvaluator, coreAnnotation) {
 
+var OPS = sharedUtil.OPS;
 var MissingDataException = sharedUtil.MissingDataException;
 var Util = sharedUtil.Util;
 var assert = sharedUtil.assert;
@@ -63,7 +64,6 @@ var Linearization = coreParser.Linearization;
 var calculateMD5 = coreCrypto.calculateMD5;
 var OperatorList = coreEvaluator.OperatorList;
 var PartialEvaluator = coreEvaluator.PartialEvaluator;
-var Annotation = coreAnnotation.Annotation;
 var AnnotationFactory = coreAnnotation.AnnotationFactory;
 
 var Page = (function PageClosure() {
@@ -266,6 +266,8 @@ var Page = (function PageClosure() {
           });
       });
 
+      // Fetch the page's annotations and add their operator lists to the
+      // page's operator list to render them.
       var annotationsPromise = pdfManager.ensure(this, 'annotations');
       return Promise.all([pageListPromise, annotationsPromise]).then(
           function(datas) {
@@ -277,10 +279,25 @@ var Page = (function PageClosure() {
           return pageOpList;
         }
 
-        var annotationsReadyPromise = Annotation.appendToOperatorList(
-          annotations, pageOpList, partialEvaluator, task, intent,
-          renderInteractiveForms);
-        return annotationsReadyPromise.then(function () {
+        // Collect the operator list promises for the annotations. Each promise
+        // is resolved with the complete operator list for a single annotation.
+        var i, ii;
+        var opListPromises = [];
+        for (i = 0, ii = annotations.length; i < ii; i++) {
+          if ((intent === 'display' && annotations[i].viewable) ||
+              (intent === 'print' && annotations[i].printable)) {
+            opListPromises.push(annotations[i].getOperatorList(
+              partialEvaluator, task, renderInteractiveForms));
+          }
+        }
+
+        return Promise.all(opListPromises).then(function(opLists) {
+          pageOpList.addOp(OPS.beginAnnotations, []);
+          for (i = 0, ii = opLists.length; i < ii; i++) {
+            pageOpList.addOpList(opLists[i]);
+          }
+          pageOpList.addOp(OPS.endAnnotations, []);
+        }).then(function() {
           pageOpList.flush(true);
           return pageOpList;
         });