From 8d6e9b7156d0f9fd90d03dca3f4934069559b07c Mon Sep 17 00:00:00 2001
From: Erik Ziegler <erik.ziegler@ulg.ac.be>
Date: Thu, 19 Nov 2015 14:30:19 +0100
Subject: [PATCH] Added Prior indicator to viewport overlay based on oldest
 study date

---
 .../viewportOverlay/viewportOverlay.html      |  2 +-
 .../viewer/viewportOverlay/viewportOverlay.js | 24 +++++++++++++++++++
 .../viewportOverlay/viewportOverlay.styl      |  6 ++++-
 3 files changed, 30 insertions(+), 2 deletions(-)

diff --git a/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.html b/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.html
index 68d7c092a..7231f1939 100644
--- a/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.html
+++ b/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.html
@@ -3,7 +3,7 @@
         <div class="topleft dicomTag">
             <div>{{formatPN patientName}}</div>
             <div>{{patientId}}</div>
-            <div></div>
+            <div class='priorIndicator'>{{prior}}</div>
         </div>
         <div class="topright dicomTag">
             <div>{{studyDescription}}</div>
diff --git a/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.js b/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.js
index 00eff947a..a2c904e73 100644
--- a/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.js
+++ b/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.js
@@ -151,5 +151,29 @@ Template.viewportOverlay.helpers({
     },
     numImages : function() {
         return getSeries.call(this, 'numImages');
+    },
+    prior : function() {
+        // This helper is updated whenever a new image is displayed in the viewport
+        Session.get('CornerstoneNewImage' + this.viewportIndex);
+        if (!this.imageId) {
+            return;
+        }
+
+        // Make sure there are more than two studies loaded in the viewer
+        //
+        // Here we sort the collection in ascending order by study date, so
+        // that we can obtain the oldest study as the first element of the array
+        //
+        // TODO= Find out if we should encode studyDate as a Date in the ViewerStudies Collection
+        var viewportStudies = ViewerStudies.find({}, {sort: {studyDate: 1}});
+        if (viewportStudies.count() < 2) {
+            return;
+        }
+
+        // Get study data
+        var study = cornerstoneTools.metaData.get('study', this.imageId);
+        if (study.instanceUid === viewportStudies.fetch()[0].studyInstanceUid) {
+            return 'Prior';
+        }
     }
 });
\ No newline at end of file
diff --git a/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.styl b/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.styl
index 7aa2261ee..4b9126b62 100644
--- a/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.styl
+++ b/Packages/viewerbase/components/viewer/viewportOverlay/viewportOverlay.styl
@@ -24,4 +24,8 @@
   .bottomright
     bottom: 3px
     right: 3px
-    text-align: right
\ No newline at end of file
+    text-align: right
+
+  .priorIndicator
+    font-weight: bold
+    color: yellow
\ No newline at end of file