LT-331 Study list context menu behaviour issues

Packages/ohif-measurements/client/components/longitudinal/longitudinalStudyListContextMenu/longitudinalStudyListContextMenu.html

@@ -2,17 +2,26 @@
     {{#dropdownForm}}
         <li><a id="viewStudies" type="button" title="View Studies">View</a></li>
         <li class="divider" role="separator"></li>
-        <li>
-            <a id="launchStudyAssociation" title="Launch Study Association">Associate</a>
+
+        {{#let classes=getAssociationClasses}}
+        <li class="{{classes}}">
+            <a id="launchStudyAssociation" class="{{classes}}" title="Launch Study Association">Associate</a>
         </li>
-        <li><a id="launchRemoveAssociation"
+        {{/let}}
+
+        {{#let classes=getRemoveAssociationClasses}}
+        <li class="{{classes}}">
+            <a id="launchRemoveAssociation"
                type="button"
+               class="{{classes}}"
                data-toggle="modal"
                data-target="#confirmRemoveTimepointAssociation"
                title="Remove Timepoint Association">
                Remove Association
            </a>
         </li>
+        {{/let}}
+
         <li class="divider" role="separator"></li>
         <li>
             <a id="viewSeriesDetails" type="button"

Packages/ohif-measurements/client/components/longitudinal/longitudinalStudyListContextMenu/longitudinalStudyListContextMenu.js

@@ -8,7 +8,61 @@ import { OHIF } from 'meteor/ohif:core';
 // See https://github.com/aldeed/meteor-template-extension
 const defaultTemplate = 'studyContextMenu';
 
+function getAssociationAssessment() {
+    // default result value
+    const assessment = {
+        selected: 0,
+        associated: 0
+    };
+    // check if timepointApi is available
+    const timepointApi = StudyList.timepointApi;
+    if (timepointApi) {
+        // Get a Cursor pointing to the selected Studies from the StudyList
+        const selectedStudies = OHIF.studylist.getSelectedStudies();
+        if (selectedStudies.length > 0) {
+            assessment.selected = selectedStudies.length;
+            // Loop through the selected Studies and return true if at least one study has no association.
+            for (let i = selectedStudies.length - 1; i >= 0; --i) {
+                let study = selectedStudies[i],
+                    timepoints = timepointApi.study(study.studyInstanceUid);
+                if (timepoints && timepoints.length > 0) {
+                    assessment.associated++;
+                }
+            }
+        }
+    }
+    return assessment;
+}
+
+Template.longitudinalStudyListContextMenu.helpers({
+
+    getAssociationClasses() {
+        const disabledClass = 'disabled';
+        let classList = '';
+
+        const assessment = getAssociationAssessment();
+        if (assessment.selected < 1 || assessment.associated > 0) {
+            classList += disabledClass;
+        }
+
+        return classList;
+    },
+
+    getRemoveAssociationClasses() {
+        const disabledClass = 'disabled';
+        let classList = '';
+
+        const assessment = getAssociationAssessment();
+        if (assessment.selected < 1 || assessment.selected !== assessment.associated) {
+            classList += disabledClass;
+        }
+
+        return classList;
+    }
+});
+
 Template.longitudinalStudyListContextMenu.replaces(defaultTemplate);
+Template[defaultTemplate].inheritsHelpersFrom('longitudinalStudyListContextMenu');
 
 StudyList.functions.launchStudyAssociation = () => OHIF.ui.showFormDialog('dialogStudyAssociation');
 StudyList.functions.removeTimepointAssociations = removeTimepointAssociations;