bugfix: fixing onhoversegment context menu always show

src/atlasViewer/atlasViewer.component.ts

@@ -165,13 +165,13 @@ export class AtlasViewer implements OnDestroy, OnInit, AfterViewInit {
             state.mouseOverSegment.constructor === Number ?
               state.mouseOverSegment.toString() :
               state.mouseOverSegment.name :
-            '' :
-          ''),
+            null :
+          null),
         distinctUntilChanged()
       ),
       this.onhoverLandmark$
     ).pipe(
-      map(([segment, onhoverLandmark]) => onhoverLandmark ? '' : segment )
+      map(([segment, onhoverLandmark]) => onhoverLandmark ? null : segment )
     )
 
   }

src/atlasViewer/atlasViewer.template.html

@@ -158,9 +158,9 @@
         {{ onhoverLandmark$ | async }} <i><small class = "mute-text">{{ toggleMessage }}</small></i>
       </div>
       <div 
-        *ngIf = "(onhoverSegment$ | async) !== ''" 
+        *ngIf = "onhoverSegment$ | async as onhoverSegment " 
         contextualBlock>
-        {{ onhoverSegment$ | async }} <i><small class = "mute-text">{{ toggleMessage }}</small></i>
+        {{ onhoverSegment }} <i><small class = "mute-text">{{ toggleMessage }}</small></i>
       </div>
       <!-- TODO Potentially implementing plugin contextual info -->
     </div>