fix(segmentation overlay): update viewport ds list upon seg delete - OHIF-2425 (#5729)

- add segmentationExists check to getSopClassHandlerModule
- now firing SEGMENTATION_REMOVED and SEGMENTATION_REPRESENTATION_REMOVED events
- centralized segmentation removal in a listener
- when a segmentation is deleted (completely), remove it from all viewports it overlays
- when a segmentation is removed from a viewport, remove it as overlay from the viewport

---------

Co-authored-by: Joe Boccanfuso <joe.boccanfuso@radicalimaging.com>
Co-authored-by: Bill Wallace <wayfarer3130@gmail.com>

extensions/cornerstone-dicom-rt/src/getSopClassHandlerModule.ts

@@ -1,5 +1,6 @@
 import { utils, Types as OhifTypes } from '@ohif/core';
 import i18n from '@ohif/i18n';
+import { segmentation as cstSegmentation } from '@cornerstonejs/tools';
 
 import { SOPClassHandlerId } from './id';
 import loadRTStruct from './loadRTStruct';
@@ -8,8 +9,6 @@ const { sopClassDictionary } = utils;
 
 const sopClassUids = [sopClassDictionary.RTStructureSetStorage];
 
-const cachedRTStructsSEG = new Set<string>();
-
 const loadPromises = {};
 
 function _getDisplaySetsFromSeries(
@@ -143,23 +142,13 @@ function _load(
   if (
     (rtDisplaySet.loading || rtDisplaySet.isLoaded) &&
     loadPromises[SOPInstanceUID] &&
-    cachedRTStructsSEG.has(rtDisplaySet.displaySetInstanceUID)
+    _segmentationExists(rtDisplaySet)
   ) {
     return loadPromises[SOPInstanceUID];
   }
 
   rtDisplaySet.loading = true;
 
-  const { unsubscribe } = segmentationService.subscribe(
-    segmentationService.EVENTS.SEGMENTATION_LOADING_COMPLETE,
-    (evt: { rtDisplaySet: { displaySetInstanceUID: string } }) => {
-      if (evt.rtDisplaySet?.displaySetInstanceUID === rtDisplaySet.displaySetInstanceUID) {
-        cachedRTStructsSEG.add(rtDisplaySet.displaySetInstanceUID);
-        unsubscribe();
-      }
-    }
-  );
-
   // We don't want to fire multiple loads, so we'll wait for the first to finish
   // and also return the same promise to any other callers.
   loadPromises[SOPInstanceUID] = new Promise<void>(async (resolve, reject) => {
@@ -219,6 +208,10 @@ function _deriveReferencedSeriesSequenceFromFrameOfReferenceSequence(
   return ReferencedSeriesSequence;
 }
 
+function _segmentationExists(segDisplaySet) {
+  return !!cstSegmentation.state.getSegmentation(segDisplaySet.displaySetInstanceUID);
+}
+
 function getSopClassHandlerModule(params: OhifTypes.Extensions.ExtensionParams) {
   const { servicesManager, extensionManager } = params;