feat(segmentation mode): Add create, and export SEG with Brushes (#3632)

platform/ui/src/contextProviders/ViewportGridProvider.tsx

@@ -70,7 +70,9 @@ const determineActiveViewportId = (state: DefaultState, newViewports: Map) => {
   const currentActiveViewport = state.viewports.get(activeViewportId);
 
   if (!currentActiveViewport) {
-    return null; // Return an appropriate value if the current active viewport is not found
+    // if there is no active viewport, we should just return the first viewport
+    const firstViewport = newViewports.values().next().value;
+    return firstViewport.viewportOptions.viewportId;
   }
 
   // for the new viewports, we should rank them by the displaySetInstanceUIDs
@@ -135,6 +137,10 @@ export function ViewportGridProvider({ children, service }) {
         payload.forEach(updatedViewport => {
           const { viewportId, displaySetInstanceUIDs } = updatedViewport;
 
+          if (!viewportId) {
+            throw new Error('ViewportId is required to set display sets for viewport');
+          }
+
           const previousViewport = viewports.get(viewportId);
 
           // Use the newly provide viewportOptions and display set options
@@ -142,8 +148,8 @@ export function ViewportGridProvider({ children, service }) {
           // That allows for easy updates of just the display set.
           const viewportOptions = merge(
             {},
-            updatedViewport?.viewportOptions,
-            previousViewport?.viewportOptions
+            previousViewport?.viewportOptions,
+            updatedViewport?.viewportOptions
           );
 
           const displaySetOptions = updatedViewport.displaySetOptions || [];
@@ -257,7 +263,7 @@ export function ViewportGridProvider({ children, service }) {
         }
 
         activeViewportIdToSet =
-          activeViewportIdToSet ?? determineActiveViewportId(state, viewports) ?? 'default';
+          activeViewportIdToSet ?? determineActiveViewportId(state, viewports);
 
         const ret = {
           ...state,