fix(Image Download): various bug fixes for image download (#3396)

- prevent non-cornerstone viewports from showing the image download dialogue
- passing the rendering engine id to ToolGroup.addViewport
- fixed the keep/dismiss aspect feature

extensions/cornerstone/src/commandsModule.ts

@@ -368,6 +368,21 @@ function commandsModule({
     },
     showDownloadViewportModal: () => {
       const { activeViewportIndex } = viewportGridService.getState();
+
+      if (
+        !cornerstoneViewportService.getCornerstoneViewportByIndex(
+          activeViewportIndex
+        )
+      ) {
+        // Cannot download a non-cornerstone viewport (image).
+        uiNotificationService.show({
+          title: 'Download Image',
+          message: 'Image cannot be downloaded',
+          type: 'error',
+        });
+        return;
+      }
+
       const { uiModalService } = servicesManager.services;
 
       if (uiModalService) {

extensions/cornerstone/src/utils/CornerstoneViewportDownloadForm.tsx

@@ -217,7 +217,7 @@ const CornerstoneViewportDownloadForm = ({
     );
 
     // add the viewport to the toolGroup
-    toolGroup.addViewport(downloadViewportId);
+    toolGroup.addViewport(downloadViewportId, renderingEngineId);
 
     Object.keys(toolGroup._toolInstances).forEach(toolName => {
       // make all tools Enabled so that they can not be interacted with