OHIF-125: Fix Exception caused by Cornerstone Tools when sending empty viewports and/or not DOM elements to its functions

Packages/viewerbase/lib/setActiveViewport.js

@@ -1,9 +1,10 @@
-setActiveViewport = function(element) {
+setActiveViewport = element => {
     if (!element) {
         return;
     }
 
-    var viewportIndex = $('.imageViewerViewport').index(element);
+    const viewportIndex = $('.imageViewerViewport').index(element);
+    const jQueryElement = $(element);
 
     // When an ActivateViewport event is fired, update the Meteor Session
     // with the viewport index that it was fired from.
@@ -14,15 +15,21 @@ setActiveViewport = function(element) {
 
     // Add the 'active' class to the parent container to highlight the active viewport
     $('#imageViewerViewports .viewportContainer').removeClass('active');
-    $(element).parents('.viewportContainer').addClass('active');
+    jQueryElement.parents('.viewportContainer').addClass('active');
 
     // Finally, enable stack prefetching and hide the reference lines from
-    // the newly activated viewport
-    enablePrefetchOnElement(element);
-    displayReferenceLines(element);
+    // the newly activated viewport that has a canvas
+
+    if (jQueryElement.find('canvas').length) {
+        // Cornerstone Tools compare DOM elements (check getEnabledElement cornerstone function)
+        // so we can't pass a jQuery object as an argument, otherwise it throws an excepetion
+        const domElement = jQueryElement.get(0);
+        enablePrefetchOnElement(domElement);
+        displayReferenceLines(domElement);
+    }
 
     // Set the div to focused, so keypress events are handled
     //$(element).focus();
     //.focus() event breaks in FF&IE
-    $(element).triggerHandler('focus');
+    jQueryElement.triggerHandler('focus');
 };