minor node editor enhancements

ui/nodeview.cpp

@@ -49,9 +49,13 @@ void NodeView::mouseReleaseEvent(QMouseEvent *event)
 
 void NodeView::wheelEvent(QWheelEvent *event)
 {
-  if (event->angleDelta().y() < 0) {
-    scale(0.9, 0.9);
+  if (event->modifiers() & Qt::ControlModifier) {
+    if (event->angleDelta().y() < 0) {
+      scale(0.9, 0.9);
+    } else {
+      scale(1.1, 1.1);
+    }
   } else {
-    scale(1.1, 1.1);
+    QGraphicsView::wheelEvent(event);
   }
 }