operator direction fixed

model-command/src/main/java/lcsb/mapviewer/commands/layout/ApplySimpleLayoutModelCommand.java

@@ -272,7 +272,7 @@ public class ApplySimpleLayoutModelCommand extends ApplyLayoutModelCommand {
       }
       Point2D productPoint = reaction.getReactants().get(0).getElement().getCenter();
       Point2D operatorPoint = getMiddlePoint(middle, productPoint);
-      operator.setLine(new PolylineData(middle, operatorPoint));
+      operator.setLine(new PolylineData(operatorPoint,middle));
       reaction.addNode(operator);
       middle = operatorPoint;
     }