functioning null-safe code

Author: Tomas Korima

core/src/main/java/de/tesis/dynaware/grapheditor/core/selections/SelectionDragManager.java

@@ -275,8 +275,10 @@ private void addPositionListeners(final Region master, final GModel model) {
                 if (nodeSkin.isSelected() && !nodeSkin.getRoot().equals(master)) {
 
                     final Region slave1 = nodeSkin.getRoot();
-                    double offset = Optional.ofNullable(nodeLayoutXOffsets.get(node)).orElse(0d);
-                    slave1.setLayoutX((Double) n + offset);
+                    Double offset = nodeLayoutXOffsets.get(node);
+                    if(offset != null) {
+                        slave1.setLayoutX((Double) n + offset);
+                    }
                 }
             }
 
@@ -289,8 +291,10 @@ private void addPositionListeners(final Region master, final GModel model) {
                     if (jointSkin.isSelected() && !jointSkin.getRoot().equals(master)) {
 
                         final Region slave2 = jointSkin.getRoot();
-                        double offset = Optional.ofNullable(jointLayoutXOffsets.get(joint)).orElse(0d);
-                        slave2.setLayoutX((Double) n + offset);
+                        Double offset = jointLayoutXOffsets.get(joint);
+                        if(offset != null) {
+                            slave2.setLayoutX((Double) n + offset);
+                        }
                     }
                 }
             }
@@ -305,8 +309,10 @@ private void addPositionListeners(final Region master, final GModel model) {
                 if (nodeSkin.isSelected() && !nodeSkin.getRoot().equals(master)) {
 
                     final Region slave1 = nodeSkin.getRoot();
-                    double offset = Optional.ofNullable(nodeLayoutYOffsets.get(node)).orElse(0d);
-                    slave1.setLayoutY((Double) n + offset);
+                    Double offset = nodeLayoutYOffsets.get(node);
+                    if(offset != null) {
+                        slave1.setLayoutY((Double) n + offset);
+                    }
                 }
             }
 
@@ -319,8 +325,10 @@ private void addPositionListeners(final Region master, final GModel model) {
                     if (jointSkin.isSelected() && !jointSkin.getRoot().equals(master)) {
 
                         final Region slave2 = jointSkin.getRoot();
-                        double offset = Optional.ofNullable(jointLayoutYOffsets.get(joint)).orElse(0d);
-                        slave2.setLayoutY((Double) n + jointLayoutYOffsets.get(joint));
+                        Double offset = jointLayoutYOffsets.get(joint);
+                        if(offset != null) {
+                            slave2.setLayoutY((Double) n + offset);
+                        }
                     }
                 }
             }