diff --git a/TULIP/src/lu/list/itis/dkd/tui/space/SpatialMatrix.java b/TULIP/src/lu/list/itis/dkd/tui/space/SpatialMatrix.java
index bfd44c1e5abaa3af7d4614e9dbb0c550138794a7..d72f9a05c88f819c8d43e901fac7eb7d18b0d58a 100644
--- a/TULIP/src/lu/list/itis/dkd/tui/space/SpatialMatrix.java
+++ b/TULIP/src/lu/list/itis/dkd/tui/space/SpatialMatrix.java
@@ -284,7 +284,10 @@ public class SpatialMatrix {
      *         are tied.
      */
     public TangibleObject getLeftMostObject() {
-        return horizontal.get(0);
+        if (horizontal.size() > 0)
+            return horizontal.get(0);
+
+        return null;
     }
 
     /**
@@ -295,7 +298,10 @@ public class SpatialMatrix {
      *         tied.
      */
     public TangibleObject getRightMostObject() {
-        return horizontal.get(horizontal.size() - 1);
+        if (horizontal.size() > 0)
+            return horizontal.get(horizontal.size() - 1);
+
+        return null;
     }
 
     /**
@@ -306,7 +312,10 @@ public class SpatialMatrix {
      *         are tied.
      */
     public TangibleObject getTopObject() {
-        return vertical.get(0);
+        if (vertical.size() > 0)
+            return vertical.get(0);
+
+        return null;
     }
 
     /**
@@ -317,7 +326,10 @@ public class SpatialMatrix {
      *         tied.
      */
     public TangibleObject getBottomObject() {
-        return vertical.get(vertical.size() - 1);
+        if (vertical.size() > 0)
+            return vertical.get(vertical.size() - 1);
+
+        return null;
     }
 
     /**
diff --git a/TULIP/src/lu/list/itis/dkd/tui/space/SpatialPositioningManager.java b/TULIP/src/lu/list/itis/dkd/tui/space/SpatialPositioningManager.java
index ab5163c536b9bc3419f523888d3408d00823d088..125d8514de0283610e3a25fa5c0e9bcad07114b6 100644
--- a/TULIP/src/lu/list/itis/dkd/tui/space/SpatialPositioningManager.java
+++ b/TULIP/src/lu/list/itis/dkd/tui/space/SpatialPositioningManager.java
@@ -164,9 +164,22 @@ public class SpatialPositioningManager implements SpatialEventListener {
      *         are tied.
      */
     public BaseWidget getLeftMostWidget() {
+        if (spatialMatrix.getLeftMostObject() == null)
+            return null;
+
         return TangibleObjectManager.getWidget(spatialMatrix.getLeftMostObject().getObjectId());
     }
 
+    /**
+     * The method will return the left-most tangible object.
+     * 
+     * @return The object with the smallest x coordinate.
+     */
+    public TangibleObject getLeftMostObject() {
+        return spatialMatrix.getLeftMostObject();
+    }
+
+
     /**
      * The method will return the right-most widget, that is, the last widget found based based on
      * its x-axis coordinate. The retrieval is based on the underlying handles.
@@ -175,9 +188,21 @@ public class SpatialPositioningManager implements SpatialEventListener {
      *         tied.
      */
     public BaseWidget getRightMostWidget() {
+        if (spatialMatrix.getRightMostObject() == null)
+            return null;
+
         return TangibleObjectManager.getWidget(spatialMatrix.getRightMostObject().getObjectId());
     }
 
+    /**
+     * The method will return the right-most tangible object.
+     * 
+     * @return The object with the largest x coordinate.
+     */
+    public TangibleObject getRightMostObject() {
+        return spatialMatrix.getRightMostObject();
+    }
+
     /**
      * The method will return the top-most widget, that is, the first widget found based based on
      * its y-axis coordinate. The retrieval is based on the underlying handles.
@@ -186,9 +211,21 @@ public class SpatialPositioningManager implements SpatialEventListener {
      *         are tied.
      */
     public BaseWidget getTopWidget() {
+        if (spatialMatrix.getTopObject() == null)
+            return null;
+
         return TangibleObjectManager.getWidget(spatialMatrix.getTopObject().getObjectId());
     }
 
+    /**
+     * The method will return the top-most tangible object.
+     * 
+     * @return The object with the smallest y coordinate.
+     */
+    public TangibleObject getTopObject() {
+        return spatialMatrix.getTopObject();
+    }
+
     /**
      * The method will return the bottom-most widget, that is, the last widget found based based on
      * its y-axis coordinate. The retrieval is based on the underlying handles.
@@ -197,9 +234,21 @@ public class SpatialPositioningManager implements SpatialEventListener {
      *         tied.
      */
     public BaseWidget getBottomWidget() {
+        if (spatialMatrix.getBottomObject() == null)
+            return null;
+
         return TangibleObjectManager.getWidget(spatialMatrix.getBottomObject().getObjectId());
     }
 
+    /**
+     * The method will return the bottom-most tangible object.
+     * 
+     * @return The object with the largest y coordinate.
+     */
+    public TangibleObject getBottomObject() {
+        return spatialMatrix.getBottomObject();
+    }
+
     /**
      * Method for returning a list of widgets that are to the left of a given widget. The method
      * either returns all objects no matter their alignment with this widget, or only returns