diff --git a/CHANGELOG.txt b/CHANGELOG.txt
index cc78417223afad64a5c2219ff93a5b708a70affc..71fa89022623d1467a624086d06941acff7e6b08 100644
--- a/CHANGELOG.txt
+++ b/CHANGELOG.txt
@@ -3,6 +3,8 @@
 + Added test method for various classes.
 + Changed update method to return whether the underlying data structure have indeed been changed.
 + Added PositionChangeListener.
++ Added method for fetching the position of the lowest ID handle from the BaseWidget.
++ Added methods to filter the list of widgets returned by getLeftMostWidget.
 
 2.1.3
 
diff --git a/TULIP/src/lu/list/itis/dkd/tui/adapter/TuiAdapter.java b/TULIP/src/lu/list/itis/dkd/tui/adapter/TuiAdapter.java
index a4e62ec73ef7cfad2f8234376e98611b902a30d1..75a5686257b43048abfa418d7ab9f80cc96f298d 100644
--- a/TULIP/src/lu/list/itis/dkd/tui/adapter/TuiAdapter.java
+++ b/TULIP/src/lu/list/itis/dkd/tui/adapter/TuiAdapter.java
@@ -17,6 +17,7 @@
 package lu.list.itis.dkd.tui.adapter;
 
 import lu.list.itis.dkd.dbc.annotation.NonNullByDefault;
+import lu.list.itis.dkd.dbc.annotation.Nullable;
 import lu.list.itis.dkd.tui.TangibleInterfaceManager;
 import lu.list.itis.dkd.tui.TangibleObjectManager;
 import lu.list.itis.dkd.tui.event.SpatialEvent;
@@ -170,8 +171,10 @@ public abstract class TuiAdapter {
      * @param listener
      *        The listener to add.
      */
-    public synchronized void addListener(SpatialEventListener listener) {
-        spatialEventListeners.add(listener);
+    public synchronized void addListener(@Nullable SpatialEventListener listener) {
+        if (null != listener) {
+            spatialEventListeners.add(listener);
+        }
     }
 
     /**
@@ -180,8 +183,10 @@ public abstract class TuiAdapter {
      * @param listener
      *        The listener to remove.
      */
-    public synchronized void removeListener(SpatialEventListener listener) {
-        spatialEventListeners.remove(listener);
+    public synchronized void removeListener(@Nullable SpatialEventListener listener) {
+        if (null != listener) {
+            spatialEventListeners.remove(listener);
+        }
     }
 
     /**
diff --git a/TULIP/src/lu/list/itis/dkd/tui/event/PositionChangeListener.java b/TULIP/src/lu/list/itis/dkd/tui/event/PositionChangeListener.java
index 77474e392c0e65fa03156120a948aa9e2bdc014c..f0835cd96c773d2a98fa87d3a275e96e3b1667a2 100644
--- a/TULIP/src/lu/list/itis/dkd/tui/event/PositionChangeListener.java
+++ b/TULIP/src/lu/list/itis/dkd/tui/event/PositionChangeListener.java
@@ -16,6 +16,7 @@
  */
 package lu.list.itis.dkd.tui.event;
 
+import lu.list.itis.dkd.dbc.annotation.NonNullByDefault;
 import lu.list.itis.dkd.tui.space.SpatialPositioningManager;
 
 import java.util.EventListener;
@@ -25,6 +26,7 @@ import java.util.EventListener;
  * @since 2.1
  * @version 2.1.4
  */
+@NonNullByDefault
 public interface PositionChangeListener extends EventListener {
 
     /**
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 09796aeb4343548be4380f87243f3bb726a325b5..94f12ee873d3f4e7d1311cd9ed46fd9f76137bf4 100644
--- a/TULIP/src/lu/list/itis/dkd/tui/space/SpatialPositioningManager.java
+++ b/TULIP/src/lu/list/itis/dkd/tui/space/SpatialPositioningManager.java
@@ -213,6 +213,59 @@ public class SpatialPositioningManager implements SpatialEventListener {
         return TangibleObjectManager.getWidget(getLeftMostObject().getObjectId());
     }
 
+    /**
+     * The method will return the left-most widget, that is, the first widget found based based on
+     * its x-axis coordinate that is not an instance of any of the classes present in the filter
+     * list. The retrieval is based on the underlying handles.
+     * 
+     * @param filter
+     *        The {@link List} of {@link Class}es that the returned widget should not be part of.
+     * 
+     * @return The widget with the smallest x-axis coordinate not in the filter list. Returns the
+     *         first if more than one are tied. Will return <code>null</code> if no object is
+     *         present.
+     */
+    public @Nullable BaseWidget getLeftMostWidget(List<Class<?>> filter) {
+        if (getLeftMostObject() == null) {
+            return null;
+        }
+
+        for (TangibleObject object : spatialMatrix.getHorizontal()) {
+            BaseWidget widget = TangibleObjectManager.getWidget(object.getObjectId());
+            if (!filter.contains(widget.getClass())) {
+                return widget;
+            }
+        }
+        return null;
+    }
+
+    /**
+     * The method will return the left-most widget, that is, the first widget found based based on
+     * its x-axis coordinate that is of the provided class. The retrieval is based on the underlying
+     * handles.
+     * 
+     * @param _class
+     *        The {@link Class} of the widget that should be returned.
+     * 
+     * @return The widget with the smallest x-axis coordinate that is of the given class. Returns
+     *         the first if more than one are tied. Will return <code>null</code> if no object is
+     *         present.
+     */
+    public @Nullable BaseWidget getLeftMostWidget(Class<?> _class) {
+        if (getLeftMostObject() == null) {
+            return null;
+        }
+
+        for (TangibleObject object : spatialMatrix.getHorizontal()) {
+            BaseWidget widget = TangibleObjectManager.getWidget(object.getObjectId());
+            if (widget.getClass().equals(_class)) {
+                return widget;
+            }
+        }
+
+        return null;
+    }
+
     /**
      * The method will return the left-most tangible object.
      * 
@@ -222,7 +275,6 @@ public class SpatialPositioningManager implements SpatialEventListener {
         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.
diff --git a/TULIP/src/lu/list/itis/dkd/tui/widget/BaseWidget.java b/TULIP/src/lu/list/itis/dkd/tui/widget/BaseWidget.java
index 08039453c0eb8a2e0a01ea8b96ca48ee46a0cb3b..84ce68dddc5b2132e46d59876f5d23b7b1fb77fa 100644
--- a/TULIP/src/lu/list/itis/dkd/tui/widget/BaseWidget.java
+++ b/TULIP/src/lu/list/itis/dkd/tui/widget/BaseWidget.java
@@ -26,11 +26,13 @@ import lu.list.itis.dkd.tui.widget.builder.BaseBuilder;
 import lu.list.itis.dkd.tui.widget.corona.Corona;
 
 import com.google.common.collect.Multimap;
+import com.google.common.collect.Ordering;
 
 import java.awt.Graphics2D;
 import java.awt.Shape;
 import java.util.ArrayList;
 import java.util.Collection;
+import java.util.Collections;
 import java.util.HashMap;
 import java.util.List;
 
@@ -217,6 +219,20 @@ public class BaseWidget {
         return positions.get(handleId);
     }
 
+    /**
+     * Method used for returning th {@link Point} that holds the position of the handle with the
+     * lowest ID. This is useful also when the widget is only represented by a single handle and one
+     * wants to recover the position of that handle.
+     * 
+     * @return The position as a {@link Point} of the handle with the lowest ID.
+     */
+    public Point getPosition() {
+        List<Integer> keys = new ArrayList<>(positions.keySet());
+        Collections.sort(keys, Ordering.natural());
+
+        return positions.get(keys.get(0));
+    }
+
     /**
      * Simple getter method for positions.
      *