diff --git a/src/org/hwo/models/ComboBoxHistoryModel.java b/src/org/hwo/models/ComboBoxHistoryModel.java
index e59e45e..081221d 100644
--- a/src/org/hwo/models/ComboBoxHistoryModel.java
+++ b/src/org/hwo/models/ComboBoxHistoryModel.java
@@ -1,36 +1,50 @@
 package org.hwo.models;
 
-import java.util.Arrays;
 import java.util.LinkedList;
-
 import javax.swing.ComboBoxModel;
 import javax.swing.event.ListDataEvent;
 import javax.swing.event.ListDataListener;
 
-public class ComboBoxHistoryModel<E> implements ComboBoxModel<E> {
+import org.hwo.models.History.HistoryListener;
+
+public class ComboBoxHistoryModel<E> implements ComboBoxModel<E>,HistoryListener<E> {
 
 	private LinkedList<ListDataListener> listDataListeners = new LinkedList<>();
-	private LinkedList<E> items = new LinkedList<>();
+	private History<E> history;
 	
 	private E selectedItem;
-	private int historySize;
 	
 	
 	public ComboBoxHistoryModel()
 	{
+		this.setHistory(new History<>());
 		this.selectedItem = null;
-		this.historySize = 10;
 	}
 	public ComboBoxHistoryModel(int historySize)
 	{
+		this.setHistory(new History<E>(historySize));
 		this.selectedItem = null;
-		this.historySize = historySize;
+	}
+	public ComboBoxHistoryModel(History<E> history){
+		this.setHistory(history);
 	}
 	
-	
+	public History<E> getHistory() {
+		return history;
+	}
+	public void setHistory(History<E> history) {
+		if (this.history != null) {
+			this.history.removeHistoryListener(this);
+		}
+		this.history = history;
+		if (this.history != null) {
+			this.history.addHistoryListener(this);
+			fireContentsChanged();
+		}
+	}
 	private void fireContentsChanged()
 	{
-		ListDataEvent lde = new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, 0, this.items.size());
+		ListDataEvent lde = new ListDataEvent(this, ListDataEvent.CONTENTS_CHANGED, 0, this.history.size());
 		for (ListDataListener l: listDataListeners) {
 			l.contentsChanged(lde);
 		}
@@ -43,12 +57,12 @@ public class ComboBoxHistoryModel<E> implements ComboBoxModel<E> {
 
 	@Override
 	public E getElementAt(int arg0) {
-		return items.get(arg0);
+		return history.get(arg0);
 	}
 
 	@Override
 	public int getSize() {
-		return items.size();
+		return history.size();
 	}
 
 	@Override
@@ -64,65 +78,54 @@ public class ComboBoxHistoryModel<E> implements ComboBoxModel<E> {
 	@Override
 	public void setSelectedItem(Object arg0) {
 		selectedItem = (E)arg0;
-		if (items.contains(selectedItem)) {
-			items.remove(selectedItem);
-		}
-		items.add(0,selectedItem);
-		if (!clampHistory()) {
-			fireContentsChanged();
+		if (selectedItem != null) {
+			this.history.add(selectedItem);
 		}
 	}
 
 	public int getHistorySize() {
-		return historySize;
+		return history.getHistorySize();
 	}
 
 	public void setHistorySize(int historySize) {
-		this.historySize = historySize;
+		this.history.setHistorySize(historySize);
 	}
 	
 	public Object[] getItems(){
-		return items.toArray();
+		return history.getItems();
 	}
 	
 	public E[] getItems(E[] at) {
-		return items.toArray(at);
+		return history.getItems(at);
 	}
 	
 	public void setItems(E[] items) {
-		this.items.clear();
-		this.items.addAll(Arrays.asList(items));
-		if (!this.items.contains(selectedItem)) {
-			selectedItem = null;
-		}
-		if (!clampHistory())
-			fireContentsChanged();
+		history.setItems(items);
 	}
 
-	private boolean clampHistory() {
-		if (items.size() > historySize) {
-			while (items.size() > historySize) {
-				items.removeLast();
-			}
-			fireContentsChanged();
-			return true;
-		}
-		return false;
-	}
 	
 	public void addElement(E element) {
-		this.items.add(0,element);
-		if (!clampHistory())
-			fireContentsChanged();
+		this.history.add(element);
 	}
 	
 	public void clear() {
-		items.clear();
-		fireContentsChanged();
+		this.history.clear();
 	}
 
 	public boolean contains(E val) {
-		return items.contains(val);
+		return history.contains(val);
+	}
+	@Override
+	public void HistoryChanged(History<E> history) {
+		fireContentsChanged();
+	}
+	@Override
+	public void HistoryItemAdded(History<E> history, E item) {
+		fireContentsChanged();		
+	}
+	@Override
+	public void HistoryItemRemoved(History<E> history, E item) {
+		fireContentsChanged();
 	}
 	
 }
diff --git a/src/org/hwo/models/History.java b/src/org/hwo/models/History.java
new file mode 100644
index 0000000..6e6ebce
--- /dev/null
+++ b/src/org/hwo/models/History.java
@@ -0,0 +1,120 @@
+package org.hwo.models;
+
+import java.util.Arrays;
+import java.util.LinkedList;
+
+public class History<E> {
+	private LinkedList<HistoryListener<E>> historyListeners = new LinkedList<>();
+	private LinkedList<E> items = new LinkedList<>();
+	private int historySize = 10;
+	
+	public History(){
+	}
+	
+	public History(int historySize) {
+		this.historySize = historySize;
+	}
+	
+	public void addHistoryListener(HistoryListener<E> listener) {
+		historyListeners.add(listener);
+	}
+	public void removeHistoryListener(HistoryListener<E> listener) {
+		historyListeners.remove(listener);
+	}
+	
+	protected void fireHistoryChanged() {
+		for (HistoryListener<E> historyListener : historyListeners) {
+			historyListener.HistoryChanged(this);
+		}
+	}
+	protected void fireHistoryItemAdded(E item) {
+		for (HistoryListener<E> historyListener : historyListeners) {
+			historyListener.HistoryItemAdded(this,item);
+		}
+	}
+	protected void fireHistoryItemRemoved(E item) {
+		for (HistoryListener<E> historyListener : historyListeners) {
+			historyListener.HistoryItemRemoved(this, item);
+		}
+	}
+	
+	public void clear() {
+		items.clear();
+		fireHistoryChanged();
+	}
+	
+	public boolean contains(E item) {
+		return items.contains(item);
+	}
+	
+	public int size() {
+		return this.items.size();
+	}
+	
+	public E get(int index) {
+		return this.items.get(index);
+	}
+	
+	public Object[] getItems(){
+		return items.toArray();
+	}
+	
+	public E[] getItems(E[] at) {
+		return items.toArray(at);
+	}
+	
+	public void setItems(E[] items) {
+		this.items.clear();
+		this.items.addAll(Arrays.asList(items));
+		fireHistoryChanged();
+		
+		clampHistory();
+	}
+	
+	public void add(E item) {
+		if (this.items.contains(item)) {
+			if (this.items.indexOf(item) > 0) {
+				this.items.remove(item);
+				this.items.add(0,item);
+				fireHistoryChanged();
+				clampHistory();
+				return;
+			}
+		} else {
+			this.items.add(0,item);
+			fireHistoryItemAdded(item);
+			clampHistory();
+		}
+	}
+	
+	public void remove(E item) {
+		this.items.remove(item);
+		fireHistoryItemRemoved(item);
+	}
+
+	private void clampHistory() {
+		if (items.size() > historySize) {
+			while (items.size() > historySize) {
+				fireHistoryItemRemoved(items.removeLast());
+			}
+		}
+	}
+	
+	
+	
+	public int getHistorySize() {
+		return historySize;
+	}
+
+	public void setHistorySize(int historySize) {
+		this.historySize = historySize;
+	}
+
+
+
+	public static interface HistoryListener<T> {
+		void HistoryChanged(History<T> history);
+		void HistoryItemAdded(History<T> history,T item);
+		void HistoryItemRemoved(History<T> history,T item);
+	}
+}