diff --git a/src/de/craftinc/gates/GateChangeListener.java b/src/de/craftinc/gates/GateChangeListener.java
new file mode 100644
index 0000000..49917f6
--- /dev/null
+++ b/src/de/craftinc/gates/GateChangeListener.java
@@ -0,0 +1,31 @@
+/*  Craft Inc. Gates
+    Copyright (C) 2011-2014 Craft Inc. Gates Team (see AUTHORS.txt)
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU Lesser General Public License as published
+    by the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU Lesser General Public License for more details.
+
+    You should have received a copy of the GNU Lesser General Public License
+    along with this program (LGPLv3).  If not, see <http://www.gnu.org/licenses/>.
+*/
+package de.craftinc.gates;
+
+
+import java.util.Map;
+
+public interface GateChangeListener
+{
+    public static final String newGate = "GateChangeListener-newGate"; // value will be null
+    public static final String removedGate = "GateChangeListener-removedGate"; // value will be null
+    public static final String changedID = "GateChangeListener-changedID"; // value will be the old ID
+    public static final String changedLocation = "GateChangeListener-changedLocation"; // value will the old location
+    public static final String changedExit = "GateChangeListener-changedExit"; // value will be the old exit
+
+    public void gateChangedHandler(final Gate g, final Map<String, Object>changeSet);
+}
diff --git a/src/de/craftinc/gates/GatesManager.java b/src/de/craftinc/gates/GatesManager.java
index 2df21c7..81fda3d 100644
--- a/src/de/craftinc/gates/GatesManager.java
+++ b/src/de/craftinc/gates/GatesManager.java
@@ -54,6 +54,20 @@ public class GatesManager
 
     protected boolean storageFileIsInvalid = false;
 
+    protected Set<GateChangeListener> changeListeners = new HashSet<GateChangeListener>();
+
+
+    public void addGateChangeListener(GateChangeListener listener)
+    {
+        this.changeListeners.add(listener);
+    }
+
+
+    public void removeGateChangeListener(GateChangeListener listener)
+    {
+        this.changeListeners.remove(listener);
+    }
+
 
 	public Gate getGateWithId(final String id)
 	{
@@ -489,6 +503,13 @@ public class GatesManager
 	{
 		this.removeGateById(oldId);
 		this.addGateWithId(g);
+
+        Map<String, Object> changeSet = new HashMap<String, Object>();
+        changeSet.put(GateChangeListener.changedID, oldId);
+
+        for (GateChangeListener l : this.changeListeners) {
+            l.gateChangedHandler(g, changeSet);
+        }
 	}
 	
 	
@@ -505,7 +526,27 @@ public class GatesManager
 
         this.removeGateByFrameLocation(oldGateFrameBlocks);
         this.addGateByFrameLocations(g);
+
+        Map<String, Object> changeSet = new HashMap<String, Object>();
+        changeSet.put(GateChangeListener.changedLocation, oldLocation);
+
+        for (GateChangeListener l : this.changeListeners) {
+            l.gateChangedHandler(g, changeSet);
+        }
 	}
+
+    // TODO: call this method!
+    public void handleGateExitChange(final Gate g, final Location oldExit)
+    {
+        // nothing to do
+
+        Map<String, Object> changeSet = new HashMap<String, Object>();
+        changeSet.put(GateChangeListener.changedExit, oldExit);
+
+        for (GateChangeListener l : this.changeListeners) {
+            l.gateChangedHandler(g, changeSet);
+        }
+    }
 	
 	
 	public void handleNewGate(final Gate g)
@@ -516,6 +557,14 @@ public class GatesManager
 		this.addGateByLocations(g);
 		this.addGateWithId(g);
         this.addGateByFrameLocations(g);
+
+
+        Map<String, Object> changeSet = new HashMap<String, Object>();
+        changeSet.put(GateChangeListener.newGate, null);
+
+        for (GateChangeListener l : this.changeListeners) {
+            l.gateChangedHandler(g, changeSet);
+        }
 	}
 	
 	
@@ -527,6 +576,13 @@ public class GatesManager
 		this.removeGateFromChunk(g, g.getLocation());
 		this.removeGateByLocation(g.getGateBlockLocations());
         this.removeGateByFrameLocation(g.getGateFrameBlocks());
+
+        Map<String, Object> changeSet = new HashMap<String, Object>();
+        changeSet.put(GateChangeListener.removedGate, null);
+
+        for (GateChangeListener l : this.changeListeners) {
+            l.gateChangedHandler(g, changeSet);
+        }
 	}