Implement interface for notification of state changes.

4 files changed, 50 insertions, 3 deletions

diff --git a/same/src/main/java/com/orbekk/same/ClientServiceImpl.java b/same/src/main/java/com/orbekk/same/ClientServiceImpl.java
index 75df9cc..7865167 100644
--- a/same/src/main/java/com/orbekk/same/ClientServiceImpl.java
+++ b/same/src/main/java/com/orbekk/same/ClientServiceImpl.java
@@ -9,7 +9,8 @@ public class ClientServiceImpl implements ClientService, UrlReceiver {
     private ConnectionManager connections;
     private State state;
     private String myUrl = null;
-
+    private StateChangedListener listener;
+    
     public ClientServiceImpl(State state, ConnectionManager connections) {
         this.state = state;
         this.connections = connections;
@@ -23,7 +24,11 @@ public class ClientServiceImpl implements ClientService, UrlReceiver {
     @Override
     public void setState(String component, String data, long revision) {
         boolean status = state.update(component, data, revision);
-        if (!status) {
+        if (status) {
+            if (listener != null) {
+                listener.stateChanged(component, data);
+            }
+        } else {
             logger.warn("Ignoring update: {}",
                     new State.Component(component, revision, data));
         }
@@ -86,4 +91,8 @@ public class ClientServiceImpl implements ClientService, UrlReceiver {
     State testGetState() {
         return state;
     }
+
+    public void setStateChangedListener(StateChangedListener listener) {
+        this.listener = listener;
+    }
 }
diff --git a/same/src/main/java/com/orbekk/same/Same.java b/same/src/main/java/com/orbekk/same/Same.java
index b70c7aa..d69061f 100644
--- a/same/src/main/java/com/orbekk/same/Same.java
+++ b/same/src/main/java/com/orbekk/same/Same.java
@@ -1,5 +1,6 @@
 package com.orbekk.same;
 
+import java.util.ArrayList;
 import java.util.List;
 
 import org.codehaus.jackson.type.TypeReference;
@@ -9,8 +10,27 @@ import org.slf4j.LoggerFactory;
 public class Same implements SameInterface {
     private Logger logger = LoggerFactory.getLogger(getClass());
     private ClientServiceImpl client;
+    private StateChangedProxy stateChangedProxy = new StateChangedProxy();
     
-    public Same(ClientServiceImpl client) {
+    private class StateChangedProxy implements StateChangedListener {
+        public List<StateChangedListener> listeners =
+                new ArrayList<StateChangedListener>();
+
+        @Override
+        public void stateChanged(String id, String data) {
+            for (StateChangedListener listener : listeners) {
+                listener.stateChanged(id, data);
+            }
+        }
+    }
+    
+    public static Same createSame(ClientServiceImpl client) {
+        Same same = new Same(client);
+        client.setStateChangedListener(same.stateChangedProxy);
+        return same;
+    }
+    
+    Same(ClientServiceImpl client) {
         this.client = client;
     }
     
@@ -39,4 +59,14 @@ public class Same implements SameInterface {
         throw new RuntimeException("Not implemented.");   
     }
 
+    @Override
+    public void addStateChangedListener(StateChangedListener listener) {
+        stateChangedProxy.listeners.add(listener);
+    }
+
+    @Override
+    public void removeStateChangedListener(StateChangedListener listener) {
+        stateChangedProxy.listeners.remove(listener);
+    }
+
 }
diff --git a/same/src/main/java/com/orbekk/same/SameInterface.java b/same/src/main/java/com/orbekk/same/SameInterface.java
index 7541636..280bd9d 100644
--- a/same/src/main/java/com/orbekk/same/SameInterface.java
+++ b/same/src/main/java/com/orbekk/same/SameInterface.java
@@ -32,4 +32,7 @@ public interface SameInterface {
      * Set from an object: Pass it, e.g., a List<String>.
      */
     void setObject(String id, Object data);
+    
+    void addStateChangedListener(StateChangedListener listener);
+    void removeStateChangedListener(StateChangedListener listener);
 }
diff --git a/same/src/main/java/com/orbekk/same/StateChangedListener.java b/same/src/main/java/com/orbekk/same/StateChangedListener.java
new file mode 100644
index 0000000..deb9369
--- /dev/null
+++ b/same/src/main/java/com/orbekk/same/StateChangedListener.java
@@ -0,0 +1,5 @@
+package com.orbekk.same;
+
+public interface StateChangedListener {
+    void stateChanged(String id, String data);
+}