From dbb86148a7b53d729085b4ace612e211d7a876ed Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Kjetil=20=C3=98rbekk?= <kjetil.orbekk@gmail.com>
Date: Tue, 28 Feb 2012 15:08:58 +0100
Subject: Add support for more than one listener to variables.

---
 same/src/main/java/com/orbekk/same/Variable.java        |  3 ++-
 same/src/main/java/com/orbekk/same/VariableFactory.java | 17 ++++++++++++-----
 .../main/java/com/orbekk/same/VariableUpdaterTask.java  |  6 +++++-
 .../test/java/com/orbekk/same/VariableFactoryTest.java  |  2 +-
 4 files changed, 20 insertions(+), 8 deletions(-)

(limited to 'same')

diff --git a/same/src/main/java/com/orbekk/same/Variable.java b/same/src/main/java/com/orbekk/same/Variable.java
index 4d42909..7f9f4d5 100644
--- a/same/src/main/java/com/orbekk/same/Variable.java
+++ b/same/src/main/java/com/orbekk/same/Variable.java
@@ -15,5 +15,6 @@ public interface Variable<T> {
     T get();
     DelayedOperation set(T value);
     void update();
-    void setOnChangeListener(OnChangeListener<T> listener);
+    void addOnChangeListener(OnChangeListener<T> listener);
+    void removeOnChangeListener(OnChangeListener<T> listener);
 }
diff --git a/same/src/main/java/com/orbekk/same/VariableFactory.java b/same/src/main/java/com/orbekk/same/VariableFactory.java
index fa9eeeb..e04e36b 100644
--- a/same/src/main/java/com/orbekk/same/VariableFactory.java
+++ b/same/src/main/java/com/orbekk/same/VariableFactory.java
@@ -1,6 +1,7 @@
 package com.orbekk.same;
 
 import java.io.IOException;
+import java.util.ArrayList;
 
 import org.codehaus.jackson.JsonGenerationException;
 import org.codehaus.jackson.map.JsonMappingException;
@@ -25,7 +26,8 @@ public class VariableFactory {
         TypeReference<T> type;
         T value;
         long revision = 0;
-        OnChangeListener<T> listener = null;
+        ArrayList<OnChangeListener<T>> listeners =
+                new ArrayList<OnChangeListener<T>>();
 
         public VariableImpl(String identifier, TypeReference<T> type) {
             this.identifier = identifier;
@@ -66,14 +68,19 @@ public class VariableFactory {
         }
 
         @Override
-        public void setOnChangeListener(OnChangeListener<T> listener) {
-            this.listener = listener;
+        public synchronized void addOnChangeListener(OnChangeListener<T> listener) {
+            listeners.add(listener);
+        }
+        
+        @Override
+        public synchronized void removeOnChangeListener(OnChangeListener<T> listener) {
+            listeners.remove(listener);
         }
 
         @Override
-        public void stateChanged(Component component) {
+        public synchronized void stateChanged(Component component) {
             if (component.getName().equals(identifier)) {
-                if (listener != null) {
+                for (OnChangeListener<T> listener : listeners) {
                     listener.valueChanged(this);
                 }
             }
diff --git a/same/src/main/java/com/orbekk/same/VariableUpdaterTask.java b/same/src/main/java/com/orbekk/same/VariableUpdaterTask.java
index 471dbc6..f696e17 100644
--- a/same/src/main/java/com/orbekk/same/VariableUpdaterTask.java
+++ b/same/src/main/java/com/orbekk/same/VariableUpdaterTask.java
@@ -7,11 +7,12 @@ import java.util.concurrent.atomic.AtomicBoolean;
 public class VariableUpdaterTask<T> extends Thread
         implements Variable.OnChangeListener<T> {
     private Variable<T> variable;
-    private T newValue;
+    private volatile T newValue;
     private AtomicBoolean hasNewValue = new AtomicBoolean(false);
     private AtomicBoolean isReady = new AtomicBoolean(true);
     
     public VariableUpdaterTask(Variable<T> variable) {
+        super("VariableUpdater");
         this.variable = variable;
     }
     
@@ -47,7 +48,9 @@ public class VariableUpdaterTask<T> extends Thread
         }
     }
     
+    @Override
     public void run() {
+        variable.addOnChangeListener(this);
         while (true) {
             waitFor(isReady);
             waitFor(hasNewValue);
@@ -56,6 +59,7 @@ public class VariableUpdaterTask<T> extends Thread
             }
             performWork();
         }
+        variable.removeOnChangeListener(this);
     }
 
     @Override
diff --git a/same/src/test/java/com/orbekk/same/VariableFactoryTest.java b/same/src/test/java/com/orbekk/same/VariableFactoryTest.java
index bd0f923..66d181e 100644
--- a/same/src/test/java/com/orbekk/same/VariableFactoryTest.java
+++ b/same/src/test/java/com/orbekk/same/VariableFactoryTest.java
@@ -72,7 +72,7 @@ public class VariableFactoryTest {
         Variable.OnChangeListener<Integer> listener =
                 mock(Variable.OnChangeListener.class);
         Variable<Integer> v = vf.create("z", intType);
-        v.setOnChangeListener(listener);
+        v.addOnChangeListener(listener);
         ((StateChangedListener) v).stateChanged(
                 new State.Component("z", 1, "abc"));
         verify(listener).valueChanged(v);
-- 
cgit v1.2.3