propagate from branch 'i2p.i2p' (head 1b82a3bfd792b71321bcbd8f3b8344664db2dc45)

to branch 'i2p.i2p.mathiasdm.desktopgui' (head 4e485a19a83a3e30425e1b1a03836f35fa4ebb50)

core/java/src/net/i2p/I2PAppContext.java

@@ -30,11 +30,13 @@ import net.i2p.util.Clock;
 import net.i2p.util.ConcurrentHashSet;
 import net.i2p.util.FileUtil;
 import net.i2p.util.FortunaRandomSource;
+import net.i2p.util.I2PProperties;
 import net.i2p.util.KeyRing;
 import net.i2p.util.LogManager;
 //import net.i2p.util.PooledRandomSource;
 import net.i2p.util.RandomSource;
 import net.i2p.util.SecureDirectory;
+import net.i2p.util.I2PProperties.I2PPropertyCallback;
 
 /**
  * <p>Provide a base scope for accessing singletons that I2P exposes.  Rather than
@@ -65,7 +67,7 @@ public class I2PAppContext {
     /** the context that components without explicit root are bound */
     protected static I2PAppContext _globalAppContext;
     
-    private Properties _overrideProps;
+    protected I2PProperties _overrideProps;
     
     private StatManager _statManager;
     private SessionKeyManager _sessionKeyManager;
@@ -168,7 +170,7 @@ public class I2PAppContext {
                     _globalAppContext = this;
             }
         }
-        _overrideProps = envProps;
+        _overrideProps = new I2PProperties(envProps);
         _statManager = null;
         _sessionKeyManager = null;
         _namingService = null;
@@ -483,6 +485,14 @@ public class I2PAppContext {
         return names;
     }
     
+    /**
+     * Add a callback, which will fire upon changes in the property
+     * given in the specific callback.
+     * Unimplemented in I2PAppContext: this only makes sense in a router context.
+     * @param callback The implementation of the callback.
+     */
+    public void addPropertyCallback(I2PPropertyCallback callback) {}
+    
     /**
      * The statistics component with which we can track various events
      * over time.

core/java/src/net/i2p/util/I2PProperties.java

@@ -0,0 +1,53 @@
+package net.i2p.util;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Properties;
+import java.util.concurrent.CopyOnWriteArrayList;
+
+/**
+ * This class contains a number of properties ((key,value)-pairs).
+ * Additionally, it adds the possibility for callbacks,
+ * to allow immediate response to changing properties.
+ * @author Mathiasdm
+ *
+ */
+public class I2PProperties extends Properties {
+	
+	/**
+	 * Keep a list of callbacks to contact the interested parties
+	 * that want to know about property changes.
+	 */
+	private final List<I2PPropertyCallback> _callbacks = new CopyOnWriteArrayList<I2PPropertyCallback>();
+
+	public I2PProperties() {
+		super();
+	}
+
+	public I2PProperties(Properties defaults) {
+		super(defaults);
+	}
+	
+	public void addCallBack(I2PPropertyCallback callback) {
+		_callbacks.add(callback);
+	}
+	
+	public void removeCallBack(I2PPropertyCallback callback) {
+		_callbacks.remove(callback);
+	}
+	
+	public Object setProperty(String key, String value) {
+		Object returnValue = super.setProperty(key, value);
+		for(I2PPropertyCallback callback: _callbacks) {
+			callback.propertyChanged(key, value);
+		}
+		return returnValue;
+	}
+	
+	public interface I2PPropertyCallback {
+		
+		public void propertyChanged(String key, String value);
+		
+	}
+
+}