--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/dwtx/draw2d/ChangeListener.d	Sun Aug 03 00:52:14 2008 +0200
@@ -0,0 +1,57 @@
+/*******************************************************************************
+ * Copyright (c) 2000, 2005 IBM Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ * Port to the D programming language:
+ *     Frank Benoit <benoit@tionex.de>
+ *******************************************************************************/
+module dwtx.draw2d.ChangeListener;
+
+import dwt.dwthelper.utils;
+import dwtx.draw2d.ChangeEvent;
+import tango.core.Traits;
+import tango.core.Tuple;
+
+/**
+ * A generic state listener
+ */
+public interface ChangeListener {
+
+/**
+ * Called when the listened to object's state has changed.
+ * @param event the ChangeEvent
+ */
+void handleStateChanged(ChangeEvent event);
+
+}
+
+// DWT Helper
+private class _DgChangeListenerT(Dg,T...) : ChangeListener {
+
+    alias ParameterTupleOf!(Dg) DgArgs;
+    static assert( is(DgArgs == Tuple!(ChangeEvent,T)),
+                "Delegate args not correct" );
+
+    Dg dg;
+    T  t;
+
+    private this( Dg dg, T t ){
+        this.dg = dg;
+        static if( T.length > 0 ){
+            this.t = t;
+        }
+    }
+
+    void handleStateChanged( ChangeEvent e ){
+        dg(e,t);
+    }
+}
+
+ChangeListener dgChangeListener( Dg, T... )( Dg dg, T args ){
+    return new _DgChangeListenerT!( Dg, T )( dg, args );
+}