--- a/dwt/custom/CTabFolderListener.d	Tue Oct 07 14:41:31 2008 +0200
+++ b/dwt/custom/CTabFolderListener.d	Tue Oct 07 16:29:55 2008 +0200
@@ -1,4 +1,4 @@
-/*******************************************************************************
+/*******************************************************************************
  * 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
@@ -7,14 +7,16 @@
  *
  * Contributors:
  *     IBM Corporation - initial API and implementation
- *     
  * Port to the D programming language:
- *     Jacob Carlborg <jacob.carlborg@gmail.com>
+ *     Frank Benoit <benoit@tionex.de>
  *******************************************************************************/
 module dwt.custom.CTabFolderListener;
 
+import dwt.internal.DWTEventListener;
 import dwt.custom.CTabFolderEvent;
-import dwt.internal.DWTEventListener;
+
+import tango.core.Traits;
+import tango.core.Tuple;
 
 /**
  * Classes which implement this interface provide a method
@@ -31,15 +33,58 @@
  */
 public interface CTabFolderListener : DWTEventListener {
 
-    /**
-     * Sent when the user clicks on the close button of an item in the CTabFolder.  The item being closed is specified
-     * in the event.item field. Setting the event.doit field to false will stop the CTabItem from closing. 
-     * When the CTabItem is closed, it is disposed.  The contents of the CTabItem (see CTabItem.setControl) will be 
-     * made not visible when the CTabItem is closed.
-     * 
-     * @param event an event indicating the item being closed
-     * 
-     * @see CTabItem#setControl
-     */
-    public void itemClosed (CTabFolderEvent event);
+/**
+ * Sent when the user clicks on the close button of an item in the CTabFolder.  The item being closed is specified
+ * in the event.item field. Setting the event.doit field to false will stop the CTabItem from closing.
+ * When the CTabItem is closed, it is disposed.  The contents of the CTabItem (see CTabItem.setControl) will be
+ * made not visible when the CTabItem is closed.
+ *
+ * @param event an event indicating the item being closed
+ *
+ * @see CTabItem#setControl
+ */
+public void itemClosed(CTabFolderEvent event);
 }
+
+
+
+/// Helper class for the dgListener template function
+private class _DgCTabFolderListenerT(Dg,T...) : CTabFolderListener {
+
+    alias ParameterTupleOf!(Dg) DgArgs;
+    static assert( is(DgArgs == Tuple!(CTabFolderEvent,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 itemClosed( CTabFolderEvent e ){
+        dg(e,t);
+    }
+}
+
+/++
+ + dgListener creates a class implementing the Listener interface and delegating the call to
+ + handleEvent to the users delegate. This template function will store also additional parameters.
+ +
+ + Examle of usage:
+ + ---
+ + void handleTextEvent (Event e, int inset ) {
+ +     // ...
+ + }
+ + text.addListener (DWT.FocusOut, dgListener( &handleTextEvent, inset ));
+ + ---
+ +/
+CTabFolderListener dgCTabFolderListener( Dg, T... )( Dg dg, T args ){
+    return new _DgCTabFolderListenerT!( Dg, T )( dg, args );
+}
+
+
+