--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/swt/SingleSelectionObservableValue.d	Tue Apr 14 11:35:29 2009 +0200
@@ -0,0 +1,105 @@
+/*******************************************************************************
+ * Copyright (c) 2005, 2008 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
+ *     Brad Reynolds - bug 164653
+ *******************************************************************************/
+module org.eclipse.jface.internal.databinding.swt.SingleSelectionObservableValue;
+
+import java.lang.all;
+
+import org.eclipse.core.databinding.observable.Diffs;
+import org.eclipse.core.databinding.observable.Realm;
+import org.eclipse.jface.internal.databinding.provisional.swt.AbstractSWTObservableValue;
+import org.eclipse.swt.widgets.Control;
+
+/**
+ * @since 1.0
+ * 
+ */
+abstract public class SingleSelectionObservableValue :
+        AbstractSWTObservableValue {
+
+    private bool updating = false;
+
+    private int currentSelection;
+
+    /**
+     * @param control
+     *            the control
+     */
+    public this(Control control) {
+        super(control);
+        init();
+    }
+    
+    /**
+     * @param realm
+     * @param control
+     */
+    public this(Realm realm, Control control) {
+        super(realm, control);
+        init();
+    }
+    
+    private void init() {       
+        currentSelection = doGetSelectionIndex();
+        doAddSelectionListener(new class() Runnable{
+            public void run() {
+                if (!updating) {
+                    int newSelection = doGetSelectionIndex();
+                    notifyIfChanged(currentSelection, newSelection);
+                    currentSelection = newSelection;
+                }
+            }
+        });
+    }
+
+    /**
+     * @param runnable
+     */
+    protected abstract void doAddSelectionListener(Runnable runnable);
+
+    public void doSetValue(Object value) {
+        try {
+            updating = true;
+            int intValue = (cast(Integer) value).intValue();
+            doSetSelectionIndex(intValue);
+            notifyIfChanged(currentSelection, intValue);
+            currentSelection = intValue;
+        } finally {
+            updating = false;
+        }
+    }
+
+    /**
+     * @param intValue
+     *            the selection index
+     */
+    protected abstract void doSetSelectionIndex(int intValue);
+
+    public Object doGetValue() {
+        return new Integer(doGetSelectionIndex());
+    }
+
+    /**
+     * @return the selection index
+     */
+    protected abstract int doGetSelectionIndex();
+
+    public Object getValueType() {
+        return Integer.TYPE;
+    }
+
+    private void notifyIfChanged(int oldValue, int newValue) {
+        if (oldValue !is newValue) {
+            fireValueChange(Diffs.createValueDiff(new Integer(
+                    oldValue), new Integer(newValue)));
+        }
+    }
+}