--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.core.databinding/src/org/eclipse/core/databinding/observable/value/AbstractObservableValue.d	Tue Apr 14 11:35:29 2009 +0200
@@ -0,0 +1,100 @@
+/*******************************************************************************
+ * Copyright (c) 2006, 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
+ *     Matthew Hall - bug 208332
+ *******************************************************************************/
+
+module org.eclipse.core.databinding.observable.value.AbstractObservableValue;
+
+import java.lang.all;
+
+import org.eclipse.core.databinding.observable.AbstractObservable;
+import org.eclipse.core.databinding.observable.ObservableTracker;
+import org.eclipse.core.databinding.observable.Realm;
+
+/**
+ * 
+ * <p>
+ * This class is thread safe. All state accessing methods must be invoked from
+ * the {@link Realm#isCurrent() current realm}. Methods for adding and removing
+ * listeners may be invoked from any thread.
+ * </p>
+ * @since 1.0
+ * 
+ */
+abstract public class AbstractObservableValue : AbstractObservable , IObservableValue {
+    /**
+     * Constructs a new instance with the default realm.
+     */
+    public this() {
+        this(Realm.getDefault());
+    }
+
+    /**
+     * @param realm
+     */
+    public this(Realm realm) {
+        super(realm);
+    }
+
+    public synchronized void addValueChangeListener(IValueChangeListener listener) {
+        addListener(ValueChangeEvent.TYPE, listener);
+    }
+
+    public synchronized void removeValueChangeListener(IValueChangeListener listener) {
+        removeListener(ValueChangeEvent.TYPE, listener);
+    }
+
+    final public void setValue(Object value) {
+        checkRealm();
+        doSetValue(value);
+    }
+
+    /**
+     * Template method for setting the value of the observable. By default the
+     * method throws an {@link UnsupportedOperationException}.
+     * 
+     * @param value
+     */
+    protected void doSetValue(Object value) {
+        throw new UnsupportedOperationException();
+    }
+
+    protected void fireValueChange(ValueDiff diff) {
+        // fire general change event first
+        super.fireChange();
+        fireEvent(new ValueChangeEvent(this, diff));
+    }
+
+    public final Object getValue() {
+        getterCalled();
+        return doGetValue();
+    }
+
+    abstract protected Object doGetValue();
+
+    public bool isStale() {
+        getterCalled();
+        return false;
+    }
+
+    private void getterCalled() {
+        ObservableTracker.getterCalled(this);
+    }
+
+    protected void fireChange() {
+        throw new RuntimeException(
+                "fireChange should not be called, use fireValueChange() instead"); //$NON-NLS-1$
+    }
+
+    public synchronized void dispose() {
+        super.dispose();
+    }
+}