--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.core.databinding/src/org/eclipse/core/internal/databinding/observable/MapEntryObservableValue.d	Tue Apr 14 11:35:29 2009 +0200
@@ -0,0 +1,111 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Marko Topolnik 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:
+ *     Marko Topolnik - initial API and implementation (bug 184830)
+ *     Matthew Hall - bug 184830
+ ******************************************************************************/
+
+module org.eclipse.core.internal.databinding.observable.MapEntryObservableValue;
+
+import java.lang.all;
+
+import org.eclipse.core.databinding.observable.Diffs;
+import org.eclipse.core.databinding.observable.IStaleListener;
+import org.eclipse.core.databinding.observable.ObservableTracker;
+import org.eclipse.core.databinding.observable.StaleEvent;
+import org.eclipse.core.databinding.observable.map.IMapChangeListener;
+import org.eclipse.core.databinding.observable.map.IObservableMap;
+import org.eclipse.core.databinding.observable.map.MapChangeEvent;
+import org.eclipse.core.databinding.observable.value.AbstractObservableValue;
+import org.eclipse.core.databinding.observable.value.IObservableValue;
+
+/**
+ * An {@link IObservableValue} that tracks the value of an entry in an
+ * {@link IObservableMap}, identified by the entry's key.
+ * 
+ * @since 1.1
+ */
+public class MapEntryObservableValue : AbstractObservableValue {
+    private IObservableMap map;
+    private Object key;
+    private Object valueType;
+
+    private IMapChangeListener changeListener = new class() IMapChangeListener {
+        public void handleMapChange(MapChangeEvent event) {
+            if (event.diff.getAddedKeys().contains(key)) {
+                final Object newValue = event.diff.getNewValue(key);
+                if (newValue !is null) {
+                    fireValueChange(Diffs.createValueDiff(null, newValue));
+                }
+            } else if (event.diff.getChangedKeys().contains(key)) {
+                fireValueChange(Diffs.createValueDiff(event.diff
+                        .getOldValue(key), event.diff.getNewValue(key)));
+            } else if (event.diff.getRemovedKeys().contains(key)) {
+                final Object oldValue = event.diff.getOldValue(key);
+                if (oldValue !is null) {
+                    fireValueChange(Diffs.createValueDiff(oldValue, null));
+                }
+            }
+        }
+    };
+
+    private IStaleListener staleListener = new class() IStaleListener {
+        public void handleStale(StaleEvent staleEvent) {
+            fireStale();
+        }
+    };
+
+    /**
+     * Creates a map entry observable.
+     * 
+     * @param map
+     *            the observable map whose entry will be tracked
+     * @param key
+     *            the key identifying the entry whose value will be tracked
+     * @param valueType
+     *            the type of the value
+     */
+    public this(IObservableMap map, Object key,
+            Object valueType) {
+        super(map.getRealm());
+        this.map = map;
+        this.key = key;
+        this.valueType = valueType;
+
+        map.addMapChangeListener(changeListener);
+        map.addStaleListener(staleListener);
+    }
+
+    public Object getValueType() {
+        return this.valueType;
+    }
+
+    public bool isStale() {
+        ObservableTracker.getterCalled(this);
+        return map.isStale();
+    }
+
+    public synchronized void dispose() {
+        if (map !is null) {
+            map.removeMapChangeListener(changeListener);
+            map.removeStaleListener(staleListener);
+            map = null;
+            changeListener = null;
+            staleListener = null;
+        }
+        super.dispose();
+    }
+
+    protected Object doGetValue() {
+        return this.map.get(this.key);
+    }
+
+    protected void doSetValue(Object value) {
+        this.map.put(this.key, value);
+    }
+}