--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.core.databinding.observable/src/org/eclipse/core/databinding/observable/set/WritableSet.d	Tue Apr 21 10:55:51 2009 +0200
@@ -0,0 +1,171 @@
+/*******************************************************************************
+ * 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 147515
+ *     Matthew Hall - bug 221351
+ *******************************************************************************/
+
+package org.eclipse.core.databinding.observable.set;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.Set;
+
+import org.eclipse.core.databinding.observable.Diffs;
+import org.eclipse.core.databinding.observable.Realm;
+
+/**
+ * Mutable (writable) implementation of {@link IObservableSet}.
+ * 
+ * <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
+ */
+public class WritableSet : ObservableSet {
+
+    /**
+     * Constructs a new empty instance in the default realm with a
+     * <code>null</code> element type.
+     * 
+     */
+    public this() {
+        this(Realm.getDefault());
+    }
+
+    /**
+     * Constructs a new instance in the default realm containing the
+     * elements of the given collection. Changes to the given collection after
+     * calling this method do not affect the contents of the created WritableSet.
+     * 
+     * @param c
+     * @param elementType
+     *            can be <code>null</code>
+     */
+    public this(Collection c, Object elementType) {
+        this(Realm.getDefault(), new HashSet(c), elementType);
+    }
+
+    /**
+     * Constructs a new empty instance in the given realm and a
+     * <code>null</code> element type.
+     * 
+     * @param realm
+     */
+    public this(Realm realm) {
+        this(realm, new HashSet(), null);
+    }
+
+    /**
+     * Constructs a new instance in the default realm with the given element
+     * type, containing the elements of the given collection. Changes to the
+     * given collection after calling this method do not affect the contents of
+     * the created WritableSet.
+     * 
+     * @param realm
+     * @param c
+     * @param elementType
+     *            can be <code>null</code>
+     */
+    public this(Realm realm, Collection c, Object elementType) {
+        super(realm, new HashSet(c), elementType);
+        this.elementType = elementType;
+    }
+
+    public bool add(Object o) {
+        getterCalled();
+        bool added = wrappedSet.add(o);
+        if (added) {
+            fireSetChange(Diffs.createSetDiff(Collections.singleton(o), Collections.EMPTY_SET));
+        }
+        return added;
+    }
+
+    public bool addAll(Collection c) {
+        getterCalled();
+        Set additions = new HashSet();
+        Iterator it = c.iterator();
+        while (it.hasNext()) {
+            Object element = it.next();
+            if (wrappedSet.add(element)) {
+                additions.add(element);
+            }
+        }
+        if (additions.size() > 0) {
+            fireSetChange(Diffs.createSetDiff(additions, Collections.EMPTY_SET));
+            return true;
+        }
+        return false;
+    }
+
+    public bool remove(Object o) {
+        getterCalled();
+        bool removed = wrappedSet.remove(o);
+        if (removed) {
+            fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, Collections
+                    .singleton(o)));
+        }
+        return removed;
+    }
+
+    public bool removeAll(Collection c) {
+        getterCalled();
+        Set removes = new HashSet();
+        Iterator it = c.iterator();
+        while (it.hasNext()) {
+            Object element = it.next();
+            if (wrappedSet.remove(element)) {
+                removes.add(element);
+            }
+        }
+        if (removes.size() > 0) {
+            fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removes));
+            return true;
+        }
+        return false;
+    }
+
+    public bool retainAll(Collection c) {
+        getterCalled();
+        Set removes = new HashSet();
+        Iterator it = wrappedSet.iterator();
+        while (it.hasNext()) {
+            Object element = it.next();
+            if (!c.contains(element)) {
+                it.remove();
+                removes.add(element);
+            }
+        }
+        if (removes.size() > 0) {
+            fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removes));
+            return true;
+        }
+        return false;
+    }
+
+    public void clear() {
+        getterCalled();
+        Set removes = new HashSet(wrappedSet);
+        wrappedSet.clear();
+        fireSetChange(Diffs.createSetDiff(Collections.EMPTY_SET, removes));
+    }
+
+    /**
+     * @param elementType can be <code>null</code>
+     * @return new instance with the default realm
+     */
+    public static WritableSet withElementType(Object elementType) {
+        return new WritableSet(Realm.getDefault(), new HashSet(), elementType);
+    }
+}