--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/org.eclipse.jface.databinding/src/org/eclipse/jface/internal/databinding/viewers/CheckboxViewerCheckedElementsObservableSet.d	Tue Apr 14 11:35:29 2009 +0200
@@ -0,0 +1,92 @@
+/*******************************************************************************
+ * Copyright (c) 2008 Matthew Hall 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:
+ *     Matthew Hall - initial API and implementation (bug 124684)
+ ******************************************************************************/
+
+module org.eclipse.jface.internal.databinding.viewers.CheckboxViewerCheckedElementsObservableSet;
+
+import java.lang.all;
+
+import java.util.Arrays;
+import java.util.Set;
+
+import org.eclipse.core.databinding.observable.Realm;
+import org.eclipse.jface.databinding.viewers.IViewerObservableSet;
+import org.eclipse.jface.viewers.CheckboxTableViewer;
+import org.eclipse.jface.viewers.CheckboxTreeViewer;
+import org.eclipse.jface.viewers.StructuredViewer;
+import org.eclipse.jface.viewers.Viewer;
+
+/**
+ * An observable set that tracks the checked elements in a CheckboxTableViewer
+ * or CheckboxTreeViewer
+ * 
+ * @since 1.2
+ */
+public class CheckboxViewerCheckedElementsObservableSet :
+        CheckableCheckedElementsObservableSet , IViewerObservableSet {
+    private StructuredViewer viewer;
+
+    /**
+     * Constructs a new instance on the given realm and checkable.
+     * 
+     * @param realm
+     *            the observable's realm
+     * @param viewer
+     *            the CheckboxTableViewer viewer to track.
+     * @param elementType
+     *            type of elements in the set
+     */
+    public this(Realm realm,
+            CheckboxTableViewer viewer, Object elementType) {
+        super(realm, viewer, elementType, createElementSet(viewer));
+        this.viewer = viewer;
+    }
+
+    /**
+     * Constructs a new instance on the given realm and checkable.
+     * 
+     * @param realm
+     *            the observable's realm
+     * @param viewer
+     *            the CheckboxTreeViewer viewer to track.
+     * @param elementType
+     *            type of elements in the set
+     */
+    public this(Realm realm,
+            CheckboxTreeViewer viewer, Object elementType) {
+        super(realm, viewer, elementType, createElementSet(viewer));
+        this.viewer = viewer;
+    }
+
+    Set createDiffSet() {
+        return ViewerElementSet.withComparer(viewer.getComparer());
+    }
+
+    private static Set createElementSet(CheckboxTableViewer viewer) {
+        Set set = ViewerElementSet.withComparer(viewer.getComparer());
+        set.addAll(Arrays.asList(viewer.getCheckedElements()));
+        return set;
+    }
+
+    private static Set createElementSet(CheckboxTreeViewer viewer) {
+        Set set = ViewerElementSet.withComparer(viewer.getComparer());
+        set.addAll(Arrays.asList(viewer.getCheckedElements()));
+        return set;
+    }
+
+    public Viewer getViewer() {
+        return viewer;
+    }
+
+    public synchronized void dispose() {
+        viewer = null;
+        super.dispose();
+    }
+}