--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/components/visual-panels/core/src/java/util/com/oracle/solaris/vp/util/swing/ValidatingListSelectionModel.java	Thu May 24 04:16:47 2012 -0400
@@ -0,0 +1,121 @@
+/*
+ * CDDL HEADER START
+ *
+ * The contents of this file are subject to the terms of the
+ * Common Development and Distribution License (the "License").
+ * You may not use this file except in compliance with the License.
+ *
+ * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
+ * or http://www.opensolaris.org/os/licensing.
+ * See the License for the specific language governing permissions
+ * and limitations under the License.
+ *
+ * When distributing Covered Code, include this CDDL HEADER in each
+ * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
+ * If applicable, add the following below this CDDL HEADER, with the
+ * fields enclosed by brackets "[]" replaced with your own identifying
+ * information: Portions Copyright [yyyy] [name of copyright owner]
+ *
+ * CDDL HEADER END
+ */
+
+/*
+ * Copyright (c) 2009, 2012, Oracle and/or its affiliates. All rights reserved.
+ */
+
+package com.oracle.solaris.vp.util.swing;
+
+import java.util.*;
+import javax.swing.DefaultListSelectionModel;
+
+public class ValidatingListSelectionModel extends DefaultListSelectionModel {
+    //
+    // Instance data
+    //
+
+    private List<Integer> selection = new LinkedList<Integer>();
+    private int anchor = -1;
+    private int lead = -1;
+
+    //
+    // DefaultListSelectionModel methods
+    //
+
+    @Override
+    protected void fireValueChanged(int firstIndex, int lastIndex,
+	boolean isAdjusting) {
+
+	if (!isAdjusting) {
+	    if (validateSelection()) {
+		save();
+		super.fireValueChanged(firstIndex, lastIndex, isAdjusting);
+	    } else {
+		setValueIsAdjusting(true);
+		revert();
+		setValueIsAdjusting(false);
+	    }
+	}
+    }
+
+    //
+    // ValidatingListSelectionModel methods
+    //
+
+    /**
+     * Verifies that the current selection is valid.  This default
+     * implementation returns {@code true}.
+     *
+     * @return	    {@code true} if the selection is valid, {@code false}
+     *		    otherwise
+     */
+    protected boolean validateSelection() {
+	return true;
+    }
+
+    protected void revert() {
+	clearSelection();
+	for (int i = 0, n = selection.size(); i < n; i++) {
+	    int first = selection.get(i);
+	    int last = first;
+	    if (i < n - 1 && selection.get(i + 1) == null) {
+		i += 2;
+		last = selection.get(i);
+	    }
+	    addSelectionInterval(first, last);
+	}
+	setAnchorSelectionIndex(anchor);
+	setLeadSelectionIndex(lead);
+    }
+
+    @SuppressWarnings({"fallthrough"})
+    protected void save() {
+	anchor = getAnchorSelectionIndex();
+	lead = getLeadSelectionIndex();
+	int min = getMinSelectionIndex();
+	int max = getMaxSelectionIndex();
+
+	selection.clear();
+	if (min < 0 || max < 0) {
+	    return;
+	}
+
+	for (int i = min; i <= max; i++) {
+	    if (isSelectedIndex(i)) {
+		int first = i;
+		selection.add(first);
+		for (i++; i <= max && isSelectedIndex(i); i++);
+		int last = i - 1;
+
+		switch (last - first) {
+		default:
+		    selection.add(null);
+
+		case 1:
+		    selection.add(last);
+
+		case 0:
+		}
+	    }
+	}
+    }
+}