--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/javax/swing/LayoutComparator.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,160 @@
+/*
+ * Copyright 2000-2004 Sun Microsystems, Inc.  All Rights Reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+package javax.swing;
+
+import java.util.Comparator;
+import java.util.LinkedList;
+import java.util.ListIterator;
+import java.awt.Component;
+import java.awt.ComponentOrientation;
+import java.awt.Window;
+
+
+/**
+ * Comparator which attempts to sort Components based on their size and
+ * position. Code adapted from original javax.swing.DefaultFocusManager
+ * implementation.
+ *
+ * @author David Mendenhall
+ */
+final class LayoutComparator implements Comparator, java.io.Serializable {
+
+    private static final int ROW_TOLERANCE = 10;
+
+    private boolean horizontal = true;
+    private boolean leftToRight = true;
+
+    void setComponentOrientation(ComponentOrientation orientation) {
+        horizontal = orientation.isHorizontal();
+        leftToRight = orientation.isLeftToRight();
+    }
+
+    public int compare(Object o1, Object o2) {
+        Component a = (Component)o1;
+        Component b = (Component)o2;
+
+        if (a == b) {
+            return 0;
+        }
+
+        // Row/Column algorithm only applies to siblings. If 'a' and 'b'
+        // aren't siblings, then we need to find their most inferior
+        // ancestors which share a parent. Compute the ancestory lists for
+        // each Component and then search from the Window down until the
+        // hierarchy branches.
+        if (a.getParent() != b.getParent()) {
+            LinkedList aAncestory, bAncestory;
+
+            for(aAncestory = new LinkedList(); a != null; a = a.getParent()) {
+                aAncestory.add(a);
+                if (a instanceof Window) {
+                    break;
+                }
+            }
+            if (a == null) {
+                // 'a' is not part of a Window hierarchy. Can't cope.
+                throw new ClassCastException();
+            }
+
+            for(bAncestory = new LinkedList(); b != null; b = b.getParent()) {
+                bAncestory.add(b);
+                if (b instanceof Window) {
+                    break;
+                }
+            }
+            if (b == null) {
+                // 'b' is not part of a Window hierarchy. Can't cope.
+                throw new ClassCastException();
+            }
+
+            for (ListIterator
+                     aIter = aAncestory.listIterator(aAncestory.size()),
+                     bIter = bAncestory.listIterator(bAncestory.size()); ;) {
+                if (aIter.hasPrevious()) {
+                    a = (Component)aIter.previous();
+                } else {
+                    // a is an ancestor of b
+                    return -1;
+                }
+
+                if (bIter.hasPrevious()) {
+                    b = (Component)bIter.previous();
+                } else {
+                    // b is an ancestor of a
+                    return 1;
+                }
+
+                if (a != b) {
+                    break;
+                }
+            }
+        }
+
+        int ax = a.getX(), ay = a.getY(), bx = b.getX(), by = b.getY();
+
+        int zOrder = a.getParent().getComponentZOrder(a) - b.getParent().getComponentZOrder(b);
+        if (horizontal) {
+            if (leftToRight) {
+
+                // LT - Western Europe (optional for Japanese, Chinese, Korean)
+
+                if (Math.abs(ay - by) < ROW_TOLERANCE) {
+                    return (ax < bx) ? -1 : ((ax > bx) ? 1 : zOrder);
+                } else {
+                    return (ay < by) ? -1 : 1;
+                }
+            } else { // !leftToRight
+
+                // RT - Middle East (Arabic, Hebrew)
+
+                if (Math.abs(ay - by) < ROW_TOLERANCE) {
+                    return (ax > bx) ? -1 : ((ax < bx) ? 1 : zOrder);
+                } else {
+                    return (ay < by) ? -1 : 1;
+                }
+            }
+        } else { // !horizontal
+            if (leftToRight) {
+
+                // TL - Mongolian
+
+                if (Math.abs(ax - bx) < ROW_TOLERANCE) {
+                    return (ay < by) ? -1 : ((ay > by) ? 1 : zOrder);
+                } else {
+                    return (ax < bx) ? -1 : 1;
+                }
+            } else { // !leftToRight
+
+                // TR - Japanese, Chinese, Korean
+
+                if (Math.abs(ax - bx) < ROW_TOLERANCE) {
+                    return (ay < by) ? -1 : ((ay > by) ? 1 : zOrder);
+                } else {
+                    return (ax > bx) ? -1 : 1;
+                }
+            }
+        }
+    }
+}