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 * Copyright (c) 1997, 2013, Oracle and/or its affiliates. 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.  Oracle designates this
 * particular file as subject to the "Classpath" exception as provided
 * by Oracle 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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 */
package javax.swing;

import java.awt.Component;
import java.awt.Container;
import java.awt.FocusTraversalPolicy;
import java.util.Comparator;


This class has been obsoleted by the 1.4 focus APIs. While client code may
still use this class, developers are strongly encouraged to use
java.awt.KeyboardFocusManager and
java.awt.DefaultKeyboardFocusManager instead.

Please see

How to Use the Focus Subsystem,
a section in The Java Tutorial, and the
Focus Specification
for more information.
Author:
Arnaud Weber, David Mendenhall/**
 * This class has been obsoleted by the 1.4 focus APIs. While client code may
 * still use this class, developers are strongly encouraged to use
 * <code>java.awt.KeyboardFocusManager</code> and
 * <code>java.awt.DefaultKeyboardFocusManager</code> instead.
 * <p>
 * Please see
 * <a href="https://docs.oracle.com/javase/tutorial/uiswing/misc/focus.html">
 * How to Use the Focus Subsystem</a>,
 * a section in <em>The Java Tutorial</em>, and the
 * <a href="../../java/awt/doc-files/FocusSpec.html">Focus Specification</a>
 * for more information.
 *
 * @author Arnaud Weber
 * @author David Mendenhall
 */
public class DefaultFocusManager extends FocusManager {

    final FocusTraversalPolicy gluePolicy =
        new LegacyGlueFocusTraversalPolicy(this);
    private final FocusTraversalPolicy layoutPolicy =
        new LegacyLayoutFocusTraversalPolicy(this);
    private final LayoutComparator comparator =
        new LayoutComparator();

    public DefaultFocusManager() {
        setDefaultFocusTraversalPolicy(gluePolicy);
    }

    public Component getComponentAfter(Container aContainer,
                                       Component aComponent)
    {
        Container root = (aContainer.isFocusCycleRoot())
            ? aContainer
            : aContainer.getFocusCycleRootAncestor();

        // Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
        // traversal policy is non-legacy, then honor it.
        if (root != null) {
            FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
            if (policy != gluePolicy) {
                return policy.getComponentAfter(root, aComponent);
            }

            comparator.setComponentOrientation(root.getComponentOrientation());
            return layoutPolicy.getComponentAfter(root, aComponent);
        }

        return null;
    }

    public Component getComponentBefore(Container aContainer,
                                        Component aComponent)
    {
        Container root = (aContainer.isFocusCycleRoot())
            ? aContainer
            : aContainer.getFocusCycleRootAncestor();

        // Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
        // traversal policy is non-legacy, then honor it.
        if (root != null) {
            FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
            if (policy != gluePolicy) {
                return policy.getComponentBefore(root, aComponent);
            }

            comparator.setComponentOrientation(root.getComponentOrientation());
            return layoutPolicy.getComponentBefore(root, aComponent);
        }

        return null;
    }

    public Component getFirstComponent(Container aContainer) {
        Container root = (aContainer.isFocusCycleRoot())
            ? aContainer
            : aContainer.getFocusCycleRootAncestor();

        // Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
        // traversal policy is non-legacy, then honor it.
        if (root != null) {
            FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
            if (policy != gluePolicy) {
                return policy.getFirstComponent(root);
            }

            comparator.setComponentOrientation(root.getComponentOrientation());
            return layoutPolicy.getFirstComponent(root);
        }

        return null;
    }

    public Component getLastComponent(Container aContainer) {
        Container root = (aContainer.isFocusCycleRoot())
            ? aContainer
            : aContainer.getFocusCycleRootAncestor();

        // Support for mixed 1.4/pre-1.4 focus APIs. If a particular root's
        // traversal policy is non-legacy, then honor it.
        if (root != null) {
            FocusTraversalPolicy policy = root.getFocusTraversalPolicy();
            if (policy != gluePolicy) {
                return policy.getLastComponent(root);
            }

            comparator.setComponentOrientation(root.getComponentOrientation());
            return layoutPolicy.getLastComponent(root);
        }

        return null;
    }

    public boolean compareTabOrder(Component a, Component b) {
        return (comparator.compare(a, b) < 0);
    }
}

final class LegacyLayoutFocusTraversalPolicy
    extends LayoutFocusTraversalPolicy
{
    LegacyLayoutFocusTraversalPolicy(DefaultFocusManager defaultFocusManager) {
        super(new CompareTabOrderComparator(defaultFocusManager));
    }
}

final class CompareTabOrderComparator implements Comparator<Component> {
    private final DefaultFocusManager defaultFocusManager;

    CompareTabOrderComparator(DefaultFocusManager defaultFocusManager) {
        this.defaultFocusManager = defaultFocusManager;
    }

    public int compare(Component o1, Component o2) {
        if (o1 == o2) {
            return 0;
        }
        return (defaultFocusManager.compareTabOrder(o1, o2)) ? -1 : 1;
    }
}