/*
 * Copyright (c) 1997, 2015, 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
 * or visit www.oracle.com if you need additional information or have any
 * questions.
 */


package javax.swing.plaf.basic;


import sun.awt.AWTAccessor;
import sun.awt.AWTAccessor.ComponentAccessor;
import sun.swing.DefaultLookup;
import sun.swing.UIAction;
import javax.swing.*;
import javax.swing.border.Border;
import java.awt.*;
import java.awt.event.*;
import java.awt.peer.ComponentPeer;
import java.awt.peer.LightweightPeer;
import java.beans.*;
import java.util.*;
import javax.swing.plaf.SplitPaneUI;
import javax.swing.plaf.ComponentUI;
import javax.swing.plaf.UIResource;
import sun.swing.SwingUtilities2;


A Basic L&F implementation of the SplitPaneUI.
Author:
Scott Violet, Steve Wilson, Ralph Kar/**
 * A Basic L&F implementation of the SplitPaneUI.
 *
 * @author Scott Violet
 * @author Steve Wilson
 * @author Ralph Kar
 */
public class BasicSplitPaneUI extends SplitPaneUI
{
    
The divider used for non-continuous layout is added to the split pane
with this object.
/**
     * The divider used for non-continuous layout is added to the split pane
     * with this object.
     */
    protected static final String NON_CONTINUOUS_DIVIDER =
        "nonContinuousDivider";


    
How far (relative) the divider does move when it is moved around by
the cursor keys on the keyboard.
/**
     * How far (relative) the divider does move when it is moved around by
     * the cursor keys on the keyboard.
     */
    protected static int KEYBOARD_DIVIDER_MOVE_OFFSET = 3;


    
JSplitPane instance this instance is providing
the look and feel for.
/**
     * JSplitPane instance this instance is providing
     * the look and feel for.
     */
    protected JSplitPane splitPane;


    
LayoutManager that is created and placed into the split pane.
/**
     * LayoutManager that is created and placed into the split pane.
     */
    protected BasicHorizontalLayoutManager layoutManager;


    
Instance of the divider for this JSplitPane.
/**
     * Instance of the divider for this JSplitPane.
     */
    protected BasicSplitPaneDivider divider;


    
Instance of the PropertyChangeListener for this JSplitPane.
/**
     * Instance of the PropertyChangeListener for this JSplitPane.
     */
    protected PropertyChangeListener propertyChangeListener;


    
Instance of the FocusListener for this JSplitPane.
/**
     * Instance of the FocusListener for this JSplitPane.
     */
    protected FocusListener focusListener;

    private Handler handler;


    
Keys to use for forward focus traversal when the JComponent is
managing focus.
/**
     * Keys to use for forward focus traversal when the JComponent is
     * managing focus.
     */
    private Set<KeyStroke> managingFocusForwardTraversalKeys;

    
Keys to use for backward focus traversal when the JComponent is
managing focus.
/**
     * Keys to use for backward focus traversal when the JComponent is
     * managing focus.
     */
    private Set<KeyStroke> managingFocusBackwardTraversalKeys;


    
The size of the divider while the dragging session is valid.
/**
     * The size of the divider while the dragging session is valid.
     */
    protected int dividerSize;


    
Instance for the shadow of the divider when non continuous layout
is being used.
/**
     * Instance for the shadow of the divider when non continuous layout
     * is being used.
     */
    protected Component nonContinuousLayoutDivider;


    
Set to true in startDragging if any of the children
(not including the nonContinuousLayoutDivider) are heavy weights.
/**
     * Set to true in startDragging if any of the children
     * (not including the nonContinuousLayoutDivider) are heavy weights.
     */
    protected boolean draggingHW;


    
Location of the divider when the dragging session began.
/**
     * Location of the divider when the dragging session began.
     */
    protected int beginDragDividerLocation;


    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke upKey;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke downKey;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke leftKey;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke rightKey;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke homeKey;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke endKey;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected KeyStroke dividerResizeToggleKey;

    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener keyboardUpLeftListener;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener keyboardDownRightListener;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener keyboardHomeListener;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener keyboardEndListener;
    
As of Java 2 platform v1.3 this previously undocumented field is no
longer used.
Key bindings are now defined by the LookAndFeel, please refer to
the key bindings specification for further details.
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this previously undocumented field is no
     * longer used.
     * Key bindings are now defined by the LookAndFeel, please refer to
     * the key bindings specification for further details.
     *
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener keyboardResizeToggleListener;


    // Private data of the instance
    private int         orientation;
    private int         lastDragLocation;
    private boolean     continuousLayout;
    private boolean     dividerKeyboardResize;
    private boolean     dividerLocationIsSet;  // needed for tracking
                                               // the first occurrence of
                                               // setDividerLocation()
    private Color dividerDraggingColor;
    private boolean rememberPaneSizes;

    // Indicates whether the one of splitpane sides is expanded
    private boolean keepHidden = false;

    
Indicates that we have painted once. /** Indicates that we have painted once. */
    // This is used by the LayoutManager to determine when it should use
    // the divider location provided by the JSplitPane. This is used as there
    // is no way to determine when the layout process has completed.
    boolean             painted;
    
If true, setDividerLocation does nothing. /** If true, setDividerLocation does nothing. */
    boolean             ignoreDividerLocationChange;

    
Constructs a BasicSplitPaneUI. /**
     * Constructs a {@code BasicSplitPaneUI}.
     */
    public BasicSplitPaneUI() {}

    
Creates a new instance of BasicSplitPaneUI. 
Params:
x – a component
Returns:
a new instance of BasicSplitPaneUI/**
     * Creates a new instance of {@code BasicSplitPaneUI}.
     *
     * @param x a component
     * @return a new instance of {@code BasicSplitPaneUI}
     */
    public static ComponentUI createUI(JComponent x) {
        return new BasicSplitPaneUI();
    }

    static void loadActionMap(LazyActionMap map) {
        map.put(new Actions(Actions.NEGATIVE_INCREMENT));
        map.put(new Actions(Actions.POSITIVE_INCREMENT));
        map.put(new Actions(Actions.SELECT_MIN));
        map.put(new Actions(Actions.SELECT_MAX));
        map.put(new Actions(Actions.START_RESIZE));
        map.put(new Actions(Actions.TOGGLE_FOCUS));
        map.put(new Actions(Actions.FOCUS_OUT_FORWARD));
        map.put(new Actions(Actions.FOCUS_OUT_BACKWARD));
    }



    
Installs the UI.
/**
     * Installs the UI.
     */
    public void installUI(JComponent c) {
        splitPane = (JSplitPane) c;
        dividerLocationIsSet = false;
        dividerKeyboardResize = false;
        keepHidden = false;
        installDefaults();
        installListeners();
        installKeyboardActions();
        setLastDragLocation(-1);
    }


    
Installs the UI defaults.
/**
     * Installs the UI defaults.
     */
    @SuppressWarnings("deprecation")
    protected void installDefaults(){
        LookAndFeel.installBorder(splitPane, "SplitPane.border");
        LookAndFeel.installColors(splitPane, "SplitPane.background",
                                  "SplitPane.foreground");
        LookAndFeel.installProperty(splitPane, "opaque", Boolean.TRUE);

        if (divider == null) divider = createDefaultDivider();
        divider.setBasicSplitPaneUI(this);

        Border    b = divider.getBorder();

        if (b == null || !(b instanceof UIResource)) {
            divider.setBorder(UIManager.getBorder("SplitPaneDivider.border"));
        }

        dividerDraggingColor = UIManager.getColor("SplitPaneDivider.draggingColor");

        setOrientation(splitPane.getOrientation());

        // note: don't rename this temp variable to dividerSize
        // since it will conflict with "this.dividerSize" field
        Integer temp = (Integer)UIManager.get("SplitPane.dividerSize");
        LookAndFeel.installProperty(splitPane, "dividerSize", temp == null? 10: temp);

        divider.setDividerSize(splitPane.getDividerSize());
        dividerSize = divider.getDividerSize();
        splitPane.add(divider, JSplitPane.DIVIDER);

        setContinuousLayout(splitPane.isContinuousLayout());

        resetLayoutManager();

        /* Install the nonContinuousLayoutDivider here to avoid having to
        add/remove everything later. */
        if(nonContinuousLayoutDivider == null) {
            setNonContinuousLayoutDivider(
                                createDefaultNonContinuousLayoutDivider(),
                                true);
        } else {
            setNonContinuousLayoutDivider(nonContinuousLayoutDivider, true);
        }

        // focus forward traversal key
        if (managingFocusForwardTraversalKeys==null) {
            managingFocusForwardTraversalKeys = new HashSet<KeyStroke>();
            managingFocusForwardTraversalKeys.add(
                KeyStroke.getKeyStroke(KeyEvent.VK_TAB, 0));
        }
        splitPane.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS,
                                        managingFocusForwardTraversalKeys);
        // focus backward traversal key
        if (managingFocusBackwardTraversalKeys==null) {
            managingFocusBackwardTraversalKeys = new HashSet<KeyStroke>();
            managingFocusBackwardTraversalKeys.add(
                KeyStroke.getKeyStroke(KeyEvent.VK_TAB, InputEvent.SHIFT_MASK));
        }
        splitPane.setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS,
                                        managingFocusBackwardTraversalKeys);
    }


    
Installs the event listeners for the UI.
/**
     * Installs the event listeners for the UI.
     */
    protected void installListeners() {
        if ((propertyChangeListener = createPropertyChangeListener()) !=
            null) {
            splitPane.addPropertyChangeListener(propertyChangeListener);
        }

        if ((focusListener = createFocusListener()) != null) {
            splitPane.addFocusListener(focusListener);
        }
    }


    
Installs the keyboard actions for the UI.
/**
     * Installs the keyboard actions for the UI.
     */
    protected void installKeyboardActions() {
        InputMap km = getInputMap(JComponent.
                                  WHEN_ANCESTOR_OF_FOCUSED_COMPONENT);

        SwingUtilities.replaceUIInputMap(splitPane, JComponent.
                                       WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,
                                       km);
        LazyActionMap.installLazyActionMap(splitPane, BasicSplitPaneUI.class,
                                           "SplitPane.actionMap");
    }

    InputMap getInputMap(int condition) {
        if (condition == JComponent.WHEN_ANCESTOR_OF_FOCUSED_COMPONENT) {
            return (InputMap)DefaultLookup.get(splitPane, this,
                                               "SplitPane.ancestorInputMap");
        }
        return null;
    }

    
Uninstalls the UI.
/**
     * Uninstalls the UI.
     */
    public void uninstallUI(JComponent c) {
        uninstallKeyboardActions();
        uninstallListeners();
        uninstallDefaults();
        dividerLocationIsSet = false;
        dividerKeyboardResize = false;
        splitPane = null;
    }


    
Uninstalls the UI defaults.
/**
     * Uninstalls the UI defaults.
     */
    protected void uninstallDefaults() {
        if(splitPane.getLayout() == layoutManager) {
            splitPane.setLayout(null);
        }

        if(nonContinuousLayoutDivider != null) {
            splitPane.remove(nonContinuousLayoutDivider);
        }

        LookAndFeel.uninstallBorder(splitPane);

        Border    b = divider.getBorder();

        if (b instanceof UIResource) {
            divider.setBorder(null);
        }

        splitPane.remove(divider);
        divider.setBasicSplitPaneUI(null);
        layoutManager = null;
        divider = null;
        nonContinuousLayoutDivider = null;

        setNonContinuousLayoutDivider(null);

        // sets the focus forward and backward traversal keys to null
        // to restore the defaults
        splitPane.setFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, null);
        splitPane.setFocusTraversalKeys(KeyboardFocusManager.BACKWARD_TRAVERSAL_KEYS, null);
    }


    
Uninstalls the event listeners for the UI.
/**
     * Uninstalls the event listeners for the UI.
     */
    protected void uninstallListeners() {
        if (propertyChangeListener != null) {
            splitPane.removePropertyChangeListener(propertyChangeListener);
            propertyChangeListener = null;
        }
        if (focusListener != null) {
            splitPane.removeFocusListener(focusListener);
            focusListener = null;
        }

        keyboardUpLeftListener = null;
        keyboardDownRightListener = null;
        keyboardHomeListener = null;
        keyboardEndListener = null;
        keyboardResizeToggleListener = null;
        handler = null;
    }


    
Uninstalls the keyboard actions for the UI.
/**
     * Uninstalls the keyboard actions for the UI.
     */
    protected void uninstallKeyboardActions() {
        SwingUtilities.replaceUIActionMap(splitPane, null);
        SwingUtilities.replaceUIInputMap(splitPane, JComponent.
                                      WHEN_ANCESTOR_OF_FOCUSED_COMPONENT,
                                      null);
    }


    
Creates a PropertyChangeListener for the JSplitPane UI. 
Returns:
an instance of PropertyChangeListener/**
     * Creates a {@code PropertyChangeListener} for the {@code JSplitPane} UI.
     *
     * @return an instance of {@code PropertyChangeListener}
     */
    protected PropertyChangeListener createPropertyChangeListener() {
        return getHandler();
    }

    private Handler getHandler() {
        if (handler == null) {
            handler = new Handler();
        }
        return handler;
    }


    
Creates a FocusListener for the JSplitPane UI. 
Returns:
an instance of FocusListener/**
     * Creates a {@code FocusListener} for the {@code JSplitPane} UI.
     *
     * @return an instance of {@code FocusListener}
     */
    protected FocusListener createFocusListener() {
        return getHandler();
    }


    
As of Java 2 platform v1.3 this method is no longer used. Subclassers previously using this method should instead create an Action wrapping the ActionListener, and register that Action by overriding installKeyboardActions and placing the Action in the SplitPane's ActionMap. Please refer to the key bindings specification for further details. 
 Creates an ActionListener for the JSplitPane UI that listens for specific key presses. 
Returns:
an instance of ActionListener
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this method is no longer used.
     * Subclassers previously using this method should instead create
     * an {@code Action} wrapping the {@code ActionListener}, and register
     * that {@code Action} by overriding {@code installKeyboardActions}
     * and placing the {@code Action} in the {@code SplitPane's ActionMap}.
     * Please refer to the key bindings specification for further details.
     * <p>
     * Creates an {@code ActionListener} for the {@code JSplitPane} UI that
     * listens for specific key presses.
     *
     * @return an instance of {@code ActionListener}
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener createKeyboardUpLeftListener() {
        return new KeyboardUpLeftHandler();
    }


    
As of Java 2 platform v1.3 this method is no longer used. Subclassers previously using this method should instead create an Action wrapping the ActionListener, and register that Action by overriding installKeyboardActions and placing the Action in the SplitPane's ActionMap. Please refer to the key bindings specification for further details. 
 Creates an ActionListener for the JSplitPane UI that listens for specific key presses. 
Returns:
an instance of ActionListener
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this method is no longer used.
     * Subclassers previously using this method should instead create
     * an {@code Action} wrapping the {@code ActionListener}, and register
     * that {@code Action} by overriding {@code installKeyboardActions}
     * and placing the {@code Action} in the {@code SplitPane's ActionMap}.
     * Please refer to the key bindings specification for further details.
     * <p>
     * Creates an {@code ActionListener} for the {@code JSplitPane} UI that
     * listens for specific key presses.
     *
     * @return an instance of {@code ActionListener}
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener createKeyboardDownRightListener() {
        return new KeyboardDownRightHandler();
    }


    
As of Java 2 platform v1.3 this method is no longer used. Subclassers previously using this method should instead create an Action wrapping the ActionListener, and register that Action by overriding installKeyboardActions and placing the Action in the SplitPane's ActionMap. Please refer to the key bindings specification for further details. 
 Creates an ActionListener for the JSplitPane UI that listens for specific key presses. 
Returns:
an instance of ActionListener
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this method is no longer used.
     * Subclassers previously using this method should instead create
     * an {@code Action} wrapping the {@code ActionListener}, and register
     * that {@code Action} by overriding {@code installKeyboardActions}
     * and placing the {@code Action} in the {@code SplitPane's ActionMap}.
     * Please refer to the key bindings specification for further details.
     * <p>
     * Creates an {@code ActionListener} for the {@code JSplitPane} UI that
     * listens for specific key presses.
     *
     * @return an instance of {@code ActionListener}
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener createKeyboardHomeListener() {
        return new KeyboardHomeHandler();
    }


    
As of Java 2 platform v1.3 this method is no longer used. Subclassers previously using this method should instead create an Action wrapping the ActionListener, and register that Action by overriding installKeyboardActions and placing the Action in the SplitPane's ActionMap. Please refer to the key bindings specification for further details. 
 Creates an ActionListener for the JSplitPane UI that listens for specific key presses. 
Returns:
an instance of ActionListener
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this method is no longer used.
     * Subclassers previously using this method should instead create
     * an {@code Action} wrapping the {@code ActionListener}, and register
     * that {@code Action} by overriding {@code installKeyboardActions}
     * and placing the {@code Action} in the {@code SplitPane's ActionMap}.
     * Please refer to the key bindings specification for further details.
     * <p>
     * Creates an {@code ActionListener} for the {@code JSplitPane} UI that
     * listens for specific key presses.
     *
     * @return an instance of {@code ActionListener}
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener createKeyboardEndListener() {
        return new KeyboardEndHandler();
    }


    
As of Java 2 platform v1.3 this method is no longer used. Subclassers previously using this method should instead create an Action wrapping the ActionListener, and register that Action by overriding installKeyboardActions and placing the Action in the SplitPane's ActionMap. Please refer to the key bindings specification for further details. 
 Creates an ActionListener for the JSplitPane UI that listens for specific key presses. 
Returns:
an instance of ActionListener
Deprecated:
As of Java 2 platform v1.3./**
     * As of Java 2 platform v1.3 this method is no longer used.
     * Subclassers previously using this method should instead create
     * an {@code Action} wrapping the {@code ActionListener}, and register
     * that {@code Action} by overriding {@code installKeyboardActions}
     * and placing the {@code Action} in the {@code SplitPane's ActionMap}.
     * Please refer to the key bindings specification for further details.
     * <p>
     * Creates an {@code ActionListener} for the {@code JSplitPane} UI that
     * listens for specific key presses.
     *
     * @return an instance of {@code ActionListener}
     * @deprecated As of Java 2 platform v1.3.
     */
    @Deprecated
    protected ActionListener createKeyboardResizeToggleListener() {
        return new KeyboardResizeToggleHandler();
    }


    
Returns the orientation for the JSplitPane. 
Returns:
the orientation/**
     * Returns the orientation for the {@code JSplitPane}.
     *
     * @return the orientation
     */
    public int getOrientation() {
        return orientation;
    }


    
Set the orientation for the JSplitPane. 
Params:
orientation – the orientation/**
     * Set the orientation for the {@code JSplitPane}.
     *
     * @param orientation the orientation
     */
    public void setOrientation(int orientation) {
        this.orientation = orientation;
    }


    
Determines whether the JSplitPane is set to use a continuous layout. 
Returns:
true if a continuous layout is set/**
     * Determines whether the {@code JSplitPane} is set to use a continuous layout.
     *
     * @return {@code true} if a continuous layout is set
     */
    public boolean isContinuousLayout() {
        return continuousLayout;
    }


    
Turn continuous layout on/off.
Params:
b – if true the continuous layout turns on/**
     * Turn continuous layout on/off.
     *
     * @param b if {@code true} the continuous layout turns on
     */
    public void setContinuousLayout(boolean b) {
        continuousLayout = b;
    }


    
Returns the last drag location of the JSplitPane. 
Returns:
the last drag location/**
     * Returns the last drag location of the {@code JSplitPane}.
     *
     * @return the last drag location
     */
    public int getLastDragLocation() {
        return lastDragLocation;
    }


    
Set the last drag location of the JSplitPane. 
Params:
l – the drag location/**
     * Set the last drag location of the {@code JSplitPane}.
     *
     * @param l the drag location
     */
    public void setLastDragLocation(int l) {
        lastDragLocation = l;
    }

    
Returns:
increment via keyboard methods./**
     * @return increment via keyboard methods.
     */
    int getKeyboardMoveIncrement() {
        return 3;
    }

    
Implementation of the PropertyChangeListener
that the JSplitPane UI uses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of the PropertyChangeListener
     * that the JSplitPane UI uses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class PropertyHandler implements PropertyChangeListener
    {
        
Constructs a PropertyHandler. /**
         * Constructs a {@code PropertyHandler}.
         */
        public PropertyHandler() {}

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.

        
Messaged from the JSplitPane the receiver is
contained in.  May potentially reset the layout manager and cause a
validate to be sent.
/**
         * Messaged from the <code>JSplitPane</code> the receiver is
         * contained in.  May potentially reset the layout manager and cause a
         * <code>validate</code> to be sent.
         */
        public void propertyChange(PropertyChangeEvent e) {
            getHandler().propertyChange(e);
        }
    }


    
Implementation of the FocusListener that the JSplitPane UI uses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of the FocusListener that the JSplitPane UI uses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class FocusHandler extends FocusAdapter
    {
        
Constructs a FocusHandler. /**
         * Constructs a {@code FocusHandler}.
         */
        public FocusHandler() {}

        // NOTE: This class exists only for backward compatibility. All
        // its functionality has been moved into Handler. If you need to add
        // new functionality add it to the Handler, but make sure this
        // class calls into the Handler.
        public void focusGained(FocusEvent ev) {
            getHandler().focusGained(ev);
        }

        public void focusLost(FocusEvent ev) {
            getHandler().focusLost(ev);
        }
    }


    
Implementation of an ActionListener that the JSplitPane UI uses for
handling specific key presses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of an ActionListener that the JSplitPane UI uses for
     * handling specific key presses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class KeyboardUpLeftHandler implements ActionListener
    {
        
Constructs a KeyboardUpLeftHandler. /**
         * Constructs a {@code KeyboardUpLeftHandler}.
         */
        public KeyboardUpLeftHandler() {}

        public void actionPerformed(ActionEvent ev) {
            if (dividerKeyboardResize) {
                splitPane.setDividerLocation(Math.max(0,getDividerLocation
                                  (splitPane) - getKeyboardMoveIncrement()));
            }
        }
    }

    
Implementation of an ActionListener that the JSplitPane UI uses for
handling specific key presses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of an ActionListener that the JSplitPane UI uses for
     * handling specific key presses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class KeyboardDownRightHandler implements ActionListener
    {
        
Constructs a KeyboardDownRightHandler. /**
         * Constructs a {@code KeyboardDownRightHandler}.
         */
        public KeyboardDownRightHandler() {}

        public void actionPerformed(ActionEvent ev) {
            if (dividerKeyboardResize) {
                splitPane.setDividerLocation(getDividerLocation(splitPane) +
                                             getKeyboardMoveIncrement());
            }
        }
    }


    
Implementation of an ActionListener that the JSplitPane UI uses for
handling specific key presses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of an ActionListener that the JSplitPane UI uses for
     * handling specific key presses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class KeyboardHomeHandler implements ActionListener
    {
        
Constructs a KeyboardHomeHandler. /**
         * Constructs a {@code KeyboardHomeHandler}.
         */
        public KeyboardHomeHandler() {}

        public void actionPerformed(ActionEvent ev) {
            if (dividerKeyboardResize) {
                splitPane.setDividerLocation(0);
            }
        }
    }


    
Implementation of an ActionListener that the JSplitPane UI uses for
handling specific key presses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of an ActionListener that the JSplitPane UI uses for
     * handling specific key presses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class KeyboardEndHandler implements ActionListener
    {
        
Constructs a KeyboardEndHandler. /**
         * Constructs a {@code KeyboardEndHandler}.
         */
        public KeyboardEndHandler() {}

        public void actionPerformed(ActionEvent ev) {
            if (dividerKeyboardResize) {
                Insets   insets = splitPane.getInsets();
                int      bottomI = (insets != null) ? insets.bottom : 0;
                int      rightI = (insets != null) ? insets.right : 0;

                if (orientation == JSplitPane.VERTICAL_SPLIT) {
                    splitPane.setDividerLocation(splitPane.getHeight() -
                                       bottomI);
                }
                else {
                    splitPane.setDividerLocation(splitPane.getWidth() -
                                                 rightI);
                }
            }
        }
    }


    
Implementation of an ActionListener that the JSplitPane UI uses for
handling specific key presses.

This class should be treated as a "protected" inner class.
Instantiate it only within subclasses of BasicSplitPaneUI.
/**
     * Implementation of an ActionListener that the JSplitPane UI uses for
     * handling specific key presses.
     * <p>
     * This class should be treated as a &quot;protected&quot; inner class.
     * Instantiate it only within subclasses of BasicSplitPaneUI.
     */
    public class KeyboardResizeToggleHandler implements ActionListener
    {
        
Constructs a KeyboardResizeToggleHandler. /**
         * Constructs a {@code KeyboardResizeToggleHandler}.
         */
        public KeyboardResizeToggleHandler() {}

        public void actionPerformed(ActionEvent ev) {
            if (!dividerKeyboardResize) {
                splitPane.requestFocus();
            }
        }
    }

    
Returns the divider between the top Components.
Returns:
the divider between the top Components/**
     * Returns the divider between the top Components.
     *
     * @return the divider between the top Components
     */
    public BasicSplitPaneDivider getDivider() {
        return divider;
    }


    
Returns the default non continuous layout divider, which is an instance of Canvas that fills in the background with dark gray. 
Returns:
the default non continuous layout divider/**
     * Returns the default non continuous layout divider, which is an
     * instance of {@code Canvas} that fills in the background with dark gray.
     *
     * @return the default non continuous layout divider
     */
    @SuppressWarnings("serial") // anonymous class
    protected Component createDefaultNonContinuousLayoutDivider() {
        return new Canvas() {
            public void paint(Graphics g) {
                if(!isContinuousLayout() && getLastDragLocation() != -1) {
                    Dimension      size = splitPane.getSize();

                    g.setColor(dividerDraggingColor);
                    if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                        g.fillRect(0, 0, dividerSize - 1, size.height - 1);
                    } else {
                        g.fillRect(0, 0, size.width - 1, dividerSize - 1);
                    }
                }
            }
        };
    }


    
Sets the divider to use when the JSplitPane is configured to not continuously layout. This divider will only be used during a dragging session. It is recommended that the passed in component be a heavy weight. 
Params:
newDivider – the new divider/**
     * Sets the divider to use when the {@code JSplitPane} is configured to
     * not continuously layout. This divider will only be used during a
     * dragging session. It is recommended that the passed in component
     * be a heavy weight.
     *
     * @param newDivider the new divider
     */
    protected void setNonContinuousLayoutDivider(Component newDivider) {
        setNonContinuousLayoutDivider(newDivider, true);
    }


    
Sets the divider to use.
Params:
newDivider – the new divider
rememberSizes – if true the pane size is remembered/**
     * Sets the divider to use.
     *
     * @param newDivider the new divider
     * @param rememberSizes if {@code true} the pane size is remembered
     */
    protected void setNonContinuousLayoutDivider(Component newDivider,
        boolean rememberSizes) {
        rememberPaneSizes = rememberSizes;
        if(nonContinuousLayoutDivider != null && splitPane != null) {
            splitPane.remove(nonContinuousLayoutDivider);
        }
        nonContinuousLayoutDivider = newDivider;
    }

    private void addHeavyweightDivider() {
        if(nonContinuousLayoutDivider != null && splitPane != null) {

            /* Needs to remove all the components and re-add them! YECK! */
            // This is all done so that the nonContinuousLayoutDivider will
            // be drawn on top of the other components, without this, one
            // of the heavyweights will draw over the divider!
            Component             leftC = splitPane.getLeftComponent();
            Component             rightC = splitPane.getRightComponent();
            int                   lastLocation = splitPane.
                                              getDividerLocation();

            if(leftC != null)
                splitPane.setLeftComponent(null);
            if(rightC != null)
                splitPane.setRightComponent(null);
            splitPane.remove(divider);
            splitPane.add(nonContinuousLayoutDivider, BasicSplitPaneUI.
                          NON_CONTINUOUS_DIVIDER,
                          splitPane.getComponentCount());
            splitPane.setLeftComponent(leftC);
            splitPane.setRightComponent(rightC);
            splitPane.add(divider, JSplitPane.DIVIDER);
            if(rememberPaneSizes) {
                splitPane.setDividerLocation(lastLocation);
            }
        }

    }


    
Returns the divider to use when the JSplitPane is configured to not continuously layout. This divider will only be used during a dragging session. 
Returns:
the divider/**
     * Returns the divider to use when the {@code JSplitPane} is configured to
     * not continuously layout. This divider will only be used during a
     * dragging session.
     *
     * @return the divider
     */
    public Component getNonContinuousLayoutDivider() {
        return nonContinuousLayoutDivider;
    }


    
Returns the JSplitPane this instance is currently contained in. 
Returns:
the instance of JSplitPane/**
     * Returns the {@code JSplitPane} this instance is currently contained
     * in.
     *
     * @return the instance of {@code JSplitPane}
     */
    public JSplitPane getSplitPane() {
        return splitPane;
    }


    
Creates the default divider.
Returns:
the default divider/**
     * Creates the default divider.
     *
     * @return the default divider
     */
    public BasicSplitPaneDivider createDefaultDivider() {
        return new BasicSplitPaneDivider(this);
    }


    
Messaged to reset the preferred sizes.
/**
     * Messaged to reset the preferred sizes.
     */
    public void resetToPreferredSizes(JSplitPane jc) {
        if(splitPane != null) {
            layoutManager.resetToPreferredSizes();
            splitPane.revalidate();
            splitPane.repaint();
        }
    }


    
Sets the location of the divider to location.
/**
     * Sets the location of the divider to location.
     */
    public void setDividerLocation(JSplitPane jc, int location) {
        if (!ignoreDividerLocationChange) {
            dividerLocationIsSet = true;
            splitPane.revalidate();
            splitPane.repaint();

            if (keepHidden) {
                Insets insets = splitPane.getInsets();
                int orientation = splitPane.getOrientation();
                if ((orientation == JSplitPane.VERTICAL_SPLIT &&
                     location != insets.top &&
                     location != splitPane.getHeight()-divider.getHeight()-insets.top) ||
                    (orientation == JSplitPane.HORIZONTAL_SPLIT &&
                     location != insets.left &&
                     location != splitPane.getWidth()-divider.getWidth()-insets.left)) {
                    setKeepHidden(false);
                }
            }
        }
        else {
            ignoreDividerLocationChange = false;
        }
    }


    
Returns the location of the divider, which may differ from what
the splitpane thinks the location of the divider is.
/**
     * Returns the location of the divider, which may differ from what
     * the splitpane thinks the location of the divider is.
     */
    public int getDividerLocation(JSplitPane jc) {
        if(orientation == JSplitPane.HORIZONTAL_SPLIT)
            return divider.getLocation().x;
        return divider.getLocation().y;
    }


    
Gets the minimum location of the divider.
/**
     * Gets the minimum location of the divider.
     */
    public int getMinimumDividerLocation(JSplitPane jc) {
        int       minLoc = 0;
        Component leftC = splitPane.getLeftComponent();

        if ((leftC != null) && (leftC.isVisible())) {
            Insets    insets = splitPane.getInsets();
            Dimension minSize = leftC.getMinimumSize();
            if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                minLoc = minSize.width;
            } else {
                minLoc = minSize.height;
            }
            if(insets != null) {
                if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                    minLoc += insets.left;
                } else {
                    minLoc += insets.top;
                }
            }
        }
        return minLoc;
    }


    
Gets the maximum location of the divider.
/**
     * Gets the maximum location of the divider.
     */
    public int getMaximumDividerLocation(JSplitPane jc) {
        Dimension splitPaneSize = splitPane.getSize();
        int       maxLoc = 0;
        Component rightC = splitPane.getRightComponent();

        if (rightC != null) {
            Insets    insets = splitPane.getInsets();
            Dimension minSize = new Dimension(0, 0);
            if (rightC.isVisible()) {
                minSize = rightC.getMinimumSize();
            }
            if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                maxLoc = splitPaneSize.width - minSize.width;
            } else {
                maxLoc = splitPaneSize.height - minSize.height;
            }
            maxLoc -= dividerSize;
            if(insets != null) {
                if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                    maxLoc -= insets.right;
                } else {
                    maxLoc -= insets.top;
                }
            }
        }
        return Math.max(getMinimumDividerLocation(splitPane), maxLoc);
    }


    
Called when the specified split pane has finished painting
its children.
/**
     * Called when the specified split pane has finished painting
     * its children.
     */
    public void finishedPaintingChildren(JSplitPane sp, Graphics g) {
        if(sp == splitPane && getLastDragLocation() != -1 &&
           !isContinuousLayout() && !draggingHW) {
            Dimension      size = splitPane.getSize();

            g.setColor(dividerDraggingColor);
            if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                g.fillRect(getLastDragLocation(), 0, dividerSize - 1,
                           size.height - 1);
            } else {
                g.fillRect(0, lastDragLocation, size.width - 1,
                           dividerSize - 1);
            }
        }
    }


    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    public void paint(Graphics g, JComponent jc) {
        if (!painted && splitPane.getDividerLocation()<0) {
            ignoreDividerLocationChange = true;
            splitPane.setDividerLocation(getDividerLocation(splitPane));
        }
        painted = true;
    }


    
Returns the preferred size for the passed in component,
This is passed off to the current layout manager.
/**
     * Returns the preferred size for the passed in component,
     * This is passed off to the current layout manager.
     */
    public Dimension getPreferredSize(JComponent jc) {
        if(splitPane != null)
            return layoutManager.preferredLayoutSize(splitPane);
        return new Dimension(0, 0);
    }


    
Returns the minimum size for the passed in component,
This is passed off to the current layout manager.
/**
     * Returns the minimum size for the passed in component,
     * This is passed off to the current layout manager.
     */
    public Dimension getMinimumSize(JComponent jc) {
        if(splitPane != null)
            return layoutManager.minimumLayoutSize(splitPane);
        return new Dimension(0, 0);
    }


    
Returns the maximum size for the passed in component,
This is passed off to the current layout manager.
/**
     * Returns the maximum size for the passed in component,
     * This is passed off to the current layout manager.
     */
    public Dimension getMaximumSize(JComponent jc) {
        if(splitPane != null)
            return layoutManager.maximumLayoutSize(splitPane);
        return new Dimension(0, 0);
    }


    
Returns the insets. The insets are returned from the border insets
of the current border.
Params:
jc – a component
Returns:
the insets/**
     * Returns the insets. The insets are returned from the border insets
     * of the current border.
     *
     * @param jc a component
     * @return the insets
     */
    public Insets getInsets(JComponent jc) {
        return null;
    }


    
Resets the layout manager based on orientation and messages it
with invalidateLayout to pull in appropriate Components.
/**
     * Resets the layout manager based on orientation and messages it
     * with invalidateLayout to pull in appropriate Components.
     */
    protected void resetLayoutManager() {
        if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
            layoutManager = new BasicHorizontalLayoutManager(0);
        } else {
            layoutManager = new BasicHorizontalLayoutManager(1);
        }
        splitPane.setLayout(layoutManager);
        layoutManager.updateComponents();
        splitPane.revalidate();
        splitPane.repaint();
    }

    
Set the value to indicate if one of the splitpane sides is expanded.
/**
     * Set the value to indicate if one of the splitpane sides is expanded.
     */
    void setKeepHidden(boolean keepHidden) {
        this.keepHidden = keepHidden;
    }

    
The value returned indicates if one of the splitpane sides is expanded.
Returns:
true if one of the splitpane sides is expanded, false otherwise./**
     * The value returned indicates if one of the splitpane sides is expanded.
     * @return true if one of the splitpane sides is expanded, false otherwise.
     */
    private boolean getKeepHidden() {
        return keepHidden;
    }

    
Should be messaged before the dragging session starts, resets
lastDragLocation and dividerSize.
/**
     * Should be messaged before the dragging session starts, resets
     * lastDragLocation and dividerSize.
     */
    protected void startDragging() {
        Component       leftC = splitPane.getLeftComponent();
        Component       rightC = splitPane.getRightComponent();
        ComponentPeer   cPeer;

        beginDragDividerLocation = getDividerLocation(splitPane);
        draggingHW = false;
        final ComponentAccessor acc = AWTAccessor.getComponentAccessor();
        if(leftC != null && (cPeer = acc.getPeer(leftC)) != null &&
           !(cPeer instanceof LightweightPeer)) {
            draggingHW = true;
        } else if(rightC != null && (cPeer = acc.getPeer(rightC)) != null
                  && !(cPeer instanceof LightweightPeer)) {
            draggingHW = true;
        }
        if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
            setLastDragLocation(divider.getBounds().x);
            dividerSize = divider.getSize().width;
            if(!isContinuousLayout() && draggingHW) {
                nonContinuousLayoutDivider.setBounds
                        (getLastDragLocation(), 0, dividerSize,
                         splitPane.getHeight());
                      addHeavyweightDivider();
            }
        } else {
            setLastDragLocation(divider.getBounds().y);
            dividerSize = divider.getSize().height;
            if(!isContinuousLayout() && draggingHW) {
                nonContinuousLayoutDivider.setBounds
                        (0, getLastDragLocation(), splitPane.getWidth(),
                         dividerSize);
                      addHeavyweightDivider();
            }
        }
    }


    
Messaged during a dragging session to move the divider to the passed in location. If continuousLayout is true the location is reset and the splitPane validated. 
Params:
location – the location of divider/**
     * Messaged during a dragging session to move the divider to the
     * passed in {@code location}. If {@code continuousLayout} is {@code true}
     * the location is reset and the splitPane validated.
     *
     * @param location the location of divider
     */
    protected void dragDividerTo(int location) {
        if(getLastDragLocation() != location) {
            if(isContinuousLayout()) {
                splitPane.setDividerLocation(location);
                setLastDragLocation(location);
            } else {
                int lastLoc = getLastDragLocation();

                setLastDragLocation(location);
                if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                    if(draggingHW) {
                        nonContinuousLayoutDivider.setLocation(
                            getLastDragLocation(), 0);
                    } else {
                        int   splitHeight = splitPane.getHeight();
                        splitPane.repaint(lastLoc, 0, dividerSize,
                                          splitHeight);
                        splitPane.repaint(location, 0, dividerSize,
                                          splitHeight);
                    }
                } else {
                    if(draggingHW) {
                        nonContinuousLayoutDivider.setLocation(0,
                            getLastDragLocation());
                    } else {
                        int    splitWidth = splitPane.getWidth();

                        splitPane.repaint(0, lastLoc, splitWidth,
                                          dividerSize);
                        splitPane.repaint(0, location, splitWidth,
                                          dividerSize);
                    }
                }
            }
        }
    }


    
Messaged to finish the dragging session. If not continuous display the dividers location will be reset. 
Params:
location – the location of divider/**
     * Messaged to finish the dragging session. If not continuous display
     * the dividers {@code location} will be reset.
     *
     * @param location the location of divider
     */
    protected void finishDraggingTo(int location) {
        dragDividerTo(location);
        setLastDragLocation(-1);
        if(!isContinuousLayout()) {
            Component   leftC = splitPane.getLeftComponent();
            Rectangle   leftBounds = leftC.getBounds();

            if (draggingHW) {
                if(orientation == JSplitPane.HORIZONTAL_SPLIT) {
                    nonContinuousLayoutDivider.setLocation(-dividerSize, 0);
                }
                else {
                    nonContinuousLayoutDivider.setLocation(0, -dividerSize);
                }
                splitPane.remove(nonContinuousLayoutDivider);
            }
            splitPane.setDividerLocation(location);
        }
    }


    
As of Java 2 platform v1.3 this method is no longer used. Instead
you should set the border on the divider.

Returns the width of one side of the divider border.
Returns:
the width of one side of the divider border
Deprecated:
As of Java 2 platform v1.3, instead set the border on the
divider./**
     * As of Java 2 platform v1.3 this method is no longer used. Instead
     * you should set the border on the divider.
     * <p>
     * Returns the width of one side of the divider border.
     *
     * @return the width of one side of the divider border
     * @deprecated As of Java 2 platform v1.3, instead set the border on the
     * divider.
     */
    @Deprecated
    protected int getDividerBorderSize() {
        return 1;
    }


    
LayoutManager for JSplitPanes that have an orientation of
HORIZONTAL_SPLIT.
/**
     * LayoutManager for JSplitPanes that have an orientation of
     * HORIZONTAL_SPLIT.
     */
    public class BasicHorizontalLayoutManager implements LayoutManager2
    {
        /* left, right, divider. (in this exact order) */
        
The size of components.
/**
         * The size of components.
         */
        protected int[]         sizes;
        
The components.
/**
         * The components.
         */
        protected Component[]   components;
        
Size of the splitpane the last time laid out. /** Size of the splitpane the last time laid out. */
        private int             lastSplitPaneSize;
        
True if resetToPreferredSizes has been invoked. /** True if resetToPreferredSizes has been invoked. */
        private boolean         doReset;
        
Axis, 0 for horizontal, or 1 for veritcal. /** Axis, 0 for horizontal, or 1 for veritcal. */
        private int             axis;


        BasicHorizontalLayoutManager() {
            this(0);
        }

        BasicHorizontalLayoutManager(int axis) {
            this.axis = axis;
            components = new Component[3];
            components[0] = components[1] = components[2] = null;
            sizes = new int[3];
        }

        //
        // LayoutManager
        //

        
Does the actual layout.
/**
         * Does the actual layout.
         */
        public void layoutContainer(Container container) {
            Dimension   containerSize = container.getSize();

            // If the splitpane has a zero size then no op out of here.
            // If we execute this function now, we're going to cause ourselves
            // much grief.
            if (containerSize.height <= 0 || containerSize.width <= 0 ) {
                lastSplitPaneSize = 0;
                return;
            }

            int         spDividerLocation = splitPane.getDividerLocation();
            Insets      insets = splitPane.getInsets();
            int         availableSize = getAvailableSize(containerSize,
                                                         insets);
            int         newSize = getSizeForPrimaryAxis(containerSize);
            int         beginLocation = getDividerLocation(splitPane);
            int         dOffset = getSizeForPrimaryAxis(insets, true);
            Dimension   dSize = (components[2] == null) ? null :
                                 components[2].getPreferredSize();

            if ((doReset && !dividerLocationIsSet) || spDividerLocation < 0) {
                resetToPreferredSizes(availableSize);
            }
            else if (lastSplitPaneSize <= 0 ||
                     availableSize == lastSplitPaneSize || !painted ||
                     (dSize != null &&
                      getSizeForPrimaryAxis(dSize) != sizes[2])) {
                if (dSize != null) {
                    sizes[2] = getSizeForPrimaryAxis(dSize);
                }
                else {
                    sizes[2] = 0;
                }
                setDividerLocation(spDividerLocation - dOffset, availableSize);
                dividerLocationIsSet = false;
            }
            else if (availableSize != lastSplitPaneSize) {
                distributeSpace(availableSize - lastSplitPaneSize,
                                getKeepHidden());
            }
            doReset = false;
            dividerLocationIsSet = false;
            lastSplitPaneSize = availableSize;

            // Reset the bounds of each component
            int nextLocation = getInitialLocation(insets);
            int counter = 0;

            while (counter < 3) {
                if (components[counter] != null &&
                    components[counter].isVisible()) {
                    setComponentToSize(components[counter], sizes[counter],
                                       nextLocation, insets, containerSize);
                    nextLocation += sizes[counter];
                }
                switch (counter) {
                case 0:
                    counter = 2;
                    break;
                case 2:
                    counter = 1;
                    break;
                case 1:
                    counter = 3;
                    break;
                }
            }
            if (painted) {
                // This is tricky, there is never a good time for us
                // to push the value to the splitpane, painted appears to
                // the best time to do it. What is really needed is
                // notification that layout has completed.
                int      newLocation = getDividerLocation(splitPane);

                if (newLocation != (spDividerLocation - dOffset)) {
                    int  lastLocation = splitPane.getLastDividerLocation();

                    ignoreDividerLocationChange = true;
                    try {
                        splitPane.setDividerLocation(newLocation);
                        // This is not always needed, but is rather tricky
                        // to determine when... The case this is needed for
                        // is if the user sets the divider location to some
                        // bogus value, say 0, and the actual value is 1, the
                        // call to setDividerLocation(1) will preserve the
                        // old value of 0, when we really want the divider
                        // location value  before the call. This is needed for
                        // the one touch buttons.
                        splitPane.setLastDividerLocation(lastLocation);
                    } finally {
                        ignoreDividerLocationChange = false;
                    }
                }
            }
        }


        
Adds the component at place.  Place must be one of
JSplitPane.LEFT, RIGHT, TOP, BOTTOM, or null (for the
divider).
/**
         * Adds the component at place.  Place must be one of
         * JSplitPane.LEFT, RIGHT, TOP, BOTTOM, or null (for the
         * divider).
         */
        public void addLayoutComponent(String place, Component component) {
            boolean isValid = true;

            if(place != null) {
                if(place.equals(JSplitPane.DIVIDER)) {
                    /* Divider. */
                    components[2] = component;
                    sizes[2] = getSizeForPrimaryAxis(component.
                                                     getPreferredSize());
                } else if(place.equals(JSplitPane.LEFT) ||
                          place.equals(JSplitPane.TOP)) {
                    components[0] = component;
                    sizes[0] = 0;
                } else if(place.equals(JSplitPane.RIGHT) ||
                          place.equals(JSplitPane.BOTTOM)) {
                    components[1] = component;
                    sizes[1] = 0;
                } else if(!place.equals(
                                    BasicSplitPaneUI.NON_CONTINUOUS_DIVIDER))
                    isValid = false;
            } else {
                isValid = false;
            }
            if(!isValid)
                throw new IllegalArgumentException("cannot add to layout: " +
                    "unknown constraint: " +
                    place);
            doReset = true;
        }


        
Returns the minimum size needed to contain the children.
The width is the sum of all the children's min widths and
the height is the largest of the children's minimum heights.
/**
         * Returns the minimum size needed to contain the children.
         * The width is the sum of all the children's min widths and
         * the height is the largest of the children's minimum heights.
         */
        public Dimension minimumLayoutSize(Container container) {
            int         minPrimary = 0;
            int         minSecondary = 0;
            Insets      insets = splitPane.getInsets();

            for (int counter=0; counter<3; counter++) {
                if(components[counter] != null) {
                    Dimension   minSize = components[counter].getMinimumSize();
                    int         secSize = getSizeForSecondaryAxis(minSize);

                    minPrimary += getSizeForPrimaryAxis(minSize);
                    if(secSize > minSecondary)
                        minSecondary = secSize;
                }
            }
            if(insets != null) {
                minPrimary += getSizeForPrimaryAxis(insets, true) +
                              getSizeForPrimaryAxis(insets, false);
                minSecondary += getSizeForSecondaryAxis(insets, true) +
                              getSizeForSecondaryAxis(insets, false);
            }
            if (axis == 0) {
                return new Dimension(minPrimary, minSecondary);
            }
            return new Dimension(minSecondary, minPrimary);
        }


        
Returns the preferred size needed to contain the children.
The width is the sum of all the preferred widths of the children and
the height is the largest preferred height of the children.
/**
         * Returns the preferred size needed to contain the children.
         * The width is the sum of all the preferred widths of the children and
         * the height is the largest preferred height of the children.
         */
        public Dimension preferredLayoutSize(Container container) {
            int         prePrimary = 0;
            int         preSecondary = 0;
            Insets      insets = splitPane.getInsets();

            for(int counter = 0; counter < 3; counter++) {
                if(components[counter] != null) {
                    Dimension   preSize = components[counter].
                                          getPreferredSize();
                    int         secSize = getSizeForSecondaryAxis(preSize);

                    prePrimary += getSizeForPrimaryAxis(preSize);
                    if(secSize > preSecondary)
                        preSecondary = secSize;
                }
            }
            if(insets != null) {
                prePrimary += getSizeForPrimaryAxis(insets, true) +
                              getSizeForPrimaryAxis(insets, false);
                preSecondary += getSizeForSecondaryAxis(insets, true) +
                              getSizeForSecondaryAxis(insets, false);
            }
            if (axis == 0) {
                return new Dimension(prePrimary, preSecondary);
            }
            return new Dimension(preSecondary, prePrimary);
        }


        
Removes the specified component from our knowledge.
/**
         * Removes the specified component from our knowledge.
         */
        public void removeLayoutComponent(Component component) {
            for(int counter = 0; counter < 3; counter++) {
                if(components[counter] == component) {
                    components[counter] = null;
                    sizes[counter] = 0;
                    doReset = true;
                }
            }
        }


        //
        // LayoutManager2
        //


        
Adds the specified component to the layout, using the specified
constraint object.
Params:
comp – the component to be added
constraints –  where/how the component is added to the layout./**
         * Adds the specified component to the layout, using the specified
         * constraint object.
         * @param comp the component to be added
         * @param constraints  where/how the component is added to the layout.
         */
        public void addLayoutComponent(Component comp, Object constraints) {
            if ((constraints == null) || (constraints instanceof String)) {
                addLayoutComponent((String)constraints, comp);
            } else {
                throw new IllegalArgumentException("cannot add to layout: " +
                                                   "constraint must be a " +
                                                   "string (or null)");
            }
        }


        
Returns the alignment along the x axis.  This specifies how
the component would like to be aligned relative to other
components.  The value should be a number between 0 and 1
where 0 represents alignment along the origin, 1 is aligned
the furthest away from the origin, 0.5 is centered, etc.
/**
         * Returns the alignment along the x axis.  This specifies how
         * the component would like to be aligned relative to other
         * components.  The value should be a number between 0 and 1
         * where 0 represents alignment along the origin, 1 is aligned
         * the furthest away from the origin, 0.5 is centered, etc.
         */
        public float getLayoutAlignmentX(Container target) {
            return 0.0f;
        }


        
Returns the alignment along the y axis.  This specifies how
the component would like to be aligned relative to other
components.  The value should be a number between 0 and 1
where 0 represents alignment along the origin, 1 is aligned
the furthest away from the origin, 0.5 is centered, etc.
/**
         * Returns the alignment along the y axis.  This specifies how
         * the component would like to be aligned relative to other
         * components.  The value should be a number between 0 and 1
         * where 0 represents alignment along the origin, 1 is aligned
         * the furthest away from the origin, 0.5 is centered, etc.
         */
        public float getLayoutAlignmentY(Container target) {
            return 0.0f;
        }


        
Does nothing. If the developer really wants to change the
size of one of the views JSplitPane.resetToPreferredSizes should
be messaged.
/**
         * Does nothing. If the developer really wants to change the
         * size of one of the views JSplitPane.resetToPreferredSizes should
         * be messaged.
         */
        public void invalidateLayout(Container c) {
        }


        
Returns the maximum layout size, which is Integer.MAX_VALUE
in both directions.
/**
         * Returns the maximum layout size, which is Integer.MAX_VALUE
         * in both directions.
         */
        public Dimension maximumLayoutSize(Container target) {
            return new Dimension(Integer.MAX_VALUE, Integer.MAX_VALUE);
        }


        //
        // New methods.
        //

        
Marks the receiver so that the next time this instance is
laid out it'll ask for the preferred sizes.
/**
         * Marks the receiver so that the next time this instance is
         * laid out it'll ask for the preferred sizes.
         */
        public void resetToPreferredSizes() {
            doReset = true;
        }

        
Resets the size of the Component at the passed in location.
Params:
index – the index of a component/**
         * Resets the size of the Component at the passed in location.
         *
         * @param index the index of a component
         */
        protected void resetSizeAt(int index) {
            sizes[index] = 0;
            doReset = true;
        }


        
Sets the sizes to newSizes. 
Params:
newSizes – the new sizes/**
         * Sets the sizes to {@code newSizes}.
         *
         * @param newSizes the new sizes
         */
        protected void setSizes(int[] newSizes) {
            System.arraycopy(newSizes, 0, sizes, 0, 3);
        }


        
Returns the sizes of the components.
Returns:
the sizes of the components/**
         * Returns the sizes of the components.
         *
         * @return the sizes of the components
         */
        protected int[] getSizes() {
            int[]         retSizes = new int[3];

            System.arraycopy(sizes, 0, retSizes, 0, 3);
            return retSizes;
        }


        
Returns the width of the passed in Components preferred size.
Params:
c – a component
Returns:
the preferred width of the component/**
         * Returns the width of the passed in Components preferred size.
         *
         * @param c a component
         * @return the preferred width of the component
         */
        protected int getPreferredSizeOfComponent(Component c) {
            return getSizeForPrimaryAxis(c.getPreferredSize());
        }


        
Returns the width of the passed in Components minimum size.
Params:
c – a component
Returns:
the minimum width of the component/**
         * Returns the width of the passed in Components minimum size.
         *
         * @param c a component
         * @return the minimum width of the component
         */
        int getMinimumSizeOfComponent(Component c) {
            return getSizeForPrimaryAxis(c.getMinimumSize());
        }


        
Returns the width of the passed in component.
Params:
c – a component
Returns:
the width of the component/**
         * Returns the width of the passed in component.
         *
         * @param c a component
         * @return the width of the component
         */
        protected int getSizeOfComponent(Component c) {
            return getSizeForPrimaryAxis(c.getSize());
        }


        
Returns the available width based on the container size and Insets. 
Params:
containerSize – a container size
insets – an insets
Returns:
the available width/**
         * Returns the available width based on the container size and
         * {@code Insets}.
         *
         * @param containerSize a container size
         * @param insets an insets
         * @return the available width
         */
        protected int getAvailableSize(Dimension containerSize,
                                       Insets insets) {
            if(insets == null)
                return getSizeForPrimaryAxis(containerSize);
            return (getSizeForPrimaryAxis(containerSize) -
                    (getSizeForPrimaryAxis(insets, true) +
                     getSizeForPrimaryAxis(insets, false)));
        }


        
Returns the left inset, unless the Insets are null in which case 0 is returned. 
Params:
insets – the insets
Returns:
the left inset/**
         * Returns the left inset, unless the {@code Insets} are null in which case
         * 0 is returned.
         *
         * @param insets the insets
         * @return the left inset
         */
        protected int getInitialLocation(Insets insets) {
            if(insets != null)
                return getSizeForPrimaryAxis(insets, true);
            return 0;
        }


        
Sets the width of the component c to be size, placing its x location at location, y to the insets.top and height to the containerSize.height less the top and bottom insets. 
Params:
c – a component
size – a new width
location – a new X coordinate
insets – an insets
containerSize – a container size/**
         * Sets the width of the component {@code c} to be {@code size}, placing its
         * x location at {@code location}, y to the {@code insets.top} and height
         * to the {@code containerSize.height} less the top and bottom insets.
         *
         * @param c a component
         * @param size a new width
         * @param location a new X coordinate
         * @param insets an insets
         * @param containerSize a container size
         */
        protected void setComponentToSize(Component c, int size,
                                          int location, Insets insets,
                                          Dimension containerSize) {
            if(insets != null) {
                if (axis == 0) {
                    c.setBounds(location, insets.top, size,
                                containerSize.height -
                                (insets.top + insets.bottom));
                }
                else {
                    c.setBounds(insets.left, location, containerSize.width -
                                (insets.left + insets.right), size);
                }
            }
            else {
                if (axis == 0) {
                    c.setBounds(location, 0, size, containerSize.height);
                }
                else {
                    c.setBounds(0, location, containerSize.width, size);
                }
            }
        }

        
If the axis == 0, the width is returned, otherwise the height.
/**
         * If the axis == 0, the width is returned, otherwise the height.
         */
        int getSizeForPrimaryAxis(Dimension size) {
            if (axis == 0) {
                return size.width;
            }
            return size.height;
        }

        
If the axis == 0, the width is returned, otherwise the height.
/**
         * If the axis == 0, the width is returned, otherwise the height.
         */
        int getSizeForSecondaryAxis(Dimension size) {
            if (axis == 0) {
                return size.height;
            }
            return size.width;
        }

        
Returns a particular value of the inset identified by the
axis and isTop

  axis isTop
   0    true    - left
   0    false   - right
   1    true    - top
   1    false   - bottom
/**
         * Returns a particular value of the inset identified by the
         * axis and <code>isTop</code><p>
         *   axis isTop
         *    0    true    - left
         *    0    false   - right
         *    1    true    - top
         *    1    false   - bottom
         */
        int getSizeForPrimaryAxis(Insets insets, boolean isTop) {
            if (axis == 0) {
                if (isTop) {
                    return insets.left;
                }
                return insets.right;
            }
            if (isTop) {
                return insets.top;
            }
            return insets.bottom;
        }

        
Returns a particular value of the inset identified by the
axis and isTop

  axis isTop
   0    true    - left
   0    false   - right
   1    true    - top
   1    false   - bottom
/**
         * Returns a particular value of the inset identified by the
         * axis and <code>isTop</code><p>
         *   axis isTop
         *    0    true    - left
         *    0    false   - right
         *    1    true    - top
         *    1    false   - bottom
         */
        int getSizeForSecondaryAxis(Insets insets, boolean isTop) {
            if (axis == 0) {
                if (isTop) {
                    return insets.top;
                }
                return insets.bottom;
            }
            if (isTop) {
                return insets.left;
            }
            return insets.right;
        }

        
Determines the components. This should be called whenever
a new instance of this is installed into an existing
SplitPane.
/**
         * Determines the components. This should be called whenever
         * a new instance of this is installed into an existing
         * SplitPane.
         */
        protected void updateComponents() {
            Component comp;

            comp = splitPane.getLeftComponent();
            if(components[0] != comp) {
                components[0] = comp;
                if(comp == null) {
                    sizes[0] = 0;
                } else {
                    sizes[0] = -1;
                }
            }

            comp = splitPane.getRightComponent();
            if(components[1] != comp) {
                components[1] = comp;
                if(comp == null) {
                    sizes[1] = 0;
                } else {
                    sizes[1] = -1;
                }
            }

            /* Find the divider. */
            Component[] children = splitPane.getComponents();
            Component   oldDivider = components[2];

            components[2] = null;
            for(int counter = children.length - 1; counter >= 0; counter--) {
                if(children[counter] != components[0] &&
                   children[counter] != components[1] &&
                   children[counter] != nonContinuousLayoutDivider) {
                    if(oldDivider != children[counter]) {
                        components[2] = children[counter];
                    } else {
                        components[2] = oldDivider;
                    }
                    break;
                }
            }
            if(components[2] == null) {
                sizes[2] = 0;
            }
            else {
                sizes[2] = getSizeForPrimaryAxis(components[2].getPreferredSize());
            }
        }

        
Resets the size of the first component to leftSize,
and the right component to the remainder of the space.
/**
         * Resets the size of the first component to <code>leftSize</code>,
         * and the right component to the remainder of the space.
         */
        void setDividerLocation(int leftSize, int availableSize) {
            boolean          lValid = (components[0] != null &&
                                       components[0].isVisible());
            boolean          rValid = (components[1] != null &&
                                       components[1].isVisible());
            boolean          dValid = (components[2] != null &&
                                       components[2].isVisible());
            int              max = availableSize;

            if (dValid) {
                max -= sizes[2];
            }
            leftSize = Math.max(0, Math.min(leftSize, max));
            if (lValid) {
                if (rValid) {
                    sizes[0] = leftSize;
                    sizes[1] = max - leftSize;
                }
                else {
                    sizes[0] = max;
                    sizes[1] = 0;
                }
            }
            else if (rValid) {
                sizes[1] = max;
                sizes[0] = 0;
            }
        }

        
Returns an array of the minimum sizes of the components.
/**
         * Returns an array of the minimum sizes of the components.
         */
        int[] getPreferredSizes() {
            int[]         retValue = new int[3];

            for (int counter = 0; counter < 3; counter++) {
                if (components[counter] != null &&
                    components[counter].isVisible()) {
                    retValue[counter] = getPreferredSizeOfComponent
                                        (components[counter]);
                }
                else {
                    retValue[counter] = -1;
                }
            }
            return retValue;
        }

        
Returns an array of the minimum sizes of the components.
/**
         * Returns an array of the minimum sizes of the components.
         */
        int[] getMinimumSizes() {
            int[]         retValue = new int[3];

            for (int counter = 0; counter < 2; counter++) {
                if (components[counter] != null &&
                    components[counter].isVisible()) {
                    retValue[counter] = getMinimumSizeOfComponent
                                        (components[counter]);
                }
                else {
                    retValue[counter] = -1;
                }
            }
            retValue[2] = (components[2] != null) ?
                getMinimumSizeOfComponent(components[2]) : -1;
            return retValue;
        }

        
Resets the components to their preferred sizes.
/**
         * Resets the components to their preferred sizes.
         */
        void resetToPreferredSizes(int availableSize) {
            // Set the sizes to the preferred sizes (if fits), otherwise
            // set to min sizes and distribute any extra space.
            int[]       testSizes = getPreferredSizes();
            int         totalSize = 0;

            for (int counter = 0; counter < 3; counter++) {
                if (testSizes[counter] != -1) {
                    totalSize += testSizes[counter];
                }
            }
            if (totalSize > availableSize) {
                testSizes = getMinimumSizes();

                totalSize = 0;
                for (int counter = 0; counter < 3; counter++) {
                    if (testSizes[counter] != -1) {
                        totalSize += testSizes[counter];
                    }
                }
            }
            setSizes(testSizes);
            distributeSpace(availableSize - totalSize, false);
        }

        
Distributes space between the two components
(divider won't get any extra space) based on the weighting. This
attempts to honor the min size of the components.
Params:
keepHidden – if true and one of the components is 0x0
                  it gets none of the extra space/**
         * Distributes <code>space</code> between the two components
         * (divider won't get any extra space) based on the weighting. This
         * attempts to honor the min size of the components.
         *
         * @param keepHidden if true and one of the components is 0x0
         *                   it gets none of the extra space
         */
        void distributeSpace(int space, boolean keepHidden) {
            boolean          lValid = (components[0] != null &&
                                       components[0].isVisible());
            boolean          rValid = (components[1] != null &&
                                       components[1].isVisible());

            if (keepHidden) {
                if (lValid && getSizeForPrimaryAxis(
                                 components[0].getSize()) == 0) {
                    lValid = false;
                    if (rValid && getSizeForPrimaryAxis(
                                     components[1].getSize()) == 0) {
                        // Both aren't valid, force them both to be valid
                        lValid = true;
                    }
                }
                else if (rValid && getSizeForPrimaryAxis(
                                   components[1].getSize()) == 0) {
                    rValid = false;
                }
            }
            if (lValid && rValid) {
                double        weight = splitPane.getResizeWeight();
                int           lExtra = (int)(weight * (double)space);
                int           rExtra = (space - lExtra);

                sizes[0] += lExtra;
                sizes[1] += rExtra;

                int           lMin = getMinimumSizeOfComponent(components[0]);
                int           rMin = getMinimumSizeOfComponent(components[1]);
                boolean       lMinValid = (sizes[0] >= lMin);
                boolean       rMinValid = (sizes[1] >= rMin);

                if (!lMinValid && !rMinValid) {
                    if (sizes[0] < 0) {
                        sizes[1] += sizes[0];
                        sizes[0] = 0;
                    }
                    else if (sizes[1] < 0) {
                        sizes[0] += sizes[1];
                        sizes[1] = 0;
                    }
                }
                else if (!lMinValid) {
                    if (sizes[1] - (lMin - sizes[0]) < rMin) {
                        // both below min, just make sure > 0
                        if (sizes[0] < 0) {
                            sizes[1] += sizes[0];
                            sizes[0] = 0;
                        }
                    }
                    else {
                        sizes[1] -= (lMin - sizes[0]);
                        sizes[0] = lMin;
                    }
                }
                else if (!rMinValid) {
                    if (sizes[0] - (rMin - sizes[1]) < lMin) {
                        // both below min, just make sure > 0
                        if (sizes[1] < 0) {
                            sizes[0] += sizes[1];
                            sizes[1] = 0;
                        }
                    }
                    else {
                        sizes[0] -= (rMin - sizes[1]);
                        sizes[1] = rMin;
                    }
                }
                if (sizes[0] < 0) {
                    sizes[0] = 0;
                }
                if (sizes[1] < 0) {
                    sizes[1] = 0;
                }
            }
            else if (lValid) {
                sizes[0] = Math.max(0, sizes[0] + space);
            }
            else if (rValid) {
                sizes[1] = Math.max(0, sizes[1] + space);
            }
        }
    }


    
LayoutManager used for JSplitPanes with an orientation of
VERTICAL_SPLIT.
/**
     * LayoutManager used for JSplitPanes with an orientation of
     * VERTICAL_SPLIT.
     *
     */
    public class BasicVerticalLayoutManager extends
            BasicHorizontalLayoutManager
    {
        
Constructs a new instance of BasicVerticalLayoutManager. /**
         * Constructs a new instance of {@code BasicVerticalLayoutManager}.
         */
        public BasicVerticalLayoutManager() {
            super(1);
        }
    }


    private class Handler implements FocusListener, PropertyChangeListener {
        //
        // PropertyChangeListener
        //
        
Messaged from the JSplitPane the receiver is
contained in.  May potentially reset the layout manager and cause a
validate to be sent.
/**
         * Messaged from the <code>JSplitPane</code> the receiver is
         * contained in.  May potentially reset the layout manager and cause a
         * <code>validate</code> to be sent.
         */
        public void propertyChange(PropertyChangeEvent e) {
            if(e.getSource() == splitPane) {
                String changeName = e.getPropertyName();

                if(changeName == JSplitPane.ORIENTATION_PROPERTY) {
                    orientation = splitPane.getOrientation();
                    resetLayoutManager();
                } else if(changeName == JSplitPane.CONTINUOUS_LAYOUT_PROPERTY){
                    setContinuousLayout(splitPane.isContinuousLayout());
                    if(!isContinuousLayout()) {
                        if(nonContinuousLayoutDivider == null) {
                            setNonContinuousLayoutDivider(
                                createDefaultNonContinuousLayoutDivider(),
                                true);
                        } else if(nonContinuousLayoutDivider.getParent() ==
                                  null) {
                            setNonContinuousLayoutDivider(
                                nonContinuousLayoutDivider,
                                true);
                        }
                    }
                } else if(changeName == JSplitPane.DIVIDER_SIZE_PROPERTY){
                    divider.setDividerSize(splitPane.getDividerSize());
                    dividerSize = divider.getDividerSize();
                    splitPane.revalidate();
                    splitPane.repaint();
                }
            }
        }

        //
        // FocusListener
        //
        public void focusGained(FocusEvent ev) {
            dividerKeyboardResize = true;
            splitPane.repaint();
        }

        public void focusLost(FocusEvent ev) {
            dividerKeyboardResize = false;
            splitPane.repaint();
        }
    }


    private static class Actions extends UIAction {
        private static final String NEGATIVE_INCREMENT = "negativeIncrement";
        private static final String POSITIVE_INCREMENT = "positiveIncrement";
        private static final String SELECT_MIN = "selectMin";
        private static final String SELECT_MAX = "selectMax";
        private static final String START_RESIZE = "startResize";
        private static final String TOGGLE_FOCUS = "toggleFocus";
        private static final String FOCUS_OUT_FORWARD = "focusOutForward";
        private static final String FOCUS_OUT_BACKWARD = "focusOutBackward";

        Actions(String key) {
            super(key);
        }

        public void actionPerformed(ActionEvent ev) {
            JSplitPane splitPane = (JSplitPane)ev.getSource();
            BasicSplitPaneUI ui = (BasicSplitPaneUI)BasicLookAndFeel.
                      getUIOfType(splitPane.getUI(), BasicSplitPaneUI.class);

            if (ui == null) {
                return;
            }
            String key = getName();
            if (key == NEGATIVE_INCREMENT) {
                if (ui.dividerKeyboardResize) {
                    splitPane.setDividerLocation(Math.max(
                              0, ui.getDividerLocation
                              (splitPane) - ui.getKeyboardMoveIncrement()));
                }
            }
            else if (key == POSITIVE_INCREMENT) {
                if (ui.dividerKeyboardResize) {
                    splitPane.setDividerLocation(
                        ui.getDividerLocation(splitPane) +
                        ui.getKeyboardMoveIncrement());
                }
            }
            else if (key == SELECT_MIN) {
                if (ui.dividerKeyboardResize) {
                    splitPane.setDividerLocation(0);
                }
            }
            else if (key == SELECT_MAX) {
                if (ui.dividerKeyboardResize) {
                    Insets   insets = splitPane.getInsets();
                    int      bottomI = (insets != null) ? insets.bottom : 0;
                    int      rightI = (insets != null) ? insets.right : 0;

                    if (ui.orientation == JSplitPane.VERTICAL_SPLIT) {
                        splitPane.setDividerLocation(splitPane.getHeight() -
                                                     bottomI);
                    }
                    else {
                        splitPane.setDividerLocation(splitPane.getWidth() -
                                                     rightI);
                    }
                }
            }
            else if (key == START_RESIZE) {
                if (!ui.dividerKeyboardResize) {
                    splitPane.requestFocus();
                } else {
                    JSplitPane parentSplitPane =
                        (JSplitPane)SwingUtilities.getAncestorOfClass(
                                         JSplitPane.class, splitPane);
                    if (parentSplitPane!=null) {
                        parentSplitPane.requestFocus();
                    }
                }
            }
            else if (key == TOGGLE_FOCUS) {
                toggleFocus(splitPane);
            }
            else if (key == FOCUS_OUT_FORWARD) {
                moveFocus(splitPane, 1);
            }
            else if (key == FOCUS_OUT_BACKWARD) {
                moveFocus(splitPane, -1);
            }
        }

        private void moveFocus(JSplitPane splitPane, int direction) {
            Container rootAncestor = splitPane.getFocusCycleRootAncestor();
            FocusTraversalPolicy policy = rootAncestor.getFocusTraversalPolicy();
            Component focusOn = (direction > 0) ?
                policy.getComponentAfter(rootAncestor, splitPane) :
                policy.getComponentBefore(rootAncestor, splitPane);
            HashSet<Component> focusFrom = new HashSet<Component>();
            if (splitPane.isAncestorOf(focusOn)) {
                do {
                    focusFrom.add(focusOn);
                    rootAncestor = focusOn.getFocusCycleRootAncestor();
                    policy = rootAncestor.getFocusTraversalPolicy();
                    focusOn = (direction > 0) ?
                        policy.getComponentAfter(rootAncestor, focusOn) :
                        policy.getComponentBefore(rootAncestor, focusOn);
                } while (splitPane.isAncestorOf(focusOn) &&
                         !focusFrom.contains(focusOn));
            }
            if ( focusOn!=null && !splitPane.isAncestorOf(focusOn) ) {
                focusOn.requestFocus();
            }
        }

        private void toggleFocus(JSplitPane splitPane) {
            Component left = splitPane.getLeftComponent();
            Component right = splitPane.getRightComponent();

            KeyboardFocusManager manager =
                KeyboardFocusManager.getCurrentKeyboardFocusManager();
            Component focus = manager.getFocusOwner();
            Component focusOn = getNextSide(splitPane, focus);
            if (focusOn != null) {
                // don't change the focus if the new focused component belongs
                // to the same splitpane and the same side
                if ( focus!=null &&
                     ( (SwingUtilities.isDescendingFrom(focus, left) &&
                        SwingUtilities.isDescendingFrom(focusOn, left)) ||
                       (SwingUtilities.isDescendingFrom(focus, right) &&
                        SwingUtilities.isDescendingFrom(focusOn, right)) ) ) {
                    return;
                }
                SwingUtilities2.compositeRequestFocus(focusOn);
            }
        }

        private Component getNextSide(JSplitPane splitPane, Component focus) {
            Component left = splitPane.getLeftComponent();
            Component right = splitPane.getRightComponent();
            Component next;
            if (focus!=null && SwingUtilities.isDescendingFrom(focus, left) &&
                right!=null) {
                next = getFirstAvailableComponent(right);
                if (next != null) {
                    return next;
                }
            }
            JSplitPane parentSplitPane = (JSplitPane)SwingUtilities.getAncestorOfClass(JSplitPane.class, splitPane);
            if (parentSplitPane!=null) {
                // focus next side of the parent split pane
                next = getNextSide(parentSplitPane, focus);
            } else {
                next = getFirstAvailableComponent(left);
                if (next == null) {
                    next = getFirstAvailableComponent(right);
                }
            }
            return next;
        }

        private Component getFirstAvailableComponent(Component c) {
            if (c!=null && c instanceof JSplitPane) {
                JSplitPane sp = (JSplitPane)c;
                Component left = getFirstAvailableComponent(sp.getLeftComponent());
                if (left != null) {
                    c = left;
                } else {
                    c = getFirstAvailableComponent(sp.getRightComponent());
                }
            }
            return c;
        }
    }
}