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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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
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 *
 * 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,
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 *
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package javax.swing.plaf.metal;

import javax.swing.*;
import javax.swing.event.*;
import javax.swing.border.*;
import javax.swing.plaf.*;
import javax.swing.plaf.basic.*;

import java.awt.*;
import java.beans.*;
import java.awt.event.*;


A Metal L&F implementation of ScrollPaneUI.

Warning:
Serialized objects of this class will not be compatible with
future Swing releases. The current serialization support is
appropriate for short term storage or RMI between applications running
the same version of Swing.  As of 1.4, support for long term storage
of all JavaBeans™
has been added to the java.beans package. Please see XMLEncoder. 
Author:
Steve Wilson/**
 * A Metal L&F implementation of ScrollPaneUI.
 * <p>
 * <strong>Warning:</strong>
 * Serialized objects of this class will not be compatible with
 * future Swing releases. The current serialization support is
 * appropriate for short term storage or RMI between applications running
 * the same version of Swing.  As of 1.4, support for long term storage
 * of all JavaBeans&trade;
 * has been added to the <code>java.beans</code> package.
 * Please see {@link java.beans.XMLEncoder}.
 *
 * @author Steve Wilson
 */
@SuppressWarnings("serial") // Same-version serialization only
public class MetalScrollPaneUI extends BasicScrollPaneUI
{

    private PropertyChangeListener scrollBarSwapListener;

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

    public void installUI(JComponent c) {

        super.installUI(c);

        JScrollPane sp = (JScrollPane)c;
        updateScrollbarsFreeStanding();
    }

    public void uninstallUI(JComponent c) {
        super.uninstallUI(c);

        JScrollPane sp = (JScrollPane)c;
        JScrollBar hsb = sp.getHorizontalScrollBar();
        JScrollBar vsb = sp.getVerticalScrollBar();
        if (hsb != null) {
            hsb.putClientProperty( MetalScrollBarUI.FREE_STANDING_PROP, null);
        }
        if (vsb != null) {
            vsb.putClientProperty( MetalScrollBarUI.FREE_STANDING_PROP, null);
        }
    }

    public void installListeners(JScrollPane scrollPane) {
        super.installListeners(scrollPane);
        scrollBarSwapListener = createScrollBarSwapListener();
        scrollPane.addPropertyChangeListener(scrollBarSwapListener);
    }

    
{@inheritDoc}
/**
     * {@inheritDoc}
     */
    protected void uninstallListeners(JComponent c) {
        super.uninstallListeners(c);
        c.removePropertyChangeListener(scrollBarSwapListener);
    }

    
Params:
scrollPane – an instance of the JScrollPane
Deprecated:
- Replaced by uninstallListeners(JComponent)/**
     * @param scrollPane an instance of the {@code JScrollPane}
     * @deprecated - Replaced by {@link #uninstallListeners(JComponent)}
     */
    @Deprecated
    public void uninstallListeners(JScrollPane scrollPane) {
        super.uninstallListeners(scrollPane);
        scrollPane.removePropertyChangeListener(scrollBarSwapListener);
    }

    
If the border of the scrollpane is an instance of
MetalBorders.ScrollPaneBorder, the client property
FREE_STANDING_PROP of the scrollbars
is set to false, otherwise it is set to true.
/**
     * If the border of the scrollpane is an instance of
     * <code>MetalBorders.ScrollPaneBorder</code>, the client property
     * <code>FREE_STANDING_PROP</code> of the scrollbars
     * is set to false, otherwise it is set to true.
     */
    private void updateScrollbarsFreeStanding() {
        if (scrollpane == null) {
            return;
        }
        Border border = scrollpane.getBorder();
        Object value;

        if (border instanceof MetalBorders.ScrollPaneBorder) {
            value = Boolean.FALSE;
        }
        else {
            value = Boolean.TRUE;
        }
        JScrollBar sb = scrollpane.getHorizontalScrollBar();
        if (sb != null) {
            sb.putClientProperty
                   (MetalScrollBarUI.FREE_STANDING_PROP, value);
        }
        sb = scrollpane.getVerticalScrollBar();
        if (sb != null) {
            sb.putClientProperty
                   (MetalScrollBarUI.FREE_STANDING_PROP, value);
        }
    }

    
Returns a new PropertyChangeListener for scroll bar swap events. 
Returns:
a new PropertyChangeListener for scroll bar swap events./**
     * Returns a new {@code PropertyChangeListener} for scroll bar swap events.
     *
     * @return a new {@code PropertyChangeListener} for scroll bar swap events.
     */
    protected PropertyChangeListener createScrollBarSwapListener() {
        return new PropertyChangeListener() {
            public void propertyChange(PropertyChangeEvent e) {
                  String propertyName = e.getPropertyName();
                  if (propertyName.equals("verticalScrollBar") ||
                      propertyName.equals("horizontalScrollBar")) {
                      JScrollBar oldSB = (JScrollBar)e.getOldValue();
                      if (oldSB != null) {
                          oldSB.putClientProperty(
                              MetalScrollBarUI.FREE_STANDING_PROP, null);
                      }
                      JScrollBar newSB = (JScrollBar)e.getNewValue();
                      if (newSB != null) {
                          newSB.putClientProperty(
                              MetalScrollBarUI.FREE_STANDING_PROP,
                              Boolean.FALSE);
                      }
                  }
                  else if ("border".equals(propertyName)) {
                      updateScrollbarsFreeStanding();
                  }
        }};
    }

}