controlpanel/event/ScrollPaneBorderListener.java

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (the "License").  You may not use this file except in compliance
 * with the License.
 *
 * You can obtain a copy of the license at legal-notices/CDDLv1_0.txt
 * or http://forgerock.org/license/CDDLv1.0.html.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at legal-notices/CDDLv1_0.txt.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information:
 *      Portions Copyright [yyyy] [name of copyright owner]
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 *
 *      Copyright 2008-2009 Sun Microsystems, Inc.
 *      Portions Copyright 2015 ForgeRock AS.
 */

package org.opends.guitools.controlpanel.event;

import java.awt.event.ComponentAdapter;
import java.awt.event.ComponentEvent;

import javax.swing.BorderFactory;
import javax.swing.JScrollPane;
import javax.swing.border.Border;
import javax.swing.border.EmptyBorder;

import org.opends.guitools.controlpanel.ui.ColorAndFontConstants;

/**
 * This is a listener that is basically used to update dynamically the border
 * of a scroll bar.  This is used when we do not want to display the borders of
 * the scrollpane if no scrollbars are visible.  So the code basically adds
 * a component listener to the scroll pane and depending on whether the scroll
 * bars are displayed or not some border to the scroll pane is added (or not).
 *
 */
public class ScrollPaneBorderListener extends ComponentAdapter
{
  private JScrollPane scroll;
  private Border emptyBorder = new EmptyBorder(0, 0, 0, 0);
  private Border etchedBorder = BorderFactory.createMatteBorder(0, 0, 1, 0,
      ColorAndFontConstants.defaultBorderColor);

  /**
   * Private constructor.
   *
   */
  private ScrollPaneBorderListener()
  {
  }

  /**
   * Returns a scroll pane border listener that will apply a border only on the
   * bottom of the scroll.
   * @param scroll the scroll pane to update.
   * @return a scroll pane border listener that will apply a border only on the
   * bottom of the scroll.
   */
  public static ScrollPaneBorderListener createBottomBorderListener(
      JScrollPane scroll)
  {
    ScrollPaneBorderListener listener = new ScrollPaneBorderListener();
    listener.scroll = scroll;
    scroll.getHorizontalScrollBar().addComponentListener(listener);
    scroll.getVerticalScrollBar().addComponentListener(listener);
    return listener;
  }

  /**
   * Returns a scroll pane border listener that will apply a border on the
   * bottom and on the top of the scroll.
   * @param scroll the scroll pane to update.
   * @return a scroll pane border listener that will apply a border on the
   * bottom and on the top of the scroll.
   */
  public static ScrollPaneBorderListener createBottomAndTopBorderListener(
      JScrollPane scroll)
  {
    ScrollPaneBorderListener listener = createBottomBorderListener(scroll);
    listener.etchedBorder = BorderFactory.createMatteBorder(1, 0, 1, 0,
        ColorAndFontConstants.defaultBorderColor);
    return listener;
  }

  /**
   * Returns a scroll pane border listener that will apply a full border to the
   * scroll.
   * @param scroll the scroll pane to update.
   * @return a scroll pane border listener that will apply a full border to the
   * scroll.
   */
  public static ScrollPaneBorderListener createFullBorderListener(
      JScrollPane scroll)
  {
    ScrollPaneBorderListener listener = createBottomBorderListener(scroll);
    listener.etchedBorder = BorderFactory.createMatteBorder(1, 1, 1, 1,
        ColorAndFontConstants.defaultBorderColor);
    return listener;
  }

  /** {@inheritDoc} */
  public void componentShown(ComponentEvent ev)
  {
    updateBorder();
  }

  /** {@inheritDoc} */
  public void componentHidden(ComponentEvent ev)
  {
    updateBorder();
  }

  /**
   * Updates the border depending on whether the scroll bars are visible or not.
   *
   */
  public void updateBorder()
  {
    boolean displayBorder = scroll.getVerticalScrollBar().isVisible() ||
    scroll.getHorizontalScrollBar().isVisible();

    if (displayBorder)
    {
      scroll.setBorder(etchedBorder);
    }
    else
    {
      scroll.setBorder(emptyBorder);
    }
  }
}