elementlayoutinformation.java

swing编写的库存管理程序。毕业设计类

/**
 * ========================================
 * JFreeReport : a free Java report library
 * ========================================
 *
 * Project Info:  http://www.jfree.org/jfreereport/index.html
 * Project Lead:  Thomas Morgner;
 *
 * (C) Copyright 2000-2003, by Simba Management Limited and Contributors.
 *
 * This library is free software; you can redistribute it and/or modify it under the terms
 * of the GNU Lesser General Public License as published by the Free Software Foundation;
 * either version 2.1 of the License, or (at your option) any later version.
 *
 * This library 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 Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public License along with this
 * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307, USA.
 *
 * -----------------------------
 * ElementLayoutInformation.java
 * -----------------------------
 * (C)opyright 2003, by Thomas Morgner and Contributors.
 *
 * Original Author:  Thomas Morgner;
 * Contributor(s):   David Gilbert (for Simba Management Limited);
 *
 * $Id: ElementLayoutInformation.java,v 1.7 2003/09/15 18:26:51 taqua Exp $
 *
 * Changes
 * -------
 * 25-Feb-2003 : Added standard header and fixed Checkstyle issues (DG);
 *
 */
package org.jfree.report.util;

import java.awt.geom.Dimension2D;
import java.awt.geom.Point2D;
import java.awt.geom.Rectangle2D;

import org.jfree.ui.FloatDimension;

/**
 * A small carrier class to encapsulate the common layout parameters. This information is a
 * utility class, don't expect to find one bound to an element.
 *
 * @author Thomas Morgner
 */
public strictfp class ElementLayoutInformation
{
  /** The absolute position of the element. */
  private Point2D absolutePosition;

  /** The current minimum size for the element. */
  private Dimension2D minimumSize;

  /** The current maximum size for the element. */
  private Dimension2D maximumSize;

  /** The current preferred size for the element. */
  private Dimension2D preferredSize;

  /**
   * Creates a new instance.
   * <p>
   * The position will be <code>rect.x, rect.y</code> and all dimensions
   * are set to <code>rect.width, rect.height</code>.
   *
   * @param rect  the rectangle that will be the base for this ElementLayoutInformation.
   *
   * @throws java.lang.NullPointerException if the given rectangle is null.
   */
  public ElementLayoutInformation(final Rectangle2D rect)
  {
    if (rect == null)
    {
      throw new NullPointerException();
    }
    absolutePosition = new Point2D.Float((float) rect.getX(), (float) rect.getY());
    final FloatDimension fdim =
        new FloatDimension((float) rect.getWidth(), (float) rect.getHeight());
    maximumSize = fdim;
    minimumSize = fdim;
    preferredSize = fdim;
  }

  /**
   * Creates a new instance.
   * <p>
   * The preferred size will be undefined (<code>null</code>).
   *
   * @param absolutePosition  the absolute position for the element.
   * @param minimumSize  the minimum size for the element.
   * @param maximumSize  the maximum size for the element.
   * @throws java.lang.NullPointerException if one of the parameters is <code>null</code>.
   */
  public ElementLayoutInformation(final Point2D absolutePosition,
                                  final Dimension2D minimumSize,
                                  final Dimension2D maximumSize)
  {
    this(absolutePosition, minimumSize, maximumSize, null);
  }

  /**
   * Creates a new instance.
   * <p>
   * If the preferred size is <code>null</code>, then it is left undefined.
   *
   * @param absolutePosition  the absolute position for the element
   * @param minimumSize  the minimum size for the element
   * @param maximumSize  the maximum size for the element
   * @param preferredSize  the preferred size or <code>null</code> if not known.
   *
   * @throws java.lang.NullPointerException if the position or max/min size is <code>null</code>.
   *
   */
  public ElementLayoutInformation(final Point2D absolutePosition,
                                  final Dimension2D minimumSize,
                                  final Dimension2D maximumSize,
                                  final Dimension2D preferredSize)
  {
    if (absolutePosition == null)
    {
      throw new NullPointerException();
    }
    if (minimumSize == null)
    {
      throw new NullPointerException();
    }
    if (maximumSize == null)
    {
      throw new NullPointerException();
    }
    this.absolutePosition = (Point2D) absolutePosition.clone();
    // the minsize cannot be greater than the max size ...
    this.minimumSize = unionMin(maximumSize, minimumSize);
    this.maximumSize = (Dimension2D) maximumSize.clone();
    if (preferredSize != null)
    {
      this.preferredSize = (Dimension2D) preferredSize.clone();
    }
  }

  /**
   * Gets the absolute positon defined in this LayoutInformation.
   *
   * @return a clone of the absolute position.
   */
  public Point2D getAbsolutePosition()
  {
    return (Point2D) absolutePosition.clone();
  }

  /**
   * Gets the minimum size defined in this LayoutInformation.
   *
   * @return a clone of the minimum size.
   */
  public Dimension2D getMinimumSize()
  {
    return (Dimension2D) minimumSize.clone();
  }

  /**
   * Gets the maximum size defined in this LayoutInformation.
   *
   * @return a clone of the maximum size.
   */
  public Dimension2D getMaximumSize()
  {
    return (Dimension2D) maximumSize.clone();
  }

  /**
   * Gets the preferred size defined in this LayoutInformation.
   *
   * @return a clone of the preferred size.
   */
  public Dimension2D getPreferredSize()
  {
    if (preferredSize == null)
    {
      return null;
    }
    return (Dimension2D) preferredSize.clone();
  }

  /**
   * Create a minimum dimension of the given 2 dimension objects. If pref is
   * not given, the max parameter is returned unchanged.
   * <p>
   * This is used to limit the element bounds to the preferred size or
   * the maximum size (in case the user misconfigured anything).
   *
   * @param max  the maximum size as retrieved from the element.
   * @param pref  the preferred size.
   *
   * @return  the minimum dimension.
   */
  public static Dimension2D unionMin(final Dimension2D max, final Dimension2D pref)
  {
    if (pref == null)
    {
      return max;
    }
    return new FloatDimension((float) Math.min(pref.getWidth(), max.getWidth()),
        (float) Math.min(pref.getHeight(), max.getHeight()));
  }

  /**
   * Returns a string representing the object (useful for debugging).
   *
   * @return A string.
   */
  public String toString()
  {
    final StringBuffer b = new StringBuffer();
    b.append("ElementLayoutInformation: \n");
    b.append("    AbsolutePos: ");
    b.append(absolutePosition);
    b.append("\n    MinSize: ");
    b.append(minimumSize);
    b.append("\n    PrefSize: ");
    b.append(preferredSize);
    b.append("\n    MaxSize: ");
    b.append(maximumSize);
    b.append("\n");
    return b.toString();
  }
}