group.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 Object Refinery 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.
 *
 * ----------
 * Group.java
 * ----------
 * (C)opyright 2000-2003, by Object Refinery Limited and Contributors.
 *
 * Original Author:  David Gilbert (for Object Refinery Limited);
 * Contributor(s):   Thomas Morgner;
 *
 * $Id: Group.java,v 1.6 2003/08/25 14:29:28 taqua Exp $
 *
 * Changes (from 8-Feb-2002)
 * -------------------------
 * 08-Feb-2002 : Updated code to work with latest version of the JCommon class library (DG);
 * 11-May-2002 : Fields are now in a list, order is important for comparision. The field list
 *               not modifyable outside this list. Header and footer are no longer allowed to
 *               contain null values. Is lastItemInGroup returns always true, if the end of the
 *               data had been reached.
 * 03-Jul-2002 : Serializable and cloneable, replaces own ReadOnlyList with standard implementation
 * 26-Jul-2002 : Introduced DataRowBackend as replacement for the raw data access
 * 05-Sep-2002 : Documentation
 * 09-Sep-2002 : Removed log messages
 * 13-Sep-2002 : Ran checkstyle against the source
 * 02-Dec-2002 : Removed To-Do item, caching of field-name to index pos is done.
 * 06-Dec-2002 : Updated changelog, removed Iterator-usage for performance reasons
 * 10-Dec-2002 : Updated Javadocs (DG);
 *
 */

package org.jfree.report;

import java.io.Serializable;
import java.util.Arrays;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import java.util.TreeSet;

import org.jfree.report.style.InvalidStyleSheetCollectionException;
import org.jfree.report.style.StyleSheetCollection;
import org.jfree.report.style.StyleSheetCollectionHelper;

/**
 * A report group.  Reports can contain any number of (nested) groups.
 * The order of the fields is important. If the group does not contain
 * any fields, the group spans the whole report from the first to the last
 * row.
 * <p>
 * The group's field list should not be modified after the group was added
 * to the group list, or the results are undefined.
 *
 * @see GroupList
 *
 * @author David Gilbert
 * @author Thomas Morgner
 */
public class Group implements Serializable, Cloneable, Comparable
{
  /**
   * Internal helper class to handle the style sheet collection properly.
   */
  private static class GroupStyleSheetCollectionHelper extends StyleSheetCollectionHelper
  {
    /** The group for which we handle the stylesheet collection. */
    private final Group group;

    /**
     * Creates a new helper for the given group.
     *
     * @param group the group whose stylesheet collection should be managed.
     */
    public GroupStyleSheetCollectionHelper(final Group group)
    {
      this.group = group;
    }

    /**
     * Handles the stylesheet collection registration for the group and
     * all group bands.
     */
    protected void handleRegisterStyleSheetCollection()
    {
      group.getFooter().registerStyleSheetCollection(this.getStyleSheetCollection());
      group.getHeader().registerStyleSheetCollection(this.getStyleSheetCollection());
    }

    /**
     * Handles the stylesheet collection unregistration for the group and
     * all group bands.
     */
    protected void handleUnregisterStyleSheetCollection()
    {
      group.getFooter().unregisterStyleSheetCollection(this.getStyleSheetCollection());
      group.getHeader().unregisterStyleSheetCollection(this.getStyleSheetCollection());
    }
  }

  /** The name of the group. */
  private String name;

  /** The fields that define the group (can be empty). */
  private TreeSet fields;

  /** Cached fields. */
  private transient String[] fieldsCached;

  /** The group header (optional). */
  private GroupHeader header;

  /** The group footer (optional). */
  private GroupFooter footer;

  /** The helper implementation that manages the stylesheet collection. */
  private GroupStyleSheetCollectionHelper styleSheetCollectionHelper;

  /** The internal constant to mark anonymous group names. */
  public static final String ANONYMOUS_GROUP_PREFIX = "anonymousGroup@";

  /**
   * Constructs a group with no fields, and an empty header and footer.
   */
  public Group()
  {
    name = ANONYMOUS_GROUP_PREFIX + super.hashCode();
    fields = new TreeSet();
    this.styleSheetCollectionHelper = new GroupStyleSheetCollectionHelper(this);
    this.footer = new GroupFooter();
    this.header = new GroupHeader();
  }

  /**
   * Defines the name for this group. The name must not be empty and must be unique within
   * the GroupList.
   *
   * @param name  the group name (null not permitted).
   */
  public void setName(final String name)
  {
    if (name == null)
    {
      throw new NullPointerException("Name must not be null");
    }

    this.name = name;
  }

  /**
   * Returns the name of the group.
   *
   * @return the group name.
   */
  public String getName()
  {
    return this.name;
  }

  /**
   * Returns the group header.
   * <P>
   * The group header is a report band that contains elements that should be printed at the
   * start of a group.
   *
   * @return the group header.
   */
  public GroupHeader getHeader()
  {
    return header;
  }

  /**
   * Sets the header for the group.
   *
   * @param header  the header (null not permitted).
   *
   * @throws NullPointerException if the given header is null
   */
  public void setHeader(final GroupHeader header)
  {
    if (header == null)
    {
      throw new NullPointerException("Header must not be null");
    }
    if (getStyleSheetCollection() != null)
    {
      this.header.unregisterStyleSheetCollection(getStyleSheetCollection());
    }
    this.header = header;
    if (getStyleSheetCollection() != null)
    {
      this.header.registerStyleSheetCollection(getStyleSheetCollection());
    }
  }

  /**
   * Returns the group footer.
   *
   * @return the footer.
   */
  public GroupFooter getFooter()
  {
    return footer;
  }

  /**
   * Sets the footer for the group.
   *
   * @param footer  the footer (null not permitted).
   * @throws NullPointerException if the given footer is null.
   */
  public void setFooter(final GroupFooter footer)
  {
    if (footer == null)
    {
      throw new NullPointerException("The footer must not be null");
    }
    if (getStyleSheetCollection() != null)
    {
      this.footer.unregisterStyleSheetCollection(getStyleSheetCollection());
    }
    this.footer = footer;
    if (getStyleSheetCollection() != null)
    {
      this.footer.registerStyleSheetCollection(getStyleSheetCollection());
    }
  }

  /**
   * Sets the fields for this group. The given list must contain Strings defining the
   * needed fields from the DataRow. Don't reference Function-Fields here, functions are
   * not supported in th groupfield definition.
   *
   * @param c  the list containing strings.
   *
   * @throws NullPointerException if the given list is null or the list contains null-values.
   */
  public void setFields(final List c)
  {
    if (c == null)
    {
      throw new NullPointerException();
    }
    fields.clear();
    fieldsCached = null;
    final Iterator it = c.iterator();
    while (it.hasNext())
    {
      final String field = (String) it.next();
      addField(field);
    }
  }

  /**
   * Adds a field to the group.  The field names must correspond to the column names in the
   * report's TableModel.
   *
   * @param name  the field name (null not permitted).
   *
   * @throws NullPointerException if the name is null
   */
  public void addField(final String name)
  {
    if (name == null)
    {
      throw new NullPointerException("Group.addField(...): name is null.");
    }
    fields.add(name);
    fieldsCached = null;
  }

  /**
   * Returns the list of fields for this group.
   *
   * @return a list (unmodifiable) of fields for the group.
   */
  public List getFields()
  {
    if (fieldsCached == null)
    {
      fieldsCached = (String[]) fields.toArray(new String[fields.size()]);
    }
    return Collections.unmodifiableList(Arrays.asList(fieldsCached));
  }

  /**
   * Returns the group fields as array.
   *
   * @return the fields as string array.
   */
  public String[] getFieldsArray()
  {
    if (fieldsCached == null)
    {
      fieldsCached = (String[]) fields.toArray(new String[fields.size()]);
    }
    return fieldsCached;
  }

  /**
   * Clones this Element.
   *
   * @return a clone of this element.
   *
   * @throws CloneNotSupportedException should never be thrown.
   */
  public Object clone() throws CloneNotSupportedException
  {
    final Group g = (Group) super.clone();
    g.fields = new TreeSet(fields);
    g.fieldsCached = fieldsCached;
    g.footer = (GroupFooter) footer.clone();
    g.header = (GroupHeader) header.clone();
    g.styleSheetCollectionHelper = new GroupStyleSheetCollectionHelper(g);
    return g;
  }

  /**
   * Compares two objects (required to be instances of the Group class).
   * The group's field lists are compared, order of the fields does not
   * matter.
   *
   * @param o  the to be compared object.
   *
   * @return an integer indicating the relative ordering of the two groups.
   */
  public int compareTo(final Object o)
  {
    final Group g = (Group) o;

    /** Remove all element, which are in both lists, they are equal */
    if (fields.size() == g.fields.size())
    {
      // both lists contain the same elements.
      if (fields.containsAll(g.fields))
      {
        return 0;
      }
      else
      {
        // groups with the same number of -, but different fields, are not compareable.
        throw new IllegalArgumentException("These groups are not comparable, they don't have any "
            + "subgroup relation");
      }
    }

    if (fields.containsAll(g.fields))
    {
      // c2 contains all elements of c1, so c1 is subgroup of c2
      return 1;
    }
    if (g.fields.containsAll(fields))
    {
      // c1 contains all elements of c2, so c2 is subgroup of c1
      return -1;
    }
    // not compareable, invalid groups
    // return 0;
    throw new IllegalArgumentException("These groups are not comparable, they don't have any "
        + "subgroup relation");
  }

  /**
   * Returns a string representation of the group (useful for debugging).
   *
   * @return A string.
   */
  public String toString()
  {
    final StringBuffer b = new StringBuffer();
    b.append("Group={Name='");
    b.append(getName());
    b.append("', fields=");
    b.append(fields);
/*    b.append(", header=");
    b.append(header);
    b.append(", footer=");
    b.append(footer);*/
    b.append("} ");
    return b.toString();
  }

  /**
   * Returns the stylesheet collection which is assigned with this group and
   * all stylesheets of this group.
   *
   * @return the stylesheet collection or null, if no collection is assigned.
   */
  public StyleSheetCollection getStyleSheetCollection()
  {
    return styleSheetCollectionHelper.getStyleSheetCollection();
  }

  /**
   * Registers the given StyleSheet collection with this group. If there is already
   * another stylesheet collection registered, this method will throw an
   * <code>InvalidStyleSheetCollectionException</code>.
   *
   * @param styleSheetCollection the stylesheet collection that should be registered.
   * @throws InvalidStyleSheetCollectionException
   * if there is already an other stylesheet registered.
   * @throws NullPointerException if the given stylesheet collection is null.
   */
  public void registerStyleSheetCollection(final StyleSheetCollection styleSheetCollection)
      throws InvalidStyleSheetCollectionException
  {
    styleSheetCollectionHelper.registerStyleSheetCollection(styleSheetCollection);
  }

  /**
   * Unregisters the given stylesheet collection from this group. If this stylesheet
   * collection is not registered with this group, this method will throw an
   * <code>InvalidStyleSheetCollectionException</code>
   *
   * @param styleSheetCollection the stylesheet collection that should be unregistered.
   * @throws InvalidStyleSheetCollectionException
   * if there is an other stylesheet collection already registered with that element.
   * @throws NullPointerException if the given stylesheet collection is null.
   */
  public void unregisterStyleSheetCollection(final StyleSheetCollection styleSheetCollection)
      throws InvalidStyleSheetCollectionException
  {
    styleSheetCollectionHelper.unregisterStyleSheetCollection(styleSheetCollection);
  }

  /**
   * Updates the stylesheet collection for this group and all bands of the group.
   * This method must be called after the group was cloned, to make sure that
   * all stylesheets are registered properly.
   * <p>
   * If you don't call this function after cloning prepare to be doomed.
   * This method will replace all inherited stylesheets with clones from the stylesheet
   * collection.
   *
   * @param sc the stylesheet collection that contains the updated information and
   * that should be assigned with that element.
   * @throws NullPointerException if the given stylesheet collection is null.
   * @throws InvalidStyleSheetCollectionException
   * if there is an other stylesheet collection already registered with that element.
   */
  public void updateStyleSheetCollection(final StyleSheetCollection sc)
      throws InvalidStyleSheetCollectionException
  {
    footer.updateStyleSheetCollection(sc);
    header.updateStyleSheetCollection(sc);
  }
}