group.java

Java的Web报表库

   */
  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 this group with an other object.
   *
   * @param o the object which should be compared with this group.
   *
   * @return true, if the given object is a group with the same name and fields,
   * false otherwise
   */
  public boolean equals(final Object o)
  {
    if (this == o)
    {
      return true;
    }
    if (!(o instanceof Group))
    {
      return false;
    }

    final Group group = (Group) o;

    if (name != null ? !name.equals(group.name) : group.name != null)
    {
      return false;
    }
    return compareTo(group) == 0;
  }

  /**
   * Calculates the hashcode for this group.
   *
   * @return the hashcode.
   */
  public int hashCode()
  {
    int result;
    result = (name != null ? name.hashCode() : 0);
    result = 29 * result + (fields != null ? fields.hashCode() : 0);
    return result;
  }

  /**
   * 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 com.jrefinery.report.targets.style.InvalidStyleSheetCollectionException
   * if there is already an other stylesheet registered.
   * @throws NullPointerException if the given stylesheet collection is null.
   */
  public void registerStyleSheetCollection(final StyleSheetCollection styleSheetCollection)
  {
    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 com.jrefinery.report.targets.style.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)
  {
    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 com.jrefinery.report.targets.style.InvalidStyleSheetCollectionException
   * if there is an other stylesheet collection already registered with that element.
   */
  public void updateStyleSheetCollection(final StyleSheetCollection sc)
  {
    footer.updateStyleSheetCollection(sc);
    header.updateStyleSheetCollection(sc);
  }
}