1    
2    /* ====================================================================
3     * The Apache Software License, Version 1.1
4     *
5     * Copyright (c) 2002 The Apache Software Foundation.  All rights
6     * reserved.
7     *
8     * Redistribution and use in source and binary forms, with or without
9     * modification, are permitted provided that the following conditions
10    * are met:
11    *
12    * 1. Redistributions of source code must retain the above copyright
13    *    notice, this list of conditions and the following disclaimer.
14    *
15    * 2. Redistributions in binary form must reproduce the above copyright
16    *    notice, this list of conditions and the following disclaimer in
17    *    the documentation and/or other materials provided with the
18    *    distribution.
19    *
20    * 3. The end-user documentation included with the redistribution,
21    *    if any, must include the following acknowledgment:
22    *       "This product includes software developed by the
23    *        Apache Software Foundation (http://www.apache.org/)."
24    *    Alternately, this acknowledgment may appear in the software itself,
25    *    if and wherever such third-party acknowledgments normally appear.
26    *
27    * 4. The names "Apache" and "Apache Software Foundation" and
28    *    "Apache POI" must not be used to endorse or promote products
29    *    derived from this software without prior written permission. For
30    *    written permission, please contact apache@apache.org.
31    *
32    * 5. Products derived from this software may not be called "Apache",
33    *    "Apache POI", nor may "Apache" appear in their name, without
34    *    prior written permission of the Apache Software Foundation.
35    *
36    * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
37    * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
38    * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
39    * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
40    * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
41    * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
42    * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
43    * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
44    * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
45    * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
46    * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
47    * SUCH DAMAGE.
48    * ====================================================================
49    *
50    * This software consists of voluntary contributions made by many
51    * individuals on behalf of the Apache Software Foundation.  For more
52    * information on the Apache Software Foundation, please see
53    * <http://www.apache.org/>.
54    */
55   
56   package org.apache.poi.poifs.dev;
57   
58   import java.util.Iterator;
59   
60   /**
61    * Interface for a drill-down viewable object. Such an object has
62    * content that may or may not be displayed, at the discretion of the
63    * viewer. The content is returned to the viewer as an array or as an
64    * Iterator, and the object provides a clue as to which technique the
65    * viewer should use to get its content.
66    *
67    * A POIFSViewable object is also expected to provide a short
68    * description of itself, that can be used by a viewer when the
69    * viewable object is collapsed.
70    *
71    * @author Marc Johnson (mjohnson at apache dot org)
72    */
73   
74   public interface POIFSViewable
75   {
76   
77       /**
78        * Get an array of objects, some of which may implement
79        * POIFSViewable
80        *
81        * @return an array of Object; may not be null, but may be empty
82        */
83   
84       public Object [] getViewableArray();
85   
86       /**
87        * Get an Iterator of objects, some of which may implement
88        * POIFSViewable
89        *
90        * @return an Iterator; may not be null, but may have an empty
91        * back end store
92        */
93   
94       public Iterator getViewableIterator();
95   
96       /**
97        * Give viewers a hint as to whether to call getViewableArray or
98        * getViewableIterator
99        *
100       * @return true if a viewer should call getViewableArray, false if
101       *         a viewer should call getViewableIterator
102       */
103  
104      public boolean preferArray();
105  
106      /**
107       * Provides a short description of the object, to be used when a
108       * POIFSViewable object has not provided its contents.
109       *
110       * @return short description
111       */
112  
113      public String getShortDescription();
114  }   // end public interface POIFSViewable
115  
116