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