1 /*
2 * $Source$
3 * $Revision$
4 *
5 * Copyright (C) 2003 Tim Pizey
6 *
7 * Part of Melati (http://melati.org), a framework for the rapid
8 * development of clean, maintainable web applications.
9 *
10 * Melati is free software; Permission is granted to copy, distribute
11 * and/or modify this software under the terms either:
12 *
13 * a) the GNU General Public License as published by the Free Software
14 * Foundation; either version 2 of the License, or (at your option)
15 * any later version,
16 *
17 * or
18 *
19 * b) any version of the Melati Software License, as published
20 * at http://melati.org
21 *
22 * You should have received a copy of the GNU General Public License and
23 * the Melati Software License along with this program;
24 * if not, write to the Free Software Foundation, Inc.,
25 * 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA to obtain the
26 * GNU General Public License and visit http://melati.org to obtain the
27 * Melati Software License.
28 *
29 * Feel free to contact the Developers of Melati (http://melati.org),
30 * if you would like to work out a different arrangement than the options
31 * outlined here. It is our intention to allow Melati to be used by as
32 * wide an audience as possible.
33 *
34 * This program is distributed in the hope that it will be useful,
35 * but WITHOUT ANY WARRANTY; without even the implied warranty of
36 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
37 * GNU General Public License for more details.
38 *
39 * Contact details for copyright holder:
40 *
41 * Tim Pizey <timp At paneris.org>
42 */
43
44 package org.melati.util;
45
46 import java.util.Enumeration;
47
48 import org.melati.poem.util.EnumUtils;
49
50 /**
51 * A {@link PagedEnumeration} which knows how big it is.
52 * Ideally SQL would allow you to start at an offset.
53 */
54 public class CountedDumbPagedEnumeration<T> extends PagedEnumerationBase<T> {
55
56 /**
57 * Constructor.
58 * @param base underlying Enumeration
59 * @param pageStart index of start of page
60 * @param pageSize how many Elements to include upon a page
61 * @param totalCount size of the underlying Enumeration
62 */
63 public CountedDumbPagedEnumeration(Enumeration<T> base,
64 int pageStart, int pageSize, int totalCount) {
65 pageStart = Math.max(pageStart, 1);
66 this.pageStart = pageStart;
67 this.pageSize = pageSize;
68 this.totalCount = totalCount;
69 //NOTE This is the bit that makes it dumb!
70 EnumUtils.skip(base, pageStart - 1);
71 page = EnumUtils.initial(base, pageSize);
72 us = page.elements();
73 currentPosition = pageStart - 1;
74 }
75
76 @Override
77 public Integer getNextPageStart() {
78 int it = pageStart + pageSize;
79 return it <= totalCount ? new Integer(it) : null;
80 }
81
82
83 }