| Classes in this File | Line Coverage | Branch Coverage | Complexity | ||||
| DumbPagedEnumeration |
|
| 1.75;1.75 |
| 1 | /* | |
| 2 | * $Source: /usr/cvsroot/melati/melati/src/site/resources/withWebmacro/org.melati.util.DumbPagedEnumeration.html,v $ | |
| 3 | * $Revision: 1.1 $ | |
| 4 | * | |
| 5 | * Copyright (C) 2000 William Chesters | |
| 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 | * William Chesters <williamc At paneris.org> | |
| 42 | * http://paneris.org/~williamc | |
| 43 | * Obrechtstraat 114, 2517VX Den Haag, The Netherlands | |
| 44 | */ | |
| 45 | ||
| 46 | package org.melati.util; | |
| 47 | ||
| 48 | import java.util.Enumeration; | |
| 49 | import java.util.Vector; | |
| 50 | ||
| 51 | import org.melati.poem.util.EnumUtils; | |
| 52 | ||
| 53 | /** | |
| 54 | * A {@link PagedEnumeration} which doesn't know how big it is. | |
| 55 | * Ideally SQL would allow you to start at an offset. | |
| 56 | */ | |
| 57 | public class DumbPagedEnumeration<T> extends PagedEnumerationBase<T> { | |
| 58 | ||
| 59 | private boolean totalCountIsMinimum; | |
| 60 | ||
| 61 | /** | |
| 62 | * Constructor. | |
| 63 | * @param base underlying Enumeration | |
| 64 | * @param pageStart index of start of page | |
| 65 | * @param pageSize how many Elements to include upon a page | |
| 66 | * @param countHorizon where to count to, may be less than total size of underlying Enumeration | |
| 67 | */ | |
| 68 | public DumbPagedEnumeration(Enumeration<T> base, | |
| 69 | 30 | int pageStart, int pageSize, int countHorizon) { |
| 70 | 30 | pageStart = Math.max(pageStart, 1); |
| 71 | 30 | this.pageStart = pageStart; |
| 72 | 30 | this.pageSize = pageSize; |
| 73 | 30 | int offset = EnumUtils.skip(base, pageStart - 1); |
| 74 | 30 | page = EnumUtils.initial(base, pageSize); |
| 75 | // NOTE This is the bit that makes it dumb! | |
| 76 | 30 | totalCount = offset + page.size() + |
| 77 | EnumUtils.skip(base, countHorizon - (offset + page.size())); | |
| 78 | 30 | totalCountIsMinimum = base.hasMoreElements(); |
| 79 | 30 | us = page.elements(); |
| 80 | 30 | currentPosition = pageStart - 1; |
| 81 | 30 | } |
| 82 | ||
| 83 | /** | |
| 84 | * {@inheritDoc} | |
| 85 | * @see org.melati.poem.util.PagedEnumerationBase#getNextPageStart() | |
| 86 | */ | |
| 87 | public Integer getNextPageStart() { | |
| 88 | 2 | int it = pageStart + pageSize; |
| 89 | 2 | return (totalCountIsMinimum || it <= totalCount) ? new Integer(it) : null; |
| 90 | } | |
| 91 | ||
| 92 | /** | |
| 93 | * @return whether there are more elements to come beyond horizon | |
| 94 | */ | |
| 95 | public boolean getTotalCountIsMinimum() { | |
| 96 | 2 | return totalCountIsMinimum; |
| 97 | } | |
| 98 | ||
| 99 | public Vector<Page> getPageStartList() { | |
| 100 | 0 | Vector<Page> ret = new Vector<Page>(totalCount / pageSize); |
| 101 | 0 | int i=1; |
| 102 | 0 | while((i-1)*pageSize < totalCount) { |
| 103 | 0 | ret.addElement(new Page(i,(i-1)*pageSize+1)); |
| 104 | 0 | i++; |
| 105 | } | |
| 106 | 0 | return ret; |
| 107 | } | |
| 108 | } |