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SmartWeb is a web application development meta framework based on Jakarta Struts, Hibernate and other open source frameworks and libraries.
/*
* The SmartWeb Framework
* Copyright (C) 2004-2006
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* For further informations on the SmartWeb Framework please visit
*
* http://smartweb.sourceforge.net
*/
package net.smartlab.web.page;
import java.util.Iterator;
import java.util.NoSuchElementException;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* TODO documentation
*
* @author rlogiacco
*/
public abstract class Paginator implements Iterator {
/* # net.smartlab.web.paging.PaginationException pe */
/**
* A constant to identify an unlimited page listing.
* www.lamiainclinazione.org
*/
public final static int UNLIMITED_PAGES = 0;
/**
* A constant to identify an unlimited item listing.
*/
public final static int UNLIMITED_ITEMS = 0;
/**
* A constant to identify the page was not setted.
*/
public final static int UNDEFINED_PAGE = -1;
/**
* Logging system accessor.
*/
protected Log logger = LogFactory.getLog(this.getClass());
/**
* The elements in the current page.
*/
protected Object[] array;
/**
* The page relative index of the current element.
*/
private int index;
/**
* The actual page index.
*/
private int page;
/**
* The number of items in all pages.
*/
private int count;
/**
* An array of page indexes directly accessibile.
*/
private int[] pages;
/**
* The last page can ever been accessed through this paginator instance.
*/
private int last;
/**
* TODO documentation
*/
protected Paginator() {
this(0, 0);
}
/**
* TODO documentation
*
* @param size
* @param pages
*/
protected Paginator(int size, int pages) {
this.array = new Object[size];
this.pages = new int[pages];
this.page = UNDEFINED_PAGE;
this.index = 0;
}
/**
* TODO documentation
*
* @return
*/
public int getPage() {
return page;
}
/**
* TODO documentation
*
* @return
*/
public int[] getPages() {
return pages;
}
/**
* TODO documentation
*
* @return
*/
public int getPageCount() {
return last;
}
/**
* TODO documentation
*
* @param size
*/
public void setPages(int size) {
if (array.length > 0) {
this.last = (count / array.length) + (count % array.length == 0 ? 0 : 1);
if (size == Paginator.UNLIMITED_PAGES || last <= size) {
this.pages = new int[last];
} else {
this.pages = new int[size];
}
}
}
/**
* TODO documentation
*
* @param page
*/
public void setPage(int page) {
if (count > 0) {
if (pages.length != UNLIMITED_PAGES && (page <= 0 || page > last)) {
throw new IndexOutOfBoundsException("Invalid page " + page);
}
if (page < pages[0] || page > pages[pages.length - 1]) {
for (int i = 0; i < pages.length; i++) {
pages[i] = (((page - 1) / pages.length) * pages.length) + i + 1;
}
if (pages[pages.length - 1] > last) {
int[] tmp = new int[last - pages[0] + 1];
System.arraycopy(pages, 0, tmp, 0, tmp.length);
this.pages = tmp;
}
}
this.index = 0;
if (page != this.page) {
this.page = page;
this.setArray();
}
}
}
/**
* TODO documentation
*
* @return
*/
public int getNext() {
if (page >= last || count == 0 || pages[pages.length - 1] >= last) {
return -1;
} else {
return pages[pages.length - 1] + 1;
}
}
/**
* TODO documentation
*
* @return
*/
public int getPrev() {
if (page <= 1 || pages[0] <= 1 || count == 0) {
return -1;
} else {
return pages[0] - 1;
}
}
/**
* TODO documentation
*
* @param count
*/
public void setCount(int count) {
this.count = count;
if (pages.length > 0) {
this.setPages(pages.length);
}
if (array.length == UNLIMITED_ITEMS) {
this.setPageSize(count);
}
}
/**
* TODO documentation
*
* @return
*/
public int getCount() {
return count;
}
/**
* TODO documentation
*
* @return
*/
public int getPageSize() {
return array.length;
}
/**
* TODO documentation
*
* @param size
*/
public void setPageSize(int size) {
if (size == UNLIMITED_ITEMS) {
this.array = new Object[size];
this.setPages(1);
} else {
this.array = new Object[size];
this.setPages(UNLIMITED_PAGES);
}
}
/**
* TODO documentation
*
* @return
*/
public int getStart() {
if (pages.length > 0) {
return ((page - 1) * array.length) + 1;
} else {
return 0;
}
}
/**
* TODO documentation
*
* @return
*/
public int getStop() {
if (pages.length > 0) {
if (page * array.length < count) {
return page * array.length;
} else {
return count;
}
} else {
return 0;
}
}
/**
* TODO documentation
*/
abstract protected void setArray();
/**
* @see java.util.Iterator#hasNext()
*/
public boolean hasNext() {
if (page == UNDEFINED_PAGE) {
this.setPage(1);
}
return index < array.length && array[index] != null;
}
/**
* @see java.util.Iterator#next()
*/
public Object next() {
try {
return array[index++];
} catch (Exception e) {
throw new NoSuchElementException();
}
}
/**
* This operation is not supported.
*
* @see java.util.Iterator#remove()
* @throws java.lang.UnsupportedOperationException
*/
public void remove() {
throw new UnsupportedOperationException();
}
/**
* TODO documentation
*/
public void reset() {
this.index = 0;
}
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