/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.wicket.markup.html.list;
import java.util.List;
import org.apache.wicket.markup.html.navigation.paging.IPageableItems;
import org.apache.wicket.model.IModel;
/**
* PageableListView is similar to ListView but provides in addition pageable views. A
* PageableListView holds pageable rows of information. The rows can be re-ordered and deleted,
* either one at a time or many at a time.
*
* @author Jonathan Locke
* @param <T>
* type of elements contained in the model's list
*/
public abstract class PageableListView<T> extends ListView<T> implements IPageableItems
{
private static final long serialVersionUID = 1L;
/** The page to show. */
private long currentPage;
/** Number of rows per page of the list view. */
private long itemsPerPage;
/**
* Constructor
*
* @param id
* See Component
* @param model
* See Component
* @param itemsPerPage
* Number of rows to show on a page
*/
public PageableListView(final String id, final IModel<? extends List<T>> model,
long itemsPerPage)
{
super(id, model);
this.itemsPerPage = itemsPerPage;
}
/**
* Creates a pageable list view having the given number of rows per page that uses the provided
* object as a simple model.
*
* @param id
* See Component
* @param list
* See Component
* @param itemsPerPage
* Number of rows to show on a page
* @see ListView#ListView(String, List)
*/
public PageableListView(final String id, final List<T> list, final long itemsPerPage)
{
super(id, list);
this.itemsPerPage = itemsPerPage;
}
/**
* Gets the index of the current page being displayed by this list view.
*
* @return Returns the currentPage.
*/
@Override
public final long getCurrentPage()
{
// If first cell is out of range, bring page back into range
while ((currentPage > 0) && ((currentPage * itemsPerPage) >= getItemCount()))
{
currentPage--;
}
return currentPage;
}
/**
* Gets the number of pages in this list view.
*
* @return The number of pages in this list view
*/
@Override
public final long getPageCount()
{
return ((getItemCount() + itemsPerPage) - 1) / itemsPerPage;
}
/**
* Gets the maximum number of rows on each page.
*
* @return the maximum number of rows on each page.
*/
@Override
public final long getItemsPerPage()
{
return itemsPerPage;
}
/**
* Sets the maximum number of rows on each page.
*
* @param itemsPerPage
* the maximum number of rows on each page.
*/
public final void setItemsPerPage(long itemsPerPage)
{
if (itemsPerPage < 0)
{
itemsPerPage = 0;
}
addStateChange();
this.itemsPerPage = itemsPerPage;
}
/**
* @return offset of first item
*/
public long getFirstItemOffset()
{
return getCurrentPage() * getItemsPerPage();
}
/**
* @see org.apache.wicket.markup.html.navigation.paging.IPageableItems#getItemCount()
*/
@Override
public long getItemCount()
{
return getList().size();
}
/**
* @see org.apache.wicket.markup.html.list.ListView#getViewSize()
*/
@Override
public int getViewSize()
{
if (getDefaultModelObject() != null)
{
super.setStartIndex((int)getFirstItemOffset());
super.setViewSize((int)getItemsPerPage());
}
return super.getViewSize();
}
/**
* Sets the current page that this list view should show.
*
* @param currentPage
* The currentPage to set.
*/
@Override
public final void setCurrentPage(long currentPage)
{
if (currentPage < 0)
{
currentPage = 0;
}
long pageCount = getPageCount();
if ((currentPage > 0) && (currentPage >= pageCount))
{
currentPage = pageCount - 1;
}
addStateChange();
this.currentPage = currentPage;
}
/**
* Prevent users from accidentally using it.
*
* @see org.apache.wicket.markup.html.list.ListView#setStartIndex(int)
* @throws UnsupportedOperationException
* always
*/
@Override
public ListView<T> setStartIndex(int startIndex) throws UnsupportedOperationException
{
throw new UnsupportedOperationException(
"You must not use setStartIndex() with PageableListView");
}
/**
* Prevent users from accidentally using it.
*
* @param size
* the view size
* @return This
* @throws UnsupportedOperationException
* always
* @see org.apache.wicket.markup.html.list.ListView#setStartIndex(int)
*/
@Override
public ListView<T> setViewSize(int size) throws UnsupportedOperationException
{
throw new UnsupportedOperationException(
"You must not use setViewSize() with PageableListView");
}
}