=== added file 'dhis-2/dhis-support/dhis-support-system/src/main/java/org/hisp/dhis/system/util/PaginatedList.java' --- dhis-2/dhis-support/dhis-support-system/src/main/java/org/hisp/dhis/system/util/PaginatedList.java 1970-01-01 00:00:00 +0000 +++ dhis-2/dhis-support/dhis-support-system/src/main/java/org/hisp/dhis/system/util/PaginatedList.java 2011-01-09 17:14:33 +0000 @@ -0,0 +1,72 @@ +package org.hisp.dhis.system.util; + +/* + * Copyright (c) 2004-2010, University of Oslo + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of the HISP project nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +import java.util.ArrayList; +import java.util.Collection; +import java.util.List; + +/** + * @author Lars Helge Overland + */ +public class PaginatedList + extends ArrayList +{ + private final int pageSize; + + private int fromIndex = 0; + + public PaginatedList( Collection collection, int pageSize ) + { + super( collection ); + this.pageSize = pageSize; + } + + /** + * Returns the next page in the list. The page size is defined by the argument + * given in the constructor. If there is no more pages, null is returned. The + * returned page is not guaranteed to have the same size as the page size. + */ + public List getPage() + { + int size = size(); + + if ( fromIndex >= size ) + { + return null; + } + + int toIndex = Math.min( ( fromIndex + pageSize ), size ); + + List page = subList( fromIndex, toIndex ); + + fromIndex = toIndex; + + return page; + } +} === added file 'dhis-2/dhis-support/dhis-support-system/src/test/java/org/hisp/dhis/system/util/PaginatedListTest.java' --- dhis-2/dhis-support/dhis-support-system/src/test/java/org/hisp/dhis/system/util/PaginatedListTest.java 1970-01-01 00:00:00 +0000 +++ dhis-2/dhis-support/dhis-support-system/src/test/java/org/hisp/dhis/system/util/PaginatedListTest.java 2011-01-09 17:14:33 +0000 @@ -0,0 +1,75 @@ +package org.hisp.dhis.system.util; + +/* + * Copyright (c) 2004-2010, University of Oslo + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are met: + * * Redistributions of source code must retain the above copyright notice, this + * list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above copyright notice, + * this list of conditions and the following disclaimer in the documentation + * and/or other materials provided with the distribution. + * * Neither the name of the HISP project nor the names of its contributors may + * be used to endorse or promote products derived from this software without + * specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED + * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE + * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR + * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES + * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; + * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON + * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS + * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +import static junit.framework.Assert.*; + +import java.util.ArrayList; +import java.util.Arrays; +import java.util.List; + +import org.junit.Test; + +/** + * @author Lars Helge Overland + */ +public class PaginatedListTest +{ + @Test + public void testGetPage() + { + PaginatedList list = new PaginatedList( Arrays.asList( "A", "B", "C" ), 2 ); + + List page = list.getPage(); + + assertNotNull( page ); + assertEquals( 2, page.size() ); + assertTrue( page.contains( "A" ) ); + assertTrue( page.contains( "B" ) ); + + page = list.getPage(); + + assertNotNull( page ); + assertEquals( 1, page.size() ); + assertTrue( page.contains( "C" ) ); + + page = list.getPage(); + + assertNull( page ); + } + + @Test + public void testGetPageEmpty() + { + PaginatedList list = new PaginatedList( new ArrayList(), 2 ); + + List page = list.getPage(); + + assertNull( page ); + } +}