| 1 | package org.ufcspa.simdecs.bn.ui.util; |
| 2 | |
| 3 | import javax.faces.model.DataModel; |
| 4 | |
| 5 | public abstract class PaginationHelper { |
| 6 | |
| 7 | private int pageSize; |
| 8 | private int page; |
| 9 | |
| 10 | public PaginationHelper(int pageSize) { |
| 11 | this.pageSize = pageSize; |
| 12 | } |
| 13 | |
| 14 | public abstract int getItemsCount(); |
| 15 | |
| 16 | public abstract DataModel createPageDataModel(); |
| 17 | |
| 18 | public int getPageFirstItem() { |
| 19 | return page * pageSize; |
| 20 | } |
| 21 | |
| 22 | public int getPageLastItem() { |
| 23 | int i = getPageFirstItem() + pageSize - 1; |
| 24 | int count = getItemsCount() - 1; |
| 25 | if (i > count) { |
| 26 | i = count; |
| 27 | } |
| 28 | if (i < 0) { |
| 29 | i = 0; |
| 30 | } |
| 31 | return i; |
| 32 | } |
| 33 | |
| 34 | public boolean isHasNextPage() { |
| 35 | return (page + 1) * pageSize + 1 <= getItemsCount(); |
| 36 | } |
| 37 | |
| 38 | public void nextPage() { |
| 39 | if (isHasNextPage()) { |
| 40 | page++; |
| 41 | } |
| 42 | } |
| 43 | |
| 44 | public boolean isHasPreviousPage() { |
| 45 | return page > 0; |
| 46 | } |
| 47 | |
| 48 | public void previousPage() { |
| 49 | if (isHasPreviousPage()) { |
| 50 | page--; |
| 51 | } |
| 52 | } |
| 53 | |
| 54 | public int getPageSize() { |
| 55 | return pageSize; |
| 56 | } |
| 57 | } |