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1   /**
2    * Copyright 2005-2014 The Kuali Foundation
3    *
4    * Licensed under the Educational Community License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    *
8    * http://www.opensource.org/licenses/ecl2.php
9    *
10   * Unless required by applicable law or agreed to in writing, software
11   * distributed under the License is distributed on an "AS IS" BASIS,
12   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13   * See the License for the specific language governing permissions and
14   * limitations under the License.
15   */
16  package org.kuali.rice.kns.util;
17  
18  /**
19   * This class provides utilities to support the rendering of tables in Kuali without using display tag.
20   * 
21   * Normally, displaytag handles the rendering of Kuali tables on various screens, but
22   * there are situations where displaytag is inadequate for the task (e.g. multiple value lookups).
23   * In particular, display tag does not handle POSTing of forms when switching between pages and sorting.
24   *
25   * @deprecated Only used in KNS classes, use KRAD.
26   */
27  @Deprecated
28  public final class TableRenderUtil {
29  	
30  	private TableRenderUtil() {
31  		throw new UnsupportedOperationException("do not call");
32  	}
33  	
34      /**
35       * Returns the minimum number of pages needed to display a result set of the given page
36       * 
37       * @param resultSize number of results
38       * @param maxRowsPerPage maximum number of rows 
39       * 
40       * @return
41       */
42      public static int computeTotalNumberOfPages(int resultSize, int maxRowsPerPage) {
43          int numPages = resultSize / maxRowsPerPage;
44          if (resultSize % maxRowsPerPage != 0) {
45              // partial page
46              numPages++;
47          }
48          return numPages;
49      }
50      
51      /**
52       * This method computes the list index of the first row of the given page
53       * 
54       * @param pageNumber first page is index 0
55       * @param resultSize the size of the list being rendered
56       * @param maxRowsPerPage max number of rows on a page
57       * @return the index in the result list of the first row of the given page 
58       */
59      public static int computeStartIndexForPage(int pageNumber, int resultSize, int maxRowsPerPage) {
60          if (pageNumber < 0 && pageNumber >= computeTotalNumberOfPages(resultSize, maxRowsPerPage)) {
61              return -1;
62          }
63          return pageNumber * maxRowsPerPage;
64      }
65      
66      /**
67       * This method computes the index of the last row of the given page
68       * 
69       * @param pageNumber first page is index 0
70       * @param resultSize the size of the list being rendered
71       * @param maxRowsPerPage max number of rows on a page
72       * @return the index in the result list of the last row of the given page 
73       */
74      public static int computeLastIndexForPage(int pageNumber, int resultSize, int maxRowsPerPage) {
75          int startIndex = computeStartIndexForPage(pageNumber, resultSize, maxRowsPerPage);
76          if (startIndex == -1) {
77              return -1;
78          }
79          if (startIndex + maxRowsPerPage - 1 < resultSize) {
80              return startIndex + maxRowsPerPage - 1;
81          }
82          // partial page
83          return resultSize - 1;
84     }
85  }