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1
24 package org.riotfamily.website.generic.view;
25
26 import java.io.UnsupportedEncodingException  ;
27 import java.net.URLEncoder ;
28
29 import javax.servlet.http.HttpServletRequest ;
30
31 import org.springframework.web.util.UrlPathHelper;
32
33
36 public class Pager {
37
38 private int currentPage;
39
40 private int pages;
41
42 private PagerItem firstPage;
43
44 private PagerItem prevPage;
45
46 private PagerItem[] prevPages;
47
48 private PagerItem[] nextPages;
49
50 private PagerItem nextPage;
51
52 private PagerItem lastPage;
53
54 private boolean gapToFirstPage;
55
56 private boolean gapToLastPage;
57
58 private String pageParam;
59
60 private String linkPrefix;
61
62 private String encodingScheme = "UTF-8";
63
64 private boolean copyParameters = true;
65
66 private UrlPathHelper urlPathHelper = new UrlPathHelper();
67
68 public Pager(int page, int pageSize, long itemCount) {
69 currentPage = page;
70 pages = (int) itemCount / pageSize + 1;
71 if (itemCount % pageSize == 0) {
72 pages--;
73 }
74 }
75
76 public void setCopyParameters(boolean copyParameters) {
77 this.copyParameters = copyParameters;
78 }
79
80 public void setEncodingScheme(String encodingScheme) {
81 this.encodingScheme = encodingScheme;
82 }
83
84 public void initialize(HttpServletRequest request, int padding,
85 String pageParam) {
86
87 this.pageParam = pageParam;
88 prepareLinkPrefix(request);
89
90 int start = currentPage - padding;
91 int end = currentPage + padding;
92
93 if (start < 0) {
94 end += -1 * start + 1;
95 }
96 if (end > pages) {
97 start -= (end - pages);
98 }
99 if (start < 1) {
100 start = 1;
101 }
102 if (end > pages) {
103 end = pages;
104 }
105
106 gapToFirstPage = start > 2;
107 gapToLastPage = end < pages - 1;
108
109 int prevCount = Math.max(currentPage - start, 0);
110 int nextCount = Math.max(end - currentPage, 0);
111
112 if (start > 1) {
113 firstPage = new PagerItem(linkPrefix, 1);
114 }
115
116 prevPages = new PagerItem[prevCount];
117 for (int i = 0; i < prevCount; i++) {
118 prevPages[i] = new PagerItem(linkPrefix, start + i);
119 }
120 if (prevCount > 0) {
121 prevPage = prevPages[prevCount - 1];
122 }
123
124 nextPages = new PagerItem[nextCount];
125 for (int i = 0; i < nextCount; i++) {
126 nextPages[i] = new PagerItem(linkPrefix, currentPage + i + 1);
127 }
128 if (nextCount > 0) {
129 nextPage = nextPages[0];
130 }
131
132 if (end < pages) {
133 lastPage = new PagerItem(linkPrefix, pages);
134 }
135 }
136
137 private void prepareLinkPrefix(HttpServletRequest request) {
138 StringBuffer url = new StringBuffer (
139 urlPathHelper.getOriginatingRequestUri(request));
140
141 url.append('?');
142 if (copyParameters) {
143 String query = urlPathHelper.getOriginatingQueryString(request);
144 if (query != null) {
145 int i = query.indexOf(pageParam);
146 if (i != -1) {
147 url.append(query.substring(0, i));
148 }
149 else {
150 url.append(query).append('&');
151 }
152 }
153 }
154 url.append(pageParam);
155 url.append('=');
156 linkPrefix = url.toString();
157 }
158
159 protected String urlEncode(String s) {
160 try {
161 return URLEncoder.encode(s, encodingScheme);
162 }
163 catch (UnsupportedEncodingException e) {
164 throw new RuntimeException (e);
165 }
166 }
167
168 public int getCurrentPage() {
169 return currentPage;
170 }
171
172 public int getPages() {
173 return pages;
174 }
175
176 public PagerItem getFirstPage() {
177 return firstPage;
178 }
179
180 public boolean isGapToFirstPage() {
181 return gapToFirstPage;
182 }
183
184 public boolean isGapToLastPage() {
185 return gapToLastPage;
186 }
187
188 public PagerItem getLastPage() {
189 return lastPage;
190 }
191
192 public PagerItem[] getNextPages() {
193 return nextPages;
194 }
195
196 public PagerItem[] getPrevPages() {
197 return prevPages;
198 }
199
200 public PagerItem getNextPage() {
201 return nextPage;
202 }
203
204 public PagerItem getPrevPage() {
205 return prevPage;
206 }
207
208 public class PagerItem {
209
210 private int number;
211
212 private String link;
213
214 public PagerItem(String linkPrefix, int number) {
215 this.number = number;
216 this.link = linkPrefix + number;
217 }
218
219 public int getNumber() {
220 return number;
221 }
222
223 public String getLink() {
224 return link;
225 }
226 }
227 } |
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