PageNavigator


1   /* 
2    * This file is part of the Echo Web Application Framework (hereinafter "Echo").
3    * Copyright (C) 2002-2005 NextApp, Inc.
4    *
5    * Version: MPL 1.1/GPL 2.0/LGPL 2.1
6    *
7    * The contents of this file are subject to the Mozilla Public License Version
8    * 1.1 (the "License"); you may not use this file except in compliance with
9    * the License. You may obtain a copy of the License at
10   * http://www.mozilla.org/MPL/
11   *
12   * Software distributed under the License is distributed on an "AS IS" basis,
13   * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
14   * for the specific language governing rights and limitations under the
15   * License.
16   *
17   * Alternatively, the contents of this file may be used under the terms of
18   * either the GNU General Public License Version 2 or later (the "GPL"), or
19   * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
20   * in which case the provisions of the GPL or the LGPL are applicable instead
21   * of those above. If you wish to allow use of your version of this file only
22   * under the terms of either the GPL or the LGPL, and not to allow others to
23   * use your version of this file under the terms of the MPL, indicate your
24   * decision by deleting the provisions above and replace them with the notice
25   * and other provisions required by the GPL or the LGPL. If you do not delete
26   * the provisions above, a recipient may use your version of this file under
27   * the terms of any one of the MPL, the GPL or the LGPL.
28   */
29  
30  package echo2example.email;
31  
32  import java.io.Serializable  ;
33  import java.util.EventListener  ;
34  import java.util.EventObject  ;
35  
36  import nextapp.echo2.app.Button;
37  import nextapp.echo2.app.Extent;
38  import nextapp.echo2.app.Label;
39  import nextapp.echo2.app.Row;
40  import nextapp.echo2.app.TextField;
41  import nextapp.echo2.app.event.ActionEvent;
42  import nextapp.echo2.app.event.ActionListener;
43  
44  /**
45   * A component which provides navigation between pages.
46   */
47  public class PageNavigator extends Row {
48  
49      /**
50       * An <code>EventListener</code> to provide notification of page index
51       * changes.
52       */
53      public static interface PageIndexChangeListener extends EventListener  , Serializable   {
54          
55          /**
56           * Provides notification of a page index change.
57           * 
58           * @param e the <code>PageIndexChangeEvent</code> describing the change
59           */
60          public void pageIndexChanged(PageIndexChangeEvent e);
61      }
62      
63      /**
64       * An <code>EventObject</code> describing a page index change
65       */
66      public class PageIndexChangeEvent extends EventObject   {
67          
68          private int newPageIndex;
69          
70          /**
71           * Creates a new <code>PageIndexChangeEvent</code>.
72           * 
73           * @param newPageIndex the new page index
74           */
75          private PageIndexChangeEvent(int newPageIndex) {
76              super(PageNavigator.this);
77              this.newPageIndex = newPageIndex;
78          }
79          
80          /**
81           * Returns the new page index.
82           * 
83           * @return the new page index 
84           */
85          public int getNewPageIndex() {
86              return newPageIndex;
87          }
88      }
89  
90      private Label totalPagesLabel;
91      private TextField pageField;
92      private int pageIndex, totalPages;
93      
94      /**
95       * Creates a new <code>PageNavigator</code>.
96       */
97      public PageNavigator() {
98          super();
99          setCellSpacing(new Extent(20));
100         
101         Button previousPageButton = new Button(Styles.ICON_24_LEFT_ARROW);
102         previousPageButton.setRolloverEnabled(true);
103         previousPageButton.setRolloverIcon(Styles.ICON_24_LEFT_ARROW_ROLLOVER);
104         previousPageButton.addActionListener(new ActionListener() {
105             public void actionPerformed(ActionEvent e) {
106                 setPageIndex(getPageIndex() - 1);
107             }
108         });
109         add(previousPageButton);
110         
111         Row entryRow = new Row();
112         entryRow.setCellSpacing(new Extent(5));
113         add(entryRow);
114         
115         Label itemLabel = new Label(Messages.getString("PageNavigator.ItemLabel"));
116         entryRow.add(itemLabel);
117         
118         pageField = new TextField();
119         pageField.setStyleName("PageNavigator.PageField");
120         pageField.setWidth(new Extent(4, Extent.EX));
121         pageField.setText("1");
122         pageField.addActionListener(new ActionListener() {
123             public void actionPerformed(ActionEvent e) {
124                 try {
125                     setPageIndex(Integer.parseInt(pageField.getText()) - 1);
126                 } catch (NumberFormatException   ex) {
127                     setPageIndex(getPageIndex());
128                 }
129             }
130         });
131         entryRow.add(pageField);
132         
133         Label prepositionLabel = new Label(Messages.getString("PageNavigator.PrepositionLabel"));
134         entryRow.add(prepositionLabel);
135         
136         totalPagesLabel = new Label("1");
137         entryRow.add(totalPagesLabel);
138         
139         Button nextPageButton = new Button(Styles.ICON_24_RIGHT_ARROW);
140         nextPageButton.setRolloverEnabled(true);
141         nextPageButton.setRolloverIcon(Styles.ICON_24_RIGHT_ARROW_ROLLOVER);
142         nextPageButton.addActionListener(new ActionListener() {
143             public void actionPerformed(ActionEvent e) {
144                 setPageIndex(getPageIndex() + 1);
145             }
146         });
147         add(nextPageButton);
148     }
149     
150     /**
151      * Adds a listener to be notified of page index changes.
152      *  
153      * @param l the listener to add
154      */
155     public void addPageIndexChangeListener(PageIndexChangeListener l) {
156         getEventListenerList().addListener(PageIndexChangeListener.class, l);
157     }
158     
159     /**
160      * Notifies <code>PageIndexChangeListener</code>s that the page index 
161      * has changed.
162      */
163     private void firePageIndexChanged() {
164         EventListener  [] listeners = getEventListenerList().getListeners(PageIndexChangeListener.class);
165         PageIndexChangeEvent e = new PageIndexChangeEvent(getPageIndex());
166         for (int i = 0; i < listeners.length; ++i) {
167             ((PageIndexChangeListener) listeners[i]).pageIndexChanged(e);
168         }
169     }
170 
171     /**
172      * Returns the current page index.
173      * 
174      * @return the current page index
175      */
176     public int getPageIndex() {
177         return pageIndex;
178     }
179     
180     /**
181      * Returns the total number of pages.
182      * 
183      * @return the total number of pages
184      */
185     public int getTotalPages() {
186         return totalPages;
187     }
188 
189     /**
190      * Removes a listener from being notified of page index changes.
191      *  
192      * @param l the listener to remove
193      */
194     public void removePageIndexChangeListener(PageIndexChangeListener l) {
195         getEventListenerList().removeListener(PageIndexChangeListener.class, l);
196     }
197 
198     /**
199      * Sets the current page index.
200      * 
201      * @param pageIndex the new page index
202      */
203     public void setPageIndex(int pageIndex) {
204         if (pageIndex < 0) {
205             pageIndex = 0;
206         }
207         if (pageIndex > 0 && pageIndex > totalPages - 1) {
208             pageIndex = totalPages - 1;
209         }
210         this.pageIndex = pageIndex;
211         pageField.setText(Integer.toString(pageIndex + 1));
212         firePageIndexChanged();
213     }
214     
215     /**
216      * Sets the total number of pages.
217      * 
218      * @param totalPages the total number of pages
219      */
220     public void setTotalPages(int totalPages) {
221         this.totalPages = totalPages;
222         if (totalPages == 0) {
223             totalPagesLabel.setText("1");
224         } else {
225             totalPagesLabel.setText(Integer.toString(totalPages));
226         }
227     }
228 }
229
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