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Java > Open Source Codes > com > jcorporate > expresso > services > html > DropDown


1 /* ====================================================================
2  * The Jcorporate Apache Style Software License, Version 1.2 05-07-2002
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61  * Portions of this software are based upon other open source
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64
65 package com.jcorporate.expresso.services.html;
66
67 import java.io.PrintWriter JavaDoc;
68 import java.util.Enumeration JavaDoc;
69 import java.util.Vector JavaDoc;
70
71
72 /**
73  * Encapsulates an HTML drop-down box on an HTML form
74  *
75  * @author Michael P. Nash
76  * @version $Revision: 1.8 $ $Date: 2004/11/17 20:48:18 $
77  */
78 public class DropDown
79         extends HtmlElement {
80     private String JavaDoc fieldName = null;
81     private String JavaDoc currentValue = ("");
82     private Vector JavaDoc values = new Vector JavaDoc(3);
83     private Vector JavaDoc labels = new Vector JavaDoc(3);
84     private String JavaDoc thisClass = (this.getClass().getName() + ".");
85
86     /**
87      * Constructor Create a new DropDown list with the specified field name
88      *
89      * @param newFieldName Field name of the new drop down, must not be null
90      * @throws HtmlException If the parameter is invalid
91      */
92     public DropDown(String JavaDoc newFieldName)
93             throws HtmlException {
94         super(newFieldName);
95
96         String JavaDoc myName = (thisClass + "DropDown(String)");
97
98         if (newFieldName == null) {
99             throw new HtmlException(myName +
100                     ":Field name must not be null for " +
101                     getName());
102         }
103
104         fieldName = newFieldName;
105     } /* DropDown(String) */
106
107     /**
108      * Create a drop down with the field name as given with a specific current value
109      *
110      * @param newFieldName Field name of the new drop-down
111      * @param newCurrentValue Current value of the drop down (selected item)
112      * @throws HtmlException If the parameters are invalid
113      */
114     public DropDown(String JavaDoc newFieldName, String JavaDoc newCurrentValue)
115             throws HtmlException {
116         super(newFieldName);
117         fieldName = newFieldName;
118         currentValue = newCurrentValue;
119     } /* DropDown(String, String) */
120
121     /**
122      * Add a new option to this drop-down
123      *
124      * @param fieldValue Value of the new option
125      * @param fieldLabel Label of the new option
126      * @throws HtmlException If the parameters are invalid
127      */
128     public synchronized void addOption(String JavaDoc fieldValue, String JavaDoc fieldLabel)
129             throws HtmlException {
130         values.addElement(fieldValue);
131         labels.addElement(fieldLabel);
132     } /* addOption(String, String) */
133
134
135     /**
136      * Display this DropDown to the appropriate PrintWriter
137      *
138      * @param out PrintWriter to display
139      * @param depth the number of tabs to indent
140      * @throws HtmlException If the DropDown cannot be displayed
141      */
142     protected synchronized void display(PrintWriter JavaDoc out, int depth)
143             throws HtmlException {
144         String JavaDoc myName = (thisClass + "display(PrintWriter)");
145
146         if (values.size() == 0) {
147             throw new HtmlException(myName + ":DropDown " + getName() +
148                     " has no choices");
149         }
150
151         this.padWithTabs(out, depth);
152         out.print("<select");
153
154         if (cSSClass != null) {
155             out.print(" class=\"" + cSSClass + "\"");
156         }
157         if (cSSID != null) {
158             out.print(" id=\"" + cSSID + "\"");
159         }
160
161         out.println(" name=" + fieldName + ">");
162
163         String JavaDoc oneValue = null;
164         String JavaDoc oneLabel = null;
165         Enumeration JavaDoc e2 = labels.elements();
166
167         for (Enumeration JavaDoc e = values.elements(); e.hasMoreElements();) {
168             oneValue = (String JavaDoc) e.nextElement();
169             oneLabel = (String JavaDoc) e2.nextElement();
170
171             if (currentValue.equals(oneValue)) {
172                 this.padWithTabs(out, depth + 1);
173                 out.println("<option selected value=\"" + oneValue + "\">" +
174                         oneLabel);
175             } else {
176                 this.padWithTabs(out, depth + 1);
177                 out.println("<option value=\"" + oneValue + "\">" + oneLabel);
178             }
179         }
180
181         this.padWithTabs(out, depth);
182         out.println("</select>");
183         setDisplayed();
184     } /* display(PrintWriter) */
185
186
187     /**
188      * Set the currently selected value for this drop-down
189      *
190      * @param newCurrentValue The value for this drop down
191      * @throws HtmlException If the parameter is invalid
192      */
193     public void setCurrentValue(String JavaDoc newCurrentValue)
194             throws HtmlException {
195         currentValue = newCurrentValue;
196     } /* setCurrentValue(String) */
197
198
199 } /* DropDown */
200
201 /* DropDown */
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