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Java > Open Source Codes > de > laures > cewolf > taglib > tags > LegendTag


1 /* ================================================================
2  * Cewolf : Chart enabling Web Objects Framework
3  * ================================================================
4  *
5  * Project Info: http://cewolf.sourceforge.net
6  * Project Lead: Guido Laures (guido@laures.de);
7  *
8  * (C) Copyright 2002, by Guido Laures
9  *
10  * This library is free software; you can redistribute it and/or modify it under the terms
11  * of the GNU Lesser General Public License as published by the Free Software Foundation;
12  * either version 2.1 of
13  * the License, or (at your option) any later version.
14  *
15  * This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY;
16  * without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
17  * See the GNU Lesser General Public License for more details.
18  *
19  * You should have received a copy of the GNU Lesser General Public License along with this
20  * library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
21  * Boston, MA 02111-1307, USA.
22  */
23
24 package de.laures.cewolf.taglib.tags;
25
26 import java.io.IOException JavaDoc;
27
28 import javax.servlet.jsp.JspException JavaDoc;
29
30 import de.laures.cewolf.CewolfException;
31 import de.laures.cewolf.ChartHolder;
32 import de.laures.cewolf.ChartImage;
33 import de.laures.cewolf.Configuration;
34 import de.laures.cewolf.Storage;
35 import de.laures.cewolf.WebConstants;
36 import de.laures.cewolf.taglib.ChartImageDefinition;
37 import de.laures.cewolf.taglib.TaglibConstants;
38 import de.laures.cewolf.taglib.html.HTMLImgTag;
39 import de.laures.cewolf.taglib.util.PageUtils;
40
41 /**
42  * Tag <legend> which can be used to render a chart's legend
43  * separately somewhere in the page.
44  * @author Guido Laures
45  */
46 public class LegendTag extends HTMLImgTag implements CewolfRootTag, TaglibConstants, WebConstants {
47
48     private static final String JavaDoc DEFAULT_MIME_TYPE = MIME_PNG;
49     private static final int DEFAULT_TIMEOUT = 300;
50     private int timeout = DEFAULT_TIMEOUT;
51     private transient String JavaDoc sessionKey;
52     private transient String JavaDoc renderer;
53     private String JavaDoc mimeType = DEFAULT_MIME_TYPE;
54
55     public int doStartTag() throws JspException JavaDoc {
56         ChartHolder cd = PageUtils.getChartHolder(getChartId(), pageContext);
57         ChartImage cid = new ChartImageDefinition(cd, width, height, ChartImage.IMG_TYPE_LEGEND, mimeType,timeout);
58         Storage storage = Configuration.getInstance(pageContext.getServletContext()).getStorage();
59         try {
60             this.sessionKey = storage.storeChartImage(cid, pageContext);
61         } catch(CewolfException cwex){
62             log.error(cwex);
63             throw new JspException JavaDoc(cwex.getMessage());
64         }
65         return SKIP_BODY;
66     }
67
68     public int doEndTag() throws JspException JavaDoc {
69         super.doStartTag();
70         final StringBuffer JavaDoc buffer = new StringBuffer JavaDoc(" SRC=\"");
71         buffer.append(getImgURL());
72         buffer.append("\"");
73         try {
74             pageContext.getOut().write(buffer.toString());
75         } catch (IOException JavaDoc ioex) {
76             reset();
77             log.error(ioex);
78             throw new JspException JavaDoc(ioex.getMessage());
79         }
80         return super.doEndTag();
81     }
82
83     /**
84     * To enable further server side scriptings on JSP output the session ID is always
85     * encoded into the image URL even if cookies are enabled on the client side.
86     */
87     protected String JavaDoc getImgURL() {
88         return ChartImgTag.buildImgURL(renderer, pageContext, sessionKey, width, height, mimeType, forceSessionId,removeAfterRender);
89     }
90
91     protected void reset() {
92         // as of a weird JSP compiler in resin
93 // a reused tag's attribute is only set if
94 // it changes. So width an height may not
95 // be unset to ensure correct values.
96 int lHeight = this.height;
97         int lWidth = this.width;
98         int lTimeout = this.timeout;
99         super.reset();
100         this.height = lHeight;
101         this.width = lWidth;
102         this.timeout = lTimeout;
103     }
104
105     public String JavaDoc getChartId() {
106         return getId();
107     }
108
109     public void setRenderer(String JavaDoc rend) {
110         this.renderer = rend;
111     }
112
113     /**
114      * Sets the mimeType.
115      * @param mimeType The mimeType to set
116      */
117     public void setMime(String JavaDoc mimeType) {
118         this.mimeType = mimeType;
119     }
120
121     /**
122      * @return Returns the timeout.
123      */
124     public int getTimeout()
125     {
126       return timeout;
127     }
128     /**
129      * @param timeout The timeout to set.
130      */
131     public void setTimeout( int timeout )
132     {
133       this.timeout = timeout;
134     }
135 }
136
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