ImageButton


1   /*
2    * Copyright 2004 The Apache Software Foundation.
3    *
4    * Licensed under the Apache 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.apache.org/licenses/LICENSE-2.0
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   * $Header:$
17   */
18  package org.apache.beehive.netui.tags.html;
19  
20  import org.apache.beehive.netui.tags.IHtmlAccessable;
21  import org.apache.beehive.netui.tags.internal.PageFlowTagUtils;
22  import org.apache.beehive.netui.tags.javascript.CoreScriptFeature;
23  import org.apache.beehive.netui.tags.javascript.ScriptRequestState;
24  import org.apache.beehive.netui.tags.rendering.AbstractHtmlState;
25  import org.apache.beehive.netui.tags.rendering.InputImageTag;
26  import org.apache.beehive.netui.tags.rendering.TagRenderingBase;
27  import org.apache.beehive.netui.tags.rendering.WriteRenderAppender;
28  import org.apache.beehive.netui.util.Bundle;
29  import org.apache.struts.Globals;
30  import org.apache.struts.config.ModuleConfig;
31  
32  import javax.servlet.ServletRequest  ;
33  import javax.servlet.http.HttpServletRequest  ;
34  import javax.servlet.http.HttpServletResponse  ;
35  import javax.servlet.jsp.JspException  ;
36  import java.net.URISyntaxException  ;
37  
38  /**
39   * Generates an <code>&lt;input type="image"></code> tag with the specified attributes. ImageButton
40   * ignores its body content.
41   * @jsptagref.tagdescription Renders an <code>&lt;input type="image"></code> tag with the specified attributes.
42   *
43   * <p><b>JavaScript</b></p>
44   * <p>If the &lt;netui:imageButton> specifies
45   * a <code>rolloverImage</code> attribute, the following JavaScript will be written to the page:</p>
46   * <pre>    function swapImage(control, image)
47   *    {
48   *        control.src = image;
49   *    }</pre>
50   * @example In this sample, an &lt;netui:imageButton> tag displays the image "house.jpg".
51   * On mouseover, the image "house_highlight.jpg" is displayed.
52   * When clicked, the &lt;netui:imageButton> will invoke the action specified by its parent
53   * &lt;netui:form> tag.
54   * <pre>    &lt;netui:form action="formSubmit">
55   *         &lt;netui:imageButton rolloverImage="house_highlight.jpg" SRC="house.jpg" />
56   *     &lt;/netui:form></pre>
57   * @netui:tag name="imageButton" description="Combines the functionality of the netui:image and netui:button tags."
58   */
59  public class ImageButton
60          extends HtmlFocusBaseTag
61          implements IHtmlAccessable
62  {
63      private InputImageTag.State _state = new InputImageTag.State();
64  
65      private String   _page;            // The module-relative URI of the image.
66      private String   _rolloverImage;   // The roll-over image of the ImageButton.
67  
68      /**
69       * Return the name of the Tag.
70       */
71      public String   getTagName()
72      {
73          return "ImageButton";
74      }
75  
76      /**
77       * This method will return the state associated with the tag.  This is used by this
78       * base class to access the individual state objects created by the tags.
79       * @return a subclass of the <code>AbstractHtmlState</code> class.
80       */
81      protected AbstractHtmlState getState()
82      {
83          return _state;
84      }
85  
86      /**
87       * Base support for the attribute tag.  This is overridden to prevent setting the <code>src</code>
88       * and <code>value</code> attributes
89       * @param name  The name of the attribute.  This value may not be null or the empty string.
90       * @param value The value of the attribute.  This may contain an expression.
91       * @param facet The name of a facet to which the attribute will be applied.  This is optional.
92       * @throws JspException A JspException may be thrown if there is an error setting the attribute.
93       */
94      public void setAttribute(String   name, String   value, String   facet)
95              throws JspException  
96      {
97          if (name != null) {
98              if (name.equals(SRC) || name.equals(VALUE)) {
99                  String   s = Bundle.getString("Tags_AttributeMayNotBeSet", new Object  []{name});
100                 registerTagError(s, null);
101             }
102             else {
103                 if (name.equals(DISABLED)) {
104                     _state.disabled = new Boolean  (value).booleanValue();
105                     return;
106                 }
107             }
108         }
109         super.setAttribute(name, value, facet);
110     }
111 
112     /**
113      * Sets the property to specify where to align the image.
114      * @param align the image alignment.
115      * @jsptagref.attributedescription The alignment of the image.
116      * @jsptagref.databindable false
117      * @jsptagref.attributesyntaxvalue <i>string_align</i>
118      * @netui:attribute required="false"  rtexprvalue="true"
119      * description="Sets the property to specify where to align the image."
120      */
121     public void setAlign(String   align)
122     {
123         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, ALIGN, align);
124     }
125 
126     /**
127      * Sets the accessKey attribute value.  This should key value of the
128      * keyboard navigation key.  It is recommended not to use the following
129      * values because there are often used by browsers <code>A, C, E, F, G,
130      * H, V, left arrow, and right arrow</code>.
131      * @param accessKey the accessKey value.
132      * @jsptagref.attributedescription The keyboard navigation key for the element.
133      * The following values are not recommended because they
134      * are often used by browsers: <code>A, C, E, F, G,
135      * H, V, left arrow, and right arrow</code>
136      * @jsptagref.databindable false
137      * @jsptagref.attributesyntaxvalue <i>string_accessKey</i>
138      * @netui:attribute required="false" rtexprvalue="true" type="char"
139      * description="The keyboard navigation key for the element.
140      * The following values are not recommended because they
141      * are often used by browsers: A, C, E, F, G,
142      * H, V, left arrow, and right arrow"
143      */
144     public void setAccessKey(char accessKey)
145     {
146         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, ACCESSKEY, Character.toString(accessKey));
147     }
148 
149     /**
150      * Sets the tabIndex of the rendered html tag.
151      * @param tabindex the tab index.
152      * @jsptagref.attributedescription The tabIndex of the rendered HTML tag.  This attribute determines the position of the
153      * rendered HTML tag in the sequence of tags that the user may advance through by pressing the TAB key.
154      * @jsptagref.databindable false
155      * @jsptagref.attributesyntaxvalue <i>string_tabIndex</i>
156      * @netui:attribute required="false" rtexprvalue="true" type="int"
157      * description="The tabIndex of the rendered HTML tag.  This attribute determines the position of the
158      * rendered HTML tag in the sequence of tags that the user may advance through by pressing the TAB key."
159      */
160     public void setTabindex(int tabindex)
161     {
162         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, TABINDEX, Integer.toString(tabindex));
163     }
164 
165     /**
166      * Sets the usemap of for the map.
167      * @param usemap the tab index.
168      * @jsptagref.attributedescription Sets the usemap of for the map.
169      * @jsptagref.databindable false
170      * @jsptagref.attributesyntaxvalue <i>string_usemap</i>
171      * @netui:attribute required="false"  rtexprvalue="true"
172      * description="Sets the usemap of for the map."
173      */
174     public void setUsemap(String   usemap)
175     {
176         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, USEMAP, usemap);
177     }
178 
179     /**
180      * Sets the ismap of for the map.
181      * @param ismap the tab index.
182      * @jsptagref.attributedescription Sets the ismap of for the map.
183      * @jsptagref.databindable false
184      * @jsptagref.attributesyntaxvalue <i>string_ismap</i>
185      * @netui:attribute required="false"  rtexprvalue="true"
186      * description="Sets the ismap of for the map."
187      */
188     public void setIsmap(String   ismap)
189     {
190         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, ISMAP, ismap);
191     }
192 
193     /**
194      * Sets the property to specify the alt text of the image.
195      * @param alt the image alt text.
196      * @jsptagref.attributedescription The alternative text of the image
197      * @jsptagref.databindable Read Only
198      * @jsptagref.attributesyntaxvalue <i>string_alt</i>
199      * @netui:attribute required="false" rtexprvalue="true"
200      * description="The alternative text of the image"
201      */
202     public void setAlt(String   alt)
203     {
204         _state.registerAttribute(AbstractHtmlState.ATTR_GENERAL, ALT, alt);
205     }
206 
207     /**
208      * Sets the roll-over image of the ImageAnchor.
209      * @param rolloverImage the rollover image.
210      * @jsptagref.attributedescription The URI of the rollover image.
211      * @jsptagref.databindable false
212      * @jsptagref.attributesyntaxvalue <i>string_rolloverImage</i>
213      * @netui:attribute required="false" rtexprvalue="true"
214      * description="The URI of the rollover image."
215      */
216     public void setRolloverImage(String   rolloverImage)
217     {
218         _rolloverImage = rolloverImage;
219     }
220 
221     /**
222      * Sets the image source URI.
223      * @param src the source URI.
224      * @jsptagref.attributedescription The image source URI
225      * @jsptagref.databindable Read Only
226      * @jsptagref.attributesyntaxvalue <i>string_src</i>
227      * @netui:attribute required="false" rtexprvalue="true"
228      * description="The image source URI"
229      * reftype="img-url"
230      */
231     public void setSrc(String   src)
232             throws JspException  
233     {
234         _state.src = src;
235     }
236 
237     /**
238      * Set the value of the ImageButton.
239      * @param value the value of the ImageButton.
240      * @jsptagref.attributedescription The value of the image button.
241      * @jsptagref.databindable false
242      * @jsptagref.attributesyntaxvalue <i>string_value</i>
243      * @netui:attribute required="false" rtexprvalue="true"
244      * description="The value of the image button."
245      */
246     public void setValue(String   value)
247     {
248         _state.value = value;
249     }
250 
251     /**
252      * Process the start of this tag.
253      * @throws JspException if a JSP exception has occurred
254      */
255     public int doStartTag() throws JspException  
256     {
257 
258         if (_rolloverImage != null && getJavaScriptAttribute(ONMOUSEOVER) == null) {
259             // cause the roll over script to be inserted
260             ScriptRequestState srs = ScriptRequestState.getScriptRequestState((HttpServletRequest  ) pageContext.getRequest());
261             WriteRenderAppender writer = new WriteRenderAppender(pageContext);
262             srs.writeFeature(getScriptReporter(), writer, CoreScriptFeature.ROLLOVER, true, false, null);
263         }
264 
265         return EVAL_BODY_BUFFERED;
266     }
267 
268     /**
269      * Save the body content of the ImageButton.
270      * @throws JspException if a JSP exception has occurred
271      */
272     public int doAfterBody() throws JspException  
273     {
274 
275         if (bodyContent != null) {
276             bodyContent.clearBody();
277         }
278         return SKIP_BODY;
279     }
280 
281     /**
282      * Process the end of this tag.
283      * @throws JspException if a JSP exception has occurred
284      */
285     public int doEndTag() throws JspException  
286     {
287         ServletRequest   req = pageContext.getRequest();
288         String   idScript = null;
289         String   tmp = null;
290 
291         // we assume that tagId will over have override id if both
292         // are defined.
293         if (getTagId() != null) {
294             idScript = renderNameAndId((HttpServletRequest  ) req, _state, null);
295         }
296 
297         HttpServletResponse   response = (HttpServletResponse  ) pageContext.getResponse();
298         tmp = src();
299         if (tmp != null) {
300             try {
301                 String   uri = PageFlowTagUtils.rewriteResourceURL(pageContext, tmp, null, null);
302                 _state.src = response.encodeURL(uri);
303             }
304             catch (URISyntaxException   e) {
305                 // report the error...
306                 String   s = Bundle.getString("Tags_Image_URLException",
307                         new Object  []{_state.src, e.getMessage()});
308                 registerTagError(s, e);
309             }
310         }
311 
312         _state.disabled = isDisabled();
313 
314         if (_rolloverImage != null) {
315 
316             if (hasErrors()) {
317                 reportErrors();
318                 localRelease();
319                 return EVAL_PAGE;
320             }
321 
322             try {
323                 String   uri = PageFlowTagUtils.rewriteResourceURL(pageContext, _rolloverImage, null, null);
324                 _rolloverImage = response.encodeURL(qualifyUrlToContext(uri));
325             }
326             catch (URISyntaxException   e) {
327                 // report the error...
328                 String   s = Bundle.getString("Tags_Rollover_Image_URLException",
329                         new Object  []{_rolloverImage, e.getMessage()});
330                 registerTagError(s, e);
331             }
332         }
333 
334         if ((getJavaScriptAttribute(ONMOUSEOUT) == null) && (_rolloverImage != null)) {
335             setOnMouseOut("swapImage(this,'" + _state.src + "')");
336         }
337         if ((getJavaScriptAttribute(ONMOUSEOVER) == null) && (_rolloverImage != null)) {
338             setOnMouseOver("swapImage(this,'" + _rolloverImage + "')");
339         }
340 
341         WriteRenderAppender writer = new WriteRenderAppender(pageContext);
342         TagRenderingBase br = TagRenderingBase.Factory.getRendering(TagRenderingBase.INPUT_IMAGE_TAG, req);
343         br.doStartTag(writer, _state);
344         br.doEndTag(writer);
345 
346         if (idScript != null)
347             write(idScript);
348 
349         // Evaluate the remainder of this page
350         localRelease();
351         return EVAL_PAGE;
352     }
353 
354     /**
355      * Release any acquired resources.
356      */
357     protected void localRelease()
358     {
359         super.localRelease();
360 
361         _state.clear();
362 
363         _page = null;
364         _rolloverImage = null;
365     }
366 
367     /**
368      * Return the base source URL that will be rendered in the <code>src</code>
369      * property for this generated element, or <code>null</code> if there is
370      * no such URL.
371      */
372     private String   src()
373     {
374 
375         // Deal with a direct context-relative page that has been specified
376         if (_page != null) {
377             HttpServletRequest   request = (HttpServletRequest  ) pageContext.getRequest();
378             ModuleConfig config = (ModuleConfig) request.getAttribute(Globals.MODULE_KEY);
379             if (config == null)
380                 return (request.getContextPath() + _page);
381             return (request.getContextPath() + config.getPrefix() + _page);
382         }
383 
384         // Deal with an absolute source that has been specified
385         if (_state.src != null)
386             return _state.src;
387         return null;
388     }
389 }
390
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