Mercurial > jdk8-mips64-public > langtools / file revision

 /*

  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package com.sun.tools.doclets.formats.html.markup;

 import java.io.IOException;

 import java.io.Writer;

 import java.util.*;

 import com.sun.tools.doclets.internal.toolkit.Content;

 import com.sun.tools.doclets.internal.toolkit.util.*;

 /**

  * Class for generating HTML tree for javadoc output.

  *

  *  <p><b>This is NOT part of any supported API.

  *  If you write code that depends on this, you do so at your own risk.

  *  This code and its internal interfaces are subject to change or

  *  deletion without notice.</b>

  *

  * @author Bhavesh Patel

  */

 public class HtmlTree extends Content {

     private HtmlTag htmlTag;

     private Map<HtmlAttr,String> attrs = Collections.<HtmlAttr,String>emptyMap();

     private List<Content> content = Collections.<Content>emptyList();

     public static final Content EMPTY = new StringContent("");

     /**

      * Constructor to construct HtmlTree object.

      *

      * @param tag HTML tag for the HtmlTree object

      */

     public HtmlTree(HtmlTag tag) {

         htmlTag = nullCheck(tag);

     }

     /**

      * Constructor to construct HtmlTree object.

      *

      * @param tag HTML tag for the HtmlTree object

      * @param contents contents to be added to the tree

      */

     public HtmlTree(HtmlTag tag, Content... contents) {

         this(tag);

         for (Content content: contents)

             addContent(content);

     }

     /**

      * Adds an attribute for the HTML tag.

      *

      * @param attrName name of the attribute

      * @param attrValue value of the attribute

      */

     public void addAttr(HtmlAttr attrName, String attrValue) {

         if (attrs.isEmpty())

             attrs = new LinkedHashMap<HtmlAttr,String>(3);

         attrs.put(nullCheck(attrName), escapeHtmlChars(attrValue));

     }

     public void setTitle(Content body) {

         addAttr(HtmlAttr.TITLE, stripHtml(body));

     }

     /**

      * Adds a style for the HTML tag.

      *

      * @param style style to be added

      */

     public void addStyle(HtmlStyle style) {

         addAttr(HtmlAttr.CLASS, style.toString());

     }

     /**

      * Adds content for the HTML tag.

      *

      * @param tagContent tag content to be added

      */

     public void addContent(Content tagContent) {

         if (tagContent == HtmlTree.EMPTY || tagContent.isValid()) {

             if (content.isEmpty())

                 content = new ArrayList<Content>();

             content.add(tagContent);

         }

     }

     /**

      * This method adds a string content to the htmltree. If the last content member

      * added is a StringContent, append the string to that StringContent or else

      * create a new StringContent and add it to the html tree.

      *

      * @param stringContent string content that needs to be added

      */

     public void addContent(String stringContent) {

         if (!content.isEmpty()) {

             Content lastContent = content.get(content.size() - 1);

             if (lastContent instanceof StringContent)

                 lastContent.addContent(stringContent);

             else

                 addContent(new StringContent(stringContent));

         }

         else

             addContent(new StringContent(stringContent));

     }

     public int charCount() {

         int n = 0;

         for (Content c : content)

             n += c.charCount();

         return n;

     }

     /**

      * Given a string, escape all special html characters and

      * return the result.

      *

      * @param s The string to check.

      * @return the original string with all of the HTML characters escaped.

      */

     private static String escapeHtmlChars(String s) {

         for (int i = 0; i < s.length(); i++) {

             char ch = s.charAt(i);

             switch (ch) {

                 // only start building a new string if we need to

                 case '<': case '>': case '&':

                     StringBuilder sb = new StringBuilder(s.substring(0, i));

                     for ( ; i < s.length(); i++) {

                         ch = s.charAt(i);

                         switch (ch) {

                             case '<': sb.append("&lt;");  break;

                             case '>': sb.append(">");  break;

                             case '&': sb.append("&"); break;

                             default:  sb.append(ch);      break;

                         }

                     }

                     return sb.toString();

             }

         }

         return s;

     }

     /**

      * Generates an HTML anchor tag.

      *

      * @param ref reference url for the anchor tag

      * @param body content for the anchor tag

      * @return an HtmlTree object

      */

     public static HtmlTree A(String ref, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.A, nullCheck(body));

         htmltree.addAttr(HtmlAttr.HREF, ref);

         return htmltree;

     }

     /**

      * Generates an HTML anchor tag with name attribute and content.

      *

      * @param name name for the anchor tag

      * @param body content for the anchor tag

      * @return an HtmlTree object

      */

     public static HtmlTree A_NAME(String name, Content body) {

         HtmlTree htmltree = HtmlTree.A_NAME(name);

         htmltree.addContent(nullCheck(body));

         return htmltree;

     }

     /**

      * Generates an HTML anchor tag with name attribute.

      *

      * @param name name for the anchor tag

      * @return an HtmlTree object

      */

     public static HtmlTree A_NAME(String name) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.A);

         htmltree.addAttr(HtmlAttr.NAME, nullCheck(name));

         return htmltree;

     }

     /**

      * Generates a CAPTION tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the CAPTION tag

      */

     public static HtmlTree CAPTION(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.CAPTION, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a CODE tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the CODE tag

      */

     public static HtmlTree CODE(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.CODE, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a DD tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the DD tag

      */

     public static HtmlTree DD(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.DD, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a DL tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the DL tag

      */

     public static HtmlTree DL(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.DL, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a DIV tag with the style class attributes. It also encloses

      * a content.

      *

      * @param styleClass stylesheet class for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the DIV tag

      */

     public static HtmlTree DIV(HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.DIV, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a DIV tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the DIV tag

      */

     public static HtmlTree DIV(Content body) {

         return DIV(null, body);

     }

     /**

      * Generates a DT tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the DT tag

      */

     public static HtmlTree DT(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.DT, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a FRAME tag.

      *

      * @param src the url of the document to be shown in the frame

      * @param name specifies the name of the frame

      * @param title the title for the frame

      * @param scrolling specifies whether to display scrollbars in the frame

      * @return an HtmlTree object for the FRAME tag

      */

     public static HtmlTree FRAME(String src, String name, String title, String scrolling) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.FRAME);

         htmltree.addAttr(HtmlAttr.SRC, nullCheck(src));

         htmltree.addAttr(HtmlAttr.NAME, nullCheck(name));

         htmltree.addAttr(HtmlAttr.TITLE, nullCheck(title));

         if (scrolling != null)

             htmltree.addAttr(HtmlAttr.SCROLLING, scrolling);

         return htmltree;

     }

     /**

      * Generates a Frame tag.

      *

      * @param src the url of the document to be shown in the frame

      * @param name specifies the name of the frame

      * @param title the title for the frame

      * @return an HtmlTree object for the SPAN tag

      */

     public static HtmlTree FRAME(String src, String name, String title) {

         return FRAME(src, name, title, null);

     }

     /**

      * Generates a FRAMESET tag.

      *

      * @param cols the size of columns in the frameset

      * @param rows the size of rows in the frameset

      * @param title the title for the frameset

      * @param onload the script to run when the document loads

      * @return an HtmlTree object for the FRAMESET tag

      */

     public static HtmlTree FRAMESET(String cols, String rows, String title, String onload) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.FRAMESET);

         if (cols != null)

             htmltree.addAttr(HtmlAttr.COLS, cols);

         if (rows != null)

             htmltree.addAttr(HtmlAttr.ROWS, rows);

         htmltree.addAttr(HtmlAttr.TITLE, nullCheck(title));

         htmltree.addAttr(HtmlAttr.ONLOAD, nullCheck(onload));

         return htmltree;

     }

     /**

      * Generates a heading tag (h1 to h6) with the title and style class attributes. It also encloses

      * a content.

      *

      * @param headingTag the heading tag to be generated

      * @param printTitle true if title for the tag needs to be printed else false

      * @param styleClass stylesheet class for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the tag

      */

     public static HtmlTree HEADING(HtmlTag headingTag, boolean printTitle,

             HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(headingTag, nullCheck(body));

         if (printTitle)

             htmltree.setTitle(body);

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a heading tag (h1 to h6) with style class attribute. It also encloses

      * a content.

      *

      * @param headingTag the heading tag to be generated

      * @param styleClass stylesheet class for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the tag

      */

     public static HtmlTree HEADING(HtmlTag headingTag, HtmlStyle styleClass, Content body) {

         return HEADING(headingTag, false, styleClass, body);

     }

     /**

      * Generates a heading tag (h1 to h6) with the title attribute. It also encloses

      * a content.

      *

      * @param headingTag the heading tag to be generated

      * @param printTitle true if the title for the tag needs to be printed else false

      * @param body content for the tag

      * @return an HtmlTree object for the tag

      */

     public static HtmlTree HEADING(HtmlTag headingTag, boolean printTitle, Content body) {

         return HEADING(headingTag, printTitle, null, body);

     }

     /**

      * Generates a heading tag (h1 to h6)  with some content.

      *

      * @param headingTag the heading tag to be generated

      * @param body content for the tag

      * @return an HtmlTree object for the tag

      */

     public static HtmlTree HEADING(HtmlTag headingTag, Content body) {

         return HEADING(headingTag, false, null, body);

     }

     /**

      * Generates an HTML tag with lang attribute. It also adds head and body

      * content to the HTML tree.

      *

      * @param lang language for the HTML document

      * @param head head for the HTML tag

      * @param body body for the HTML tag

      * @return an HtmlTree object for the HTML tag

      */

     public static HtmlTree HTML(String lang, Content head, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.HTML, nullCheck(head), nullCheck(body));

         htmltree.addAttr(HtmlAttr.LANG, nullCheck(lang));

         return htmltree;

     }

     /**

      * Generates a LI tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the LI tag

      */

     public static HtmlTree LI(Content body) {

         return LI(null, body);

     }

     /**

      * Generates a LI tag with some content.

      *

      * @param styleClass style for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the LI tag

      */

     public static HtmlTree LI(HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.LI, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a LINK tag with the rel, type, href and title attributes.

      *

      * @param rel relevance of the link

      * @param type type of link

      * @param href the path for the link

      * @param title title for the link

      * @return an HtmlTree object for the LINK tag

      */

     public static HtmlTree LINK(String rel, String type, String href, String title) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.LINK);

         htmltree.addAttr(HtmlAttr.REL, nullCheck(rel));

         htmltree.addAttr(HtmlAttr.TYPE, nullCheck(type));

         htmltree.addAttr(HtmlAttr.HREF, nullCheck(href));

         htmltree.addAttr(HtmlAttr.TITLE, nullCheck(title));

         return htmltree;

     }

     /**

      * Generates a META tag with the http-equiv, content and charset attributes.

      *

      * @param httpEquiv http equiv attribute for the META tag

      * @param content type of content

      * @param charSet character set used

      * @return an HtmlTree object for the META tag

      */

     public static HtmlTree META(String httpEquiv, String content, String charSet) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.META);

         htmltree.addAttr(HtmlAttr.HTTP_EQUIV, nullCheck(httpEquiv));

         htmltree.addAttr(HtmlAttr.CONTENT, nullCheck(content));

         htmltree.addAttr(HtmlAttr.CHARSET, nullCheck(charSet));

         return htmltree;

     }

     /**

      * Generates a META tag with the name and content attributes.

      *

      * @param name name attribute

      * @param content type of content

      * @return an HtmlTree object for the META tag

      */

     public static HtmlTree META(String name, String content) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.META);

         htmltree.addAttr(HtmlAttr.NAME, nullCheck(name));

         htmltree.addAttr(HtmlAttr.CONTENT, nullCheck(content));

         return htmltree;

     }

     /**

      * Generates a NOSCRIPT tag with some content.

      *

      * @param body content of the noscript tag

      * @return an HtmlTree object for the NOSCRIPT tag

      */

     public static HtmlTree NOSCRIPT(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.NOSCRIPT, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a P tag with some content.

      *

      * @param body content of the Paragraph tag

      * @return an HtmlTree object for the P tag

      */

     public static HtmlTree P(Content body) {

         return P(null, body);

     }

     /**

      * Generates a P tag with some content.

      *

      * @param styleClass style of the Paragraph tag

      * @param body content of the Paragraph tag

      * @return an HtmlTree object for the P tag

      */

     public static HtmlTree P(HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.P, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a SCRIPT tag with the type and src attributes.

      *

      * @param type type of link

      * @param src the path for the script

      * @return an HtmlTree object for the SCRIPT tag

      */

     public static HtmlTree SCRIPT(String type, String src) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.SCRIPT);

         htmltree.addAttr(HtmlAttr.TYPE, nullCheck(type));

         htmltree.addAttr(HtmlAttr.SRC, nullCheck(src));

         return htmltree;

     }

     /**

      * Generates a SMALL tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the SMALL tag

      */

     public static HtmlTree SMALL(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.SMALL, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a SPAN tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the SPAN tag

      */

     public static HtmlTree SPAN(Content body) {

         return SPAN(null, body);

     }

     /**

      * Generates a SPAN tag with style class attribute and some content.

      *

      * @param styleClass style class for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the SPAN tag

      */

     public static HtmlTree SPAN(HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.SPAN, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a SPAN tag with id and style class attributes. It also encloses

      * a content.

      *

      * @param id the id for the tag

      * @param styleClass stylesheet class for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the SPAN tag

      */

     public static HtmlTree SPAN(String id, HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.SPAN, nullCheck(body));

         htmltree.addAttr(HtmlAttr.ID, nullCheck(id));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a Table tag with border, width and summary attributes and

      * some content.

      *

      * @param border border for the table

      * @param width width of the table

      * @param summary summary for the table

      * @param body content for the table

      * @return an HtmlTree object for the TABLE tag

      */

     public static HtmlTree TABLE(int border, int width, String summary,

             Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.TABLE, nullCheck(body));

         htmltree.addAttr(HtmlAttr.BORDER, Integer.toString(border));

         htmltree.addAttr(HtmlAttr.WIDTH, Integer.toString(width));

         htmltree.addAttr(HtmlAttr.SUMMARY, nullCheck(summary));

         return htmltree;

     }

     /**

      * Generates a Table tag with style class, border, cell padding,

      * cellspacing and summary attributes and some content.

      *

      * @param styleClass style of the table

      * @param border border for the table

      * @param cellPadding cell padding for the table

      * @param cellSpacing cell spacing for the table

      * @param summary summary for the table

      * @param body content for the table

      * @return an HtmlTree object for the TABLE tag

      */

     public static HtmlTree TABLE(HtmlStyle styleClass, int border, int cellPadding,

             int cellSpacing, String summary, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.TABLE, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         htmltree.addAttr(HtmlAttr.BORDER, Integer.toString(border));

         htmltree.addAttr(HtmlAttr.CELLPADDING, Integer.toString(cellPadding));

         htmltree.addAttr(HtmlAttr.CELLSPACING, Integer.toString(cellSpacing));

         htmltree.addAttr(HtmlAttr.SUMMARY, nullCheck(summary));

         return htmltree;

     }

     /**

      * Generates a Table tag with border, cell padding,

      * cellspacing and summary attributes and some content.

      *

      * @param border border for the table

      * @param cellPadding cell padding for the table

      * @param cellSpacing cell spacing for the table

      * @param summary summary for the table

      * @param body content for the table

      * @return an HtmlTree object for the TABLE tag

      */

     public static HtmlTree TABLE(int border, int cellPadding,

             int cellSpacing, String summary, Content body) {

         return TABLE(null, border, cellPadding, cellSpacing, summary, body);

     }

     /**

      * Generates a TD tag with style class attribute and some content.

      *

      * @param styleClass style for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the TD tag

      */

     public static HtmlTree TD(HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.TD, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         return htmltree;

     }

     /**

      * Generates a TD tag for an HTML table with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the TD tag

      */

     public static HtmlTree TD(Content body) {

         return TD(null, body);

     }

     /**

      * Generates a TH tag with style class and scope attributes and some content.

      *

      * @param styleClass style for the tag

      * @param scope scope of the tag

      * @param body content for the tag

      * @return an HtmlTree object for the TH tag

      */

     public static HtmlTree TH(HtmlStyle styleClass, String scope, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.TH, nullCheck(body));

         if (styleClass != null)

             htmltree.addStyle(styleClass);

         htmltree.addAttr(HtmlAttr.SCOPE, nullCheck(scope));

         return htmltree;

     }

     /**

      * Generates a TH tag with scope attribute and some content.

      *

      * @param scope scope of the tag

      * @param body content for the tag

      * @return an HtmlTree object for the TH tag

      */

     public static HtmlTree TH(String scope, Content body) {

         return TH(null, scope, body);

     }

     /**

      * Generates a TITLE tag with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the TITLE tag

      */

     public static HtmlTree TITLE(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.TITLE, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a TR tag for an HTML table with some content.

      *

      * @param body content for the tag

      * @return an HtmlTree object for the TR tag

      */

     public static HtmlTree TR(Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.TR, nullCheck(body));

         return htmltree;

     }

     /**

      * Generates a UL tag with the style class attribute and some content.

      *

      * @param styleClass style for the tag

      * @param body content for the tag

      * @return an HtmlTree object for the UL tag

      */

     public static HtmlTree UL(HtmlStyle styleClass, Content body) {

         HtmlTree htmltree = new HtmlTree(HtmlTag.UL, nullCheck(body));

         htmltree.addStyle(nullCheck(styleClass));

         return htmltree;

     }

     /**

      * {@inheritDoc}

      */

     public boolean isEmpty() {

         return (!hasContent() && !hasAttrs());

     }

     /**

      * Returns true if the HTML tree has content.

      *

      * @return true if the HTML tree has content else return false

      */

     public boolean hasContent() {

         return (!content.isEmpty());

     }

     /**

      * Returns true if the HTML tree has attributes.

      *

      * @return true if the HTML tree has attributes else return false

      */

     public boolean hasAttrs() {

         return (!attrs.isEmpty());

     }

     /**

      * Returns true if the HTML tree has a specific attribute.

      *

      * @param attrName name of the attribute to check within the HTML tree

      * @return true if the HTML tree has the specified attribute else return false

      */

     public boolean hasAttr(HtmlAttr attrName) {

         return (attrs.containsKey(attrName));

     }

     /**

      * Returns true if the HTML tree is valid. This check is more specific to

      * standard doclet and not exactly similar to W3C specifications. But it

      * ensures HTML validation.

      *

      * @return true if the HTML tree is valid

      */

     public boolean isValid() {

         switch (htmlTag) {

             case A :

                 return (hasAttr(HtmlAttr.NAME) || (hasAttr(HtmlAttr.HREF) && hasContent()));

             case BR :

                 return (!hasContent() && (!hasAttrs() || hasAttr(HtmlAttr.CLEAR)));

             case FRAME :

                 return (hasAttr(HtmlAttr.SRC) && !hasContent());

             case HR :

                 return (!hasContent());

             case IMG :

                 return (hasAttr(HtmlAttr.SRC) && hasAttr(HtmlAttr.ALT) && !hasContent());

             case LINK :

                 return (hasAttr(HtmlAttr.HREF) && !hasContent());

             case META :

                 return (hasAttr(HtmlAttr.CONTENT) && !hasContent());

             case SCRIPT :

                 return ((hasAttr(HtmlAttr.TYPE) && hasAttr(HtmlAttr.SRC) && !hasContent()) ||

                         (hasAttr(HtmlAttr.TYPE) && hasContent()));

             default :

                 return hasContent();

         }

     }

     /**

      * Returns true if the element is an inline element.

      *

      * @return true if the HTML tag is an inline element

      */

     public boolean isInline() {

         return (htmlTag.blockType == HtmlTag.BlockType.INLINE);

     }

     /**

      * {@inheritDoc}

      */

     @Override

     public boolean write(Writer out, boolean atNewline) throws IOException {

         if (!isInline() && !atNewline)

             out.write(DocletConstants.NL);

         String tagString = htmlTag.toString();

         out.write("<");

         out.write(tagString);

         Iterator<HtmlAttr> iterator = attrs.keySet().iterator();

         HtmlAttr key;

         String value;

         while (iterator.hasNext()) {

             key = iterator.next();

             value = attrs.get(key);

             out.write(" ");

             out.write(key.toString());

             if (!value.isEmpty()) {

                 out.write("=\"");

                 out.write(value);

                 out.write("\"");

             }

         }

         out.write(">");

         boolean nl = false;

         for (Content c : content)

             nl = c.write(out, nl);

         if (htmlTag.endTagRequired()) {

             out.write("</");

             out.write(tagString);

             out.write(">");

         }

         if (!isInline()) {

             out.write(DocletConstants.NL);

             return true;

         } else {

             return false;

         }

     }

     /**

      * Given a Content node, strips all html characters and

      * return the result.

      *

      * @param body The content node to check.

      * @return the plain text from the content node

      *

      */

     private static String stripHtml(Content body) {

         String rawString = body.toString();

         // remove HTML tags

         rawString = rawString.replaceAll("\\<.*?>", " ");

         // consolidate multiple spaces between a word to a single space

         rawString = rawString.replaceAll("\\b\\s{2,}\\b", " ");

         // remove extra whitespaces

         return rawString.trim();

     }

 }