langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/markup/HtmlTree.java
changeset 35426 374342e56a56
parent 33920 bd731341c405
child 36500 d31e4986dc8b
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/langtools/src/jdk.javadoc/share/classes/jdk/javadoc/internal/doclets/formats/html/markup/HtmlTree.java	Sat Nov 28 18:52:17 2015 -0800
@@ -0,0 +1,978 @@
+/*
+ * Copyright (c) 2010, 2016, 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 jdk.javadoc.internal.doclets.formats.html.markup;
+
+import java.io.IOException;
+import java.io.Writer;
+import java.nio.charset.Charset;
+import java.util.ArrayList;
+import java.util.BitSet;
+import java.util.Collections;
+import java.util.Iterator;
+import java.util.LinkedHashMap;
+import java.util.List;
+import java.util.Map;
+
+import jdk.javadoc.internal.doclets.formats.html.markup.HtmlAttr.Role;
+import jdk.javadoc.internal.doclets.toolkit.Content;
+import jdk.javadoc.internal.doclets.toolkit.util.DocletConstants;
+
+/**
+ * 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<>(3);
+        attrs.put(nullCheck(attrName), escapeHtmlChars(attrValue));
+    }
+
+    public void setTitle(Content body) {
+        addAttr(HtmlAttr.TITLE, stripHtml(body));
+    }
+
+    public void setRole(Role role) {
+        addAttr(HtmlAttr.ROLE, role.toString());
+    }
+
+    /**
+     * 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 instanceof ContentBuilder) {
+            for (Content content: ((ContentBuilder)tagContent).contents) {
+                addContent(content);
+            }
+        }
+        else if (tagContent == HtmlTree.EMPTY || tagContent.isValid()) {
+            if (content.isEmpty())
+                content = new ArrayList<>();
+            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("&gt;");  break;
+                            case '&': sb.append("&amp;"); break;
+                            default:  sb.append(ch);      break;
+                        }
+                    }
+                    return sb.toString();
+            }
+        }
+        return s;
+    }
+
+    /**
+     * A set of ASCII URI characters to be left unencoded.
+     */
+    public static final BitSet NONENCODING_CHARS = new BitSet(256);
+
+    static {
+        // alphabetic characters
+        for (int i = 'a'; i <= 'z'; i++) {
+            NONENCODING_CHARS.set(i);
+        }
+        for (int i = 'A'; i <= 'Z'; i++) {
+            NONENCODING_CHARS.set(i);
+        }
+        // numeric characters
+        for (int i = '0'; i <= '9'; i++) {
+            NONENCODING_CHARS.set(i);
+        }
+        // Reserved characters as per RFC 3986. These are set of delimiting characters.
+        String noEnc = ":/?#[]@!$&'()*+,;=";
+        // Unreserved characters as per RFC 3986 which should not be percent encoded.
+        noEnc += "-._~";
+        for (int i = 0; i < noEnc.length(); i++) {
+            NONENCODING_CHARS.set(noEnc.charAt(i));
+        }
+    }
+
+    private static String encodeURL(String url) {
+        StringBuilder sb = new StringBuilder();
+        for (byte c : url.getBytes(Charset.forName("UTF-8"))) {
+            if (NONENCODING_CHARS.get(c & 0xFF)) {
+                sb.append((char) c);
+            } else {
+                sb.append(String.format("%%%02X", c & 0xFF));
+            }
+        }
+        return sb.toString();
+    }
+
+    /**
+     * 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, encodeURL(ref));
+        return htmltree;
+    }
+
+    /**
+     * Generates an HTML anchor tag with an id or a name attribute and content.
+     *
+     * @param htmlVersion the version of the generated HTML
+     * @param attr name or id attribute for the anchor tag
+     * @param body content for the anchor tag
+     * @return an HtmlTree object
+     */
+    public static HtmlTree A(HtmlVersion htmlVersion, String attr, Content body) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.A);
+        htmltree.addAttr((htmlVersion == HtmlVersion.HTML4)
+                ? HtmlAttr.NAME
+                : HtmlAttr.ID,
+                nullCheck(attr));
+        htmltree.addContent(nullCheck(body));
+        return htmltree;
+    }
+
+    /**
+     * Generates an HTML anchor tag with id attribute and a body.
+     *
+     * @param id id for the anchor tag
+     * @param body body for the anchor tag
+     * @return an HtmlTree object
+     */
+    public static HtmlTree A_ID(String id, Content body) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.A);
+        htmltree.addAttr(HtmlAttr.ID, nullCheck(id));
+        htmltree.addContent(nullCheck(body));
+        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 FOOTER tag with role attribute.
+     *
+     * @return an HtmlTree object for the FOOTER tag
+     */
+    public static HtmlTree FOOTER() {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.FOOTER);
+        htmltree.setRole(Role.CONTENTINFO);
+        return htmltree;
+    }
+
+    /**
+     * Generates a HEADER tag with role attribute.
+     *
+     * @return an HtmlTree object for the HEADER tag
+     */
+    public static HtmlTree HEADER() {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.HEADER);
+        htmltree.setRole(Role.BANNER);
+        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 IFRAME 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 IFRAME tag
+     */
+    public static HtmlTree IFRAME(String src, String name, String title) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.IFRAME);
+        htmltree.addAttr(HtmlAttr.SRC, nullCheck(src));
+        htmltree.addAttr(HtmlAttr.NAME, nullCheck(name));
+        htmltree.addAttr(HtmlAttr.TITLE, nullCheck(title));
+        return htmltree;
+    }
+
+    /**
+     * Generates a INPUT tag with some id.
+     *
+     * @param type the type of input
+     * @param id id for the tag
+     * @return an HtmlTree object for the INPUT tag
+     */
+    public static HtmlTree INPUT(String type, String id) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.INPUT);
+        htmltree.addAttr(HtmlAttr.TYPE, nullCheck(type));
+        htmltree.addAttr(HtmlAttr.ID, nullCheck(id));
+        htmltree.addAttr(HtmlAttr.VALUE, " ");
+        htmltree.addAttr(HtmlAttr.DISABLED, "disabled");
+        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 MAIN tag with role attribute.
+     *
+     * @return an HtmlTree object for the MAIN tag
+     */
+    public static HtmlTree MAIN() {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.MAIN);
+        htmltree.setRole(Role.MAIN);
+        return htmltree;
+    }
+
+    /**
+     * Generates a MAIN tag with role attribute and some content.
+     *
+     * @param body content of the MAIN tag
+     * @return an HtmlTree object for the MAIN tag
+     */
+    public static HtmlTree MAIN(Content body) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.MAIN, nullCheck(body));
+        htmltree.setRole(Role.MAIN);
+        return htmltree;
+    }
+
+    /**
+     * Generates a MAIN tag with role attribute, style attribute and some content.
+     *
+     * @param styleClass style of the MAIN tag
+     * @param body content of the MAIN tag
+     * @return an HtmlTree object for the MAIN tag
+     */
+    public static HtmlTree MAIN(HtmlStyle styleClass, Content body) {
+        HtmlTree htmltree = HtmlTree.MAIN(body);
+        if (styleClass != null) {
+            htmltree.addStyle(styleClass);
+        }
+        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);
+        String contentCharset = content + "; charset=" + charSet;
+        htmltree.addAttr(HtmlAttr.HTTP_EQUIV, nullCheck(httpEquiv));
+        htmltree.addAttr(HtmlAttr.CONTENT, contentCharset);
+        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 NAV tag with the role attribute.
+     *
+     * @return an HtmlTree object for the NAV tag
+     */
+    public static HtmlTree NAV() {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.NAV);
+        htmltree.setRole(Role.NAVIGATION);
+        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 src) {
+        HtmlTree htmltree = HtmlTree.SCRIPT();
+        htmltree.addAttr(HtmlAttr.SRC, nullCheck(src));
+        return htmltree;
+    }
+
+    /**
+     * Generates a SCRIPT tag with the type attribute.
+     *
+     * @return an HtmlTree object for the SCRIPT tag
+     */
+    public static HtmlTree SCRIPT() {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.SCRIPT);
+        htmltree.addAttr(HtmlAttr.TYPE, "text/javascript");
+        return htmltree;
+    }
+
+    /**
+     * Generates a SECTION tag with role attribute.
+     *
+     * @return an HtmlTree object for the SECTION tag
+     */
+    public static HtmlTree SECTION() {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.SECTION);
+        htmltree.setRole(Role.REGION);
+        return htmltree;
+    }
+
+    /**
+     * Generates a SECTION tag with role attribute and some content.
+     *
+     * @param body content of the section tag
+     * @return an HtmlTree object for the SECTION tag
+     */
+    public static HtmlTree SECTION(Content body) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.SECTION, nullCheck(body));
+        htmltree.setRole(Role.REGION);
+        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 style class and summary attributes and some content.
+     *
+     * @param styleClass style 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(HtmlStyle styleClass, String summary, Content body) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.TABLE, nullCheck(body));
+        if (styleClass != null)
+            htmltree.addStyle(styleClass);
+        htmltree.addAttr(HtmlAttr.SUMMARY, nullCheck(summary));
+        return htmltree;
+    }
+
+    /**
+     * Generates a Table tag with style class attribute and some content.
+     *
+     * @param styleClass style of the table
+     * @param body content for the table
+     * @return an HtmlTree object for the TABLE tag
+     */
+    public static HtmlTree TABLE(HtmlStyle styleClass, Content body) {
+        HtmlTree htmltree = new HtmlTree(HtmlTag.TABLE, nullCheck(body));
+        if (styleClass != null) {
+            htmltree.addStyle(styleClass);
+        }
+        return htmltree;
+    }
+
+    /**
+     * 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.ID) || (hasAttr(HtmlAttr.HREF) && hasContent()));
+            case BR :
+                return (!hasContent() && (!hasAttrs() || hasAttr(HtmlAttr.CLEAR)));
+            case IFRAME :
+                return (hasAttr(HtmlAttr.SRC) && !hasContent());
+            case HR :
+            case INPUT:
+                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();
+    }
+}