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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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package jdk.javadoc.internal.doclets.formats.html.markup;

import jdk.javadoc.internal.doclets.formats.html.SectionName;
import jdk.javadoc.internal.doclets.toolkit.Content;
import jdk.javadoc.internal.doclets.toolkit.util.DocLink;
import jdk.javadoc.internal.doclets.toolkit.util.DocPath;


Factory for HTML A elements, both links (with a href attribute) and anchors (with an id or name attribute). Most methods in this class are static factory methods. The exceptions are those methods that directly or indirectly depend on the HTML version being used, when determining valid HTML names (ids), and those methods that generate anchors. 
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.

/**
 * Factory for HTML A elements, both links (with a {@code href} attribute)
 * and anchors (with an {@code id} or {@code name} attribute).
 *
 * Most methods in this class are static factory methods.
 * The exceptions are those methods that directly or indirectly depend on the HTML version
 * being used, when determining valid HTML names (ids),
 * and those methods that generate anchors.
 *
 *  <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>
 */
public class Links {

    private final HtmlVersion version;

    
Creates a Links object for a specific HTML version. The version is used by the getName method to help determine valid HTML names (ids), and to determine whether to use an id or name attribute when creating anchors. 
Params:
  • version – the HTML version
/**
     * Creates a {@code Links} object for a specific HTML version.
     * The version is used by the {@link #getName(String) getName} method
     * to help determine valid HTML names (ids), and to determine whether
     * to use an {@code id} or {@code name} attribute when creating anchors.
     *
     * @param version the HTML version
     */
    public Links(HtmlVersion version) {
        this.version = version;
    }

    
Creates an anchor of the form <a id="name"><!-- --></a>. In HTML4, a name attribute will be generated instead of an id attribute. 
Params:
  • name – the value for the id or name attribute
Returns:a content tree for the anchor
/**
     * Creates an anchor of the form {@code <a id="name"><!-- --></a>}.
     * In HTML4, a {@code name} attribute will be generated instead of an {@code id} attribute.
     *
     * @param name the value for the {@code id} or {@code name} attribute
     * @return a content tree for the anchor
     */
    public Content createAnchor(String name) {
        return createAnchor(getName(name), null);
    }

    
Creates an anchor of the form <a id="sectionName"><!-- --></a>. In HTML4, a name attribute will be generated instead of an id attribute. 
Params:
  • sectionName – the value for the id or name attribute
Returns:a content tree for the anchor
/**
     * Creates an anchor of the form {@code <a id="sectionName"><!-- --></a>}.
     * In HTML4, a {@code name} attribute will be generated instead of an {@code id} attribute.
     *
     * @param sectionName the value for the {@code id} or {@code name} attribute
     * @return a content tree for the anchor
     */
    public Content createAnchor(SectionName sectionName) {
        return createAnchor(sectionName.getName(), null);
    }

    
Creates an anchor of the form <a id="sectionNameName"><!-- --></a>. In HTML4, a name attribute will be generated instead of an id attribute. 
Params:
  • sectionName – the first part of the value for the id or name attribute
  • name – the second part of the value for the id or name attribute
Returns:a content tree for the anchor
/**
     * Creates an anchor of the form {@code <a id="sectionNameName"><!-- --></a>}.
     * In HTML4, a {@code name} attribute will be generated instead of an {@code id} attribute.
     *
     * @param sectionName the first part of the value for the {@code id} or {@code name} attribute
     * @param name the second part of the value for the {@code id} or {@code name} attribute
     * @return a content tree for the anchor
     */
    public Content createAnchor(SectionName sectionName, String name) {
        return createAnchor(sectionName.getName() + getName(name), null);
    }

    
Creates an anchor of the form <a id="anchorName">content</a>. In HTML4, a name attribute will be generated instead of an id attribute. 
Params:
  • name – the value for the id or name attribute
  • content – the content that should be added to the anchor,
             or null, to use an empty comment
Returns:a content tree for the marker anchor
/**
     * Creates an anchor of the form {@code <a id="anchorName">content</a>}.
     * In HTML4, a {@code name} attribute will be generated instead of an {@code id} attribute.
     *
     * @param name the value for the {@code id} or {@code name} attribute
     * @param content the content that should be added to the anchor,
     *              or null, to use an empty comment
     * @return a content tree for the marker anchor
     */
    public Content createAnchor(String name, Content content) {
        return HtmlTree.A(version, name, (content == null ? EMPTY_COMMENT : content));
    }

    private static final Content EMPTY_COMMENT = new Comment(" ");

    
Creates a link of the form <a href="#where">label</a>. 
Params:
  • where –      the position of the link in the file
  • label –      the content for the link
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="#where">label</a>}.
     *
     * @param where      the position of the link in the file
     * @param label      the content for the link
     * @return a content tree for the link
     */
    public Content createLink(String where, Content label) {
        DocLink l = DocLink.fragment(getName(where));
        return Links.createLink(l, label, "", "");
    }

    
Creates a link of the form <a href="#sectionName">label</a>. 
Params:
  • sectionName –   the section name to which the link will be created
  • label –         the content for the link
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="#sectionName">label</a>}.
     *
     * @param sectionName   the section name to which the link will be created
     * @param label         the content for the link
     * @return a content tree for the link
     */
    public static Content createLink(SectionName sectionName, Content label) {
        DocLink l =  DocLink.fragment(sectionName.getName());
        return Links.createLink(l, label, "", "");
    }

    
Creates a link of the form <a href="#sectionNameWhere">label</a>. 
Params:
  • sectionName –   the section name combined with where to which the link
                     will be created
  • where –         the fragment combined with sectionName to which the link
                     will be created
  • label –         the content for the link
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="#sectionNameWhere">label</a>}.
     *
     * @param sectionName   the section name combined with where to which the link
     *                      will be created
     * @param where         the fragment combined with sectionName to which the link
     *                      will be created
     * @param label         the content for the link
     * @return a content tree for the link
     */
    public Content createLink(SectionName sectionName, String where, Content label) {
        DocLink l =  DocLink.fragment(sectionName.getName() + getName(where));
        return Links.createLink(l, label, "", "");
    }

    
Creates a link of the form <a href="#stylename" title="title" target="target">label</a>. 
Params:
  • sectionName –   the section name to which the link will be created
  • label –     the content for the link
  • title –     the title for the link
  • target –    the target for the link, or null
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="#stylename" title="title" target="target">label</a>}.
     *
     * @param sectionName   the section name to which the link will be created
     * @param label     the content for the link
     * @param title     the title for the link
     * @param target    the target for the link, or null
     * @return a content tree for the link
     */
    public static Content createLink(SectionName sectionName, Content label, String title, String target) {
        DocLink l = DocLink.fragment(sectionName.getName());
        return createLink(l, label, title, target);
    }

    
Creates a link of the form <a href="path">label</a>. 
Params:
  • path –   the path for the link
  • label –  the content for the link
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="path">label</a>}.
     *
     * @param path   the path for the link
     * @param label  the content for the link
     * @return a content tree for the link
     */
    public static Content createLink(DocPath path, String label) {
        return Links.createLink(path, new StringContent(label), false, "", "");
    }

    
Creates a link of the form <a href="path">label</a>. 
Params:
  • path –   the path for the link
  • label –  the content for the link
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="path">label</a>}.
     *
     * @param path   the path for the link
     * @param label  the content for the link
     * @return a content tree for the link
     */
    public static Content createLink(DocPath path, Content label) {
        return Links.createLink(path, label, "", "");
    }

    
Creates a link of the form <a href="path" title="title" target="target">label</a>. If strong is set, the label will be wrapped in <span style="typeNameLink">...</span>. 
Params:
  • path –      the path for the link
  • label –     the content for the link
  • strong –  whether to wrap the label in a SPAN element
  • title –     the title for the link
  • target –    the target for the link, or null
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="path" title="title" target="target">label</a>}.
     * If {@code strong} is set, the label will be wrapped in
     *      {@code <span style="typeNameLink">...</span>}.
     *
     * @param path      the path for the link
     * @param label     the content for the link
     * @param strong    whether to wrap the {@code label} in a SPAN element
     * @param title     the title for the link
     * @param target    the target for the link, or null
     * @return a content tree for the link
     */
    public static Content createLink(DocPath path, Content label, boolean strong,
            String title, String target) {
        return createLink(new DocLink(path), label, strong, title, target);
    }

    
Creates a link of the form <a href="path" title="title" target="target">label</a>. 
Params:
  • path –      the path for the link
  • label –     the content for the link
  • title –     the title for the link
  • target –    the target for the link, or null
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="path" title="title" target="target">label</a>}.
     *
     * @param path      the path for the link
     * @param label     the content for the link
     * @param title     the title for the link
     * @param target    the target for the link, or null
     * @return a content tree for the link
     */
    public static Content createLink(DocPath path, Content label, String title, String target) {
        return Links.createLink(new DocLink(path), label, title, target);
    }

    
Creates a link of the form <a href="link">label</a>. 
Params:
  • link –      the details for the link
  • label –     the content for the link
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="link">label</a>}.
     *
     * @param link      the details for the link
     * @param label     the content for the link
     * @return a content tree for the link
     */
    public static Content createLink(DocLink link, Content label) {
        return Links.createLink(link, label, "", "");
    }

    
Creates a link of the form <a href="path" title="title" target="target">label</a>. 
Params:
  • link –      the details for the link
  • label –     the content for the link
  • title –     the title for the link
  • target –    the target for the link, or null
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="path" title="title" target="target">label</a>}.
     *
     * @param link      the details for the link
     * @param label     the content for the link
     * @param title     the title for the link
     * @param target    the target for the link, or null
     * @return a content tree for the link
     */
    public static Content createLink(DocLink link, Content label, String title, String target) {
        HtmlTree anchor = HtmlTree.A(link.toString(), label);
        if (title != null && title.length() != 0) {
            anchor.addAttr(HtmlAttr.TITLE, title);
        }
        if (target != null && target.length() != 0) {
            anchor.addAttr(HtmlAttr.TARGET, target);
        }
        return anchor;
    }

    
Creates a link of the form <a href="link" title="title" target="target">label</a>. If strong is set, the label will be wrapped in <span style="typeNameLink">...</span>. 
Params:
  • link –      the details for the link
  • label –     the content for the link
  • strong –  whether to wrap the label in a SPAN element
  • title –     the title for the link
  • target –    the target for the link, or null
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="link" title="title" target="target">label</a>}.
     * If {@code strong} is set, the label will be wrapped in
     *      {@code <span style="typeNameLink">...</span>}.
     *
     * @param link      the details for the link
     * @param label     the content for the link
     * @param strong    whether to wrap the {@code label} in a SPAN element
     * @param title     the title for the link
     * @param target    the target for the link, or null
     * @return a content tree for the link
     */
    public static Content createLink(DocLink link, Content label, boolean strong,
            String title, String target) {
        return createLink(link, label, strong, title, target, false);
    }

    
Creates a link of the form <a href="link" title="title" target="target">label</a>. If strong is set, the label will be wrapped in <span style="typeNameLink">...</span>. 
Params:
  • link –       the details for the link
  • label –      the content for the link
  • strong –  whether to wrap the label in a SPAN element
  • title –      the title for the link
  • target –     the target for the link, or null
  • isExternal – is the link external to the generated documentation
Returns:a content tree for the link
/**
     * Creates a link of the form {@code <a href="link" title="title" target="target">label</a>}.
     * If {@code strong} is set, the label will be wrapped in
     *      {@code <span style="typeNameLink">...</span>}.
     *
     * @param link       the details for the link
     * @param label      the content for the link
     * @param strong     whether to wrap the {@code label} in a SPAN element
     * @param title      the title for the link
     * @param target     the target for the link, or null
     * @param isExternal is the link external to the generated documentation
     * @return a content tree for the link
     */
    public static Content createLink(DocLink link, Content label, boolean strong,
            String title, String target, boolean isExternal) {
        Content body = label;
        if (strong) {
            body = HtmlTree.SPAN(HtmlStyle.typeNameLink, body);
        }
        HtmlTree l = HtmlTree.A(link.toString(), body);
        if (title != null && title.length() != 0) {
            l.addAttr(HtmlAttr.TITLE, title);
        }
        if (target != null && target.length() != 0) {
            l.addAttr(HtmlAttr.TARGET, target);
        }
        if (isExternal) {
            l.setStyle(HtmlStyle.externalLink);
        }
        return l;
    }

    
Creates a link.

Params:
  • link –       the details for the link
  • label –      the content for the link
  • isExternal – is the link external to the generated documentation
Returns:a content tree for the link
/**
     * Creates a link.
     *
     * @param link       the details for the link
     * @param label      the content for the link
     * @param isExternal is the link external to the generated documentation
     * @return a content tree for the link
     */
    public static Content createLink(DocLink link, Content label, boolean isExternal) {
        HtmlTree anchor = HtmlTree.A(link.toString(), label);
        anchor.setStyle(HtmlStyle.externalLink);
        return anchor;
    }


    
Converts a name to a valid HTML name (id). This depends on the HTML version specified when the Links object was created. 
Params:
  • name – the string that needs to be converted to a valid HTML name
Returns:a valid HTML name
/**
     * Converts a name to a valid HTML name (id).
     * This depends on the HTML version specified when the {@code Links} object was created.
     *
     * @param name the string that needs to be converted to a valid HTML name
     * @return a valid HTML name
     */
    public String getName(String name) {
        /* The HTML 4 spec at http://www.w3.org/TR/html4/types.html#h-6.2 mentions
         * that the name/id should begin with a letter followed by other valid characters.
         * The HTML 5 spec (draft) is more permissive on names/ids where the only restriction
         * is that it should be at least one character long and should not contain spaces.
         * The spec draft is @ http://www.w3.org/html/wg/drafts/html/master/dom.html#the-id-attribute.
         *
         * For HTML 4, we need to check for non-characters at the beginning of the name and
         * substitute it accordingly, "_" and "$" can appear at the beginning of a member name.
         * The method substitutes "$" with "Z:Z:D" and will prefix "_" with "Z:Z".
         */

        if (version == HtmlVersion.HTML5) {
            return name.replaceAll(" +", "");
        }

        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < name.length(); i++) {
            char ch = name.charAt(i);
            switch (ch) {
                case '(':
                case ')':
                case '<':
                case '>':
                case ',':
                    sb.append('-');
                    break;
                case ' ':
                case '[':
                    break;
                case ']':
                    sb.append(":A");
                    break;
                // Any appearance of $ needs to be substituted with ":D" and not with hyphen
                // since a field name "P$$ and a method P(), both valid member names, can end
                // up as "P--". A member name beginning with $ needs to be substituted with
                // "Z:Z:D".
                case '$':
                    if (i == 0)
                        sb.append("Z:Z");
                    sb.append(":D");
                    break;
                // A member name beginning with _ needs to be prefixed with "Z:Z" since valid anchor
                // names can only begin with a letter.
                case '_':
                    if (i == 0)
                        sb.append("Z:Z");
                    sb.append(ch);
                    break;
                default:
                    sb.append(ch);
            }
        }
        return sb.toString();
    }

}