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package jdk.javadoc.internal.doclets.toolkit.util;

import java.util.*;

import javax.lang.model.element.Element;
import javax.lang.model.element.ModuleElement;
import javax.lang.model.element.PackageElement;
import javax.lang.model.element.TypeElement;

import jdk.javadoc.internal.doclets.toolkit.BaseConfiguration;
import jdk.javadoc.internal.doclets.toolkit.BaseOptions;
import jdk.javadoc.internal.doclets.toolkit.Resources;

Provides methods for creating an array of class, method and
field names to be included as meta keywords in the HTML header
of class pages.  These keywords improve search results
on browsers that look for keywords.
 
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.
/**
 * Provides methods for creating an array of class, method and
 * field names to be included as meta keywords in the HTML header
 * of class pages.  These keywords improve search results
 * on browsers that look for keywords.
 *
 *  <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 MetaKeywords {

    private final BaseOptions options;
    private final Resources resources;
    private final Utils utils;

    
Constructor
/**
     * Constructor
     */
    public MetaKeywords(BaseConfiguration configuration) {
        options = configuration.getOptions();
        resources = configuration.getDocResources();
        utils = configuration.utils;
    }

    
Returns an array of strings where each element
is a class, method or field name.  This array is
used to create one meta keyword tag for each element.
Method parameter lists are converted to "()" and
overloads are combined.
Constructors are not included because they have the same
name as the class, which is already included.
Nested class members are not included because their
definitions are on separate pages.
/**
     * Returns an array of strings where each element
     * is a class, method or field name.  This array is
     * used to create one meta keyword tag for each element.
     * Method parameter lists are converted to "()" and
     * overloads are combined.
     *
     * Constructors are not included because they have the same
     * name as the class, which is already included.
     * Nested class members are not included because their
     * definitions are on separate pages.
     */
    public List<String> getMetaKeywords(TypeElement typeElement) {
        ArrayList<String> results = new ArrayList<>();

        // Add field and method keywords only if -keywords option is used
        if (options.keywords()) {
            results.addAll(getClassKeyword(typeElement));
            results.addAll(getMemberKeywords(utils.getFields(typeElement)));
            results.addAll(getMemberKeywords(utils.getMethods(typeElement)));
        }
        ((ArrayList)results).trimToSize();
        return results;
    }

    
Get the current class for a meta tag keyword, as the first
and only element of an array list.
/**
     * Get the current class for a meta tag keyword, as the first
     * and only element of an array list.
     */
    protected List<String> getClassKeyword(TypeElement typeElement) {
        ArrayList<String> metakeywords = new ArrayList<>(1);
        String cltypelower = utils.isInterface(typeElement) ? "interface" : "class";
        metakeywords.add(utils.getFullyQualifiedName(typeElement) + " " + cltypelower);
        return metakeywords;
    }

    
Get the package keywords.
/**
     * Get the package keywords.
     */
    public List<String> getMetaKeywords(PackageElement packageElement) {
        List<String> result = new ArrayList<>(1);
        if (options.keywords()) {
            String pkgName = utils.getPackageName(packageElement);
            result.add(pkgName + " " + "package");
        }
        return result;
    }

    
Get the module keywords.
Params:
mdle – the module being documented/**
     * Get the module keywords.
     *
     * @param mdle the module being documented
     */
    public List<String> getMetaKeywordsForModule(ModuleElement mdle) {
        if (options.keywords()) {
            return Arrays.asList(mdle.getQualifiedName() + " " + "module");
        } else {
            return Collections.emptyList();
        }
    }

    
Get the overview keywords.
/**
     * Get the overview keywords.
     */
    public List<String> getOverviewMetaKeywords(String title, String docTitle) {
         List<String> result = new ArrayList<>(1);
        if (options.keywords()) {
            String windowOverview = resources.getText(title);
            if (docTitle.length() > 0) {
                result.add(windowOverview + ", " + docTitle);
            } else {
                result.add(windowOverview);
            }
        }
        return result;
    }

    
Get members for meta tag keywords as an array,
where each member name is a string element of the array.
The parameter lists are not included in the keywords;
therefore all overloaded methods are combined.

Example: getValue(Object) is returned in array as getValue()
Params:
members –  array of members to be added to keywords/**
     * Get members for meta tag keywords as an array,
     * where each member name is a string element of the array.
     * The parameter lists are not included in the keywords;
     * therefore all overloaded methods are combined.<br>
     * Example: getValue(Object) is returned in array as getValue()
     *
     * @param members  array of members to be added to keywords
     */
    protected List<String> getMemberKeywords(List<? extends Element> members) {
        ArrayList<String> results = new ArrayList<>();
        for (Element member : members) {
            String membername = utils.isMethod(member)
                    ? utils.getSimpleName(member) + "()"
                    : utils.getSimpleName(member);
            if (!results.contains(membername)) {
                results.add(membername);
            }
        }
        ((ArrayList)results).trimToSize();
        return results;
    }
}