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 * Copyright (c) 2003, 2018, Oracle and/or its affiliates. All rights reserved.
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
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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.ExecutableElement;
import javax.lang.model.element.TypeElement;
import javax.lang.model.type.TypeMirror;

import com.sun.source.doctree.DocTree;
import jdk.javadoc.internal.doclets.toolkit.BaseConfiguration;
import jdk.javadoc.internal.doclets.toolkit.taglets.InheritableTaglet;


Search for the requested documentation.  Inherit documentation if necessary.
 
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.

Author:Jamie Ho
/**
 * Search for the requested documentation.  Inherit documentation if necessary.
 *
 *  <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 Jamie Ho
 */
public class DocFinder {

    public static final class DocTreeInfo {
        public final DocTree docTree;
        public final Element element;

        public DocTreeInfo() {
            this.docTree = null;
            this.element = null;
        }

        public DocTreeInfo(DocTree docTree, Element baseElement) {
            this.docTree = docTree;
            this.element = baseElement;
        }

        @Override
        public String toString() {
            return "DocTreeInfo{" + "docTree=" + docTree + ", element=" + element + '}';
        }
    }

    
The class that encapsulates the input.

/**
     * The class that encapsulates the input.
     */
    public static class Input {
        
The element to search documentation from.

/**
         * The element to search documentation from.
         */
        public Element element;
        
The taglet to search for documentation on behalf of. Null if we want
to search for overall documentation.

/**
         * The taglet to search for documentation on behalf of. Null if we want
         * to search for overall documentation.
         */
        public InheritableTaglet taglet = null;

        
The id of the tag to retrieve documentation for.

/**
         * The id of the tag to retrieve documentation for.
         */
        public String tagId = null;

        
The tag to retrieve documentation for.  This is only used for the
inheritDoc tag.

/**
         * The tag to retrieve documentation for.  This is only used for the
         * inheritDoc tag.
         */
        public final DocTreeInfo docTreeInfo;

        
True if we only want to search for the first sentence.

/**
         * True if we only want to search for the first sentence.
         */
        public boolean isFirstSentence = false;

        
True if we are looking for documentation to replace the inheritDocTag.

/**
         * True if we are looking for documentation to replace the inheritDocTag.
         */
        public boolean isInheritDocTag = false;

        
Used to distinguish between type variable param tags and regular
param tags.

/**
         * Used to distinguish between type variable param tags and regular
         * param tags.
         */
        public boolean isTypeVariableParamTag = false;

        public final Utils utils;

        public Input(Utils utils, Element element, InheritableTaglet taglet, DocTreeInfo dtInfo,
                boolean isFirstSentence, boolean isInheritDocTag) {
            this.utils = utils;
            this.element = element;
            this.taglet = taglet;
            this.isFirstSentence = isFirstSentence;
            this.isInheritDocTag = isInheritDocTag;
            this.docTreeInfo = dtInfo;
        }

        public Input(Utils utils, Element element, InheritableTaglet taglet, String tagId) {
            this(utils, element);
            this.taglet = taglet;
            this.tagId = tagId;
        }

        public Input(Utils utils, Element element, InheritableTaglet taglet, String tagId,
            boolean isTypeVariableParamTag) {
            this(utils, element);
            this.taglet = taglet;
            this.tagId = tagId;
            this.isTypeVariableParamTag = isTypeVariableParamTag;
        }

        public Input(Utils utils, Element element, InheritableTaglet taglet) {
            this(utils, element);
            this.taglet = taglet;
        }

        public Input(Utils utils, Element element) {
            if (element == null)
                throw new NullPointerException();
            this.element = element;
            this.utils = utils;
            this.docTreeInfo = new DocTreeInfo();
        }

        public Input(Utils utils, Element element, boolean isFirstSentence) {
            this(utils, element);
            this.isFirstSentence = isFirstSentence;
        }

        public Input copy(Utils utils) {
            if (this.element == null) {
                throw new NullPointerException();
            }
            Input clone = new Input(utils, this.element, this.taglet, this.docTreeInfo,
                    this.isFirstSentence, this.isInheritDocTag);
            clone.tagId = this.tagId;
            clone.isTypeVariableParamTag = this.isTypeVariableParamTag;
            return clone;
        }

        
For debugging purposes

Returns:string representation
/**
         * For debugging purposes
         * @return string representation
         */
        @Override
        public String toString() {
            String encl = element == null ? "" : element.getEnclosingElement().toString() + "::";
            return "Input{" + "element=" + encl + element
                    + ", taglet=" + taglet
                    + ", tagId=" + tagId + ", tag=" + docTreeInfo
                    + ", isFirstSentence=" + isFirstSentence
                    + ", isInheritDocTag=" + isInheritDocTag
                    + ", isTypeVariableParamTag=" + isTypeVariableParamTag
                    + ", utils=" + utils + '}';
        }
    }

    
The class that encapsulates the output.

/**
     * The class that encapsulates the output.
     */
    public static class Output {
        
The tag that holds the documentation.  Null if documentation
is not held by a tag.

/**
         * The tag that holds the documentation.  Null if documentation
         * is not held by a tag.
         */
        public DocTree holderTag;

        
The Doc object that holds the documentation.

/**
         * The Doc object that holds the documentation.
         */
        public Element holder;

        
The inherited documentation.

/**
         * The inherited documentation.
         */
        public List<? extends DocTree> inlineTags = Collections.emptyList();

        
False if documentation could not be inherited.

/**
         * False if documentation could not be inherited.
         */
        public boolean isValidInheritDocTag = true;

        
When automatically inheriting throws tags, you sometime must inherit
more than one tag.  For example if the element declares that it throws
IOException and the overridden element has throws tags for IOException and
ZipException, both tags would be inherited because ZipException is a
subclass of IOException.  This subclass of DocFinder.Output allows
multiple tag inheritence.

/**
         * When automatically inheriting throws tags, you sometime must inherit
         * more than one tag.  For example if the element declares that it throws
         * IOException and the overridden element has throws tags for IOException and
         * ZipException, both tags would be inherited because ZipException is a
         * subclass of IOException.  This subclass of DocFinder.Output allows
         * multiple tag inheritence.
         */
        public List<DocTree> tagList  = new ArrayList<>();

        
Returns a string representation for debugging purposes

Returns:string
/**
         * Returns a string representation for debugging purposes
         * @return string
         */
        @Override
        public String toString() {
            String encl = holder == null ? "" : holder.getEnclosingElement().toString() + "::";
            return "Output{" + "holderTag=" + holderTag
                    + ", holder=" + encl + holder
                    + ", inlineTags=" + inlineTags
                    + ", isValidInheritDocTag=" + isValidInheritDocTag
                    + ", tagList=" + tagList + '}';
        }
    }

    
Search for the requested comments in the given element.  If it does not
have comments, return documentation from the overridden element if possible.
If the overridden element does not exist or does not have documentation to
inherit, search for documentation to inherit from implemented methods.

Params:
  • input – the input object used to perform the search.
Returns:an Output object representing the documentation that was found.
/**
     * Search for the requested comments in the given element.  If it does not
     * have comments, return documentation from the overridden element if possible.
     * If the overridden element does not exist or does not have documentation to
     * inherit, search for documentation to inherit from implemented methods.
     *
     * @param input the input object used to perform the search.
     *
     * @return an Output object representing the documentation that was found.
     */
    public static Output search(BaseConfiguration configuration, Input input) {
        Output output = new Output();
        Utils utils = configuration.utils;
        if (input.isInheritDocTag) {
            //Do nothing because "element" does not have any documentation.
            //All it has is {@inheritDoc}.
        } else if (input.taglet == null) {
            //We want overall documentation.
            output.inlineTags = input.isFirstSentence
                    ? utils.getFirstSentenceTrees(input.element)
                    : utils.getFullBody(input.element);
            output.holder = input.element;
        } else {
            input.taglet.inherit(input, output);
        }

        if (output.inlineTags != null && !output.inlineTags.isEmpty()) {
            return output;
        }
        output.isValidInheritDocTag = false;
        Input inheritedSearchInput = input.copy(configuration.utils);
        inheritedSearchInput.isInheritDocTag = false;
        if (utils.isMethod(input.element)) {
            ExecutableElement overriddenMethod = utils.overriddenMethod((ExecutableElement) input.element);
            if (overriddenMethod != null) {
                inheritedSearchInput.element = overriddenMethod;
                output = search(configuration, inheritedSearchInput);
                output.isValidInheritDocTag = true;
                if (!output.inlineTags.isEmpty()) {
                    return output;
                }
            }
            //NOTE:  When we fix the bug where ClassDoc.interfaceTypes() does
            //       not pass all implemented interfaces, we will use the
            //       appropriate element here.
            TypeElement encl = utils.getEnclosingTypeElement(input.element);
            VisibleMemberTable vmt = configuration.getVisibleMemberTable(encl);
            List<ExecutableElement> implementedMethods =
                    vmt.getImplementedMethods((ExecutableElement)input.element);
            for (ExecutableElement implementedMethod : implementedMethods) {
                inheritedSearchInput.element = implementedMethod;
                output = search(configuration, inheritedSearchInput);
                output.isValidInheritDocTag = true;
                if (!output.inlineTags.isEmpty()) {
                    return output;
                }
            }
        } else if (utils.isTypeElement(input.element)) {
            TypeMirror t = ((TypeElement) input.element).getSuperclass();
            Element superclass = utils.asTypeElement(t);
            if (superclass != null) {
                inheritedSearchInput.element = superclass;
                output = search(configuration, inheritedSearchInput);
                output.isValidInheritDocTag = true;
                if (!output.inlineTags.isEmpty()) {
                    return output;
                }
            }
        }
        return output;
    }
}