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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 * 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.
 *
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package com.sun.tools.doclets.internal.toolkit.taglets;

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

/**
 * The interface for a custom tag used by Doclets. A custom
 * tag must implement this interface.  To be loaded and used by
 * doclets at run-time, the taglet must have a static method called
 * <code>register</code> that accepts a {@link java.util.Map} as an
 * argument with the following signature:
 * <pre>
 *   public void register(Map map)
 * </pre>
 * This method should add an instance of the custom taglet to the map
 * with the name of the taglet as the key.  If overriding a taglet,
 * to avoid a name conflict, the overridden taglet must be deleted from
 * the map before an instance of the new taglet is added to the map.
 * <p>
 * It is recommended that the taglet throw an exception when it fails
 * to register itself.  The exception that it throws is up to the user.
 * <p>
 * Here are two sample taglets: <br>
 * <ul>
 *     <li><a href="{@docRoot}/ToDoTaglet.java">ToDoTaglet.java</a>
 *         - Standalone taglet</li>
 *     <li><a href="{@docRoot}/UnderlineTaglet.java">UnderlineTaglet.java</a>
 *         - Inline taglet</li>
 * </ul>
 * <p>
 * For more information on how to create your own Taglets, please see the
 * <a href="{@docRoot}/overview.html">Taglet Overview</a>.
 *
 * @since 1.4
 * @author Jamie Ho
 */

public interface Taglet {

    /**
     * Return true if this <code>Taglet</code>
     * is used in field documentation.
     * @return true if this <code>Taglet</code>
     * is used in field documentation and false
     * otherwise.
     */
    public abstract boolean inField();

    /**
     * Return true if this <code>Taglet</code>
     * is used in constructor documentation.
     * @return true if this <code>Taglet</code>
     * is used in constructor documentation and false
     * otherwise.
     */
    public abstract boolean inConstructor();

    /**
     * Return true if this <code>Taglet</code>
     * is used in method documentation.
     * @return true if this <code>Taglet</code>
     * is used in method documentation and false
     * otherwise.
     */
    public abstract boolean inMethod();

    /**
     * Return true if this <code>Taglet</code>
     * is used in overview documentation.
     * @return true if this <code>Taglet</code>
     * is used in method documentation and false
     * otherwise.
     */
    public abstract boolean inOverview();

    /**
     * Return true if this <code>Taglet</code>
     * is used in package documentation.
     * @return true if this <code>Taglet</code>
     * is used in package documentation and false
     * otherwise.
     */
    public abstract boolean inPackage();

    /**
     * Return true if this <code>Taglet</code>
     * is used in type documentation (classes or
     * interfaces).
     * @return true if this <code>Taglet</code>
     * is used in type documentation and false
     * otherwise.
     */
    public abstract boolean inType();

    /**
     * Return true if this <code>Taglet</code>
     * is an inline tag. Return false otherwise.
     * @return true if this <code>Taglet</code>
     * is an inline tag and false otherwise.
     */
    public abstract boolean isInlineTag();

    /**
     * Return the name of this custom tag.
     * @return the name of this custom tag.
     */
    public abstract String getName();

    /**
     * Given the <code>Tag</code> representation of this custom
     * tag, return its Content representation, which is output
     * to the generated page.
     * @param tag the <code>Tag</code> representation of this custom tag.
     * @param writer a {@link TagletWriter} Taglet writer.
     * @throws IllegalArgumentException thrown when the method is not supported by the taglet.
     * @return the Content representation of this <code>Tag</code>.
     */
    public abstract Content getTagletOutput(Tag tag, TagletWriter writer) throws IllegalArgumentException;

    /**
     * Given a <code>Doc</code> object, check if it holds any tags of
     * this type.  If it does, return the string representing the output.
     * If it does not, return null.
     * @param holder a {@link Doc} object holding the custom tag.
     * @param writer a {@link TagletWriter} Taglet writer.
     * @throws IllegalArgumentException thrown when the method is not supported by the taglet.
     * @return the TagletOutput representation of this <code>Tag</code>.
     */
    public abstract Content getTagletOutput(Doc holder, TagletWriter writer) throws IllegalArgumentException;

    @Override
    public abstract String toString();
}
