aoqi@0: /*
aoqi@0:  * Copyright (c) 2010, 2013, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.  Oracle designates this
aoqi@0:  * particular file as subject to the "Classpath" exception as provided
aoqi@0:  * by Oracle in the LICENSE file that accompanied this code.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: package com.sun.tools.doclets.internal.toolkit;
aoqi@0: 
aoqi@0: import java.io.IOException;
aoqi@0: import java.io.StringWriter;
aoqi@0: import java.io.Writer;
aoqi@0: 
aoqi@0: import com.sun.tools.doclets.internal.toolkit.util.*;
aoqi@0: 
aoqi@0: /**
aoqi@0:  * A class to create content for javadoc output pages.
aoqi@0:  *
aoqi@0:  *  <p><b>This is NOT part of any supported API.
aoqi@0:  *  If you write code that depends on this, you do so at your own risk.
aoqi@0:  *  This code and its internal interfaces are subject to change or
aoqi@0:  *  deletion without notice.</b>
aoqi@0:  *
aoqi@0:  * @author Bhavesh Patel
aoqi@0:  */
aoqi@0: public abstract class Content {
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns a string representation of the content.
aoqi@0:      *
aoqi@0:      * @return string representation of the content
aoqi@0:      */
aoqi@0:     @Override
aoqi@0:     public String toString() {
aoqi@0:         StringWriter out = new StringWriter();
aoqi@0:         try {
aoqi@0:             write(out, true);
aoqi@0:         } catch (IOException e) {
aoqi@0:             // cannot happen from StringWriter
aoqi@0:             throw new DocletAbortException(e);
aoqi@0:         }
aoqi@0:         return out.toString();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Adds content to the existing content.
aoqi@0:      *
aoqi@0:      * @param content content that needs to be added
aoqi@0:      */
aoqi@0:     public abstract void addContent(Content content);
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Adds a string content to the existing content.
aoqi@0:      *
aoqi@0:      * @param stringContent the string content to be added
aoqi@0:      */
aoqi@0:     public abstract void addContent(String stringContent);
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Writes content to a writer.
aoqi@0:      *
aoqi@0:      */
aoqi@0:     public abstract boolean write(Writer writer, boolean atNewline) throws IOException ;
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns true if the content is empty.
aoqi@0:      *
aoqi@0:      * @return true if no content to be displayed else return false
aoqi@0:      */
aoqi@0:     public abstract boolean isEmpty();
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Returns true if the content is valid.
aoqi@0:      *
aoqi@0:      * @return true if the content is valid else return false
aoqi@0:      */
aoqi@0:     public boolean isValid() {
aoqi@0:         return !isEmpty();
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Return the number of characters of plain text content in this object
aoqi@0:      * (optional operation.)
aoqi@0:      * @return the number of characters of plain text content in this
aoqi@0:      */
aoqi@0:     public int charCount() {
aoqi@0:         return 0;
aoqi@0:     }
aoqi@0: 
aoqi@0:     /**
aoqi@0:      * Checks for null values.
aoqi@0:      *
aoqi@0:      * @param t reference type to check for null values
aoqi@0:      * @return the reference type if not null or else throws a null pointer exception
aoqi@0:      */
aoqi@0:     protected static <T> T nullCheck(T t) {
aoqi@0:         t.getClass();
aoqi@0:         return t;
aoqi@0:     }
aoqi@0: }