bpatel@766: /*
jjg@1359:  * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved.
bpatel@766:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
bpatel@766:  *
bpatel@766:  * This code is free software; you can redistribute it and/or modify it
bpatel@766:  * under the terms of the GNU General Public License version 2 only, as
bpatel@766:  * published by the Free Software Foundation.  Oracle designates this
bpatel@766:  * particular file as subject to the "Classpath" exception as provided
bpatel@766:  * by Oracle in the LICENSE file that accompanied this code.
bpatel@766:  *
bpatel@766:  * This code is distributed in the hope that it will be useful, but WITHOUT
bpatel@766:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
bpatel@766:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
bpatel@766:  * version 2 for more details (a copy is included in the LICENSE file that
bpatel@766:  * accompanied this code).
bpatel@766:  *
bpatel@766:  * You should have received a copy of the GNU General Public License version
bpatel@766:  * 2 along with this work; if not, write to the Free Software Foundation,
bpatel@766:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
bpatel@766:  *
bpatel@766:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
bpatel@766:  * or visit www.oracle.com if you need additional information or have any
bpatel@766:  * questions.
bpatel@766:  */
bpatel@766: 
bpatel@766: package com.sun.tools.doclets.internal.toolkit;
bpatel@766: 
bpatel@766: import com.sun.tools.doclets.internal.toolkit.util.*;
bpatel@766: 
bpatel@766: /**
bpatel@766:  * A class to create content for javadoc output pages.
bpatel@766:  *
jjg@1359:  *  <p><b>This is NOT part of any supported API.
jjg@1359:  *  If you write code that depends on this, you do so at your own risk.
jjg@1359:  *  This code and its internal interfaces are subject to change or
jjg@1359:  *  deletion without notice.</b>
jjg@1359:  *
bpatel@766:  * @author Bhavesh Patel
bpatel@766:  */
bpatel@766: public abstract class Content {
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Returns a string representation of the content.
bpatel@766:      *
bpatel@766:      * @return string representation of the content
bpatel@766:      */
bpatel@766:     public String toString() {
bpatel@766:         StringBuilder contentBuilder = new StringBuilder();
bpatel@766:         write(contentBuilder);
bpatel@766:         return contentBuilder.toString();
bpatel@766:     }
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Adds content to the existing content.
bpatel@766:      *
bpatel@766:      * @param content content that needs to be added
bpatel@766:      */
bpatel@766:     public abstract void addContent(Content content);
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Adds a string content to the existing content.
bpatel@766:      *
bpatel@766:      * @param stringContent the string content to be added
bpatel@766:      */
bpatel@766:     public abstract void addContent(String stringContent);
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Writes content to a StringBuilder.
bpatel@766:      *
bpatel@766:      */
bpatel@766:     public abstract void write(StringBuilder contentBuilder);
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Returns true if the content is empty.
bpatel@766:      *
bpatel@766:      * @return true if no content to be displayed else return false
bpatel@766:      */
bpatel@766:     public abstract boolean isEmpty();
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Returns true if the content is valid.
bpatel@766:      *
bpatel@766:      * @return true if the content is valid else return false
bpatel@766:      */
bpatel@766:     public boolean isValid() {
bpatel@766:         return !isEmpty();
bpatel@766:     }
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Checks for null values.
bpatel@766:      *
bpatel@766:      * @param t reference type to check for null values
bpatel@766:      * @return the reference type if not null or else throws a null pointer exception
bpatel@766:      */
bpatel@766:     protected static <T> T nullCheck(T t) {
bpatel@766:         t.getClass();
bpatel@766:         return t;
bpatel@766:     }
bpatel@766: 
bpatel@766:     /**
bpatel@766:      * Returns true if the content ends with a newline character. Empty content
bpatel@766:      * is considered as ending with new line.
bpatel@766:      *
bpatel@766:      * @param contentBuilder content to test for newline character at the end
bpatel@766:      * @return true if the content ends with newline.
bpatel@766:      */
bpatel@819:     protected boolean endsWithNewLine(StringBuilder contentBuilder) {
bpatel@819:         int contentLength = contentBuilder.length();
bpatel@819:         if (contentLength == 0) {
bpatel@819:             return true;
bpatel@819:         }
bpatel@819:         int nlLength = DocletConstants.NL.length();
bpatel@819:         if (contentLength < nlLength) {
bpatel@819:             return false;
bpatel@819:         }
bpatel@819:         int contentIndex = contentLength - 1;
bpatel@819:         int nlIndex = nlLength - 1;
bpatel@819:         while (nlIndex >= 0) {
bpatel@819:             if (contentBuilder.charAt(contentIndex) != DocletConstants.NL.charAt(nlIndex)) {
bpatel@819:                 return false;
bpatel@819:             }
bpatel@819:             contentIndex--;
bpatel@819:             nlIndex--;
bpatel@819:         }
bpatel@819:         return true;
bpatel@766:     }
bpatel@766: }