1 /*
   2  * Copyright (c) 2010, 2019, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package jdk.javadoc.internal.doclets.formats.html.markup;
  27 
  28 import java.io.IOException;
  29 import java.io.Writer;
  30 
  31 import jdk.javadoc.internal.doclets.toolkit.Content;
  32 import jdk.javadoc.internal.doclets.toolkit.util.DocletConstants;
  33 
  34 /**
  35  * Class for generating raw HTML content to be added to HTML pages of javadoc output.
  36  *
  37  *  <p><b>This is NOT part of any supported API.
  38  *  If you write code that depends on this, you do so at your own risk.
  39  *  This code and its internal interfaces are subject to change or
  40  *  deletion without notice.</b>
  41  *
  42  * @author Bhavesh Patel
  43  */
  44 public class RawHtml extends Content {
  45 
  46     private final String rawHtmlContent;
  47 
  48     private final static String ZERO_WIDTH_SPACE = "​";
  49 
  50     public static final Content nbsp = new RawHtml("&nbsp;");
  51 
  52     public static final Content zws = new RawHtml(ZERO_WIDTH_SPACE);
  53 
  54     /**
  55      * Constructor to construct a RawHtml object.
  56      *
  57      * @param rawHtml raw HTML text to be added
  58      */
  59     public RawHtml(CharSequence rawHtml) {
  60         rawHtmlContent = rawHtml.toString();
  61     }
  62 
  63     /**
  64      * This method is not supported by the class.
  65      *
  66      * @param content content that needs to be added
  67      * @throws UnsupportedOperationException always
  68      */
  69     public void add(Content content) {
  70         throw new UnsupportedOperationException();
  71     }
  72 
  73     /**
  74      * This method is not supported by the class.
  75      *
  76      * @param stringContent string content that needs to be added
  77      * @throws UnsupportedOperationException always
  78      */
  79     @Override
  80     public void add(CharSequence stringContent) {
  81         throw new UnsupportedOperationException();
  82     }
  83 
  84     /**
  85      * {@inheritDoc}
  86      */
  87     public boolean isEmpty() {
  88         return rawHtmlContent.isEmpty();
  89     }
  90 
  91     /**
  92      * {@inheritDoc}
  93      */
  94     @Override
  95     public String toString() {
  96         return rawHtmlContent;
  97     }
  98 
  99     private enum State { TEXT, ENTITY, TAG, STRING }
 100 
 101     @Override
 102     public int charCount() {
 103         return charCount(rawHtmlContent);
 104     }
 105 
 106     static int charCount(CharSequence htmlText) {
 107         State state = State.TEXT;
 108         int count = 0;
 109         int entityStart = 0;
 110         for (int i = 0; i < htmlText.length(); i++) {
 111             char c = htmlText.charAt(i);
 112             switch (state) {
 113                 case TEXT:
 114                     switch (c) {
 115                         case '<':
 116                             state = State.TAG;
 117                             break;
 118                         case '&':
 119                             state = State.ENTITY;
 120                             entityStart = i;
 121                             break;
 122                         default:
 123                             count++;
 124                     }
 125                     break;
 126 
 127                 case ENTITY:
 128                     if (c == ';') {
 129                         state = State.TEXT;
 130                         if (!isZeroWidthSpace(htmlText, entityStart, i+1))
 131                             count++;
 132                     }
 133                     break;
 134 
 135                 case TAG:
 136                     switch (c) {
 137                         case '"':
 138                             state = State.STRING;
 139                             break;
 140                         case '>':
 141                             state = State.TEXT;
 142                             break;
 143                     }
 144                     break;
 145 
 146                 case STRING:
 147                     if (c == '"') {
 148                         state = State.TAG;
 149                     }
 150                     break;
 151             }
 152         }
 153         return count;
 154     }
 155 
 156     /**
 157      * {@inheritDoc}
 158      */
 159     @Override
 160     public boolean write(Writer out, boolean atNewline) throws IOException {
 161         out.write(rawHtmlContent);
 162         return rawHtmlContent.endsWith(DocletConstants.NL);
 163     }
 164 
 165     private static boolean isZeroWidthSpace(CharSequence cs, int start, int end) {
 166         if (end - start != ZERO_WIDTH_SPACE.length())
 167             return false;
 168         for (int i = 0; i < ZERO_WIDTH_SPACE.length(); i++) {
 169             if (ZERO_WIDTH_SPACE.charAt(i) != cs.charAt(i + start))
 170                 return false;
 171         }
 172         return true;
 173     }
 174 }