1/*
2 * Copyright (c) 2010, 2016, 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
26package jdk.javadoc.internal.doclets.formats.html.markup;
27
28import java.io.IOException;
29import java.io.Writer;
30
31import jdk.javadoc.internal.doclets.toolkit.Content;
32import jdk.javadoc.internal.doclets.toolkit.util.DocletConstants;
33
34/**
35 * Class for generating document type for 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 */
44public class DocType extends Content {
45
46    private String docType;
47
48    public static final DocType TRANSITIONAL =
49            new DocType("Transitional", "http://www.w3.org/TR/html4/loose.dtd");
50
51    public static final DocType HTML5 = new DocType();
52
53    /**
54     * Constructor to construct a DocType object.
55     *
56     * @param type the doctype to be added
57     * @param dtd the dtd of the doctype
58     */
59    private DocType(String type, String dtd) {
60        docType = "<!DOCTYPE HTML PUBLIC \"-//W3C//DTD HTML 4.01 " + type +
61                "//EN\" \"" + dtd + "\">" + DocletConstants.NL;
62    }
63
64    /**
65     * Constructor to construct a DocType object.
66     */
67    private DocType() {
68        docType = "<!DOCTYPE HTML>" + DocletConstants.NL;
69    }
70
71    /**
72     * This method is not supported by the class.
73     *
74     * @param content content that needs to be added
75     * @throws UnsupportedOperationException always
76     */
77    public void addContent(Content content) {
78        throw new UnsupportedOperationException();
79    }
80
81    /**
82     * This method is not supported by the class.
83     *
84     * @param stringContent string content that needs to be added
85     * @throws UnsupportedOperationException always
86     */
87    @Override
88    public void addContent(CharSequence stringContent) {
89        throw new UnsupportedOperationException();
90    }
91
92    /**
93     * {@inheritDoc}
94     */
95    public boolean isEmpty() {
96        return (docType.length() == 0);
97    }
98
99    /**
100     * {@inheritDoc}
101     */
102    @Override
103    public boolean write(Writer out, boolean atNewline) throws IOException {
104        out.write(docType);
105        return true; // guaranteed by constructor
106    }
107}
108