1/*
2    Copyright (C) 1999 Lars Knoll (knoll@mpi-hd.mpg.de)
3    Copyright (C) 2006 Alexey Proskuryakov (ap@nypop.com)
4    Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
5
6    This library is free software; you can redistribute it and/or
7    modify it under the terms of the GNU Library General Public
8    License as published by the Free Software Foundation; either
9    version 2 of the License, or (at your option) any later version.
10
11    This library is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14    Library General Public License for more details.
15
16    You should have received a copy of the GNU Library General Public License
17    along with this library; see the file COPYING.LIB.  If not, write to
18    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
19    Boston, MA 02110-1301, USA.
20
21*/
22
23#ifndef TextResourceDecoder_h
24#define TextResourceDecoder_h
25
26#include "TextEncoding.h"
27
28namespace WebCore {
29
30class HTMLMetaCharsetParser;
31
32class TextResourceDecoder : public RefCounted<TextResourceDecoder> {
33public:
34    enum EncodingSource {
35        DefaultEncoding,
36        AutoDetectedEncoding,
37        EncodingFromXMLHeader,
38        EncodingFromMetaTag,
39        EncodingFromCSSCharset,
40        EncodingFromHTTPHeader,
41        UserChosenEncoding,
42        EncodingFromParentFrame
43    };
44
45    static PassRefPtr<TextResourceDecoder> create(const String& mimeType, const TextEncoding& defaultEncoding = TextEncoding(), bool usesEncodingDetector = false)
46    {
47        return adoptRef(new TextResourceDecoder(mimeType, defaultEncoding, usesEncodingDetector));
48    }
49    ~TextResourceDecoder();
50
51    void setEncoding(const TextEncoding&, EncodingSource);
52    const TextEncoding& encoding() const { return m_encoding; }
53
54    String decode(const char* data, size_t length);
55    String flush();
56
57    void setHintEncoding(const TextResourceDecoder* hintDecoder)
58    {
59        // hintEncoding is for use with autodetection, which should be
60        // only invoked when hintEncoding comes from auto-detection.
61        if (hintDecoder && hintDecoder->m_source == AutoDetectedEncoding)
62            m_hintEncoding = hintDecoder->encoding().name();
63    }
64
65    void useLenientXMLDecoding() { m_useLenientXMLDecoding = true; }
66    bool sawError() const { return m_sawError; }
67
68private:
69    TextResourceDecoder(const String& mimeType, const TextEncoding& defaultEncoding,
70                        bool usesEncodingDetector);
71
72    enum ContentType { PlainText, HTML, XML, CSS }; // PlainText only checks for BOM.
73    static ContentType determineContentType(const String& mimeType);
74    static const TextEncoding& defaultEncoding(ContentType, const TextEncoding& defaultEncoding);
75
76    size_t checkForBOM(const char*, size_t);
77    bool checkForCSSCharset(const char*, size_t, bool& movedDataToBuffer);
78    bool checkForHeadCharset(const char*, size_t, bool& movedDataToBuffer);
79    bool checkForMetaCharset(const char*, size_t);
80    void detectJapaneseEncoding(const char*, size_t);
81    bool shouldAutoDetect() const;
82
83    ContentType m_contentType;
84    TextEncoding m_encoding;
85    OwnPtr<TextCodec> m_codec;
86    EncodingSource m_source;
87    const char* m_hintEncoding;
88    Vector<char> m_buffer;
89    bool m_checkedForBOM;
90    bool m_checkedForCSSCharset;
91    bool m_checkedForHeadCharset;
92    bool m_useLenientXMLDecoding; // Don't stop on XML decoding errors.
93    bool m_sawError;
94    bool m_usesEncodingDetector;
95
96    OwnPtr<HTMLMetaCharsetParser> m_charsetParser;
97};
98
99}
100
101#endif
102