1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/*
* Copyright (c) 2008, 2009, Google Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are
* met:
*
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following disclaimer
* in the documentation and/or other materials provided with the
* distribution.
* * Neither the name of Google Inc. nor the names of its
* contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
* A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
* OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifndef ICOImageDecoder_h
#define ICOImageDecoder_h
#include "BMPImageReader.h"
namespace WebCore {
class PNGImageDecoder;
// This class decodes the ICO and CUR image formats.
class ICOImageDecoder : public ImageDecoder {
public:
ICOImageDecoder(bool premultiplyAlpha);
virtual ~ICOImageDecoder();
// ImageDecoder
virtual String filenameExtension() const { return "ico"; }
virtual void setData(SharedBuffer*, bool allDataReceived);
virtual bool isSizeAvailable();
virtual IntSize size() const;
virtual IntSize frameSizeAtIndex(size_t) const;
virtual bool setSize(unsigned width, unsigned height);
virtual size_t frameCount();
virtual RGBA32Buffer* frameBufferAtIndex(size_t);
// CAUTION: setFailed() deletes all readers and decoders. Be careful to
// avoid accessing deleted memory, especially when calling this from
// inside BMPImageReader!
virtual bool setFailed();
private:
enum ImageType {
Unknown,
BMP,
PNG,
};
struct IconDirectoryEntry {
IntSize m_size;
uint16_t m_bitCount;
uint32_t m_imageOffset;
};
// Returns true if |a| is a preferable icon entry to |b|.
// Larger sizes, or greater bitdepths at the same size, are preferable.
static bool compareEntries(const IconDirectoryEntry& a, const IconDirectoryEntry& b);
inline uint16_t readUint16(int offset) const
{
return BMPImageReader::readUint16(m_data.get(), m_decodedOffset + offset);
}
inline uint32_t readUint32(int offset) const
{
return BMPImageReader::readUint32(m_data.get(), m_decodedOffset + offset);
}
// If the desired PNGImageDecoder exists, gives it the appropriate data.
void setDataForPNGDecoderAtIndex(size_t);
// Decodes the entry at |index|. If |onlySize| is true, stops decoding
// after calculating the image size. If decoding fails but there is no
// more data coming, sets the "decode failure" flag.
void decode(size_t index, bool onlySize);
// Decodes the directory and directory entries at the beginning of the
// data, and initializes members. Returns true if all decoding
// succeeded. Once this returns true, all entries' sizes are known.
bool decodeDirectory();
// Decodes the specified entry.
bool decodeAtIndex(size_t);
// Processes the ICONDIR at the beginning of the data. Returns true if
// the directory could be decoded.
bool processDirectory();
// Processes the ICONDIRENTRY records after the directory. Keeps the
// "best" entry as the one we'll decode. Returns true if the entries
// could be decoded.
bool processDirectoryEntries();
// Reads and returns a directory entry from the current offset into
// |data|.
IconDirectoryEntry readDirectoryEntry();
// Determines whether the desired entry is a BMP or PNG. Returns true
// if the type could be determined.
ImageType imageTypeAtIndex(size_t);
// An index into |m_data| representing how much we've already decoded.
// Note that this only tracks data _this_ class decodes; once the
// BMPImageReader takes over this will not be updated further.
size_t m_decodedOffset;
// The headers for the ICO.
typedef Vector<IconDirectoryEntry> IconDirectoryEntries;
IconDirectoryEntries m_dirEntries;
// The image decoders for the various frames.
typedef Vector<OwnPtr<BMPImageReader> > BMPReaders;
BMPReaders m_bmpReaders;
typedef Vector<OwnPtr<PNGImageDecoder> > PNGDecoders;
PNGDecoders m_pngDecoders;
// Valid only while a BMPImageReader is decoding, this holds the size
// for the particular entry being decoded.
IntSize m_frameSize;
};
} // namespace WebCore
#endif
|
