1/*
2 * Copyright (C) 2004, 2005, 2006 Apple Computer, Inc.  All rights reserved.
3 * Copyright (C) 2007-2008 Torch Mobile, Inc.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice, this list of conditions and the following disclaimer.
10 * 2. Redistributions in binary form must reproduce the above copyright
11 *    notice, this list of conditions and the following disclaimer in the
12 *    documentation and/or other materials provided with the distribution.
13 *
14 * THIS SOFTWARE IS PROVIDED BY APPLE COMPUTER, INC. ``AS IS'' AND ANY
15 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE COMPUTER, INC. OR
18 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
19 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
20 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
21 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
22 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
24 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 */
26
27#ifndef ImageSource_h
28#define ImageSource_h
29
30#include "ImageOrientation.h"
31#include "NativeImagePtr.h"
32
33#include <wtf/Forward.h>
34#include <wtf/Noncopyable.h>
35#include <wtf/Vector.h>
36
37#if USE(CG)
38typedef struct CGImageSource* CGImageSourceRef;
39typedef const struct __CFData* CFDataRef;
40#endif
41
42namespace WebCore {
43
44class ImageOrientation;
45class IntPoint;
46class IntSize;
47class SharedBuffer;
48
49#if USE(CG)
50typedef CGImageSourceRef NativeImageDecoderPtr;
51#else
52class ImageDecoder;
53typedef ImageDecoder* NativeImageDecoderPtr;
54#endif
55
56#if USE(CG)
57#define NativeImageDecoder ImageDecoder
58#else
59typedef ImageDecoder NativeImageDecoder;
60#endif
61
62// Right now GIFs are the only recognized image format that supports animation.
63// The animation system and the constants below are designed with this in mind.
64// GIFs have an optional 16-bit unsigned loop count that describes how an
65// animated GIF should be cycled.  If the loop count is absent, the animation
66// cycles once; if it is 0, the animation cycles infinitely; otherwise the
67// animation plays n + 1 cycles (where n is the specified loop count).  If the
68// GIF decoder defaults to cAnimationLoopOnce in the absence of any loop count
69// and translates an explicit "0" loop count to cAnimationLoopInfinite, then we
70// get a couple of nice side effects:
71//   * By making cAnimationLoopOnce be 0, we allow the animation cycling code in
72//     BitmapImage.cpp to avoid special-casing it, and simply treat all
73//     non-negative loop counts identically.
74//   * By making the other two constants negative, we avoid conflicts with any
75//     real loop count values.
76const int cAnimationLoopOnce = 0;
77const int cAnimationLoopInfinite = -1;
78const int cAnimationNone = -2;
79
80class ImageSource {
81    WTF_MAKE_NONCOPYABLE(ImageSource);
82public:
83    enum AlphaOption {
84        AlphaPremultiplied,
85        AlphaNotPremultiplied
86    };
87
88    enum GammaAndColorProfileOption {
89        GammaAndColorProfileApplied,
90        GammaAndColorProfileIgnored
91    };
92
93#if USE(CG)
94    enum ShouldSkipMetadata {
95        DoNotSkipMetadata,
96        SkipMetadata
97    };
98#endif
99
100    ImageSource(AlphaOption alphaOption = AlphaPremultiplied, GammaAndColorProfileOption gammaAndColorProfileOption = GammaAndColorProfileApplied);
101    ~ImageSource();
102
103    // Tells the ImageSource that the Image no longer cares about decoded frame
104    // data -- at all (if |destroyAll| is true), or before frame
105    // |clearBeforeFrame| (if |destroyAll| is false).  The ImageSource should
106    // delete cached decoded data for these frames where possible to keep memory
107    // usage low.  When |destroyAll| is true, the ImageSource should also reset
108    // any local state so that decoding can begin again.
109    //
110    // Implementations that delete less than what's specified above waste
111    // memory.  Implementations that delete more may burn CPU re-decoding frames
112    // that could otherwise have been cached, or encounter errors if they're
113    // asked to decode frames they can't decode due to the loss of previous
114    // decoded frames.
115    //
116    // Callers should not call clear(false, n) and subsequently call
117    // createFrameAtIndex(m) with m < n, unless they first call clear(true).
118    // This ensures that stateful ImageSources/decoders will work properly.
119    //
120    // The |data| and |allDataReceived| parameters should be supplied by callers
121    // who set |destroyAll| to true if they wish to be able to continue using
122    // the ImageSource.  This way implementations which choose to destroy their
123    // decoders in some cases can reconstruct them correctly.
124    void clear(bool destroyAll,
125               size_t clearBeforeFrame = 0,
126               SharedBuffer* data = NULL,
127               bool allDataReceived = false);
128
129    bool initialized() const;
130
131    void setData(SharedBuffer* data, bool allDataReceived);
132    String filenameExtension() const;
133
134    bool isSizeAvailable();
135    IntSize size(RespectImageOrientationEnum = DoNotRespectImageOrientation) const;
136    IntSize frameSizeAtIndex(size_t, RespectImageOrientationEnum = DoNotRespectImageOrientation) const;
137
138    bool getHotSpot(IntPoint&) const;
139
140    size_t bytesDecodedToDetermineProperties() const;
141
142    int repetitionCount();
143
144    size_t frameCount() const;
145
146    // Callers should not call this after calling clear() with a higher index;
147    // see comments on clear() above.
148    PassNativeImagePtr createFrameAtIndex(size_t);
149
150    float frameDurationAtIndex(size_t);
151    bool frameHasAlphaAtIndex(size_t); // Whether or not the frame actually used any alpha.
152    bool frameIsCompleteAtIndex(size_t); // Whether or not the frame is completely decoded.
153    ImageOrientation orientationAtIndex(size_t) const; // EXIF image orientation
154
155    // Return the number of bytes in the decoded frame. If the frame is not yet
156    // decoded then return 0.
157    unsigned frameBytesAtIndex(size_t) const;
158
159#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
160    static unsigned maxPixelsPerDecodedImage() { return s_maxPixelsPerDecodedImage; }
161    static void setMaxPixelsPerDecodedImage(unsigned maxPixels) { s_maxPixelsPerDecodedImage = maxPixels; }
162#endif
163
164private:
165    NativeImageDecoderPtr m_decoder;
166
167#if !USE(CG)
168    AlphaOption m_alphaOption;
169    GammaAndColorProfileOption m_gammaAndColorProfileOption;
170#endif
171#if ENABLE(IMAGE_DECODER_DOWN_SAMPLING)
172    static unsigned s_maxPixelsPerDecodedImage;
173#endif
174};
175
176}
177
178#endif
179