diff options
Diffstat (limited to 'WebCore/platform/image-decoders/ImageDecoder.h')
| -rw-r--r-- | WebCore/platform/image-decoders/ImageDecoder.h | 110 |
1 files changed, 58 insertions, 52 deletions
diff --git a/WebCore/platform/image-decoders/ImageDecoder.h b/WebCore/platform/image-decoders/ImageDecoder.h index 8d27072..002395b 100644 --- a/WebCore/platform/image-decoders/ImageDecoder.h +++ b/WebCore/platform/image-decoders/ImageDecoder.h @@ -46,18 +46,21 @@ namespace WebCore { - // The RGBA32Buffer object represents the decoded image data in RGBA32 format. This buffer is what all - // decoders write a single frame into. Frames are then instantiated for drawing by being handed this buffer. + // The RGBA32Buffer object represents the decoded image data in RGBA32 + // format. This buffer is what all decoders write a single frame into. + // Frames are then instantiated for drawing by being handed this buffer. class RGBA32Buffer { public: enum FrameStatus { FrameEmpty, FramePartial, FrameComplete }; enum FrameDisposalMethod { - // If you change the numeric values of these, make sure you audit all - // users, as some users may cast raw values to/from these constants. - DisposeNotSpecified, // Leave frame in framebuffer - DisposeKeep, // Leave frame in framebuffer - DisposeOverwriteBgcolor, // Clear frame to transparent - DisposeOverwritePrevious, // Clear frame to previous framebuffer contents + // If you change the numeric values of these, make sure you audit + // all users, as some users may cast raw values to/from these + // constants. + DisposeNotSpecified, // Leave frame in framebuffer + DisposeKeep, // Leave frame in framebuffer + DisposeOverwriteBgcolor, // Clear frame to transparent + DisposeOverwritePrevious, // Clear frame to previous framebuffer + // contents }; #if PLATFORM(SKIA) || PLATFORM(QT) typedef uint32_t PixelData; @@ -67,15 +70,11 @@ namespace WebCore { RGBA32Buffer(); - // For backends which refcount their data, this constructor doesn't need - // to create a new copy of the image data, only increase the ref count. - // - // This exists because ImageDecoder keeps a Vector<RGBA32Buffer>, and - // Vector requires this constructor. - RGBA32Buffer(const RGBA32Buffer& other) - { - operator=(other); - } + RGBA32Buffer(const RGBA32Buffer& other) { operator=(other); } + + // For backends which refcount their data, this operator doesn't need to + // create a new copy of the image data, only increase the ref count. + RGBA32Buffer& operator=(const RGBA32Buffer& other); // Deletes the pixel data entirely; used by ImageDecoder to save memory // when we no longer need to display a frame and only need its metadata. @@ -142,8 +141,6 @@ namespace WebCore { #endif private: - RGBA32Buffer& operator=(const RGBA32Buffer& other); - int width() const; int height() const; @@ -188,26 +185,33 @@ namespace WebCore { Vector<PixelData> m_bytes; IntSize m_size; // The size of the buffer. This should be the // same as ImageDecoder::m_size. - bool m_hasAlpha; // Whether or not any of the pixels in the buffer have transparency. + bool m_hasAlpha; // Whether or not any of the pixels in the buffer + // have transparency. #endif - IntRect m_rect; // The rect of the original specified frame within the overall buffer. - // This will always just be the entire buffer except for GIF frames - // whose original rect was smaller than the overall image size. - FrameStatus m_status; // Whether or not this frame is completely finished decoding. + IntRect m_rect; // The rect of the original specified frame within + // the overall buffer. This will always just be + // the entire buffer except for GIF frames whose + // original rect was smaller than the overall + // image size. + FrameStatus m_status; // Whether or not this frame is completely + // finished decoding. unsigned m_duration; // The animation delay. FrameDisposalMethod m_disposalMethod; - // What to do with this frame's data when initializing the next frame. + // What to do with this frame's data when + // initializing the next frame. }; - // The ImageDecoder class represents a base class for specific image format decoders - // (e.g., GIF, JPG, PNG, ICO) to derive from. All decoders decode into RGBA32 format - // and the base class manages the RGBA32 frame cache. + // The ImageDecoder class represents a base class for specific image format + // decoders (e.g., GIF, JPG, PNG, ICO) to derive from. All decoders decode + // into RGBA32 format and the base class manages the RGBA32 frame cache. + // + // ENABLE(IMAGE_DECODER_DOWN_SAMPLING) allows image decoders to write + // directly to scaled output buffers by down sampling. Call + // setMaxNumPixels() to specify the biggest size that decoded images can + // have. Image decoders will deflate those images that are bigger than + // m_maxNumPixels. (Not supported by all image decoders yet) class ImageDecoder : public Noncopyable { public: - // ENABLE(IMAGE_DECODER_DOWN_SAMPLING) allows image decoders to write directly to - // scaled output buffers by down sampling. Call setMaxNumPixels() to specify the - // biggest size that decoded images can have. Image decoders will deflate those - // images that are bigger than m_maxNumPixels. (Not supported by all image decoders yet) ImageDecoder() : m_scaled(false) , m_failed(false) @@ -224,21 +228,22 @@ namespace WebCore { // needing to write a dedicated setData() implementation. static ImageDecoder* create(const SharedBuffer& data); - // The the filename extension usually associated with an undecoded image of this type. + // The the filename extension usually associated with an undecoded image + // of this type. virtual String filenameExtension() const = 0; - // All specific decoder plugins must do something with the data they are given. bool isAllDataReceived() const { return m_isAllDataReceived; } + virtual void setData(SharedBuffer* data, bool allDataReceived) { m_data = data; m_isAllDataReceived = allDataReceived; } - // Whether or not the size information has been decoded yet. This default - // implementation just returns true if the size has been set and we have not - // seen a failure. Decoders may want to override this to lazily decode - // enough of the image to get the size. + // Whether or not the size information has been decoded yet. This + // default implementation just returns true if the size has been set and + // we have not seen a failure. Decoders may want to override this to + // lazily decode enough of the image to get the size. virtual bool isSizeAvailable() { return !m_failed && m_sizeAvailable; @@ -266,10 +271,10 @@ namespace WebCore { return size(); } - // Called by the image decoders to set their decoded size, this also check - // the size for validity. It will return true if the size was set, or false - // if there is an error. On error, the m_failed flag will be set and the - // caller should immediately stop decoding. + // Called by the image decoders to set their decoded size, this also + // checks the size for validity. It will return true if the size was + // set, or false if there is an error. On error, the m_failed flag will + // be set and the caller should immediately stop decoding. virtual bool setSize(unsigned width, unsigned height) { if (isOverSize(width, height)) { @@ -281,29 +286,30 @@ namespace WebCore { return true; } - // The total number of frames for the image. Classes that support multiple frames - // will scan the image data for the answer if they need to (without necessarily - // decoding all of the individual frames). + // The total number of frames for the image. Classes that support + // multiple frames will scan the image data for the answer if they need + // to (without necessarily decoding all of the individual frames). virtual size_t frameCount() { return 1; } // The number of repetitions to perform for an animation loop. virtual int repetitionCount() const { return cAnimationNone; } - // Called to obtain the RGBA32Buffer full of decoded data for rendering. The - // decoder plugin will decode as much of the frame as it can before handing - // back the buffer. + // Called to obtain the RGBA32Buffer full of decoded data for rendering. + // The decoder plugin will decode as much of the frame as it can before + // handing back the buffer. virtual RGBA32Buffer* frameBufferAtIndex(size_t) = 0; - // Whether or not the underlying image format even supports alpha transparency. + // Whether or not the underlying image format even supports alpha + // transparency. virtual bool supportsAlpha() const { return true; } bool failed() const { return m_failed; } void setFailed() { m_failed = true; } // Wipe out frames in the frame buffer cache before |clearBeforeFrame|, - // assuming this can be done without breaking decoding. Different decoders - // place different restrictions on what frames are safe to destroy, so this - // is left to them to implement. + // assuming this can be done without breaking decoding. Different + // decoders place different restrictions on what frames are safe to + // destroy, so this is left to them to implement. // For convenience's sake, we provide a default (empty) implementation, // since in practice only GIFs will ever use this. virtual void clearFrameBufferCache(size_t clearBeforeFrame) { } |