Moving GraphicsContext and dependencies from core to platform.

Source/core/platform/image-decoders/gif/GIFImageReader.h

-/* -*- Mode: C; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
-/* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla Communicator client code.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 1998
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either the GNU General Public License Version 2 or later (the "GPL"), or
- * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
-#ifndef GIFImageReader_h
-#define GIFImageReader_h
-
-// Define ourselves as the clientPtr.  Mozilla just hacked their C++ callback class into this old C decoder,
-// so we will too.
-#include "platform/SharedBuffer.h"
-#include "core/platform/image-decoders/gif/GIFImageDecoder.h"
-#include "wtf/OwnPtr.h"
-#include "wtf/PassOwnPtr.h"
-#include "wtf/Vector.h"
-
-#define MAX_DICTIONARY_ENTRY_BITS 12
-#define MAX_DICTIONARY_ENTRIES    4096 // 2^MAX_DICTIONARY_ENTRY_BITS
-#define MAX_COLORS                256
-#define BYTES_PER_COLORMAP_ENTRY  3
-
-const int cLoopCountNotSeen = -2;
-
-// List of possible parsing states.
-enum GIFState {
-    GIFType,
-    GIFGlobalHeader,
-    GIFGlobalColormap,
-    GIFImageStart,
-    GIFImageHeader,
-    GIFImageColormap,
-    GIFImageBody,
-    GIFLZWStart,
-    GIFLZW,
-    GIFSubBlock,
-    GIFExtension,
-    GIFControlExtension,
-    GIFConsumeBlock,
-    GIFSkipBlock,
-    GIFDone,
-    GIFCommentExtension,
-    GIFApplicationExtension,
-    GIFNetscapeExtensionBlock,
-    GIFConsumeNetscapeExtension,
-    GIFConsumeComment
-};
-
-struct GIFFrameContext;
-
-// LZW decoder state machine.
-class GIFLZWContext {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    GIFLZWContext(WebCore::GIFImageDecoder* client, const GIFFrameContext* frameContext)
-        : codesize(0)
-        , codemask(0)
-        , clearCode(0)
-        , avail(0)
-        , oldcode(0)
-        , firstchar(0)
-        , bits(0)
-        , datum(0)
-        , ipass(0)
-        , irow(0)
-        , rowsRemaining(0)
-        , rowIter(0)
-        , m_client(client)
-        , m_frameContext(frameContext)
-    { }
-
-    bool prepareToDecode();
-    bool outputRow(GIFRow::const_iterator rowBegin);
-    bool doLZW(const unsigned char* block, size_t bytesInBlock);
-    bool hasRemainingRows() { return rowsRemaining; }
-
-private:
-    // LZW decoding states and output states.
-    int codesize;
-    int codemask;
-    int clearCode; // Codeword used to trigger dictionary reset.
-    int avail; // Index of next available slot in dictionary.
-    int oldcode;
-    unsigned char firstchar;
-    int bits; // Number of unread bits in "datum".
-    int datum; // 32-bit input buffer.
-    int ipass; // Interlace pass; Ranges 1-4 if interlaced.
-    size_t irow; // Current output row, starting at zero.
-    size_t rowsRemaining; // Rows remaining to be output.
-
-    unsigned short prefix[MAX_DICTIONARY_ENTRIES];
-    unsigned char suffix[MAX_DICTIONARY_ENTRIES];
-    unsigned short suffixLength[MAX_DICTIONARY_ENTRIES];
-    GIFRow rowBuffer; // Single scanline temporary buffer.
-    GIFRow::iterator rowIter;
-
-    // Initialized during construction and read-only.
-    WebCore::GIFImageDecoder* m_client;
-    const GIFFrameContext* m_frameContext;
-};
-
-// Data structure for one LZW block.
-struct GIFLZWBlock {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    GIFLZWBlock(size_t position, size_t size)
-        : blockPosition(position)
-        , blockSize(size)
-    {
-    }
-
-    size_t blockPosition;
-    size_t blockSize;
-};
-
-class GIFColorMap {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    typedef Vector<WebCore::ImageFrame::PixelData> Table;
-
-    GIFColorMap()
-        : m_isDefined(false)
-        , m_position(0)
-        , m_colors(0)
-    {
-    }
-
-    // Set position and number of colors for the RGB table in the data stream.
-    void setTablePositionAndSize(size_t position, size_t colors)
-    {
-        m_position = position;
-        m_colors = colors;
-    }
-    void setDefined() { m_isDefined = true; }
-    bool isDefined() const { return m_isDefined; }
-
-    // Build RGBA table using the data stream.
-    void buildTable(const unsigned char* data, size_t length);
-    const Table& table() const { return m_table; }
-
-private:
-    bool m_isDefined;
-    size_t m_position;
-    size_t m_colors;
-    Table m_table;
-};
-
-// Frame output state machine.
-struct GIFFrameContext {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    GIFFrameContext(int id)
-        : m_frameId(id)
-        , m_xOffset(0)
-        , m_yOffset(0)
-        , m_width(0)
-        , m_height(0)
-        , m_transparentPixel(kNotFound)
-        , m_disposalMethod(WebCore::ImageFrame::DisposeNotSpecified)
-        , m_dataSize(0)
-        , m_progressiveDisplay(false)
-        , m_interlaced(false)
-        , m_delayTime(0)
-        , m_currentLzwBlock(0)
-        , m_isComplete(false)
-        , m_isHeaderDefined(false)
-        , m_isDataSizeDefined(false)
-    {
-    }
-
-    ~GIFFrameContext()
-    {
-    }
-
-    void addLzwBlock(size_t position, size_t size)
-    {
-        m_lzwBlocks.append(GIFLZWBlock(position, size));
-    }
-
-    bool decode(const unsigned char* data, size_t length, WebCore::GIFImageDecoder* client, bool* frameDecoded);
-
-    int frameId() const { return m_frameId; }
-    void setRect(unsigned x, unsigned y, unsigned width, unsigned height)
-    {
-        m_xOffset = x;
-        m_yOffset = y;
-        m_width = width;
-        m_height = height;
-    }
-    WebCore::IntRect frameRect() const { return WebCore::IntRect(m_xOffset, m_yOffset, m_width, m_height); }
-    unsigned xOffset() const { return m_xOffset; }
-    unsigned yOffset() const { return m_yOffset; }
-    unsigned width() const { return m_width; }
-    unsigned height() const { return m_height; }
-    size_t transparentPixel() const { return m_transparentPixel; }
-    void setTransparentPixel(size_t pixel) { m_transparentPixel = pixel; }
-    WebCore::ImageFrame::DisposalMethod disposalMethod() const { return m_disposalMethod; }
-    void setDisposalMethod(WebCore::ImageFrame::DisposalMethod disposalMethod) { m_disposalMethod = disposalMethod; }
-    unsigned delayTime() const { return m_delayTime; }
-    void setDelayTime(unsigned delay) { m_delayTime = delay; }
-    bool isComplete() const { return m_isComplete; }
-    void setComplete() { m_isComplete = true; }
-    bool isHeaderDefined() const { return m_isHeaderDefined; }
-    void setHeaderDefined() { m_isHeaderDefined = true; }
-    bool isDataSizeDefined() const { return m_isDataSizeDefined; }
-    int dataSize() const { return m_dataSize; }
-    void setDataSize(int size)
-    {
-        m_dataSize = size;
-        m_isDataSizeDefined = true;
-    }
-    bool progressiveDisplay() const { return m_progressiveDisplay; }
-    void setProgressiveDisplay(bool progressiveDisplay) { m_progressiveDisplay = progressiveDisplay; }
-    bool interlaced() const { return m_interlaced; }
-    void setInterlaced(bool interlaced) { m_interlaced = interlaced; }
-
-    void clearDecodeState() { m_lzwContext.clear(); }
-    const GIFColorMap& localColorMap() const { return m_localColorMap; }
-    GIFColorMap& localColorMap() { return m_localColorMap; }
-
-private:
-    int m_frameId;
-    unsigned m_xOffset;
-    unsigned m_yOffset; // With respect to "screen" origin.
-    unsigned m_width;
-    unsigned m_height;
-    size_t m_transparentPixel; // Index of transparent pixel. Value is kNotFound if there is no transparent pixel.
-    WebCore::ImageFrame::DisposalMethod m_disposalMethod; // Restore to background, leave in place, etc.
-    int m_dataSize;
-
-    bool m_progressiveDisplay; // If true, do Haeberli interlace hack.
-    bool m_interlaced; // True, if scanlines arrive interlaced order.
-
-    unsigned m_delayTime; // Display time, in milliseconds, for this image in a multi-image GIF.
-
-    OwnPtr<GIFLZWContext> m_lzwContext;
-    Vector<GIFLZWBlock> m_lzwBlocks; // LZW blocks for this frame.
-    GIFColorMap m_localColorMap;
-
-    size_t m_currentLzwBlock;
-    bool m_isComplete;
-    bool m_isHeaderDefined;
-    bool m_isDataSizeDefined;
-};
-
-class GIFImageReader {
-    WTF_MAKE_FAST_ALLOCATED;
-public:
-    GIFImageReader(WebCore::GIFImageDecoder* client = 0)
-        : m_client(client)
-        , m_state(GIFType)
-        , m_bytesToConsume(6) // Number of bytes for GIF type, either "GIF87a" or "GIF89a".
-        , m_bytesRead(0)
-        , m_version(0)
-        , m_screenWidth(0)
-        , m_screenHeight(0)
-        , m_loopCount(cLoopCountNotSeen)
-        , m_parseCompleted(false)
-    {
-    }
-
-    ~GIFImageReader()
-    {
-    }
-
-    void setData(PassRefPtr<WebCore::SharedBuffer> data) { m_data = data; }
-    bool parse(WebCore::GIFImageDecoder::GIFParseQuery);
-    bool decode(size_t frameIndex);
-
-    size_t imagesCount() const
-    {
-        if (m_frames.isEmpty())
-            return 0;
-
-        // This avoids counting an empty frame when the file is truncated right after
-        // GIFControlExtension but before GIFImageHeader.
-        // FIXME: This extra complexity is not necessary and we should just report m_frames.size().
-        return m_frames.last()->isHeaderDefined() ? m_frames.size() : m_frames.size() - 1;
-    }
-    int loopCount() const { return m_loopCount; }
-
-    const GIFColorMap& globalColorMap() const
-    {
-        return m_globalColorMap;
-    }
-
-    const GIFFrameContext* frameContext(size_t index) const
-    {
-        return index < m_frames.size() ? m_frames[index].get() : 0;
-    }
-
-    bool parseCompleted() const { return m_parseCompleted; }
-
-    void clearDecodeState(size_t index) { m_frames[index]->clearDecodeState(); }
-
-private:
-    bool parseData(size_t dataPosition, size_t len, WebCore::GIFImageDecoder::GIFParseQuery);
-    void setRemainingBytes(size_t);
-
-    const unsigned char* data(size_t dataPosition) const
-    {
-        return reinterpret_cast<const unsigned char*>(m_data->data()) + dataPosition;
-    }
-
-    void addFrameIfNecessary();
-    bool currentFrameIsFirstFrame() const
-    {
-        return m_frames.isEmpty() || (m_frames.size() == 1u && !m_frames[0]->isComplete());
-    }
-
-    WebCore::GIFImageDecoder* m_client;
-
-    // Parsing state machine.
-    GIFState m_state; // Current decoder master state.
-    size_t m_bytesToConsume; // Number of bytes to consume for next stage of parsing.
-    size_t m_bytesRead; // Number of bytes processed.
-
-    // Global (multi-image) state.
-    int m_version; // Either 89 for GIF89 or 87 for GIF87.
-    unsigned m_screenWidth; // Logical screen width & height.
-    unsigned m_screenHeight;
-    GIFColorMap m_globalColorMap;
-    int m_loopCount; // Netscape specific extension block to control the number of animation loops a GIF renders.
-
-    Vector<OwnPtr<GIFFrameContext> > m_frames;
-
-    RefPtr<WebCore::SharedBuffer> m_data;
-    bool m_parseCompleted;
-};
-
-#endif