[WIP] Move ImageDecoders to SkCodec

third_party/WebKit/Source/platform/image-decoders/ico/ICOImageDecoder.h

-/*
- * 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 "platform/image-decoders/FastSharedBufferReader.h"
-#include "platform/image-decoders/bmp/BMPImageReader.h"
-#include <memory>
-
-namespace blink {
-
-class PNGImageDecoder;
-
-// This class decodes the ICO and CUR image formats.
-class PLATFORM_EXPORT ICOImageDecoder final : public ImageDecoder {
-  WTF_MAKE_NONCOPYABLE(ICOImageDecoder);
-
- public:
-  ICOImageDecoder(AlphaOption, const ColorBehavior&, size_t max_decoded_bytes);
-  ~ICOImageDecoder() override;
-
-  // ImageDecoder:
-  String FilenameExtension() const override { return "ico"; }
-  void OnSetData(SegmentReader*) override;
-  IntSize Size() const override;
-  IntSize FrameSizeAtIndex(size_t) const override;
-  bool SetSize(unsigned width, unsigned height) override;
-  bool FrameIsCompleteAtIndex(size_t) const override;
-  // CAUTION: SetFailed() deletes all readers and decoders.  Be careful to
-  // avoid accessing deleted memory, especially when calling this from
-  // inside BMPImageReader!
-  bool SetFailed() override;
-  bool HotSpot(IntPoint&) const override;
-
- private:
-  enum ImageType {
-    kUnknown,
-    BMP,
-    PNG,
-  };
-
-  enum FileType {
-    ICON = 1,
-    CURSOR = 2,
-  };
-
-  struct IconDirectoryEntry {
-    DISALLOW_NEW_EXCEPT_PLACEMENT_NEW();
-    IntSize size_;
-    uint16_t bit_count_;
-    IntPoint hot_spot_;
-    uint32_t image_offset_;
-    uint32_t byte_size_;
-  };
-
-  // 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);
-
-  // ImageDecoder:
-  void DecodeSize() override { Decode(0, true); }
-  size_t DecodeFrameCount() override;
-  void Decode(size_t index) override { Decode(index, false); }
-
-  // TODO (scroggo): These functions are identical to functions in
-  // BMPImageReader. Share code?
-  inline uint8_t ReadUint8(size_t offset) const {
-    return fast_reader_.GetOneByte(decoded_offset_ + offset);
-  }
-
-  inline uint16_t ReadUint16(int offset) const {
-    char buffer[2];
-    const char* data =
-        fast_reader_.GetConsecutiveData(decoded_offset_ + offset, 2, buffer);
-    return BMPImageReader::ReadUint16(data);
-  }
-
-  inline uint32_t ReadUint32(int offset) const {
-    char buffer[4];
-    const char* data =
-        fast_reader_.GetConsecutiveData(decoded_offset_ + offset, 4, buffer);
-    return BMPImageReader::ReadUint32(data);
-  }
-
-  // If the desired PNGImageDecoder exists, gives it the appropriate data.
-  void SetDataForPNGDecoderAtIndex(size_t);
-
-  // Decodes the entry at |index|.  If |only_size| 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 only_size);
-
-  // 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();
-
-  // Stores the hot-spot for |index| in |hot_spot| and returns true,
-  // or returns false if there is none.
-  bool HotSpotAtIndex(size_t index, IntPoint& hot_spot) const;
-
-  // 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);
-
-  FastSharedBufferReader fast_reader_;
-
-  // An index into |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 decoded_offset_;
-
-  // Which type of file (ICO/CUR) this is.
-  FileType file_type_;
-
-  // The headers for the ICO.
-  typedef Vector<IconDirectoryEntry> IconDirectoryEntries;
-  IconDirectoryEntries dir_entries_;
-
-  // Count of directory entries is parsed from header before initializing
-  // dir_entries_. dir_entries_ is populated only when full header
-  // information including directory entries is available.
-  size_t dir_entries_count_;
-
-  // The image decoders for the various frames.
-  typedef Vector<std::unique_ptr<BMPImageReader>> BMPReaders;
-  BMPReaders bmp_readers_;
-  typedef Vector<std::unique_ptr<PNGImageDecoder>> PNGDecoders;
-  PNGDecoders png_decoders_;
-
-  // Valid only while a BMPImageReader is decoding, this holds the size
-  // for the particular entry being decoded.
-  IntSize frame_size_;
-
-  // Used to pass on to an internally created PNG decoder.
-  const ColorBehavior color_behavior_;
-};
-
-}  // namespace blink
-
-#endif