/* * 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" #include "PNGImageDecoder.h" namespace WebCore { // This class decodes the ICO and CUR image formats. class ICOImageDecoder : public BMPImageReader { public: // See comments on |m_preferredIconSize| below. ICOImageDecoder(const IntSize& preferredIconSize) : m_preferredIconSize(preferredIconSize) , m_imageType(Unknown) { m_andMaskState = NotYetDecoded; } virtual String filenameExtension() const { return "ico"; } // BMPImageReader virtual void decodeImage(SharedBuffer* data); virtual RGBA32Buffer* frameBufferAtIndex(size_t index); // ImageDecoder virtual bool isSizeAvailable() const; virtual IntSize size() const; private: enum ImageType { Unknown, BMP, PNG, }; // These are based on the Windows ICONDIR and ICONDIRENTRY structs, but // with unnecessary entries removed. struct IconDirectory { uint16_t idCount; }; struct IconDirectoryEntry { uint16_t bWidth; // 16 bits so we can represent 256 as 256, not 0 uint16_t bHeight; // " uint16_t wBitCount; uint32_t dwImageOffset; }; // Processes the ICONDIR at the beginning of the data. Returns true if the // directory could be decoded. bool processDirectory(SharedBuffer*); // 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(SharedBuffer*); // Reads and returns a directory entry from the current offset into |data|. IconDirectoryEntry readDirectoryEntry(SharedBuffer*); // Returns true if |entry| is a preferable icon entry to m_dirEntry. // Larger sizes, or greater bitdepths at the same size, are preferable. bool isBetterEntry(const IconDirectoryEntry&) const; // Called when the image to be decoded is a PNG rather than a BMP. // Instantiates a PNGImageDecoder, decodes the image, and copies the // results locally. void decodePNG(SharedBuffer*); // The entry size we should prefer. If this is empty, we choose the // largest available size. If no entries of the desired size are // available, we pick the next larger size. IntSize m_preferredIconSize; // The headers for the ICO. IconDirectory m_directory; IconDirectoryEntry m_dirEntry; // The PNG decoder, if we need to use one. PNGImageDecoder m_pngDecoder; // What kind of image data is stored at the entry we're decoding. ImageType m_imageType; }; } // namespace WebCore #endif