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// Copyright 2008, 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 BASE_GFX_PNG_DECODER_H__
#define BASE_GFX_PNG_DECODER_H__
#include <vector>
#include "base/basictypes.h"
class SkBitmap;
// Interface for decoding PNG data. This is a wrapper around libpng,
// which has an inconvenient interface for callers. This is currently designed
// for use in tests only (where we control the files), so the handling isn't as
// robust as would be required for a browser (see Decode() for more). WebKit
// has its own more complicated PNG decoder which handles, among other things,
// partially downloaded data.
class PNGDecoder {
public:
enum ColorFormat {
// 3 bytes per pixel (packed), in RGB order regardless of endianness.
// This is the native JPEG format.
FORMAT_RGB,
// 4 bytes per pixel, in RGBA order in memory regardless of endianness.
FORMAT_RGBA,
// 4 bytes per pixel, in BGRA order in memory regardless of endianness.
// This is the default Windows DIB order.
FORMAT_BGRA
};
// Decodes the PNG data contained in input of length input_size. The
// decoded data will be placed in *output with the dimensions in *w and *h
// on success (returns true). This data will be written in the 'format'
// format. On failure, the values of these output variables are undefined.
//
// This function may not support all PNG types, and it hasn't been tested
// with a large number of images, so assume a new format may not work. It's
// really designed to be able to read in something written by Encode() above.
static bool Decode(const unsigned char* input, size_t input_size,
ColorFormat format, std::vector<unsigned char>* output,
int* w, int* h);
// A convenience function for decoding PNGs as previously encoded by the PNG
// encoder. Chrome encodes png in the format PNGDecoder::FORMAT_BGRA.
//
// Returns true if data is non-null and can be decoded as a png, false
// otherwise.
static bool Decode(const std::vector<unsigned char>* data, SkBitmap* icon);
// Create a SkBitmap from a decoded BGRA DIB. The caller owns the returned
// SkBitmap.
static SkBitmap* CreateSkBitmapFromBGRAFormat(
std::vector<unsigned char>& bgra, int width, int height);
private:
DISALLOW_EVIL_CONSTRUCTORS(PNGDecoder);
};
#endif // BASE_GFX_PNG_DECODER_H__
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