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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "nsIconDecoder.h"
#include "RasterImage.h"
#include "SurfacePipeFactory.h"
using namespace mozilla::gfx;
namespace mozilla {
namespace image {
static const uint32_t ICON_HEADER_SIZE = 2;
nsIconDecoder::nsIconDecoder(RasterImage* aImage)
: Decoder(aImage)
, mLexer(Transition::To(State::HEADER, ICON_HEADER_SIZE),
Transition::TerminateSuccess())
, mBytesPerRow() // set by ReadHeader()
{
// Nothing to do
}
nsIconDecoder::~nsIconDecoder()
{ }
LexerResult
nsIconDecoder::DoDecode(SourceBufferIterator& aIterator, IResumable* aOnResume)
{
MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
return mLexer.Lex(aIterator, aOnResume,
[=](State aState, const char* aData, size_t aLength) {
switch (aState) {
case State::HEADER:
return ReadHeader(aData);
case State::ROW_OF_PIXELS:
return ReadRowOfPixels(aData, aLength);
case State::FINISH:
return Finish();
default:
MOZ_CRASH("Unknown State");
}
});
}
LexerTransition<nsIconDecoder::State>
nsIconDecoder::ReadHeader(const char* aData)
{
// Grab the width and height.
uint8_t width = uint8_t(aData[0]);
uint8_t height = uint8_t(aData[1]);
// The input is 32bpp, so we expect 4 bytes of data per pixel.
mBytesPerRow = width * 4;
// Post our size to the superclass.
PostSize(width, height);
// Icons have alpha.
PostHasTransparency();
// If we're doing a metadata decode, we're done.
if (IsMetadataDecode()) {
return Transition::TerminateSuccess();
}
MOZ_ASSERT(!mImageData, "Already have a buffer allocated?");
Maybe<SurfacePipe> pipe =
SurfacePipeFactory::CreateSurfacePipe(this, 0, Size(), OutputSize(),
FullFrame(), SurfaceFormat::B8G8R8A8,
SurfacePipeFlags());
if (!pipe) {
return Transition::TerminateFailure();
}
mPipe = Move(*pipe);
MOZ_ASSERT(mImageData, "Should have a buffer now");
return Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
}
LexerTransition<nsIconDecoder::State>
nsIconDecoder::ReadRowOfPixels(const char* aData, size_t aLength)
{
MOZ_ASSERT(aLength % 4 == 0, "Rows should contain a multiple of four bytes");
auto result = mPipe.WritePixels<uint32_t>([&]() -> NextPixel<uint32_t> {
if (aLength == 0) {
return AsVariant(WriteState::NEED_MORE_DATA); // Done with this row.
}
uint32_t pixel;
memcpy(&pixel, aData, 4);
aData += 4;
aLength -= 4;
return AsVariant(pixel);
});
MOZ_ASSERT(result != WriteState::FAILURE);
Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
if (invalidRect) {
PostInvalidation(invalidRect->mInputSpaceRect,
Some(invalidRect->mOutputSpaceRect));
}
return result == WriteState::FINISHED
? Transition::To(State::FINISH, 0)
: Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
}
LexerTransition<nsIconDecoder::State>
nsIconDecoder::Finish()
{
PostFrameStop();
PostDecodeDone();
return Transition::TerminateSuccess();
}
} // namespace image
} // namespace mozilla
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