void DeferredImageDecoder::prepareLazyDecodedFrames()
{
if (!s_enabled
|| !m_actualDecoder
|| !m_actualDecoder->isSizeAvailable()
|| m_actualDecoder->filenameExtension() == "ico")
return;
activateLazyDecoding();
const size_t previousSize = m_lazyDecodedFrames.size();
m_lazyDecodedFrames.resize(m_actualDecoder->frameCount());
for (size_t i = previousSize; i < m_lazyDecodedFrames.size(); ++i) {
OwnPtr<ImageFrame> frame(adoptPtr(new ImageFrame()));
frame->setSkBitmap(createLazyDecodingBitmap(i));
frame->setDuration(m_actualDecoder->frameDurationAtIndex(i));
frame->setStatus(m_actualDecoder->frameIsCompleteAtIndex(i) ? ImageFrame::FrameComplete : ImageFrame::FramePartial);
m_lazyDecodedFrames[i] = frame.release();
}
// The last lazy decoded frame created from previous call might be
// incomplete so update its state.
if (previousSize)
m_lazyDecodedFrames[previousSize - 1]->setStatus(m_actualDecoder->frameIsCompleteAtIndex(previousSize - 1) ? ImageFrame::FrameComplete : ImageFrame::FramePartial);
if (m_allDataReceived) {
m_repetitionCount = m_actualDecoder->repetitionCount();
m_actualDecoder.clear();
m_data = nullptr;
}
}
ImageFrame* DeferredImageDecoder::frameBufferAtIndex(size_t index)
{
// Only defer image decoding if this is a single frame image. The reason is
// because a multiframe is usually animated GIF. Animation is handled by
// BitmapImage which uses some metadata functions that do synchronous image
// decoding.
if (s_enabled
&& m_actualDecoder
&& m_actualDecoder->repetitionCount() == cAnimationNone
&& m_actualDecoder->isSizeAvailable()
&& m_actualDecoder->frameCount() == 1) {
m_size = m_actualDecoder->size();
m_filenameExtension = m_actualDecoder->filenameExtension();
m_orientation = m_actualDecoder->orientation();
SkBitmap lazyDecodedSkBitmap = createLazyDecodingBitmap();
m_lazyDecodedFrame.setSkBitmap(lazyDecodedSkBitmap);
// Don't mark the frame as completely decoded until the underlying
// decoder has really decoded it. Until then, our data and metadata may
// be incorrect, so callers can't rely on them.
m_lazyDecodedFrame.setStatus(ImageFrame::FramePartial);
}
return m_actualDecoder ? m_actualDecoder->frameBufferAtIndex(index) : &m_lazyDecodedFrame;
}
