imgContainerGIF currently implements only one function of imgIDecoderObserver .. OnDataAvailable(..). nsGIFDecoder2 sends OnDataAvailable calls when it has image data ready. imgRequest::OnDataAvailable gets them and calls imgContainerGIF::OnDataAvailable before firing off OnDataAvailable of the other observers in order to ensure the composited frame is current. Instead of nsGIFDecoder2 going in a round about way to get to imgContainerGIF, nsGIFDecoder2 could just call a function in imgContainerGIF directly. It already has a reference to the imgContainerGIF object. So the steps to "fix" this "bug" are: 1) Create a public function in imgContainerGIF to handle new frame data. Call it NewFrameData(..), move code from imgContainerGIF::OnDataAvailable(..) to it. 2) remove imgIDecoderObserver from imgContainerGIF 3) Where nsGIFDecoder2 calls OnDataAvailable, make it call NewFrameData first Unfortunately, we can't remove the call in imgRequest::OnDataAvailable to imgIContainer::OnDataAvailable, because we don't know if any other classes inheriting from imgIContainer require being called (perhaps imgContainerART does) I don't really think this will effect performance, but it will make imgContainerGIF more readable.

>we don't know if any other classes >inheriting from imgIContainer require being called (perhaps imgContainerART does) well, you could check on that (ART) and if it doesn't require it, remove it...

imgContainerART doesn't implement imgIDecoderObserver (from what I've been told), so I removed that call in imgRequest as well as what I said in Comment #0.

Now with NS_STATIC_CAST(NS_STATIC_CAST())

Comment on attachment 108080 [details] [diff] [review] remove imgIDecoderObserver I've been told that imgContainerART doesn't implement imgIDecoderObserver, so code removal in imgRequest is okay. :)

Comment on attachment 108080 [details] [diff] [review] remove imgIDecoderObserver sr=tor

Checking in src/imgRequest.cpp; /cvsroot/mozilla/modules/libpr0n/src/imgRequest.cpp,v <-- imgRequest.cpp new revision: 1.72; previous revision: 1.71 done Checking in decoders/gif/imgContainerGIF.cpp; /cvsroot/mozilla/modules/libpr0n/decoders/gif/imgContainerGIF.cpp,v <-- imgContainerGIF.cpp new revision: 1.8; previous revision: 1.7 done Checking in decoders/gif/imgContainerGIF.h; /cvsroot/mozilla/modules/libpr0n/decoders/gif/imgContainerGIF.h,v <-- imgContainerGIF.h new revision: 1.4; previous revision: 1.3 done Checking in decoders/gif/nsGIFDecoder2.cpp; /cvsroot/mozilla/modules/libpr0n/decoders/gif/nsGIFDecoder2.cpp,v <-- nsGIFDecoder2.cpp new revision: 1.41; previous revision: 1.40 done Checking in decoders/gif/nsGIFDecoder2.h; /cvsroot/mozilla/modules/libpr0n/decoders/gif/nsGIFDecoder2.h,v <-- nsGIFDecoder2.h new revision: 1.21; previous revision: 1.20 done