[webkit-qt] startAnimation and nativeImageForCurrentFrame order

Mon Apr 19 06:04:18 PDT 2010

In Firefox, you will see a nice animating background. In QtLauncher, you
see a still image:

<html><body
background="http://www.mathworks.com/matlabcentral/fx_files/21944/1/content/DancingPeaks.gif"></body></html>

(any animated gif will do)

If you agree, I will file a bug and fix it myself.

Zoltan

> Hi,
>
> I am not sure this is a potential bug, but I would be curious about your
> opinion:
>
> In ImageQt.cpp - BitmapImage::draw: In my machine the
> nativeImageForCurrentFrame() clears the m_reader argument of
> ImageDecoderQt through forceLoadEverything() call. The startAnimation()
> requires this m_reader to detect the paramters of any animation. Since the
> startAnimation() is called before nativeImageForCurrentFrame(), the
> animation works here.
>
> However:
> In Image.cpp - Image::drawTiled (both) calls Qt specific drawPattern()
> before the startAnimation(), and naturally, drawPattern() (in ImageQt.cpp)
> calls nativeImageForCurrentFrame() to get the current frame. Since
> nativeImageForCurrentFrame() clears the m_reader, the animation probably
> never starts in Qt.
>
> If I understand correctly, WebKit probably does not force any calling
> order for startAnimation() and nativeImageForCurrentFrame(), while the Qt
> implementation does. Am I see right? Is this intended?
>
> Zoltan