Bug 143488 – [Gtk] Animation is not stopped when animation class is removed

• Component: Animations
• Status: NEW

[Eduard Kegulskiy]

Created attachment 250278 [details]
HTML file showing the problem

The problem is found with GTK port when accelerated Compositing is used.

The attached test application is doing the following steps:
1. Apply translateZ(0) to <p> element
2. Apply CSS class called .delayedScrollingLabelA.animate to perform animation using -webkit-animation property.
3. Remove .delayedScrollingLabelA.animate class.

At step (3), it is expected that animation should stop, however it continues. The problem does not happen if step (1) is omitted.

[Eduard Kegulskiy]

The problem seems to be in GraphicsLayerTextureMapper class.

Specifically, when animation is added, the GraphicsLayerTextureMapper::addAnimation() is called which does 2 things:
1. add new animation to m_animations set
2. calls notifyChange(AnimationChange) to notify m_layer that its own internal set of animations has been modified.

However, when animation is removed via GraphicsLayerTextureMapper::removeAnimation(), the code only removes the animation from the m_animations set, but does not notify the m_layer.

The proposed patch would be to add notifyChange(AnimationChange) call to both removeAnimation() and pauseAnimation() as following:

void GraphicsLayerTextureMapper::pauseAnimation(const String& animationName, double timeOffset)
{
    m_animations.pause(animationName, timeOffset);
    notifyChange(AnimationChange);
}

void GraphicsLayerTextureMapper::removeAnimation(const String& animationName)
{
    m_animations.remove(animationName);
    notifyChange(AnimationChange);
}

[Eduard Kegulskiy]

Hi Alexei,

do you think this bug is GTK-only? The GraphicsLayerTextureMapper class seems to be common code for all ports since it resides under webcore/platform/graphics/texmap folder?

(sorry if I misunderstand something, I am new to webkit development community)