[iOS] Non-native scrolling animations are disabled

• Component: Scrolling
• Status: NEW ---

[Martin Robinson]

"Non-native" scrolling animations are disabled for iOS even when the RenderLayer specifies that the ScrollAnimator should be used. This is currently implemented via an #ifdef [1]

#if ENABLE(SMOOTH_SCROLLING) && !PLATFORM(IOS_FAMILY)
    if (m_scrollableArea.scrollAnimatorEnabled() && !behavior.contains(ScrollBehavior::NeverAnimate)) {
        m_scrollAnimation->setCurrentPosition(m_currentPosition);
        return m_scrollAnimation->scroll(orientation, granularity, step, multiplier);
    }
#endif


This bug tracks deciding whether or not it makes sense to remove this exception. An example of when this would come into play would be when a keyboard is plugged into an iOS device and the user scrolls via pageup / pagedown or the arrow keys.

1. https://github.com/WebKit/WebKit/blob/3148d6dc25355456915544ce7e6e070c7ebf213a/Source/WebCore/platform/ScrollAnimator.cpp#L103

[Radar WebKit Bug Importer]

<rdar://problem/76099562>