Async scrolling (APZ) has been enabled for a new input method, scrollbar dragging, on the Nightly branch.
This was initially implemented by Benoit Girard about a year ago, briefly enabled on Nightly, and then disabled again due to regressions that we didn't have the time to fix at the time. It languished on the back burner until it was picked up recently by Kevin Wern, a volunteer contributor who has been doing some great work for APZ. Thanks, Kevin, for getting this in good enough shape to enable on Nightly again! There are three known issues with this feature. Two of them are hard to reproduce: Bug 1249750 - Content area occasionally goes blank when dragging scrollbar with APZ drag enabled Bug 1250649 - async drag: Dragging while the scrollbar's max value changes permanently breaks scrolling If you encounter these, please post testcases / URLs to these bugs. The third one, bug 1251617, is that a quick drag on a long page results in checkerboarding. This is hard to fix, and can be thought of as a conscious tradeoff: we're deliberately allowing you to drag faster than we can paint the content you're moving over. If you have any thoughts about this tradeoff, please post them to this bug. If you encounter any other regressions related to scrollbar dragging, please file bugs blocking bug 1211610, which is the tracking bug for this work. Thanks, Botond _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform
