diff --git a/css-overflow-3/Overview.bs b/css-overflow-3/Overview.bs index 74e77fbf5dc4..afdcd3efe021 100644 --- a/css-overflow-3/Overview.bs +++ b/css-overflow-3/Overview.bs @@ -391,6 +391,20 @@ Scrolling Overflow uses the principal writing mode for determining its [=scroll origin=] and [=initial scroll position=]. + Note: In the case where a [=scroll container=] (or one of its ancestors) + is the target of a graphical transform, + the UA might need to take this transform into account + when mapping user inputs to scrolling operations. + For instance, on a touch screen where the user scrolls + by directly dragging the content, + the transform would be expected to be taken into account + to match the direction of scrolling to the gesture. + On the other hand, other user inputs + (such as the Page Down key, or a 1D scroll wheel) + might be more naturally interpreted ignoring the transform. + Choosing the appropriate behavior for each scrolling mechanism + is the responsibility of the UA. +