From 02e25a3f48bd0cd1be349513a024d71891d64de0 Mon Sep 17 00:00:00 2001 From: Tab Atkins Date: Fri, 5 Jun 2015 14:58:43 -0700 Subject: [PATCH] [css-containment] Clarify that geometry is clipped by contain:paint, too, so you don't get scrollbars from invisible abspos or something. --- css-containment/Overview.bs | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/css-containment/Overview.bs b/css-containment/Overview.bs index d1c37d9fc6d..2ac0f3bc65c 100644 --- a/css-containment/Overview.bs +++ b/css-containment/Overview.bs @@ -192,6 +192,7 @@ Paint Containment Giving an element paint containment has the following effects: 1. The contents of the element must be clipped to the element's content box. + This includes both the paint of the descendants and their geometry (similar to overflow). 2. The element must act as a containing block for absolutely positioned and fixed positioned descendants. 3. The element must be a formatting context. @@ -203,5 +204,10 @@ Paint Containment 2. If the containing element is ''overflow:visible'', the UA can reserve "canvas" space for the element exactly the element's size. - (Normally, UAs often predictively overpaint elements somewhat, - so scrolls can start showing content immediately.) + (In similar, scrollable, situations, like ''overflow: hidden'', + it's possible to scroll to the currently-clipped content, + so UAs often predictively overpaint somewhat + so there's something to see as soon as the scroll happens, + rather than a frame later.) + +