- From: Valdrin Koshi via GitHub <sysbot+gh@w3.org>
- Date: Fri, 12 Aug 2016 02:15:40 +0000
- To: public-css-archive@w3.org
valdrinkoshi has just created a new issue for https://github.com/w3c/csswg-drafts: == [css-positioning] position: fixed within a stacking context == The spec of `position: fixed` specifies that: > Fixed positioning is similar to absolute positioning. The only difference is that for a fixed positioned box, the containing block is established by the viewport. https://www.w3.org/TR/css-position-3/#fixed-pos https://www.w3.org/TR/css-position-3/#containing-block But it is not obvious what happens if a `position:fixed` element is contained in a parent that creates a stacking context. What happens is that the fixed element participates to the scroll and gets clipped http://jsbin.com/kehexi/3/edit?html,output ```html <style> .container { border: 1px solid gray; width: 200px; height: 200px; overflow: auto; transform: translateZ(0); } .tall { height: 400px; } .fixed { position: fixed; padding: 20px; top: 80px; left: 80px; width: 150px; background-color: orange; } </style> <div class="container"> <div class="tall"></div> <div class="fixed"> I should not scroll! <br> I should not get clipped! </div> </div> ``` Resulting in <img width="358" alt="screen shot 2016-08-11 at 7 12 02 pm" src="https://cloud.githubusercontent.com/assets/6173664/17610928/a1987606-5ff7-11e6-96e1-849fd036b6b8.png"> Is this an expected behavior for `position: fixed`? From the spec, I'd expect it to render in the top stacking context and not participate to the scrolling (e.g. comment the `transform: translateZ(0)` of `.container`) <img width="292" alt="screen shot 2016-08-11 at 7 12 10 pm" src="https://cloud.githubusercontent.com/assets/6173664/17610942/c748543e-5ff7-11e6-8678-38c9d804d493.png"> Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/400 using your GitHub account
Received on Friday, 12 August 2016 02:15:50 UTC