W3C home > Mailing lists > Public > www-style@w3.org > January 2009

Re: [css3-background] does border-radius round the border-image ?

From: Bert Bos <bert@w3.org>
Date: Wed, 21 Jan 2009 19:41:21 +0100
To: www-style@w3.org
Message-Id: <200901211941.22041.bert@w3.org>

On Thursday 15 January 2009 21:07, David Hyatt wrote:
> On Jan 13, 2009, at 11:45 AM, Brad Kemper wrote:

> > By the way, neither WebKit or FireFox (Minefield) are currently
> > doing any clipping of the foreground when 'overfow' is hidden, as
> > this text says it should. I agree that they should do so, and maybe
> > that just hasn't yet been implemented but will be.
> It will be.  I'm the one who proposed the overflow change in the
> first place. :)

The text says now: "Other effects that clip to the border or padding 
edge (such as ‘overflow’)". However, 'overflow' doesn't clip to the 
border or padding edge, but to the content edge.

I don't think content should be clipped because of 'border-radius', even 
if the radius is so large that the border ends up behind the content. 
If you set 'overflow: scroll', you assume that all content can be made 
visible by scrolling, but if the corners are clipped, those parts 
remain unreachable.

(On the other hand, scrolling mechanisms that can scroll beyond the 0% 
and 100% marks will have to be introduced by browsers at some point 
anyway, because there are already many pages that have content off the 
left side (because the content is centered, but wider than the window) 
and the only way to make that content visible currently is to turn off 
the style sheets...)

Remark 1:

The fact that a scrollbar looks even more ugly on an element with 
rounded corners than with rectangular ones suggests that browsers 
should use a different scrolling mechanism, reserving the scrollbars 
just for the viewport. Maybe one solution is a combination of moving 
content with the mouse (hand cursor) and a panner that pops up in a 
corner of the element when the mouse hovers over the content. It's 
probably also a good idea to allow the overflowing element to get the 
focus (by tabbing) and scroll with the cursor keys.

Maybe one can also pop up a tooltip-like window of reasonable size (with 
scrollbars) that shows more (or all) of the content of the element, 
while allowing the user to continue interacting with the rest of the 

(We also have the marquee effect and in the future maybe paged elements, 
which allow the user to flip through the hidden content of an element; 
but those two effects are probably only to be applied when the designer 
asks for them with the 'overflow-style' property.)

Remark 2:

Clipping the content seems not very useful, but *shaping* the content 
and reflowing it would be cool. (Though probably too difficult for CSS, 
except in a few easy cases, such as with the contour keyword[1,2].)

[1] http://lists.w3.org/Archives/Public/www-style/2007Apr/0182.html
[2] http://lists.w3.org/Archives/Public/www-style/2007Apr/0185.html

  Bert Bos                                ( W 3 C ) http://www.w3.org/
  http://www.w3.org/people/bos                               W3C/ERCIM
  bert@w3.org                             2004 Rt des Lucioles / BP 93
  +33 (0)4 92 38 76 92            06902 Sophia Antipolis Cedex, France
Received on Wednesday, 21 January 2009 18:41:59 UTC

This archive was generated by hypermail 2.3.1 : Monday, 2 May 2016 14:38:23 UTC