- From: fantasai <fantasai.lists@inkedblade.net>
- Date: Wed, 09 Sep 2009 12:57:01 -0700
- To: www-style@w3.org
Summary:
- Discussion of box-shadow and border-image.
Brad actioned to come up with a rough proposal for all desired shadow
functionality for comparison
fantasai actioned to add more control to existing box-shadow through
honoring background-clip and border-image-outset
- RESOLVED: Republish Media Queries and CSS2.1 after Bert adds media_list
grammar rule
- CSS2.1 Issue 128 'display: run-in' clarifications bounced back to mailing
list for discussion
- fantasai to respond to UPnP forum message wrt status of CSS2.1
====== Full minutes below ======
Present:
César Acebal
Tab Atkins
Bert Bos
Elika Etemad
Sylvain Galineau
Daniel Glazman
Brad Kemper
Chris Lilley
Hĺkon Wium Lie
<RRSAgent> logging to http://www.w3.org/2009/09/02-CSS-irc
Scribe: fantasai
* sylvaing speaking of boxes and diagrams, second Gerard Talbot's comment
that the inline formatting model could use visual back-up
Some discussion of box-shadow
<fantasai> who's minuting?
<glazou> fantasai: that's outside of the call
Bert: I don't want to have a non-continuous border change the shape of the
box. I still want the box to be rectangular.
<glazou> we did not start yet
Agenda
------
Daniel: I'm back from summer break, not quite caught up with everything
Daniel: Extra agenda item from Chris
ChrisL: It's already in the Agenda
box-shadow and border-image
---------------------------
ChrisL: ...
ChrisL: You know the diagram with the border and padding edge etc?
ChrisL: Imagine a similar diagram with the corners rounded
ChrisL: I asked which diagram we use (?)
<ChrisL> http://www.w3.org/Style/Group/css2-src/images/boxdim.png
ChrisL: Bert said the boxes should be rectangular
ChrisL: but you have a different clipping effect
ChrisL: I also asked if the border-image affects the geometric layout
of these boxes
ChrisL: And I was told no, it doesn't
...
Brad: So the question is, when is the border-radius applied and when
is it not
fantasai: The border-radius is applied to the definition of the boxes
for rendering effects, but not for layout
fantasai: for layout you only care about the edges, not the shape of
the corners
<TabAtkins> http://www.bradclicks.com/cssplay/curved-corner-image.html
ChrisL: So there's no way to prevent text from leaking other than
providing sufficient padding
fantasai: right
<sylvaing> CSS2 borders clip at the inner border edge; Brad's example
clipped at the outer border edge
ChrisL: was the rendering that Brad showed per spec or an implementation bug?
fantasai: Implementation bug. The spec says to follow the curve for
clipping effects, jumping from one curve to the other isn't
a reasonable interpretation
ChrisL: fantasai's suggesting this particular unioning algorithm
ChrisL: I think it'll look a little odd. I can produce images that look
good, and some that look bad with it
ChrisL: You don't need to do edge detection
ChrisL: As you rightly pointed out, spread is a complicated operation
and if you have a raster image it's out of the question
ChrisL: blur radius is fine, but spread basically moves the geometry
out and that's difficult to do without actual geometry
Brad: I disagree with the notion of doing alpha channel for box channel
without taking into account border styles or backgrounds
Brad: I don't see why border-image should have a special alpha-based
channel behavior
Brad: I'd rather see a proper drop-shadow effect rather than this
half-effort for border-image
ChrisL: It's hard to address pieces of the border image otherwise
Brad: If we had a drop-shadow property, it could have a switch on it
that says what it affects: borders, border-images, everything, etc.
Brad: So far box-shadow only takes into account the border box
ChrisL: it does take into account border-radius
Brad: Still limited to flat edges and possibly curved corners
Brad: If you have a dashed border going around the curve
Brad: It's going to be a flat border until you put a border image
* TabAtkins or hell, just an identical border-image of a dashed border.
Brad: You'd get a different effect if you had a border-image shashed
border vs a UA-defined dashed border
<ChrisL> http://www.bradclicks.com/cssplay/border-image/Alladins_Lamp.png
fantasai: Two things come to mind from this discussion
fantasai: One is, we could use the background-clip on the bottommost
background layer to determine whether the dashes fall inside
the box-shadow's auto-opaque area or outside it
fantasai: box-shadow is supposed to represent clipping the box out and
pulling it forward of the canvas
fantasai: if you filled it with background paint, then it's obvious
that in the default case (background-clip: border-box) your
box would be rectangular even in the case of dashed borders
fantasai: but if you set background-clip: padding-box, the dashes are
outside the background paint region
fantasai: and if you were clipping out the box, you'd clip around the
dashes, leaving gaps in between
fantasai: the other thought was, Brad mentioned perhaps never
alpha-channel-masking the border area
fantasai: and if the author needed alpha-channel masking, it would only
apply to regions of the border-image outset beyond the border-box
Tab: If we're trying to be intelligent about alpha, we can't just pay
attention to the bottommost background unless we say background is
automatically opaque
fantasai: we're saying that the background is automatically opaque
Brad: The box shape that you're shadowing, it's not really paying
attention to the alpha of the box it's just pretending it's opaque
...
Brad thinks authors will want more controls over what is drop-shadowed
fantasai: we can always add more controls later, and this would just be
the default behavior
Tab: Maye be don't need to make this behavior that intelligent then
ChrisL: I was agreeing with fantasai, but now I see both designers not happy
ChrisL: If we make it less intelligent, then you always get a rectangle
Brad: Initially my feeling was to suppress the shadow, because of your
argument that we're not changing the box shape we're just decorating it
<Bert> (Maybe we can define shaped boxes some day, which shape the content
box and hence the text, rather than just the border...)
fantasai: How about you take an action item to draw up a proposal for what
kind of controls we want in the future
fantasai: so that we know whether box-shadow conflicts with that or adds to it
SteveZ: Two comments. First, this is hard to follow without pictures
<ChrisL> I'm happy to make diagrams, once we decide what to make a diagram *of*
* TabAtkins hack possibility: <div style=width:0 margin:20px border-image:foo>
<div style=margin:-20px /></div>
<glazou> did I hear howcome on the call ?
<glazou> who said "'I support Bert" ?
SteveZ: Second, what I'm hearing is that Tab and Brad want to shine a light
through the box, and take the shadow from that, and having part of
the border-image take part in that and part of it not
Brad: I like the idea of using backgrond-clip to determine which box gets
shadowed
Bert, Hakon: I think it makes it all too complicated
ACTION: Brad to come up with full shadow proposal (not finalized, but to
see where we're going)
ACTION: fantasai draw up proposal for box-shadow modified by ideas posted here
Media Queries
-------------
RESOLVED: Republish Media Queries and CSS 2.1 after Bert adds media_list
grammar rule
discussion of process requirements for republishing CRs
CSS2.1 Issue 128
----------------
<glazou> http://lists.w3.org/Archives/Public/www-style/2009Jul/0025.html
display: run-in clarifications
Bert: We'd made some progress on the mailing list after some very good
questions from bz
Bert: So we know ... and where floating children are displayed
Bert: What we don't have yet is what happens with :first-line and :first-letter
Tab: I support Sylvain that :first-line/:first-letter still cause problems.
Tab: Don't know for the positioning ancesters of an abspos child of the
run-in.
Bert: My position is that it's the element hierarchy rather than the box
hierarchy
Bert: That's how I interpret the rules in 10.1
Tab: You should get in on the thread; bz is expressing the opposite
fantasai: Sounds like we need more mailing list discussion
Message from UPnP forum
-----------------------
<glazou> http://lists.w3.org/Archives/Public/www-style/2009Aug/0605.html
Daniel: I just noticed this email yesterday
Daniel: Apparently Toby wants an answer before today
ACTION: fantasai respond to Toby
SteveZ: You can invite them to contribute test cases
ChrisL: I think asking them to help review test cases would be better :)
SteveZ: ok, /contribute/ to the test suite process
Meeting closed
Received on Wednesday, 9 September 2009 19:57:48 UTC