[csswg-drafts] [css-color] Improve descriptions of system colors (#3803)

tabatkins has just created a new issue for https://github.com/w3c/csswg-drafts:

== [css-color] Improve descriptions of system colors ==
**[On Sun, 18 Feb 2001 dbaron wrote:](https://lists.w3.org/Archives/Member/w3c-css-wg/2001JanMar/0265.html)**
> Until today, I never understood why there were so many, seemingly
> rendundant, system colors for 3-D objects in section 18.2 of CSS2.
> Today I was forced to understand how the Windows colors work so that I
> could correct Mozilla's system colors implementation in the GTK port.
> 
> I think we should (whether for CSS2 errata or for CSS3) use clearer
> definitions of these colors so that one doesn't have to
> reverse-engineer the Windows system color APIs to figure out what the
> CSS system color definitions mean. (See [1] and [2] for a description
> of this API.)
> 
> So that other people implementing system colors on non-Windows
> platforms don't have to do the same reverse-engineering that I
> benefited from and puzzling over the definitions that I did, I propose
> the following new definitions as a start to clearer definitions (but
> see below):
> 
> ButtonFace
> The face background color for 3-D elements that appear 3-D due to
> one layer of surrounding border.
> 
> ButtonHighlight
> The color of the border facing the light source for 3-D elements
> that appear 3-D due to one layer of surrounding border.
> 
> ButtonShadow
> The color of the border away from the light source for 3-D elements
> that appear 3-D due to one layer of surrounding border.
> 
> ThreeDDarkShadow
> The color of the darker (generally outer) of the two borders away
> from the light source for 3-D elements that appear 3-D due to two
> concentric layers of surrounding border.
> 
> ThreeDFace
> The face background color for 3-D elements that appear 3-D due to
> two concentric layers of surrounding border.
> 
> ThreeDHighlight
> The color of the lighter (generally outer) of the two borders facing
> the light source for 3-D elements that appear 3-D due to two
> concentric layers of surrounding border.
> 
> ThreeDLightShadow
> The color of the darker (generally inner) of the two borders facing
> the light source for 3-D elements that appear 3-D due to two
> concentric layers of surrounding border.
> 
> ThreeDShadow
> The color of the lighter (generally inner) of the two borders away
> from the light source for 3-D elements that appear 3-D due to two
> concentric layers of surrounding border.
> 
> I'm pretty sure these descriptions fit the way system colors are
> implemented across-platforms (Windows, Mac, and soon to be GTK) in
> Mozilla. Are they implemented this way in MacIE? (I assume this
> is how they're implemented in WinIE, since the colors come straight
> from the Windows API.)
> 
> I don't think these descriptions correctly describe how these colors
> are used to represent depressed buttons, though. (That's why I said
> "generally inner" and "generally outer" rather than "inner" and
> "outer".) Any thoughts about how to improve them?

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/3803 using your GitHub account

Received on Thursday, 4 April 2019 18:04:32 UTC