- From: Alan Gresley <alan@css-class.com>
- Date: Tue, 06 Sep 2011 12:01:32 +1000
- To: Marat Tanalin <mtanalin@yandex.ru>
- CC: "Tab Atkins Jr." <jackalmage@gmail.com>, www-style@w3.org
On 6/09/2011 9:32 AM, Marat Tanalin wrote: > 06.09.2011, 03:03, "Tab Atkins Jr."<jackalmage@gmail.com>: >> I don't understand how you think rgba() is wrong and how it can be >> replaced by 'background-opacity'. Colors are used in far more than >> just 'background-color'. Partially-transparent border or text >> colors are useful, and specifying them with an alpha color is >> simple (better than adding 'border-color-opacity' and >> 'color-opacity' properties, for certain). Alpha colors are also >> very useful as color-stops in gradients, where there is absolutely >> no way to replace them with a property. > > Just most often rgba is used for background in practice. You are > right that it might be used with border-color or color (though, > e.g., semi-transparent text color is used far rarely). Don't forget that rgba can also be used for text-shadow and box-shadow [1]. Also, rgba can be build up in layers to produce more colors [2] [3] (example is with hsla). >> After more thought on the matter of 1- or 2-digit hex shorthands, >> though, I've now come down against it. I gave my reasoning against >> 2-digit grays previously in the thread (the expansion rule is >> different than for 3-digit color). > > Even if expansion rule is different, it does not mean this is > something bad. > >> As for 1-digit grays, I no longer think they're a good idea. When >> Colors 4 gets written I'll be pushing for (or writing, if I end >> up the editor) 4- and 8-digit hex colors so you can specify alpha >> without having to switch to rgba() and convert your components to >> decimal. I don't think it's good to add a new hex variant that >> can't similarly receive an alpha. (Obviously, having #0 expand >> into #00000000 isn't useful. Adding a second digit, like having >> #0c expand into #000000cc, is just confusing.) > > rgba values (including its probable hex syntax) is a topic for > another thread (if someone needs it at all) and is quite alien thing > in this thread, in my opinion. Let's try to isolate regular > hex-values discussion here. I don't see why you say this. rgba and 8-digit hex color are the same thing. rgb and 6-digit hex color are the same thing. The only difference between the two are their notation. I am in agreement with Tab here. #0c expanding into #000000cc is not a good thing and can lead to confusion. >> The benefit of 1-digit grays is extremely minimal. You get to hit >> a key once instead of three times. It's the same key all three >> times, too, so the burden of hitting it thrice is basically nil. > > It's not about key-hitting. #ccc just _redundant_ compared with #c. #ccc became redundant in a sense when 32-bit processors came out. I would suggest you read about the development of computer color and true color [4]. > So, if we able to shorten #cccccc to #ccc, then shortening #ccc to > #c (as well as #acacac to #ac) seem just logical. It's not about shortening. The reserved has happened. Please read about web-safe colors [5]. >> I am still okay with a gray() function, though, which takes a >> single number/percentage, and then optionally an alpha value. I'm >> not sure if we *need* it, but I'm favorably disposed to it. > > The topic is not about some new functions, it's about shortening > existing hex values. I would recommend that you look into the concept or reasoning behind a gray() function. I see no reason to shorten hex values where their use was for a legacy 16-bit processor. You seem to be making a argument that #ccc was created as a shorthand for #cccccc where the reverse is true. 1. http://css-class.com/test/css/shadows/text-shadow2.htm 2. http://css-class.com/test/css/colors/color-transparent1.htm 3. http://css-class.com/test/images/hsla-color-merging.png 4. http://en.wikipedia.org/wiki/Color_depth#Truecolor 5. http://en.wikipedia.org/wiki/Web_colors#Web-safe_colors -- Alan Gresley http://css-3d.org/ http://css-class.com/
Received on Tuesday, 6 September 2011 02:01:27 UTC