Module:Color contrast/sandbox
 | This is the module sandbox page for Module:Color contrast (diff). |
.svg/60px-Test_Template_Info-Icon_-_Version_(2).svg.png){kind=icon}
 | This module is rated as ready for general use. It has reached a mature form and is thought to be relatively bug-free and ready for use wherever appropriate. It is ready to mention on help pages and other Wikipedia resources as an option for new users to learn. To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing. |
 | This module is subject to page protection. It is a highly visible module in use by a very large number of pages, or is substituted very frequently. Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is protected from editing. |
 | This Lua module is used on approximately 534,000 pages, or roughly 1% of all pages. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them. |
 | This module depends on the following other modules: |
This module is used primarily by
- {{Color contrast ratio}}
- {{RGBColorToLum}}
- {{Color contrast conformance}}
- {{Ensure AAA contrast ratio}}
- {{Ensure AA contrast ratio}}
- {{Greater color contrast ratio}}
It is also used for tracking within
and for documentation in
The formulas used are stated in WCAG 2.x specifications. WCAG is the main guideline for creating accessible interfaces on the web.
Usage
[edit]To use this module, you may use one of the above listed templates or invoke the module directly
- To compute relative luminescence:
{{RGBColorToLum|color}}or{{#invoke:Color contrast|lum|color}} - To compute a contrast ratio between two colors:
{{Color contrast ratio|color1|color2|error=?}}or{{#invoke:Color contrast|ratio|color1|color2|error=?}} - To determine which of two colors (color2a and color2b) has the greater contrast ratio with a particular color (color1):
{{Greater color contrast ratio|color1|color2a|color2b}}or{{#invoke:Color contrast|greatercontrast|color1|color2a|color2b}} - To compute the contrast ratio between the background and text colors specified in a css style string:
{{#invoke:Color contrast|styleratio|css style statement string|default background color|default text color}}
---- This module implements-- {{Color contrast ratio}}-- {{Greater color contrast ratio}}-- {{ColorToLum}}-- {{RGBColorToLum}}--localp={}localHTMLcolor=mw.loadData('Module:Color contrast/colors')localfunctionsRGB(v)if(v<=0.03928)thenv=v/12.92elsev=math.pow((v+0.055)/1.055,2.4)endreturnvendlocalfunctionrgbdec2lum(R,G,B)if(0<=RandR<256and0<=GandG<256and0<=BandB<256)thenreturn0.2126*sRGB(R/255)+0.7152*sRGB(G/255)+0.0722*sRGB(B/255)elsereturn''endendlocalfunctionhsl2lum(h,s,l)if(0<=handh<360and0<=sands<=1and0<=landl<=1)thenlocalc=(1-math.abs(2*l-1))*slocalx=c*(1-math.abs(math.fmod(h/60,2)-1))localm=l-c/2localr,g,b=m,m,mif(0<=handh<60)thenr=r+cg=g+xelseif(60<=handh<120)thenr=r+xg=g+celseif(120<=handh<180)theng=g+cb=b+xelseif(180<=handh<240)theng=g+xb=b+celseif(240<=handh<300)thenr=r+xb=b+celseif(300<=handh<360)thenr=r+cb=b+xendreturnrgbdec2lum(255*r,255*g,255*b)elsereturn''endendlocalfunctioncolor2lum(c)if(c==nil)thenreturn''end-- html '#' entityc=c:gsub("#","#")-- whitespacec=c:match('^%s*(.-)[%s;]*$')-- unstrip nowiki strip markersc=mw.text.unstripNoWiki(c)-- lowercasec=c:lower()-- first try to look it uplocalL=HTMLcolor[c]if(L~=nil)thenreturnLend-- convert from hslifmw.ustring.match(c,'^hsl%([%s]*[0-9][0-9%.]*[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*%)$')thenlocalh,s,l=mw.ustring.match(c,'^hsl%([%s]*([0-9][0-9%.]*)[%s]*,[%s]*([0-9][0-9%.]*)%%[%s]*,[%s]*([0-9][0-9%.]*)%%[%s]*%)$')returnhsl2lum(tonumber(h),tonumber(s)/100,tonumber(l)/100)end-- convert from rgbifmw.ustring.match(c,'^rgb%([%s]*[0-9][0-9]*[%s]*,[%s]*[0-9][0-9]*[%s]*,[%s]*[0-9][0-9]*[%s]*%)$')thenlocalR,G,B=mw.ustring.match(c,'^rgb%([%s]*([0-9][0-9]*)[%s]*,[%s]*([0-9][0-9]*)[%s]*,[%s]*([0-9][0-9]*)[%s]*%)$')returnrgbdec2lum(tonumber(R),tonumber(G),tonumber(B))end-- convert from rgb percentifmw.ustring.match(c,'^rgb%([%s]*[0-9][0-9%.]*%%[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*%)$')thenlocalR,G,B=mw.ustring.match(c,'^rgb%([%s]*([0-9][0-9%.]*)%%[%s]*,[%s]*([0-9][0-9%.]*)%%[%s]*,[%s]*([0-9][0-9%.]*)%%[%s]*%)$')returnrgbdec2lum(255*tonumber(R)/100,255*tonumber(G)/100,255*tonumber(B)/100)end-- remove leading # (if there is one) and whitespacec=mw.ustring.match(c,'^[%s#]*([a-f0-9]*)[%s]*$')-- split into rgblocalcs=mw.text.split(cor'','')if(#cs==6)thenlocalR=16*tonumber('0x'..cs[1])+tonumber('0x'..cs[2])localG=16*tonumber('0x'..cs[3])+tonumber('0x'..cs[4])localB=16*tonumber('0x'..cs[5])+tonumber('0x'..cs[6])returnrgbdec2lum(R,G,B)elseif(#cs==3)thenlocalR=16*tonumber('0x'..cs[1])+tonumber('0x'..cs[1])localG=16*tonumber('0x'..cs[2])+tonumber('0x'..cs[2])localB=16*tonumber('0x'..cs[3])+tonumber('0x'..cs[3])returnrgbdec2lum(R,G,B)end-- failure, return blankreturn''end-- This exports the function for use in other modules.-- The colour is passed as a string.functionp._lum(color)returncolor2lum(color)endfunctionp._greatercontrast(args)localbias=tonumber(args['bias']or'0')or0localcss=(args['css']andargs['css']~='')andtrueorfalselocalv1=color2lum(args[1]or'')localc2=args[2]or'white'localv2=color2lum(c2)localc3=args[3]or'black'localv3=color2lum(c3)localratio1=-1;localratio2=-1;if(type(v1)=='number'andtype(v2)=='number')thenratio1=(v2+0.05)/(v1+0.05)ratio1=(ratio1<1)and1/ratio1orratio1endif(type(v1)=='number'andtype(v3)=='number')thenratio2=(v3+0.05)/(v1+0.05)ratio2=(ratio2<1)and1/ratio2orratio2endifcssthenlocalc1=args[1]or''ifmw.ustring.match(c1,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')ormw.ustring.match(c1,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')thenc1='#'..c1endifmw.ustring.match(c2,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')ormw.ustring.match(c2,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')thenc2='#'..c2endifmw.ustring.match(v3,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')ormw.ustring.match(v3,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')thenc3='#'..c3endreturn'background-color:'..c1..'; color:'..((ratio1>0)and(ratio2>0)and((ratio1+bias>ratio2)andc2orc3)or'')..';'endreturn(ratio1>0)and(ratio2>0)and((ratio1+bias>ratio2)andc2orc3)or''endfunctionp._ratio(args)localv1=color2lum(args[1])localv2=color2lum(args[2])if(type(v1)=='number'andtype(v2)=='number')then-- v1 should be the brighter of the two.ifv2>v1thenv1,v2=v2,v1endreturn(v1+0.05)/(v2+0.05)elsereturnargs['error']or'?'endendfunctionp._styleratio(args)localstyle=(args[1]or''):lower()localbg,fg='white','black'locallum_bg,lum_fg=1,0ifargs[2]thenlocallum=color2lum(args[2])iflum~=''thenbg,lum_bg=args[2],lumendendifargs[3]thenlocallum=color2lum(args[3])iflum~=''thenfg,lum_fg=args[3],lumendendlocalslist=mw.text.split(mw.ustring.gsub(mw.ustring.gsub(styleor'','&#[Xx]23;','#'),'#','#'),';')fork=1,#slistdolocals=slist[k]localk,v=s:match('^[%s]*([^:]-):([^:]-)[%s;]*$')k=kor''v=vor''if(k:match('^[%s]*(background)[%s]*$')ork:match('^[%s]*(background%-color)[%s]*$'))thenlocallum=color2lum(v)if(lum~='')thenbg,lum_bg=v,lumendelseif(k:match('^[%s]*(color)[%s]*$'))thenlocallum=color2lum(v)if(lum~='')thenbg,lum_fg=v,lumendendendiflum_bg>lum_fgthenreturn(lum_bg+0.05)/(lum_fg+0.05)elsereturn(lum_fg+0.05)/(lum_bg+0.05)endend--[[Use {{#invoke:Color contrast|somecolor}} directly or{{#invoke:Color contrast}} from a wrapper template.Parameters: -- |1= — required; A color to check.--]]functionp.lum(frame)localcolor=frame.args[1]orframe:getParent().args[1]returnp._lum(color)endfunctionp.ratio(frame)localargs=frame.args[1]andframe.argsorframe:getParent().argsreturnp._ratio(args)endfunctionp.styleratio(frame)localargs=frame.args[1]andframe.argsorframe:getParent().argsreturnp._styleratio(args)endfunctionp.greatercontrast(frame)localargs=frame.args[1]andframe.argsorframe:getParent().argsreturnp._greatercontrast(args)endreturnp