Modul:Color contrast

--
-- 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)then
v=v/12.92
else
v=math.pow((v+0.055)/1.055,2.4)
end
returnv
end
localfunctionrgbdec2lum(R,G,B)
if(0<=RandR<256and0<=GandG<256and0<=BandB<256)then
return0.2126*sRGB(R/255)+0.7152*sRGB(G/255)+0.0722*sRGB(B/255)
else
return''
end
end
localfunctionhsl2lum(h,s,l)
if(0<=handh<360and0<=sands<=1and0<=landl<=1)then
localc=(1-math.abs(2*l-1))*s
localx=c*(1-math.abs(math.fmod(h/60,2)-1))
localm=l-c/2
localr,g,b=m,m,m
if(0<=handh<60)then
r=r+c
g=g+x
elseif(60<=handh<120)then
r=r+x
g=g+c
elseif(120<=handh<180)then
g=g+c
b=b+x
elseif(180<=handh<240)then
g=g+x
b=b+c
elseif(240<=handh<300)then
r=r+x
b=b+c
elseif(300<=handh<360)then
r=r+c
b=b+x
end
returnrgbdec2lum(255*r,255*g,255*b)
else
return''
end
end
localfunctioncolor2lum(c)
if(c==nil)then
return''
end
-- html '#' entity
c=c:gsub("&#35;","#")
-- whitespace
c=c:match('^%s*(.-)[%s;]*$')
-- unstrip nowiki strip markers
c=mw.text.unstripNoWiki(c)
-- lowercase
c=c:lower()
-- first try to look it up
localL=HTMLcolor[c]
if(L~=nil)then
returnL
end
-- convert from hsl
ifmw.ustring.match(c,'^hsl%([%s]*[0-9][0-9%.]*[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*%)$')then
localh,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]*%)$')
returnhsl2lum(tonumber(h),tonumber(s)/100,tonumber(l)/100)
end
-- convert from rgb
ifmw.ustring.match(c,'^rgb%([%s]*[0-9][0-9]*[%s]*,[%s]*[0-9][0-9]*[%s]*,[%s]*[0-9][0-9]*[%s]*%)$')then
localR,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]*%)$')
returnrgbdec2lum(tonumber(R),tonumber(G),tonumber(B))
end
-- convert from rgb percent
ifmw.ustring.match(c,'^rgb%([%s]*[0-9][0-9%.]*%%[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*,[%s]*[0-9][0-9%.]*%%[%s]*%)$')then
localR,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]*%)$')
returnrgbdec2lum(255*tonumber(R)/100,255*tonumber(G)/100,255*tonumber(B)/100)
end
-- remove leading # (if there is one) and whitespace
c=mw.ustring.match(c,'^[%s#]*([a-f0-9]*)[%s]*$')
-- split into rgb
localcs=mw.text.split(cor'','')
if(#cs==6)then
localR=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)then
localR=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 blank
return''
end
-- This exports the function for use in other modules.
-- The colour is passed as a string.
functionp._lum(color)
returncolor2lum(color)
end
functionp._greatercontrast(args)
localbias=tonumber(args['bias']or'0')or0
localcss=(args['css']andargs['css']~='')andtrueorfalse
localv1=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')then
ratio1=(v2+0.05)/(v1+0.05)
ratio1=(ratio1<1)and1/ratio1orratio1
end
if(type(v1)=='number'andtype(v3)=='number')then
ratio2=(v3+0.05)/(v1+0.05)
ratio2=(ratio2<1)and1/ratio2orratio2
end
ifcssthen
localc1=args[1]or''
ifmw.ustring.match(c1,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')or
mw.ustring.match(c1,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')then
c1='#'..c1
end
ifmw.ustring.match(c2,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')or
mw.ustring.match(c2,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')then
c2='#'..c2
end
ifmw.ustring.match(v3,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')or
mw.ustring.match(v3,'^[A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9][A-Fa-f0-9]$')then
c3='#'..c3
end
return'background-color:'..c1..'; color:'..((ratio1>0)and(ratio2>0)and((ratio1+bias>ratio2)andc2orc3)or'')..';'
end
return(ratio1>0)and(ratio2>0)and((ratio1+bias>ratio2)andc2orc3)or''
end
functionp._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>v1then
v1,v2=v2,v1
end
return(v1+0.05)/(v2+0.05)
else
returnargs['error']or'?'
end
end
functionp._styleratio(args)
localstyle=(args[1]or''):lower()
localbg,fg='white','black'
locallum_bg,lum_fg=1,0
ifargs[2]then
locallum=color2lum(args[2])
iflum~=''thenbg,lum_bg=args[2],lumend
end
ifargs[3]then
locallum=color2lum(args[3])
iflum~=''thenfg,lum_fg=args[3],lumend
end
localslist=mw.text.split(mw.ustring.gsub(mw.ustring.gsub(styleor'','&#[Xx]23;','#'),'&#35;','#'),';')
fork=1,#slistdo
locals=slist[k]
localk,v=s:match('^[%s]*([^:]-):([^:]-)[%s;]*$')
k=kor''
v=vor''
if(k:match('^[%s]*(background)[%s]*$')ork:match('^[%s]*(background%-color)[%s]*$'))then
locallum=color2lum(v)
if(lum~='')thenbg,lum_bg=v,lumend
elseif(k:match('^[%s]*(color)[%s]*$'))then
locallum=color2lum(v)
if(lum~='')thenbg,lum_fg=v,lumend
end
end
iflum_bg>lum_fgthen
return(lum_bg+0.05)/(lum_fg+0.05)
else
return(lum_fg+0.05)/(lum_bg+0.05)
end
end
--[[
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)
end
functionp.ratio(frame)
localargs=frame.args[1]andframe.argsorframe:getParent().args
returnp._ratio(args)
end
functionp.styleratio(frame)
localargs=frame.args[1]andframe.argsorframe:getParent().args
returnp._styleratio(args)
end
functionp.greatercontrast(frame)
localargs=frame.args[1]andframe.argsorframe:getParent().args
returnp._greatercontrast(args)
end
returnp