Module:Box-header

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This module creates the header section for boxed content. It implements {{box-header}}. It is intended to mainly be used in portals, but can also be used elsewhere.

Usage

{{#invoke:Box-header|boxHeader}}

For use in templates; calls _boxHeader with the parameters passed to the template as arguments.

{{#invoke:Box-header|_boxHeader|args}}

For use in modules; constructs the box header (and the start of the box body). The args are the parameters accepted by Template:Box-header. (The output may need to be expanded, depending on the values in the args.)

{{#invoke:Box-header|autoColour}}

For use in templates; calls _autoColour with the parameters passed to the template as arguments.

{{#invoke:Box-header|_autoColour|args}}

For use in modules; calculates appropriate colours for the box header, and then constructs it using _boxHeader. The args are the parameters accepted by Template:Box-header colour – the same as for Template:Box-header, apart from those specifying colours and the title. (The output may need to be expanded, depending on the values in the args.)

See also

The above documentation is transcluded from Module:Box-header/doc. (edit | history)
Editors can experiment in this module's sandbox (edit | diff) and testcases (create) pages.
Subpages of this module.

local p = {}
---------- Config data ----------
local namedColours = mw.loadData( 'Module:Sandbox/Evad37/Box-header/colours' )
local modes = {
	lightest = { sat=0.10, val=1.00 },
	light    = { sat=0.15, val=0.95 },
	normal   = { sat=0.40, val=0.85 },
	dark     = { sat=0.90, val=0.70 },
	darkest  = { sat=1.00, val=0.45 },
	content  = { sat=0.04, val=1.00 }
}
local min_contrast_ratio_normal_text = 0.7
local min_contrast_ratio_large_text  = 0.45

-- Template parameter names
--   Specify each as either a single string, or a table of strings (aliases)
--   Aliases are checked left-to-right, i.e. `{ "one", "two" }` is equivalent to using `{{{one| {{{two|}}} }}}` in a template
local parameterNames = {
	['1'] = {'1', 1},
	['2'] = {'2', 2},
	['colour'] = {'colour', 'color'},
	['mode'] = 'mode',
	['watch'] = 'watch'
}

---------- Dependecies ----------
local colourContrastModule = require('Module:Color contrast')
local hex = require( 'luabit.hex' )

---------- Utility functions ----------
function getParameterValue(args, parameter)
	suffix = suffix or ''
	if type( parameterNames[parameter] ) ~= 'table' then
		return args[parameterNames[parameter]]
	end
	for _i, parameterAlias in ipairs(parameterNames[parameter]) do
		if args[parameterAlias] then
			return args[parameterAlias]
		end
	end
	return nil
end

function setCleanArgs(argsTable)
	local cleanArgs = {}
	for key, val in pairs(argsTable) do
		if type(val) == 'string' then
			val = val:match('^%s*(.-)%s*$')
			if val ~= '' then
				cleanArgs[key] = val
			end
		else
			cleanArgs[key] = val
		end
	end
	return cleanArgs
end

local function normaliseHexTriplet(hexString)
	if not hexString then return nil end
	local hexComponent = string.match(hexString, '^#(%x%x%x)$') or '^#(%x%x%x%x%x%x)$'
	if hexComponent and #hexComponent == 6 then
		return hexString
	end
	if hexComponent and #hexComponent == 3 then
		local r = mw.ustring.rep(mw.ustring.sub(hexComponent, 1, 1), 2)
		local b = mw.ustring.rep(mw.ustring.sub(hexComponent, 2, 2), 2)
		local g = mw.ustring.rep(mw.ustring.sub(hexComponent, 3, 3), 2)
		return '#' .. mw.ustring.upper(r .. g .. b)
	end
	return nil
end

---------- Conversions ----------
local function decimalToPaddedHex(number)
	local prefixedHex = hex.to_hex(tonumber(number)) -- prefixed with '0x'
	local padding =  #prefixedHex == 3 and '0' or '' 
	return mw.ustring.gsub(prefixedHex, '0x', padding)
end
local function hexToDecimal(hexNumber)
	return tonumber(hexNumber, 16)
end
local function RGBtoHexTriplet(R, G, B)
	return '#' .. decimalToPaddedHex(R) .. decimalToPaddedHex(G) .. decimalToPaddedHex(B)
end
local function hexTripletToRGB(hexTriplet)
	local R_hex, G_hex, B_hex = string.match(hexTriplet, '(%x%x)(%x%x)(%x%x)')
	return hexToDecimal(R_hex), hexToDecimal(G_hex), hexToDecimal(B_hex)
end
local function HSVtoRGB(H, S, V) -- per [[HSL and HSV#Converting_to_RGB]]
	local C = V * S
	local H_prime = H / 60
	local X = C * ( 1 - math.abs(math.fmod(H_prime, 2) - 1) )
	local R1, G1, B1
	if H_prime <= 1 then
		R1 = C
		G1 = X
		B1 = 0
	elseif H_prime <= 2 then
		R1 = X
		G1 = C
		B1 = 0
	elseif H_prime <= 3 then
		R1 = 0
		G1 = C
		B1 = X
	elseif H_prime <= 4 then
		R1 = 0
		G1 = X
		B1 = C
	elseif H_prime <= 5 then
		R1 = X
		G1 = 0
		B1 = C
	elseif H_prime <= 6 then
		R1 = C
		G1 = 0
		B1 = X
	end	
	local m = V - C
	local R = R1 + m
	local G = G1 + m
	local B = B1 + m

	local R_255 = math.floor(R*255)
	local G_255 = math.floor(G*255)
	local B_255 = math.floor(B*255)
	return R_255, G_255, B_255
end
local function RGBtoHue(R_255, G_255, B_255) -- per [[HSL and HSV#Hue and chroma]]
	local R = R_255/255
	local G = G_255/255
	local B = B_255/255

	local M = math.max(R, G, B)
	local m = math.min(R, G, B)
	local C = M - m
	local H_prime
	if C == 0 then
		return null
	elseif M == R then
		H_prime = math.fmod((G - B)/C, 6)
	elseif M == G then
		H_prime = (B - R)/C + 2
	elseif M == B then
		H_prime = (R - G)/C + 4
	end
	local H = 60 * H_prime
	return H
end
local function nameToHexTriplet(name)
	if not name then return nil end
	local codename = mw.ustring.gsub(mw.ustring.lower(name), ' ', '')
	return namedColours[codename]
end

---------- Choose colours ----------
local function calculateColours(H, S, V, minContrast)
	local bgColour = RGBtoHexTriplet(HSVtoRGB(H, S, V))
	local textColour = colourContrastModule._greatercontrast({bgColour})
	local contrast = colourContrastModule._ratio({ bgColour, textColour })
	if contrast >= minContrast then
		return bgColour, textColour
	elseif textColour == '#FFFFFF' then
		-- make the background darker and slightly increase the saturation
		return calculateColours(H, math.min(1, S+0.01), math.max(0, V-0.03), minContrast)
	else
		-- make the background lighter and slightly decrease the saturation
		return calculateColours(H, math.max(0, S-0.01), math.min(1, V+0.03), minContrast)
	end
end

local function makeColours(hue, modeName)
	local mode = modes[modeName]
	if not hue then -- grey
		mode.sat = 0
		hue = 0
	end
	local border = RGBtoHexTriplet(HSVtoRGB(hue, 0.15, 0.75))
	local titleBackground, titleForeground = calculateColours(hue, mode.sat, mode.val, min_contrast_ratio_large_text)
	local contentBackground, contentForeground = calculateColours(hue, modes.content.sat, modes.content.val, min_contrast_ratio_normal_text)
	return border, titleForeground, titleBackground, contentForeground, contentBackground
end

local function findHue(colour)
	local colourAsNumber = tonumber(colour)
	if colourAsNumber and ( -1 < colourAsNumber ) and ( colourAsNumber < 360) then
		return colourAsNumber
	end

	local colourAsHexTriplet = normaliseHexTriplet(colour) or nameToHexTriplet(colour)
	if colourAsHexTriplet then
		return RGBtoHue(hexTripletToRGB(colourAsHexTriplet))
	end
	return null
end

local function normaliseDescription(description)
	if not description or not modes[mw.ustring.lower(description)] then
		return 'normal'
	end
	return mw.ustring.lower(description)
end
---------- Build output ----------
local function boxHeader(args)
	-- TODO
	return nil
end

local function boxBody(args)
	-- TODO
	return nil
end



---------- Main ----------

-- Entry point for templates
function p.main(frame)
	local parent = frame.getParent(frame)
	local boxTemplateName, boxTemplateArgs = p._main(parent.args)
	return frame:expandTemplate{ title = boxTemplateName, args = boxTemplateArgs }
end

-- Entry point for modules
function p._main(_args)
	local args = setCleanArgs(_args)

	local hue = findHue(getParameterValue(args, 'colour'))
	local mode = normaliseDescription(getParameterValue(args, 'mode'))

	local border, titleForeground, titleBackground, contentForeground, contentBackground = makeColours(hue, mode)
	
	local boxTemplateName = getParameterValue(args, 'watch') and 'Box-header' .. getParameterValue(args, 'watch') or 'Box-header'
	local boxTemplateArgs = {
		title = getParameterValue(args, '1') or '',
		editpage = getParameterValue(args, '2') or '',
		noedit =  getParameterValue(args, '2') and '' or 'yes',
		border = border,
		titleforeground = titleForeground,
		titlebackground = titleBackground,
		foreground = contentForeground,
		background = contentBackground
	}
	return boxTemplateName, boxTemplateArgs
end
	
return p