Skip to content

Commit

Permalink
Add text/html show method for styled strings
Browse files Browse the repository at this point in the history
  • Loading branch information
@tecosaur
tecosaur committed May 18, 2023
1 parent a7278d7 commit 65b393f
Showing 1 changed file with 173 additions and 0 deletions.
173 changes: 173 additions & 0 deletions base/strings/io.jl
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1025,3 +1025,176 @@ function show(io::IO, ::MIME"text/plain", c::StyledChar)
show(io, c.char)
end
end

"""
A mapping between ANSI named colors and 8-bit colors for use in HTML
representations.
"""
const HTML_BASIC_COLORS = Dict{Symbol, SimpleColor}(
:black => SimpleColor(0x00, 0x00, 0x00),
:red => SimpleColor(0x80, 0x00, 0x00),
:green => SimpleColor(0x00, 0x80, 0x00),
:yellow => SimpleColor(0x80, 0x80, 0x00),
:blue => SimpleColor(0x00, 0x00, 0x80),
:magenta => SimpleColor(0x80, 0x00, 0x80),
:cyan => SimpleColor(0x00, 0x80, 0x80),
:white => SimpleColor(0xc0, 0xc0, 0xc0),
:bright_black => SimpleColor(0x80, 0x80, 0x80),
:grey => SimpleColor(0x80, 0x80, 0x80),
:gray => SimpleColor(0x80, 0x80, 0x80),
:bright_red => SimpleColor(0xff, 0x00, 0x00),
:bright_green => SimpleColor(0x00, 0xff, 0x00),
:bright_yellow => SimpleColor(0xff, 0xff, 0x00),
:bright_blue => SimpleColor(0x00, 0x00, 0xff),
:bright_magenta => SimpleColor(0xff, 0x00, 0xff),
:bright_cyan => SimpleColor(0x00, 0xff, 0xff),
:bright_white => SimpleColor(0xff, 0xff, 0xff))

function htmlcolor(io::IO, color::SimpleColor)
if color.value isa Symbol
if color.value === :default
print(io, "initial")
elseif (fg = get(FACES, color.value, FACES[:default]).foreground) != SimpleColor(color.value)
htmlcolor(io, fg)
else
htmlcolor(io, get(HTML_BASIC_COLORS, color.value, SimpleColor(:default)))
end
else
(; r, g, b) = color.value
print(io, '#')
r < 0x10 && print(io, '0')
print(io, string(r, base=16))
g < 0x10 && print(io, '0')
print(io, string(g, base=16))
b < 0x10 && print(io, '0')
print(io, string(b, base=16))
end
end

const HTML_WEIGHT_MAP = Dict{Symbol, Int}(
:thin => 100,
:extralight => 200,
:light => 300,
:semilight => 300,
:normal => 400,
:medium => 500,
:semibold => 600,
:bold => 700,
:extrabold => 800,
:black => 900)

function htmlstyle(io::IO, face::Face, lastface::Face=FACES[:default])
print(io, "<span style=\"")
foreground, background =
ifelse(face.inverse === true,
(face.background, face.foreground),
(face.foreground, face.background))
lastforeground, lastbackground =
ifelse(lastface.inverse === true,
(lastface.background, lastface.foreground),
(lastface.foreground, lastface.background))
if foreground != lastforeground
print(io, "color: ")
htmlcolor(io, foreground)
print(io, ';')
end
if background != lastbackground
print(io, "background-color: ")
htmlcolor(io, background)
print(io, ';')
end
face.font == lastface.font ||
print(io, "font-family: \"",
replace(face.font, '"' => "&quot;", ''' => "&#39;"), '"')
face.weight == lastface.weight ||
print(io, "font-weight: ", get(HTML_WEIGHT_MAP, face.weight, 400), ';')
face.slant == lastface.slant ||
print(io, "font-style: ", String(face.slant), ';')
face.underline == lastface.underline ||
if face.underline isa Tuple # Color and style
color, style = face.underline
print(io, "text-decoration: ")
if !isnothing(color)
htmlcolor(io, color)
print(io, ' ')
end
print(io, if style == :straight "solid "
elseif style == :double "double "
elseif style == :curly "wavy "
elseif style == :dotted "dotted "
elseif style == :dashed "dashed "
else "" end)
print(io, "underline;")
elseif face.underline isa SimpleColor
print(io, "text-decoration: ")
htmlcolor(io, face.underline)
if lastface.underline isa Tuple && last(lastface.underline) != :straight
print(io, " solid")
end
print(io, " underline;")
else # must be a Bool
print(io, "text-decoration: ")
if lastface.underline isa SimpleColor
print(io, "currentcolor ")
elseif lastface.underline isa Tuple
first(lastface.underline) isa SimpleColor &&
print(io, "currentcolor ")
last(lastface.underline) != :straight &&
print(io, "straight ")
end
print(io, ifelse(face.underline, "underline;", "none;"))
end
face.strikethrough == lastface.strikethrough ||
print(io, ifelse(face.strikethrough,
"text-decoration: line-through",
ifelse(face.underline === false,
"text-decoration: none", "")))
print(io, "\">")
end

function show(io::IO, ::MIME"text/html", s::Union{<:StyledString, SubString{<:StyledString}}; wrap::Symbol=:pre)
htmlescape(str) = replace(str, '&' => "&amp;", '<' => "&lt;", '>' => "&gt;")
buf = IOBuffer() # Avoid potential overhead in repeatadly printing a more complex IO
wrap == :none ||
print(buf, '<', String(wrap), '>')
lastface::Face = FACES[:default]
stylestackdepth = 0
for (str, styles) in eachstyle(s)
face = getface(styles)
link = let idx=findfirst(==(:link) ∘ first, styles)
if !isnothing(idx)
string(last(styles[idx]))::String
end end
!isnothing(link) && print(buf, "<a href=\"", link, "\">")
if face == FACES[:default]
print(buf, "</span>" ^ stylestackdepth)
stylestackdepth = 0
elseif (lastface.inverse, lastface.foreground, lastface.background) !=
(face.inverse, face.foreground, face.background)
# We can't un-inherit colors well, so we just need to reset and apply
print(buf, "</span>" ^ stylestackdepth)
htmlstyle(buf, face, FACES[:default])
stylestackdepth = 1
else
htmlstyle(buf, face, lastface)
stylestackdepth += 1
end
if wrap == :p
newpara = false
for para in eachsplit(str, "\n\n")
newpara && print(buf, "</p>\n<p>")
print(buf, htmlescape(para))
newpara = true
end
else
print(buf, htmlescape(str))
end
!isnothing(link) && print(buf, "</a>")
lastface = face
end
print(buf, "</span>" ^ stylestackdepth)
wrap == :none ||
print(buf, "</", String(wrap), '>')
write(io, take!(buf))
nothing
end

0 comments on commit 65b393f

Please sign in to comment.