A buggy scope highlighter for ZeroBrane Studio

scopecolor.lua

local golden_ratio = (1+math.sqrt(5))/2
local offset = 0.05

local function HSVtoRGB(h, s, v)
    if s == 0 then
        return v,v,v
    end
    h = h/60
    i = math.floor( h )
    f = h - i
    p = v * ( 1 - s )
    q = v * ( 1 - s * f )
    t = v * ( 1 - s * ( 1 - f ) )
    if i == 0 then r, g, b = v, t, p
    elseif i == 1 then r, g, b = q, v, p
    elseif i == 2 then r, g, b = p, v, t
    elseif i == 3 then r, g, b = p, q, v
    elseif i == 4 then r, g, b = t, p, v
    elseif i == 5 then r, g, b = v, p, q
    end
    return math.floor(r * 255), math.floor(g * 255), math.floor(b * 255)
end

local function goldenColor(i)
    return HSVtoRGB(((offset + (golden_ratio * i) )% 1)*360,1,1)
end

local function defaultdict(default_value_factory)
    local mt = {
        __index = function(t, key)
            if not rawget(t, key) then
                rawset(t, key, default_value_factory(key))
            end
            return rawget(t, key)
        end
    }
    return setmetatable({}, mt)
end

local indicators = defaultdict(function(n) 
    return ide:AddIndicator("scopecolor.ind" .. n)
end)

local editor_indicators = defaultdict(function(editor)
    return defaultdict(function(n) 
        local i = indicators[n]
        local color = wx.wxColour(goldenColor(n))
        editor:IndicatorSetStyle(i, wxstc.wxSTC_INDIC_ROUNDBOX)
        editor:IndicatorSetUnder(i, true)
        editor:IndicatorSetForeground(i, color)
        editor:IndicatorSetAlpha(i, 34)
        
        return i
    end)
end)

local function ApplyContextStyles(editor, style_tree)
    print(style_tree, style_tree.color)
    if style_tree.color ~= 0 then
        for i=1,#style_tree.segments/2 do
            local start, finish = style_tree.segments[i*2-1], style_tree.segments[i*2]
            local indicator = editor_indicators[editor][style_tree.color]
            
            editor:SetIndicatorCurrent(indicator)
            editor:IndicatorFillRange(start, finish - start)
        end
    end
    
    for i, child in ipairs(style_tree.children) do
        ApplyContextStyles(editor, child)
    end
end

local function ApplyColors(editor)
    local tokens = editor:GetTokenList()
    
    for _, indicator in pairs(editor_indicators[editor]) do
        editor:SetIndicatorCurrent(indicator)
        editor:IndicatorClearRange(0, #editor:GetText())
    end
    
    local tree = {parent = nil, children = {}, color = 0, next_color = 1, segments={0}}
    local current = tree
    for i, t in ipairs(tokens) do
        if t[1] == "Scope" then
            local position = t.fpos + #t.name
            current = {
                parent = current,
                color = current.color + 1,
                next_color = current.color + 2,
                segments = {},
                children = {}
            }
            table.insert(current.parent.children, current)
            current.parent.next_color = current.color + 1
            table.insert(current.segments, position)
            table.insert(current.parent.segments, position)
        elseif t[1] == "EndScope" then
            local position = 0
             --if t.name == "then" then
                 --position = tokens[i-1].fpos + #tokens[i-1].name - 1
             --else
                position = t.fpos - 1
             --end
            table.insert(current.segments, position)
            table.insert(current.parent.segments, position)
            
            current = current.parent
        end
    end
    table.insert(tree.segments, #editor:GetText())
    
    ApplyContextStyles(editor, tree)
end

return {
    name = "Scopecolor",
    description = "Highlights scopes for improved visual clarity",
    author = "Llamageddon",
    version = 0.7,

    onRegister = function(self) end,

    onUnRegister = function(self) end,
    
    onEditorCharAdded = function(self, editor, event)
        if ide.config.scopecolor and ide.config.scopecolor.enabled == false then return end
        
        pcall(ApplyColors, editor) -- Catch errors, they're caused by user still editing
    end,
    
    onEditorLoad = function(self, editor)
        -- For some reason causes a crash on startup
        -- ApplyColors(editor)
    end,
}