LuaRT syntax highlighting example with Edit widget

syntax.wlua

--
--  luaRT syntax.lua example
--  A syntax higlighting Edit widget
--  Author: Samir Tine
--

local ui = require "ui"

local SyntaxEdit = Object(ui.Edit)

function SyntaxEdit:constructor(...)
  local keyword_color = 0xCC2020
  local keywords = {  ["and"] = true, ["break"] = true, ["do"] = true, ["else"] = true, ["elseif"] = true,
                    ["end"] = true, ["for"] = true, ["function"] = true, ["goto"] = true, ["if"] = true, ["in"] = true, 
                    ["local"] = true, ["not"] = true, ["or"] = true, ["repeat"] = true, ["return"] = true, ["then"] = true, ["until"] = true, ["while"] = true }
  
  -- keywords property => Get/set a table with keywords
  function self:get_keywords()
    return keywords
  end
  
  function self:set_keywords(keywords_table)
    keywords = keywords_table
  end
  
  -- kwcolor property => Get/set the keywords color
  function self:get_kwcolor()
    return keyword_color
  end
  
  function self:set_kwcolor(c)
    keyword_color = c
  end
  
  ui.Edit.constructor(self, ...)
end

-- onChange event : parse and recolorize the keywords in the text 
function SyntaxEdit:onChange()
  local from = self.selection.from
  local to = self.selection.to
  
  self.selection.from = 1
  self.selection.to = 0
  self.selection.color = 0x000000
  
  local start = 1
  local text = self.text:gsub("\r\n", "\n")
	while start < string.len(text) do
    local s, e = text:find("%w+", start)
    if s ~= nil then
      local word = text:sub(s, e)
      start = e+1
      if self.keywords[word] ~= nil then
        self.selection.from = s
        self.selection.to = start
        self.selection.color = 0xCC2020
      end
    else
      break;
    end
  end
  self.selection.from = from
  self.selection.to = to
end


-- create a simple window 
local win = ui.Window("Syntax highlighting sample", "fixed", 520, 460)
local edit = SyntaxEdit(win, "", 10, 10, 500, 440)
-- set edit.properties
edit.autovscroll = false
edit.font = "Lucida Console"
edit.fontsize = 9
edit.wordwrap = true

win:show()

-- update user interface
repeat
	ui.update()
until not win.visible