example

    local window = tui.Window.create(uiManager)
    window:setSize(39, 26)
    local label = tui.Label.create(uiManager)
    label:setPos(2, 3)
    label:setText("Hello World")
    label:setOnclick(function() print("Click") end)
    window:addChild(label)
    local layout = tui.ReactorLayout.create(uiManager)
    layout:setPos(4, 5)
    window:addChild(layout)
    layout:setReactor(reactor)
    local gauge = tui.ReactorTempGauge.create(uiManager)
    gauge:setSize(32, 2)
    gauge:setPos(3, 22)
    window:addChild(gauge)
    gauge:setReactor(reactor)
    local timerId = os.startTimer(0.5)
    while(true) do
        local event, timer = os.pullEvent("timer")
        if(timer == timerId) then
            layout:update()
            gauge:update()
            local temp = reactor:getTemp()
            label:setText(tostring(temp).." degC -> "..string.format("%.2f", reactor.tempRate))
            timerId = os.startTimer(0.5)
        end
    end

parallel.waitForAll(function() uiManager:renderThread() end,
    function() uiManager:touchThread() end)

tui.lua

function inherits(child, parent)
    local meta = getmetatable(child)
    child._b = { }
    for k,v in pairs(getmetatable(parent)) do
        if(meta[k] == nil) then
            meta[k] = v
        else
            child._b[k] = v
        end
    end
    setmetatable(child, meta)
    for k,v in pairs(parent) do
        if(type(v) ~= "function") then
            child[k] = v
        end
    end
end

function drawBox(mon, posX, posY, width, height, color)
    mon.setBackgroundColor(color)
    for y = 0, height - 1, 1 do
        for x = 0, width - 1, 1 do
            if(y == 0 or x == 0 or y == height - 1 or x == width - 1) then
                mon.setCursorPos(posX + x, posY + y)
                mon.write(" ")
            end
        end
    end
end

function drawFilledBox(mon, posX, posY, width, height, color)
    mon.setBackgroundColor(color)
    for y = 0, height - 1, 1 do
        for x = 0, width - 1, 1 do
            mon.setCursorPos(posX + x, posY + y)
            mon.write(" ")
        end
    end
end

local BASE_EVENT_NAME = "tui_update_"
local TOUCH_EVENT_NAME = "monitor_touch"

Tui = { }
Tui.__index = Tui

function Tui.create(mon, side)
    local tui = { }
    setmetatable(tui, Tui)
    tui.components = { }
    tui.mon = mon
    tui.side = side
    tui.event_name = BASE_EVENT_NAME..tostring(tui)
    return tui
end

function Tui:addComponent(comp)
    self.components[tostring(comp)] = comp
end

function Tui:renderThread()
    self.mon.clear()
    while(true) do
        local event, id = os.pullEvent(self.event_name)
        local comp = self.components[id]
        comp:render(self.mon)
    end
end

function Tui:touchThread()
    while(true) do
        local event, side, x, y = os.pullEvent(TOUCH_EVENT_NAME)
        if(side == self.side) then
            for k,v in pairs(self.components) do
                if(v.visible and v.onclick ~= nil) then
                    local posX, posY = v:getPos(true)
                    local width, height = v:getSize()
                    if(posX <= x and x <= posX + width
                        and posY <= y and y <= posY + height) then
                        v.onclick()
                    end
                end
            end
        else
            os.queueEvent(event, side, x, y) --maybe?
        end
    end
end

Component = { }
Component.__index = Component

function Component.create(tui)
    local component = { }
    setmetatable(component, Component)
    component.x = 1
    component.y = 1
    component.width = 0
    component.height = 0
    component.bgcolor = colors.black
    component.fgcolor = colors.white
    component.visible = true
    component.parent = nil
    component.children = { }
    component.tui = tui
    component.onclick = nil
    component.widthLast = component.width
    component.heightLast = component.height
    component.xLast = component.x
    component.yLast = component.y
    return component
end

function Component:update()
    if(not self.visible) then
        return
    end
    os.queueEvent(self.tui.event_name, tostring(self))
    for k,v in pairs(self.children) do
        v:update()
    end
end

function Component:setPos(x, y)
    self.x = x
    self.y = y
    self:update()
end

function Component:setSize(width, height)
    self.width = width
    self.height = height
    self:update()
end

function Component:setVisible(visible)
    self.visible = visible
    self:update()
end

function Component:addChild(child)
    table.insert(self.children, child)
    child.parent = self
    self:update()
end

function Component:removeChild(child)
    for k,v in pairs(self.children) do
        if(child == v) then
            table.remove(self.children, k)
            child.parent = nil
            self:update()
            return true
        end
    end
    return false
end

function Component:render(mon)
    if(self.parent ~= nil and
        (self.widthLast ~= self.width or self.heightLast ~= self.height or
            self.x ~= self.xLast or self.y ~= self.yLast)) then
        self.widthLast = self.width
        self.heightLast = self.height
        self.xLast = self.x
        self.yLast = self.y
        self.parent:update()
    end
    return false
end

function Component:getPos(absolute)
    if(self.parent ~= nil and absolute) then
        local offsetX, offsetY = self.parent:getPos()
        return offsetX + self.x, offsetY + self.y
    else
        return self.x, self.y
    end
end

function Component:getSize()
    return self.width, self.height
end

function Component:setOnclick(listener)
    self.onclick = listener
end

Window = { }
Window.__index = Window

function Window.create(tui)
    local window =  { }
    setmetatable(window, Window)
    inherits(window, Component.create())
    window.tui = tui
    tui:addComponent(window)
    window:update()
    return window
end

function Window:render(mon)
    self._b.render(self)
    local x, y = self:getPos(true)
    local width, height = self:getSize()
    drawBox(mon, x, y,width, height, self.fgcolor)
    drawFilledBox(mon, x + 1, y + 1, width - 2, height - 2, self.bgcolor)
end

Label = { }
Label.__index = Label

function Label.create(tui)
    local label = { }
    setmetatable(label, Label)
    inherits(label, Component.create())
    label.text = ""
    label.tui = tui
    tui:addComponent(label)
    label:update()
    return label
end

function Label:setText(text)
    self.text = text
    self.width = #text
    self.height = 1
    self:update()
end

function Label:render(mon)
    self._b.render(self)
    local x, y = self:getPos(true)
    local width, height = self:getSize()
    drawFilledBox(mon, x, y, width, height, self.bgcolor)
    mon.setBackgroundColor(self.bgcolor)
    mon.setTextColor(self.fgcolor)
    mon.setCursorPos(x, y)
    mon.write(self.text)
end