OC/Button

local rect = require "rectangle"
local unicode = require "unicode"

--CONST--
local STATUS_ENABLED = 0
local STATUS_DISABLED = 5
local STATUS_BLINK = 10

--UTILS--
local function alignTextToCenterRect(rectangle, text)
    local x = rectangle.sx + rectangle.width/2 - unicode.len(text)/2
    local y = rectangle.sy + rectangle.height/2

    return x, y
end

--Default settings
local default_design = {
    blink_time = 0.2,

    [STATUS_ENABLED] = {
        bg = 0x00ff00,
        fg = 0xffffff,
        char = ' '
    },

    [STATUS_DISABLED] = {
        bg = 0xffffff,
        fg = 0,
        char = ' '
    },

    [STATUS_BLINK] = {
        bg = 0xff0000,
        fg = 0,
        char = ' '
    }
}

local default_text = ' '

local default_action = function()
    --nothing
end

--BUTTON API--
local buttonAPI = {}

function buttonAPI.create(gpu, rectangle, text, action, design, status)
    button = {}

    button.gpu       = gpu
    button.rectangle = rectangle
    button.design    = design or default_design
    button.text      = text or default_text
    button.action    = action or default_action
    button.status    = status or STATUS_ENABLED

    function button:redraw()
        self.gpu.setBackground( self.design[self.status].bg )
        self.gpu.setForeground( self.design[self.status].fg )
        self.gpu.fill( self.rectangle.sx, self.rectangle.sy, self.rectangle.width, self.rectangle.height, self.design[self.status].char )

        local textX, textY = alignTextToCenterRect(self.rectangle, self.text)
        self.gpu.set( textX, textY, self.text )
    end

    function button:handler(event)
        if ( event[1] == "touch" and event[5] == 0 ) then
            if ( self.status == STATUS_ENABLED ) then
                if ( rect.PointInRect(event[3], event[4], self.rectangle) ) then
                    self.action()

                    self.status = STATUS_BLINK
                    self:redraw()
                    os.sleep(self.design.blink_time)
                    self.status = STATUS_ENABLED
                    self:redraw()
                end
            end
        end
    end

    return button
end

return buttonAPI
--pastebin -f get J5jHxja6 lib/button.lua