UI API

-- GLOBALS
termWidth, termHeight = term.getSize()

-- FUNCTIONS

---- BUTTON

Button = {
    x = 0,
    y = 0,
    w = 0,
    h = 0,
    callBack = nil,
    backColor = nil,
    textColor = nil,
    label = "button"
}

function Button:new (o, x, y, w, h, label, textColor, backColor, callBack)
    local o = setmetatable({}, {__index = self})
    o.__index = o
    o.x = x or 1
    if o.x < 1 or o.x > termWidth then o.x = 1 end
    o.y = y or 1
    if o.y < 1 or o.y > termHeight then o.y = 1 end
    o.w = w or 10
    if o.x + o.w > termWidth or o.w < 1 then o.w = 1 end
    o.h = h or 10
    if o.y + o.h > termHeight or o.h < 1 then o.h = 1 end
    o.label = label or "button"
    o.textColor = textColor or colors.white
    o.backColor = backColor or colors.green
    o.callBack = callBack

    return o
end

function Button:draw ()
    term.setCursorPos(self.x, self.y)
    local textLength = #self.label
    local buttonLength = math.max(self.w, textLength)
    for i = 1, self.h, 1 do
        term.blit(string.rep(" ", buttonLength), string.rep(colors.toBlit(self.textColor), buttonLength), string.rep(colors.toBlit(self.backColor), buttonLength))
        term.setCursorPos(self.x, self.y + i)
    end
    term.setCursorPos(buttonLength/2 - textLength/2 + self.x, self.h/2 + self.y)
    term.setTextColor(self.textColor)
    term.blit(self.label, string.rep(colors.toBlit(self.textColor), textLength), string.rep(colors.toBlit(self.backColor), textLength))
end

function Button:isClicked(x, y)
    if x >= self.x and x <= self.x + self.w - 1 and y >= self.y and y <= self.y + self.h - 1 then
        if type(self.callBack) == "function" then
            return self.callBack()
        elseif type(self.callBack) == "table" then
            return self.callBack[1](self.callBack[2])
        end
        local func = load(self.callBack)
        return func()
    end
end

---- RECTANGLE

function drawRectangle(x, y, w, h, color, text, textcolor)
    term.setCursorPos(x, y)
    for i = 1, h, 1 do
        term.blit(string.rep(" ", w), string.rep(1, w), string.rep(colors.toBlit(color), w))
        term.setCursorPos(x, y + i)
    end

    if text ~= nil then
        term.setCursorPos(w / 2 - #text / 2 + x, h / 2 + x)
        term.blit(text, string.rep(colors.toBlit(textcolor), #text), string.rep(colors.toBlit(color), #text))
    end
end