local color = require("color")
local GUI = require("GUI")
local MineOSInterface = require("MineOSInterface")

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-- Create a tabbed window and register it in MineOS environment
local mainContainer, window = MineOSInterface.addWindow(GUI.tabbedWindow(1, 1, 88, 25))

-- Add some stuff into it's tab bar
window.tabBar:addItem("Tab 1")
window.tabBar:addItem("Tab 2")
window.tabBar:addItem("Tab 3")
window.tabBar:addItem("Yay another tab")

-- Add a single cell layout to window
local layout = window:addChild(GUI.layout(1, 4, window.width, window.height - window.tabBar.height, 1, 1))

-- Add a horizontal slider to layout
local slider = layout:addChild(GUI.slider(1, 1, 26, 0x66DB80, 0x0, 0x009200, 0xAAAAAA, 0, 100, 100, false, "Brightness: ", "%"))
-- Attach callback-function .onValueChanged to it
slider.onValueChanged = function()
    -- Calculate "brightness" color value
    local channelValue = math.floor(slider.value / slider.maximumValue * 255)
    local newColor = color.RGBToInteger(channelValue, channelValue, channelValue)
    -- Set new color to all required widgets
    window.backgroundPanel.colors.background = newColor
    window.tabBar.colors.selected.background = newColor
    window.tabBar.colors.selected.text = 0xFFFFFF - newColor
    -- Draw changes on screen
    mainContainer:drawOnScreen()
end

-- Call slider callback function once to calculate brightess and draw data on screen
slider.onValueChanged()