yui-examples/examples/optionsmenu.lua

--- Options screen example
--
-- A fairly complete configuration menu to demonstrate
-- several types of widgets coexisting.
-- Many widgets' behavior is tuned by their attributes.
--
-- Relevant code to build UI inside: makeOptionsMenu().
--
-- Layout: Rows, Columns
-- Widget: Button, Checkbox, Choice, Input, Label, Slider, Spacer

local yui = require 'lib.yui'

local Button = yui.Button
local Checkbox = yui.Checkbox
local Choice = yui.Choice
local Columns = yui.Columns
local Input = yui.Input
local Label = yui.Label
local Rows = yui.Rows
local Slider = yui.Slider
local Spacer = yui.Spacer
local Ui = yui.Ui

local GUI_WIDTH = 500
local GUI_HEIGHT = 300
local FONT_SIZE = 32

-- A dummy save file, for demo purposes.
local dummySave = {}

-- Dummy config load mock.
function dummySave.load()
    local config = {}

    -- The default configuration
    local defconfig = {
        name = "Player 1",
        graphics = 'medium',
        lang = 'en',
        fullscreen = false,
        musicVolume = 80,
        sfxVolume = 90
    }

    local saved = dummySave.latest or defconfig

    print("Loading configuration: {")
    for k,v in pairs(saved) do
        config[k] = v

        print(("\t%s = %s,"):format(k, v))
    end
    print("}")

    return config
end
-- Dummy config save mock
function dummySave.save(config)
    dummySave.latest = {}

    print("Saving configuration: {")
    for k,v in pairs(config) do
        dummySave.latest[k] = v

        print(("\t%s = %s,"):format(k, v))
    end
    print("}")
end

-- Center rectangle on screen.
local function centerRectOnScreen(w, h)
    local x = math.floor((love.graphics.getWidth() - w) / 2)
    local y = math.floor((love.graphics.getHeight() - h) / 2)

    return x, y
end

-- Actual menu creation.
local function makeOptionsMenu()
    -- Position the UI
    local x,y = centerRectOnScreen(GUI_WIDTH, GUI_HEIGHT)
    local vpad = 8
    local hpad = 4

    local w = (GUI_WIDTH - hpad) / 2   -- cut away padding from widget width
    local h = (GUI_HEIGHT - vpad) / 9  -- 9 rows (Spacer counts as 2)

    -- Load configuration "from disk"
    local config = dummySave.load()

    -- Make configuration editable via UI
    return Ui.new {
        x = x, y = y,

        Rows {
            padding = vpad,

            Columns {
                padding = hpad,

                Label {
                    w = w, h = h,
                    text = "Name"
                },
                Input {
                    text = config.name,  -- populate initial value

                    onChange = function(_, text)
                        config.name = text  -- write changed value back
                    end
                }
            },
            Columns {
                padding = hpad,

                Label {
                    w = w, h = h,
                    text = "Language"
                },
                Choice {
                    -- We don't want languages to be translated.
                    notranslate = true,

                    choices = {
                        { text = "English", value = 'en' },  -- just kidding, only English in demo :)
                        -- { text = "Français", value = 'fr' },
                        -- { text = "Italiano", value = 'it' },
                        -- { text = "日本語", value = 'ja' }
                    },
                    default = config.lang,
                    nowrap = true,

                    onChange = function(_, choice) config.lang = choice.value end
                }
            },
            Columns {
                padding = hpad,

                Label {
                    w = w, h = h,
                    text = "Graphics"
                },
                Choice {
                    choices = {
                        -- Text may be localized,
                        -- so map entries to well known enum values.
                        { text = "Fastest", value = 'low' },
                        { text = "Normal", value = 'medium' },
                        { text = "Best",  value = 'high' }
                    },
                    default = config.graphics,
                    nowrap = true,

                    onChange = function(_, choice) config.graphics = choice.value end
                }
            },
            Columns {
                padding = hpad,

                Label {
                    w = w, h = h,
                    text = "Fullscreen"
                },
                Checkbox {
                    checked = config.fullscreen,

                    onChange = function(_, checked) config.fullscreen = checked end
                }
            },
            Columns {
                padding = hpad,

                Label {
                    w = w, h = h,
                    text = "Music"
                },
                Slider {
                    min = 0, max = 100,
                    value = config.musicVolume,

                    onChange = function(_, value) config.musicVolume = value end
                }
            },
            Columns {
                padding = hpad,

                Label {
                    w = w, h = h,
                    text = "Effects"
                },
                Slider {
                    min = 0, max = 100,
                    value = config.sfxVolume,

                    onChange = function(_, value) config.sfxVolume = value end
                }
            },

            Spacer { h = 2*h },  -- leave 2 rows out.

            Columns {
                padding = hpad,

                Button {
                    w = w, h = h,
                    text = "Back",

                    cancelfocus = true, -- gets focused on ESC.

                    onHit = function() love.event.quit() end
                },
                Button {
                    text = "Apply",

                    onHit = function()
                        -- Save configuration "on disk"
                        dummySave.save(config)
                    end
                }
            }
        }
    }
end

function love.load()
    guiFont = love.graphics.newFont('fonts/PixelDroidMenu.ttf', FONT_SIZE)
    gui = makeOptionsMenu()
end

function love.update(dt)
    -- Let the UI update its status
    gui:update(dt)
end

-- Options menu contains a text input field,
-- this requires propagating LÖVE input events to UI.
function love.keypressed(key, scan, isrepeat)
    gui:keypressed(key, scan, isrepeat)
end
function love.keyreleased(key, scan)
    gui:keyreleased(key, scan)
end
function love.textinput(text)
    gui:textinput(text)
end
function love.textedited(text, start, len)
    gui:textedited(text, start, len)
end

function love.draw()
    love.graphics.setFont(guiFont)

    -- Draw menu title
    local title = "Options"
    local tw = guiFont:getWidth(title)
    local th = guiFont:getHeight()
    local tx = (love.graphics.getWidth() - tw) / 2
    local ty = th*2
    love.graphics.print(title, tx,ty)

    -- Draw UI
    gui:draw()
end