Hammerspoon init script to auto-arrange for three screens.

init.lua

-- https://en.wikipedia.org/wiki/Web_colors#X11_color_names
-- hs.streamdeck.init(function(connected, sd)
--  device = hs.streamdeck.getDevice(1)
--   device.setButtonColor("1", hs.drawing.color.x11.teal)
-- end)

applications = { "Messages", "iTunes", "Skype for Business", "iTerm2", "Microsoft Outlook", "HipChat", "Microsoft OneNote", "MacVim", "RubyMine", "Firefox" }

hs.hotkey.bind({"cmd", "alt", "ctrl"}, "pageup", function()

  for _k, app_name in pairs(applications) do
    hs.application.launchOrFocus(app_name)
    print(app_name)
    app = hs.application.find(app_name)
    if app then
      hs.application.unhide(app)
    end
  end

  local lgUltra="LG Ultra HD"
  local windowLayout = {
    -- upper right quadrant
    {"Slack", nil, lgUltra, hs.geometry.rect(0,0,0.5,0.5), nil, nil},
    -- upper left quadrant
    {"Notes", nil, lgUltra, hs.geometry.rect(0.5,0,0.5,0.5), nil, nil},
    -- lower right quadrant
    {"Skype for Business", nil, lgUltra, hs.geometry.rect(0.5,0.5,0.5,0.5), nil, nil},
    -- lower left quadrant
    {"iTerm2", nil, lgUltra, hs.geometry.rect(0,0.5,0.5,0.5), nil, nil}
  }
  hs.layout.apply(windowLayout)

  local laptopScreen="Color LCD"
  local windowLayout = {
    {"Microsoft Outlook", nil, laptopScreen, hs.geometry.rect(0.5,0,0.5,0.5), nil, nil},
    {"HipChat", nil, laptopScreen, hs.geometry.rect(0.5,0.5,0.5,0.5), nil, nil},
    {"Microsoft OneNote", nil, laptopScreen, hs.geometry.rect(0,0.5,0.5,0.5), nil, nil},
    {"Notes", nil, laptopScreen, hs.geometry.rect(0,0,0.5,0.5), nil, nil}
  }
  hs.layout.apply(windowLayout)

  local seiki4KScreen="SE39UY04"
  local windowLayout = {
    {"MacVim", nil, seiki4KScreen, hs.geometry.rect(0,0,0.5,0.5), nil, nil},
    {"Emacs", nil, seiki4KScreen, hs.geometry.rect(0.5,0,0.5,0.5), nil, nil},
    {"RubyMine-EAP", nil, seiki4KScreen, hs.geometry.rect(0,0.5,0.5,0.5), nil, nil},
    {"iTerm2", nil, seiki4KScreen, hs.geometry.rect(0.5,0.5,0.5,0.5), nil, nil}
  }
  hs.layout.apply(windowLayout)
end)

-- Convert a lua table into a lua syntactically correct string
function table_to_string(tbl)
    local result = "{"
    for k, v in pairs(tbl) do
        -- Check the key type (ignore any numerical keys - assume its an array)
        if type(k) == "string" then
            result = result.."[\""..k.."\"]".."="
        end

        -- Check the value type
        if type(v) == "table" then
            result = result..table_to_string(v)
        elseif type(v) == "boolean" then
            result = result..tostring(v)
        else
            result = result.."\""..v.."\""
        end
        result = result..","
    end
    -- Remove leading commas from the result
    if result ~= "" then
        result = result:sub(1, result:len()-1)
    end
    return result.."}"
end

hs.hotkey.bind({}, "f13", function()
  hs.location.start()
  locationTable = hs.location.get()
  hs.eventtap.keyStrokes(locationTable["latitude"] .. "," .. locationTable["longitude"])
  print(table_to_string(locationTable))
end)


function move_to_third(r,c)
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local extents = screen:frame()

  f.x = extents.x + (extents.w / 3) * c
  f.y = extents.y + (extents.h / 3) * r
  f.w = extents.w / 3
  f.h = extents.h / 3
  win:setFrame(f)
end

function move_to_two_third_horz(c)
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local extents = screen:frame()

  f.x = extents.x + (extents.w / 3) * c
  f.y = extents.y
  f.w = extents.w / 3 * 2
  f.h = extents.h
  win:setFrame(f)
end

function move_to_two_third_vert(r)
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local extents = screen:frame()

  f.x = extents.x
  f.y = extents.y + (extents.h / 3) * r
  f.w = extents.w
  f.h = extents.h / 3 * 2
  win:setFrame(f)
end


function move_to_four_ninths(r,c)
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local extents = screen:frame()

  f.x = extents.x + (extents.w / 3) * c
  f.y = extents.y + (extents.h / 3) * r
  f.w = extents.w / 3 * 2
  f.h = extents.h / 3 * 2
  win:setFrame(f)
end

function move_to_fourth(r,c)
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local extents = screen:frame()

  f.x = extents.x + (extents.w / 4) * c
  f.y = extents.y + (extents.h / 4) * r
  f.w = extents.w / 4
  f.h = extents.h / 4
  win:setFrame(f)
end


for i=0,15 do
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, string.format("%x", i), function()
    move_to_fourth(math.floor(i/4),i%4)
  end)
end
for i=1,9 do
  hs.hotkey.bind({"cmd", "alt", "ctrl"}, "pad"..tostring(i), function()
    move_to_third(math.floor((9-i)/3),(i-1)%3)
  end)
end
for i=1,9 do
  hs.hotkey.bind({"cmd", "alt", "ctrl", "shift"}, "pad"..tostring(i), function()
    if i == 1 then move_to_four_ninths(1,0)
    elseif i == 3 then move_to_four_ninths(1,1)
    elseif i == 7 then move_to_four_ninths(0,0)
    elseif i == 9 then move_to_four_ninths(0,1)
    elseif i == 2 then move_to_two_third_vert(1)
    elseif i == 4 then move_to_two_third_horz(0)
    elseif i == 6 then move_to_two_third_horz(1)
    elseif i == 8 then move_to_two_third_vert(0)
    end
  end)
end




-- https://www.hammerspoon.org/docs/hs.application.watcher.html
-- https://www.lua.org/pil/9.1.html
-- https://stackoverflow.com/questions/16984540/how-to-pass-a-function-as-a-parameter-in-lua
-- hs.application.watcher.new()

-- TODO Plan:
-- Create application watcher
--
currentApp = ""
function applicationWatcher(appName, eventType, appObject)
  if(eventType == hs.application.watcher.activated) then
    if (appName == "HipChat") then
      currentApp = "HipChat"
    end
    if (appName == "Google Chrome") then
      currentApp = "Chrome"
    end
  end
end

function alertCurrent()
  hs.alert(currentApp)
end

--hs.timer.doEvery(5, alertCurrent)