My hammerspoon config

init.lua

-----------------------------------------------------------------------
-- References:
-- https://github.com/apesic/dotfiles/blob/master/.hammerspoon/init.lua
-- https://learnxinyminutes.com/docs/lua/
-----------------------------------------------------------------------

----------------
-- Configuration
----------------

-- Make the alerts look nicer.
hs.alert.defaultStyle.strokeColor =  {white = 1, alpha = 0}
hs.alert.defaultStyle.fillColor =  {white = 0.05, alpha = 0.75}
hs.alert.defaultStyle.radius =  10

-- Disable the slow default window animations.
hs.window.animationDuration = 0

-- Modifier sets that I use
local mash_app = {"cmd", "ctrl"}

---------------------
-- Window positioning
---------------------

function moveLeftHalf()
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local max = screen:frame()
  f.x = max.x
  f.y = max.y
  f.w = max.w / 2
  f.h = max.h
  win:setFrame(f)
end

function moveRightHalf()
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local max = screen:frame()
  f.x = max.x + (max.w / 2)
  f.y = max.y
  f.w = max.w / 2
  f.h = max.h
  win:setFrame(f)
end

function maximize()
  local win = hs.window.focusedWindow()
  local f = win:frame()
  local screen = win:screen()
  local max = screen:frame()
  f.x = max.x
  f.y = max.y
  f.w = max.w
  f.h = max.h
  win:setFrame(f)
end

function moveToScreen(screenPos)
  window = hs.window.focusedWindow()
  screen = hs.screen.find({x=screenPos, y=0})
  window:moveToScreen(screen)
end

hs.hotkey.bind(mash_app, "1", function()
  moveToScreen(0)
  moveLeftHalf()
end)

hs.hotkey.bind(mash_app, "2", function()
  moveToScreen(0)
  moveRightHalf()
end)

hs.hotkey.bind(mash_app, "3", function()
  moveToScreen(1)
  moveLeftHalf()
end)

hs.hotkey.bind(mash_app, "4", function()
  moveToScreen(1)
  moveRightHalf()
end)

hs.hotkey.bind(mash_app, "M", maximize)

-------------------------------------
-- Application focusing shortcuts
-------------------------------------

-- Like hs.application.launchOrFocus, except that it works for apps created using Epichrome.
-- I'm not sure why this implementation has different behavior than hs.application.launchOrFocus.
-- Reference: https://github.com/Hammerspoon/hammerspoon/issues/304
function myLaunchOrFocus(appName)
   local app = hs.appfinder.appFromName(appName)
   if app == nil then
      hs.application.launchOrFocus(appName)
   else
      windows = app:allWindows()
      if windows[1] then
         windows[1]:focus()
      end
   end
end

hs.hotkey.bind(mash_app, 'L', function() myLaunchOrFocus('Google Chrome') end)
hs.hotkey.bind(mash_app, 'J', function() myLaunchOrFocus('Emacs') end)
hs.hotkey.bind(mash_app, 'K', function() myLaunchOrFocus('/Applications/iTerm.app') end)
hs.hotkey.bind(mash_app, 'U', function() myLaunchOrFocus('Gmail') end)
hs.hotkey.bind(mash_app, 'Y', function() myLaunchOrFocus('GmailPersonal') end)
hs.hotkey.bind(mash_app, ',', function() myLaunchOrFocus('Slack') end)
hs.hotkey.bind(mash_app, 'N', function() myLaunchOrFocus('Terminal') end)
hs.hotkey.bind({"cmd", "ctrl", "shift"}, 'N', function () myLaunchOrFocus('Spotify') end)
hs.hotkey.bind(mash_app, 'O', function() myLaunchOrFocus('Org') end)
hs.hotkey.bind(mash_app, 'C', function() myLaunchOrFocus('GCalendar') end)

-------------------------------------
-- Window layouts
-------------------------------------

local leftScreen = hs.screen{x=0,y=0}
local centerScreen = hs.screen{x=1,y=0}
local rightScreen = hs.screen{x=2,y=0}

local threeScreenLayout = {
 {"Emacs", nil, centerScreen, hs.layout.maximized, nil, nil},
 {"Google Chrome", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"iTerm2", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"Gmail", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"GmailPersonal", nil, leftScreen, hs.layout.right50, nil, nil},
 {"GCalendar", nil, centerScreen, hs.layout.left50, nil, nil},
 {"Slack", nil, leftScreen, hs.layout.right50, nil, nil},
 {"MacVim", nil, leftScreen, hs.layout.right50, nil, nil},
 {"Org", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Xcode", nil, centerScreen, hs.layout.right50, nil, nil},
 {"Finder", nil, centerScreen, hs.layout.left50, nil, nil},
 {"Preview", nil, centerScreen, hs.layout.left50, nil, nil},
 {"OmniGraffle 6", nil, centerScreen, hs.layout.maximized, nil, nil},
 {"Terminal", nil, centerScreen, hs.layout.left50, nil, nil},
 {"Spotify", nil, centerScreen, hs.layout.left50, nil, nil},
 {"PowerPoint", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Calendar", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"System Preferences", nil, leftScreen, hs.layout.left50, nil, nil}
}

local twoScreenLayout = {
 {"Emacs", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"Google Chrome", nil, leftScreen, hs.layout.left50, nil, nil},
 {"iTerm2", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"Gmail", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"GmailPersonal", nil, leftScreen, hs.layout.left50, nil, nil},
 {"GCalendar", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Slack", nil, leftScreen, hs.layout.right50, nil, nil},
 {"MacVim", nil, leftScreen, hs.layout.right50, nil, nil},
 {"Org", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Xcode", nil, leftScreen, hs.layout.right50, nil, nil},
 {"Finder", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Preview", nil, leftScreen, hs.layout.left50, nil, nil},
 {"OmniGraffle 6", nil, leftScreen, hs.layout.maximized, nil, nil},
 {"Terminal", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Spotify", nil, leftScreen, hs.layout.left50, nil, nil},
 {"PowerPoint", nil, leftScreen, hs.layout.left50, nil, nil},
 {"Calendar", nil, leftScreen, hs.layout.left50, nil, nil},
 {"System Preferences", nil, leftScreen, hs.layout.left50, nil, nil}
}

function switchLayout()
  local numScreens = #hs.screen.allScreens()
  local layout = {}
  if numScreens == 1 then
    layout = twoScreenLayout
  elseif numScreens == 2 then
    layout = twoScreenLayout
  elseif numScreens == 3 then
    layout = threeScreenLayout
  end
  hs.layout.apply(layout)
end

hs.hotkey.bind(mash_app, "'", function()
  switchLayout()
end)

-------------------
-- Other shortcuts
-------------------

-- Lock the screen. This may also be possible with hs.caffeinate.lockScreen.
hs.hotkey.bind({"cmd", "alt", "ctrl"}, "l", function()
  os.execute("/Users/phil/scripts/macos/lock_screen.sh")
end)

-- Lock the screen. This may also be possible with hs.caffeinate.lockScreen.
hs.hotkey.bind(mash_app, "9", function()
  os.execute("/Users/phil/scripts/macos/lock_screen.sh")
end)

function getVolumeIncrement()
  local volume = hs.audiodevice.current().volume
  -- When the volume gets near zero, change it in smaller increments. Otherwise even the first increment
  -- above zero may be too loud.
  -- NOTE(phil): I noticed that using a decimal smaller than 0.4 will sometimes result in the volume remaining
  -- unchanged after calling setVolume, as if OSX only lets you change the volume by large increments.
  if volume < 2 then return 0.4 else return 2 end
end

hs.hotkey.bind(mash_app, "9", function()
  hs.audiodevice.defaultOutputDevice():setVolume(hs.audiodevice.current().volume - getVolumeIncrement())
end)

hs.hotkey.bind(mash_app, "0", function()
  hs.audiodevice.defaultOutputDevice():setVolume(hs.audiodevice.current().volume + getVolumeIncrement())
end)

-- Show date time and battery
hs.hotkey.bind(mash_app, 'T', function()
  local seconds = 3
  local message = os.date("%I:%M%p") .. "\n" .. os.date("%a %b %d") .. "\nBattery: " ..
     hs.battery.percentage() .. "%"
  hs.alert.show(message, seconds)
end)

-- Shortcut to reload this hammerspoon config
hs.hotkey.bind({"cmd", "alt", "ctrl"}, "R", function() hs.reload() end)
hs.alert.show("Config loaded")

My hammerspoon config is now checked in here