February 18, 2015

Switching from Slate to Hammerspoon

My beloved Slate has seen no activity on github for two years and I fear that it has become abandonware. There is a fork that is active but I decided to have a look around at some of the options open to me for window management. I’ve tried Spectacle, Moom and Divvy and none of them stuck. I’m so used to my Slate shortcuts now that changing to anything else seems like work. I decided to have a look at Mjolnir and that lead me to a recent fork of it called Hammerspoon. Hammerspoon, like Mjolnir before it, depends on a simple lua config file, residing – in this case – in ~/.hammerspoon/init.lua. I cobbled together a config that duplicates my Slate setup and have been using Hammerspoon as a drop-in replacement for the past few days and it’s working great. Here’s my init.lua file:

-----------------------------------------------
-- Set up
-----------------------------------------------

local hyper = {"shift", "cmd", "alt", "ctrl"}

-----------------------------------------------
-- hyper d for left one half window
-----------------------------------------------

hs.hotkey.bind(hyper, "d", function()
    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)

-----------------------------------------------
-- hyper g for right one half window
-----------------------------------------------

hs.hotkey.bind(hyper, "g", function()
    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)

-----------------------------------------------
-- hyper f for fullscreen
-----------------------------------------------

hs.hotkey.bind(hyper, "f", function()
    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)

-----------------------------------------------
-- hyper r for top left one quarter window
-----------------------------------------------

hs.hotkey.bind(hyper, "r", function()
    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 / 2
    win:setFrame(f)
end)

-----------------------------------------------
-- hyper t for top right one quarter window
-----------------------------------------------

hs.hotkey.bind(hyper, "t", function()
    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 / 2
    win:setFrame(f)
end)

-----------------------------------------------
-- hyper v for bottom left one quarter window
-----------------------------------------------

hs.hotkey.bind(hyper, "v", function()
    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 + (max.h / 2)
    f.w = max.w / 2
    f.h = max.h / 2
    win:setFrame(f)
end)

-----------------------------------------------
-- hyper c for bottom right one quarter window
-----------------------------------------------

hs.hotkey.bind(hyper, "c", function()
    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 + (max.h / 2)
    f.w = max.w / 2
    f.h = max.h / 2
    win:setFrame(f)
end)

-----------------------------------------------
-- Reload config on write
-----------------------------------------------

function reload_config(files)
    hs.reload()
end
hs.pathwatcher.new(os.getenv("HOME") .. "/.hammerspoon/", reload_config):start()
hs.alert.show("Config loaded")

-----------------------------------------------
-- Hyper i to show window hints
-----------------------------------------------

hs.hotkey.bind(hyper, "i", function()
    hs.hints.windowHints()
end)

-----------------------------------------------
-- Hyper hjkl to switch window focus
-----------------------------------------------

hs.hotkey.bind(hyper, 'k', function()
    hs.window.focusedWindow():focusWindowNorth()
end)

hs.hotkey.bind(hyper, 'j', function()
    hs.window.focusedWindow():focusWindowSouth()
end)

hs.hotkey.bind(hyper, 'l', function()
    hs.window.focusedWindow():focusWindowEast()
end)

hs.hotkey.bind(hyper, 'h', function()
    hs.window.focusedWindow():focusWindowWest()
end)

This all depends on having a Hyper key (Command + Shift + Control + Alt) available – you can read how to set Caps Lock up as one in this post by the ever-awesome Brett Terpstra. Hammerspoon, and Mjolnir, can do a whole lot more than just window management and there’s oodles of room for endless tweaking if you’re so inclined. Have a look at the Hammerspoon API docs and go crazy.

Update 12/06/15 I’ve tweaked this a little to cover cases where there is no active window, see here for details.