Hammerspoon config inspired by Spacemacs

Rationale

Keyboard-oriented workflows are often far more efficient and less frustrating than similar mouse-driven techniques. However, the most popular strategy in that space is to use a multitude of keyboard shortcuts. And obviously, that approach is not very scalable. You start adding keyboard shortcuts for various actions, and soon you will be blocked by conflicting shortcuts.

Command composability (first explored in Vi and later expanded in its successor Vim), although does require some initial learning and getting used to, allows you to expand your keyboard-oriented workflow with a minimal effort to memorize keys. There’s so much you can do with the h/j/k/l keys alone.

However, the “one-dimensional” approach utilized in vanilla Vim, where a single modal (to switch from Normal to Edit to Select mode) is used, also has limitations. Fortunately, the basic idea of modality can be expanded further. The Spacemacs project is an excellent example of where that was done. In Spacemacs there is a single primary “modifier” key SPACE. To trigger an action, user is required to press a mnemonically recognizable combination of keys (that usually starts with SPACE key), e.g., SPC w m is used to maximize the current window/buffer.

The Spacehammer project explores these ideas to allow you to take your keyboard-driven workflow to the next level. Jumping between applications, controlling the size and position of their windows, searching for things, etc. - everything follows simple, mnemonic semantics. It lets you keep your fingers on the home row and liberates you from having to memorize a myriad of keystrokes, or require you to drag your hand to reach for mouse/touchpad/arrow keys - which inevitably slows you down.

Fennel

Spacehammer initially was written in Lua (as the majority of Hammerspoon configs), but later was completely re-written in Fennel - a tiny Lisp that compiles to Lua. There is nothing wrong with Lua, but Lisp has many benefits (sadly often overlooked and ignored by majority of programmers today). Switching to Fennel allowed us to keep the code more structured and concise.

Installation

Install Hammerspoon

You can use brew:

brew install hammerspoon

Install Fennel >= v1.0.0

brew install luarocks

luarocks install fennel

Older versions of Fennel are incompatible with Spacehammer.

Clone Spacehammer

git clone https://github.com/agzam/spacehammer ~/.hammerspoon

LEAD keybinding

LEAD is the main and major keybinding that invokes the main Spacehammer modal. By default it is set to Option+SPC, but it can be re-configured in ~/.spacehammer/config.fnl by changing the :mods and :key bindings for the lib.modal:activate-modal action string. You might want to set it, for example, to Ctrl+Shift+SPC.

If you want to use Cmd+SPC as LEAD you will have to rebind it in your system, since it is normally used for Spotlight.

Unbinding Cmd+SPC in system preferences.

Go to your Preferences/Keyboard, find Cmd+SPC keybinding and change it to something else. Unfortunately, simply disabling it sometimes is not enough. You’d have to set it to be something else e.g. Ctrl+Cmd+Shift+\ or anything else , it doesn’t really matter, since you can then un-check the checkbox and disable it.

Features

LEAD w - Window management

• hjkl - moving windows around halves of the screen
• Ctrl + hjkl - for jumping between application windows (handy for side by side windows)
• w - jump to previous window
• n/p - moving current window to prev/next monitor
• Option + hjkl - moving in increments (works across monitors)
• Shift + hjkl - re-sizing active window
• g - re-sizing with hs.grid
• m - maximize active window
• c - center active window
• u - undo last window operation (similar to Spacemacs’s SPC w u)

LEAD a - Apps (quick jump)

• e - Emacs
• g - Chrome
• i - iTerm
• s - Slack

you can add more, also try LEAD j j

LEAD SPC - open Alfred search bar

pressing SPC in the main modal takes you to Alfred search popup, pressing SPC in other modals returns to previous modal.

LEAD m - multimedia controls

Why not use media-keys?

a) because different external keyboards impose their own ways to control media.

b) because Spacehammer allows you to keep fingers on the home row.

By default LEAD m a - jump to music app is configured to work with Spotify, but you can change that in ~/.spacehammer/config.fnl

Edit anything [with Emacs]

You can edit any text in any app Cmd+Ctrl+O. Currently, it supports only Emacs. Read more here.

Other features

Alternative App Switcher Option n/p

Simple tab switcher for Chrome and iTerm Option j/k

Slack Desktop App enhancements

• Scroll through current Slack thread Ctrl-j/Ctrl-k (slow) or Ctrl-e/Ctrl-y (fast)
• Jump to the end of the thread with Cmd-g
• Add emoji to the last message - Cmd-r (Slack’s default Cmd-Shift+\ is quite inconvenient)
• Jump back and forth through history - Ctrl-o/Ctrl-i

Customizing

Update menus, menu items, bindings, and app-specific features

All menu, app, and key bindings are defined in ~/.spacehammer/config.fnl. That is your custom config and will be safe from any upstream changes to the default config.fnl. The reason to keep it in its own directory is so that it can be maintained in version-control in your own repo.

Modal Menu Items

Menu items are listed when you press LEAD and they can be nested.

Items map a key binding to an action, either a function or =”module:function-name”= string.

Menu items may either define an action or a table list of items.

For menu items that should be repeated, add repeatable: true to the item table. The repeatable flag keeps the menu option after the action has been triggered. Repeating a menu item is ideal for actions like window layouts where you may wish to move the window from the left third to the right third.

(local launch-alfred {:title  "Alfred"
                      :key    :SPACE
                      :action (fn [] (hs.appplication.launchOrFocus "Alfred"))})
(local slack-jump {:title  "Slack"
                   :key    :s
                   :action "slack:quick-switcher"})
(local window-inc {:title  "Window Halves"
                   :mods   [:cmd]
                   :key    :l
                   :action "windows:resize-inc-right"})
(local submenu {:title "Submenu"
                :key   :t
                :items [{:key    :m
                         :title  "Show a message"
                         :action (fn [] (alert "I'm a submenu action"))}]})
(local config {:items [launch-alfred
                       slack-jump
                       window-inc
                       submenu]})

Lifecycle methods

Menu items may also define :enter and :exit functions or action strings. The parent menu item will call the enter function when it is opened and exit when it is closed. This may be used to manage more complex or dynamic menus.

Global keys

Global keys are used to set up universal hot-keys for the actions you specify. Unlike menu items they do not require a title attribute. Additionally you may specify :repeat true to repeat the action while the key is held down.

If you place :hyper as a mod, it will use a hyper mode that can be configured by the hyper config attribute. This can be used to help create bindings that won’t interfere with other apps. For instance you may make your hyper trigger the virtual :F18 key and use a program like karabiner-elements to map caps-lock to F18.

(local config {:hyper {:key :F18}
               :keys  [{:mods   [:cmd]
                        :key    :space
                        :action "lib.modal:activate-modal"}
                       {:mods   [:cmd]
                        :key    :h
                        :action "chrome:prev-tab"
                        :repeat true}
                       {:mods   [:hyper]
                        :key    :f
                        :action (fn [] (alert "Haha you pressed f!"))}]})

App specific customizations

Configure separate menu options and key bindings while specified apps are active. Additionally, several lifecycle functions or action strings may be provided for each app.

• :activate When an application receives keyboard focus
• :deactivate When an application loses keyboard focus
• :launch When an application is launched
• :close When an application is terminated

(local emacs-config
       {:key "Emacs"
        :activate "vim:disable"
        :deactivate "vim:enable"
        :launch "emacs:maximize"
        :items []
        :keys []})

(local config {:apps [emacs-config]})

Replacing spacehammer behavior

The ~/.spacehammer directory is added to the module search paths. If you wish to change the behavior of a feature, such as vim mode, you can create ~/.spacehammer/vim.fnl to override the default implementation.