Hammerspoon ShiftIt

A ShiftIt like Hammerspoon window management configuration.

Installation

Step 1

Install Hammerspoon if you haven't yet. Download the latest release here and drag it to /Applications.

Alternatively you can install it using brew:

brew install --cask hammerspoon

Step 2

Make sure Hammerspoon is started (You should see the a Hammerspoon logo in your menubar).

Download the ShiftIt spoon. Unzip the downloaded file and open the spoon (Make sure you open the unzipped ShiftIt.spoon file using Finder so Hammerspoon will move it to the correct location).

Hammerspoon should prompt that the newly installed spoon is now available.

Alternatively you can use SpoonInstall

Step 3

Click on the Hammerspoon menubar icon and click on 'Open Config'. An init.lua file should now open in your editor of choice.

Paste the following configuration in the init.lua file, save it and close it.

hs.loadSpoon("ShiftIt")
spoon.ShiftIt:bindHotkeys({})

Click on the Hammerspoon menubar icon again, and click on 'Reload Config'.

Step 4

Make sure Hammerspoon has the 'Accessibility' permissions. Without those permissions, it can't move and modify windows.

Go to System Preferences > Security & Privacy > Accessibility and make sure Hammerspoon.app is checked.

If you just enabled permissions for Hammerspoon, you might need to restart the application for the permissions to take effect.

Step 5 (optional)

Configure the Shiftit spoon to your preference.

• Multiple window cycle sizes allows you to override the default 50% window size for snapping to sides and corners
• Override key mappings allows you to override the default key bindings.

The ShiftIt spoon is now ready to use, enjoy.

Having issues? Check out the Known issues section, have a look in the issues section, or create a new issue.

Usage (default keys)

Snap to sides

• ctrl(^) + alt(⌥) + cmd(⌘) + left Snap current window to the left half to the screen
• ctrl(^) + alt(⌥) + cmd(⌘) + right Snap current window to the right half to the screen
• ctrl(^) + alt(⌥) + cmd(⌘) + up Snap current window to the top half to the screen
• ctrl(^) + alt(⌥) + cmd(⌘) + down Snap current window to the bottom half to the screen

Snap to corners

• ctrl(^) + alt(⌥) + cmd(⌘) + 1 Snap current window to the left top quarter to the screen
• ctrl(^) + alt(⌥) + cmd(⌘) + 2 Snap current window to the right top quarter to the screen
• ctrl(^) + alt(⌥) + cmd(⌘) + 3 Snap current window to the left bottom quarter to the screen
• ctrl(^) + alt(⌥) + cmd(⌘) + 4 Snap current window to the right bottom quarter to the screen

• ctrl(^) + alt(⌥) + cmd(⌘) + M Maximise current window
• ctrl(^) + alt(⌥) + cmd(⌘) + C Centralize current window
• ctrl(^) + alt(⌥) + cmd(⌘) + - Make current window smaller
• ctrl(^) + alt(⌥) + cmd(⌘) + = Make current window bigger

• ctrl(^) + alt(⌥) + cmd(⌘) + F Toggle full screen for current window

• ctrl(^) + alt(⌥) + cmd(⌘) + Z Toggle zoom for current window

• ctrl(^) + alt(⌥) + cmd(⌘) + N Move current window to next screen

• ctrl(^) + alt(⌥) + cmd(⌘) + P Move current window to previous screen

Known issues

"attempt to index nil value" error while using shortcuts

If after installation you run into errors like attempt to index a nil value, please make sure to verify that Hammerspoon has the right permissions on your Mac.

Go to System Preferences > Security & Privacy > Accessibility and make sure Hammerspoon.app is checked.

"attempt to index nil value" error during startup

If Hammerspoon prints errors during initialisation, like "attempt to index nil value" from Hammerspoon's init script (~/.hammerspoon/init.lua), the ShiftIt spoon may have been misconfigured.

Make sure that the Spoon name, provided in installation step 3 matches with the folder name in ~/.hammerspoon/Spoons (without the .spoon extension).

For example, if the name in the init script is "ShiftIt", the Spoon in the ~/.hammerspoon/Spoons folder should be ShiftIt.spoon.

If those are different, change the name in the Hammerspoon init.lua configuration to be aligned with the name in the Spoons folder.

Configuration

The default key mapping looks like this:

{
  left = { { 'ctrl', 'alt', 'cmd' }, 'left' },
  right = { { 'ctrl', 'alt', 'cmd' }, 'right' },
  up = { { 'ctrl', 'alt', 'cmd' }, 'up' },
  down = { { 'ctrl', 'alt', 'cmd' }, 'down' },
  upleft = { { 'ctrl', 'alt', 'cmd' }, '1' },
  upright = { { 'ctrl', 'alt', 'cmd' }, '2' },
  botleft = { { 'ctrl', 'alt', 'cmd' }, '3' },
  botright = { { 'ctrl', 'alt', 'cmd' }, '4' },
  maximum = { { 'ctrl', 'alt', 'cmd' }, 'm' },
  toggleFullScreen = { { 'ctrl', 'alt', 'cmd' }, 'f' },
  toggleZoom = { { 'ctrl', 'alt', 'cmd' }, 'z' },
  center = { { 'ctrl', 'alt', 'cmd' }, 'c' },
  nextScreen = { { 'ctrl', 'alt', 'cmd' }, 'n' },
  previousScreen = { { 'ctrl', 'alt', 'cmd' }, 'p' },
  resizeOut = { { 'ctrl', 'alt', 'cmd' }, '=' },
  resizeIn = { { 'ctrl', 'alt', 'cmd' }, '-' }
}

Configure multiple window cycle sizes

You can configure multiple window cycle sizes by adding the following line after loading the ShiftIt spoon:

spoon.ShiftIt:setWindowCyclingSizes({ 50, 33, 67 }, { 50 })

The first argument ({ 50, 33, 67 }) sets the horizontal window cycle sizes, in the provided order. The second argument ({ 50 }) sets the vertical window cycle sizes, in this example it only sets one.

The above settings will toggle the window through these steps, when repeatingly hitting ctrl(^) + alt(⌥) + cmd(⌘) + left:

Overriding key mappings

You can pass the part of the key mappings that you want to override to the bindHotkeys() function. For example:

-- Use Vim arrow keys
spoon.ShiftIt:bindHotkeys({
  left = { { 'ctrl', 'alt', 'cmd' }, 'h' },
  down = { { 'ctrl', 'alt', 'cmd' }, 'j' },
  up = { { 'ctrl', 'alt', 'cmd' }, 'k' },
  right = { { 'ctrl', 'alt', 'cmd' }, 'l' },
})

Alternative installations

SpoonInstall

If you use SpoonInstall:

• Load the spoon as following using the repository https://github.com/peterklijn/hammerspoon-shiftit.
• Add this config to your ~/.hammerspoon/init.lua

hs.loadSpoon("SpoonInstall")

spoon.SpoonInstall.repos.ShiftIt = {
   url = "https://github.com/peterklijn/hammerspoon-shiftit",
   desc = "ShiftIt spoon repository",
   branch = "master",
}

spoon.SpoonInstall:andUse("ShiftIt", { repo = "ShiftIt" })