Playing with Hammerspoon
I started using Hammerspoon recently. My keyboard remapping of CAPS LOCK to
Ctrl when pressing and Esc when tapping had stopped working after upgrading
to macOS Sierra. Turns out the current version of Karabiner doesn't
work with Sierra (Oct-2016).
After finding out I could emulate the same behavior with Hammerspoon thanks to this gist, I gave it a try to see what else it could do. That's how I ended up writing the following Lua utility.
The idea is to provide an easy way of showing keystrokes on the screen. It's inspired by other tools like Keycastr which for some reason I couldn't get to work.
function showKeyPress(tap_event) local duration = 1.5 -- popup duration local modifiers = "" -- key modifiers string representation local flags = tap_event:getFlags() local character = hs.keycodes.map[tap_event:getKeyCode()] -- we only want to read special characters via getKeyCode, so we -- use this subset of hs.keycodes.map local special_chars = { ["f1"] = true, ["f2"] = true, ["f3"] = true, ["f4"] = true, ["f5"] = true, ["f6"] = true, ["f7"] = true, ["f8"] = true, ["f9"] = true, ["f10"] = true, ["f11"] = true, ["f12"] = true, ["f13"] = true, ["f14"] = true, ["f15"] = true, ["f16"] = true, ["f17"] = true, ["f18"] = true, ["f19"] = true, ["f20"] = true, ["pad"] = true, ["pad*"] = true, ["pad+"] = true, ["pad/"] = true, ["pad-"] = true, ["pad="] = true, ["pad0"] = true, ["pad1"] = true, ["pad2"] = true, ["pad3"] = true, ["pad4"] = true, ["pad5"] = true, ["pad6"] = true, ["pad7"] = true, ["pad8"] = true, ["pad9"] = true, ["padclear"] = true, ["padenter"] = true, ["return"] = true, ["tab"] = true, ["space"] = true, ["delete"] = true, ["escape"] = true, ["help"] = true, ["home"] = true, ["pageup"] = true, ["forwarddelete"] = true, ["end"] = true, ["pagedown"] = true, ["left"] = true, ["right"] = true, ["down"] = true, ["up"] = true } -- if we have a simple character (no modifiers), we want a shorter -- popup duration. if (not flags.shift and not flags.cmd and not flags.alt and not flags.ctrl) then duration = 0.3 end -- we want to get regular characters via getCharacters as it -- "cleans" the key for us (e.g. for a "⇧-5" keypress we want -- to show "⇧-%"). if special_chars[character] == nil then character = tap_event:getCharacters(true) if flags.shift then character = string.lower(character) end end -- make some known special characters look good if character == "return" then character = "⏎" elseif character == "delete" then character = "⌫" elseif character == "escape" then character = "⎋" elseif character == "space" then character = "SPC" elseif character == "up" then character = "↑" elseif character == "down" then character = "↓" elseif character == "left" then character = "←" elseif character == "right" then character = "→" end -- get modifiers' string representation if flags.ctrl then modifiers = modifiers .. "C-" end if flags.cmd then modifiers = modifiers .. "⌘-" end if flags.shift then modifiers = modifiers .. "⇧-" end if flags.alt then modifiers = modifiers .. "⌥-" end -- actually show the popup hs.alert.show(modifiers .. character, duration) end local key_tap = hs.eventtap.new( {hs.eventtap.event.types.keyDown}, showKeyPress ) -- Enable/Disable Keypress Show Mode with "C-⌘-⇧-p" k = hs.hotkey.modal.new({"cmd", "shift", "ctrl"}, 'P') function k:entered() hs.alert.show("Enabling Keypress Show Mode", 1.5) key_tap:start() end function k:exited() hs.alert.show("Disabling Keypress Show Mode", 1.5) end k:bind({"cmd", "shift", "ctrl"}, 'P', function() key_tap:stop() k:exit() end)
Currently it looks like this:
As far as I know, there's currently no way of setting the popup position on the screen, so it always appears on the middle. Even so, I'm pretty happy I gave Hammerspoon a try and hope I can come up with other useful hacks.