Hammerspoon Configuration

init.lua

local last_alert = nil

function displaySong(player)
    artist, name = player.getCurrentArtist(), player.getCurrentTrack()

    if (last_alert ~= nil) then
        hs.alert.closeSpecific(last_alert)
    end

    last_alert = hs.alert.show(artist .. " - " .. name)
end

function PlayNext()
    if (hs.itunes.isPlaying()) then
        hs.itunes.next()
        displaySong(hs.itunes)
    elseif (hs.spotify.isPlaying()) then
        hs.spotify.next()
        displaySong(hs.spotify)
    end
end

function PlayPrevious()
    if (hs.itunes.isPlaying()) then
        hs.itunes.previous()
        displaySong(hs.itunes)
    elseif (hs.spotify.isPlaying()) then
        hs.spotify.previous()
        displaySong(hs.spotify)
    end
end

local last_paused = ""

function PlayPause()
    if (last_paused == "") then
        if (hs.spotify.isPlaying()) then
            last_paused = "spotify"
            hs.spotify.playpause()
        elseif (hs.itunes.isPlaying()) then
            last_paused = "itunes"
            hs.itunes.playpause()
        elseif (hs.spotify.isRunning()) then
            last_paused = "spotify"
            hs.spotify.playpause()
        elseif (hs.itunes.isRunning()) then
            last_paused = "itunes"
            hs.itunes.playpause()
        end
    elseif (last_paused == "itunes") then
        last_paused = ""
        hs.itunes.play()
    elseif (last_paused == "spotify") then
        last_paused = ""
        hs.spotify.play()
    end
end

local hhkbHotkeys = {
    hs.hotkey.bind({}, "f11", function()
        PlayPrevious()
    end),
    hs.hotkey.bind({}, "f12", function()
        PlayNext()
    end),
    hs.hotkey.bind({}, "help", function()
        PlayPause()
    end),
}

local hhkbWatcher = nil

function enableHotkeys(hk)
    for i, v in ipairs(hk) do
        v:enable()
    end
end

function disableHotkeys(hk)
    for i, v in ipairs(hk) do
        v:disable()
    end
end

function usbDeviceCallback(data)
    if (data["productName"] == "HHKB Professional") then
        if (data["eventType"] == "added") then
            enableHotkeys(hhkbHotkeys)
        elseif (data["eventType"] == "removed") then
            disableHotkeys(hhkbHotkeys)
        end
    end
end

hhkbWatcher = hs.usb.watcher.new(usbDeviceCallback)
hhkbWatcher:start()