Hammerspoon App Focus Alert

focusAlert.lua

-- --------------------------
-- Alert When App Not Focused
-- --------------------------

local alertInSeconds = 60 * 20
local alertAppName = 'App You Want to Focus Here'

local alertTimer

local function stopTimerAlertTimer()
  if alertTimer then
    alertTimer.stop()
    alertTimer = nil
  end
end

local function notificationClicked()
  hs.application.launchOrFocus(alertAppName)
end

local function sendNotification()
  local notification = hs.notify.new(notificationClicked,
    {
      title = 'Time to focus ' .. alertAppName,
      informativeText = 'Click to return',
      soundName = 'Glass.aiff'
    })
  notification:send()
end

local function appFocused(appName, eventType)
  if appName ~= alertAppName then
    return
  end

  if eventType == hs.application.watcher.activated then
    stopTimerAlertTimer()
    hs.alert.show('Welcome back to ' .. alertAppName)
  elseif eventType == hs.application.watcher.deactivated then
    stopTimerAlertTimer()
    alertTimer = hs.timer.delayed.new(alertInSeconds, sendNotification)
    alertTimer:start()
    hs.alert.show(alertInSeconds / 60 .. ' minute return timer started for ' .. alertAppName)
  end
end

if alertAppName then
  local watcher = hs.application.watcher.new(appFocused)
  watcher:start()
end