Mac Setup for Teachers: Ready to Project and Share

Projecting your screen to a room is the least forgiving thing a Mac does. Notifications become public, the display sleeps during the one long explanation, and everyone can read your desktop. Five minutes of setup fixes all of it, and once it is done it stays done.

Silence everything before the screen goes up

A message preview on a projector is the incident everyone remembers. Build a Focus mode you can turn on from the menu bar:

1. System Settings → Focus, add one called Teaching.
2. Allow notifications from nobody.
3. Under Options, turn off Allow time-sensitive notifications, which otherwise still get through.
4. Turn off Badges too, so app icons stay quiet.
5. Make sure Control Centre is showing Focus so you can switch it on in one click.

macOS also mirrors your Focus to your iPhone, so the phone on the desk stops buzzing at the same time.

Stop the display sleeping mid-lesson

Screen savers during a long explanation are a classroom classic. Two routes:

# keep the display awake for a 50 minute lesson, then stop
caffeinate -d -t 3000

# or until you press Control-C
caffeinate -d

The settings route is System Settings → Lock Screen, where you can raise the display-off time while plugged in. Raise it rather than disabling it entirely, so the Mac still locks itself when you leave the room.

Hide what the room should not see

• Desktop icons — hide them entirely so a folder called "appraisal" is never on a projector:

  defaults write com.apple.finder CreateDesktop -bool false && killall Finder
  
  # bring them back
  defaults delete com.apple.finder CreateDesktop && killall Finder

• Hide every other app — Option-Command-H with your teaching app in front. One keystroke, whole screen clear.
• Check the Dock — recent apps show what you had open before class. Turn them off in Desktop & Dock.
• Close browser tabs, or use a separate browser profile for teaching so autocomplete never suggests something personal in front of the room.

Make it readable from the back

1. When the projector is connected, open System Settings → Displays and choose a scaled resolution that shows Larger Text. Mirroring at native resolution is why the back row cannot read anything.
2. Increase the pointer size in Accessibility → Display → Pointer, and turn on Shake mouse pointer to locate.
3. Learn Control-Option-Command-8 for instant screen inversion, and the zoom shortcuts in Accessibility → Zoom: holding Control and scrolling magnifies the screen, which is the fastest way to show a detail.

Managing a room of Macs

If you teach in a lab rather than from your own machine, two built-ins are worth knowing. Screen Sharing is included with macOS: enable it in System Settings → General → Sharing → Screen Sharing, and you can view or control another Mac on the same network by opening its name in the Finder sidebar and clicking Share Screen.

The second is AirPlay. Most modern Macs can receive AirPlay from an iPad or iPhone, in General → AirDrop & Handoff → AirPlay Receiver, which is a quick way to put a student's tablet on the projector without cables or an adapter that has gone missing.

Recording a lesson

Press Command-Shift-5, and before recording open the Options menu and turn on Show Mouse Clicks. Students following a recording need to see where you clicked. Choose the microphone in the same menu, and set a save location that is not the desktop so your recordings do not pile up where the class can see them.