revised 10/2023: changed the file name of the Launch Agent plist
The Voxel uses QLab to control critical aspects of our building, such has HVAC and work lights. Similarly, for projects such as museum installations or interactive exhibits, a robust unattended QLab installation may be required.
Note that this list differs from the official A Computer Prepares - QLab 5 Edition instructions from Figure 53. Those instructions are optimized for a typical QLab Mac with an operator running intense shows.
Rather than optimizing for performance, these instructions are focused on configuring a QLab Mac for months of reliable unattended operation.
This checklist generally assumes you are starting with a fresh Mac. If a well-loved Mac is being repurposed to an unattended use, it's a good idea to reinstall macOS.
| Category | Setting | Value | macOS Version |
|---|---|---|---|
| Sound | Alert volume | 0% | |
| Sound | Play sound on startup | OFF | |
| Sound | Play user interface sound effects | OFF | |
| Sound | Play feedback when volume is changed | OFF | |
| General - Software Update | Check for updates | OFF | |
| General - Login Items | Open at Login | Remove all unnecessary items | |
| General - Login Items | Allow in the Background | Remove all unnecessary items | |
| General - Sharing | Screen Sharing | ON | |
| General - AirDrop & Handoff | AirDrop | No One | |
| General - AirDrop & Handoff | AirPlay Receiver | OFF | |
| Desktop & Dock | Mission Control - Displays have separate Spaces | OFF | |
| Desktop & Dock | Desktop & Stage Manager - Click wallpaper to reveal desktop | Only in Stage Manager | 14.0 Sonoma |
| Energy Saver | Start up automatically after a power failure | ON | |
| Energy Saver | Wake for network access | ON | |
| Lock Screen | Start Screen Saver when inactive | Never | |
| Lock Screen | Turn display off when inactive | Never | |
| Lock Screen | Require password after screen saver begins or display is turned off | Never | |
| Users & Groups | Automatically log in as | (your user account) |
A Launch Agent is a special instruction document for macOS. In this case, it asks the OS to open QLab 5 when the user logs in. After that, if QLab crashes or is quit by a user, it will automatically open QLab again.
Place this plist file in Users > (your user account) > Library > LaunchAgents. Typically the Library folder is hidden, so you must use the Go to Folder... pane to get there. In Finder, select the Go menu then choose Go to Folder... and type in ~/Library/LaunchAgents.
<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
<plist version="1.0">
<dict>
<key>KeepAlive</key>
<true/>
<key>Label</key>
<string>com.figure53.QLab.5</string>
<key>ProgramArguments</key>
<array>
<string>/Applications/QLab.app/Contents/MacOS/QLab</string>
</array>
<key>RunAtLoad</key>
<true/>
<key>ProcessType</key>
<string>Interactive</string>
</dict>
</plist>
In QLab, navigate to the QLab menu and choose QLab Preferences....
| Setting | Value |
|---|---|
| At launch | Restore most recent workspaces |
| Automatically check for updates | OFF |
In QLab, navigate to the Tools menu and choose Black out desktop backgrounds.
In your QLab Workspace, make a Timeline Group that starts your show. Though you might have cues on Wall Clock triggers, consider what the show's behavior should be if the power briefly went out after the times have passed. Program defensively.
In Workspace Settings > General, point the When workspace opens, start cue number option to your startup Group.
It might be useful to be notified when QLab has been restarted. A Script Cue can be crafted to send text messages via the macOS Messages app on an internet-connected Mac. Messages may only be sent to iOS devices unless you have a cellular iPhone set up for Text Message Forwarding.
tell application "Messages"
set myid to get id of first account
set theBuddy to participant "+1 ??? ???-????" of account id myid
send ("QLab launched @ " & time string of (current date)) to theBuddy
end tell