Disable Screen Mirroring Keystroke When I'm stumbling around trying to find the keystroke for lowering the screen brightness in quarter-segments (which happens to be Option ⌥+Shift ⇧+Brightness-down (F1)), I usually wind up hitting Command ⌘+Brightness-down, which puts my multi-monitor setup into mirrored mode, thus messing up my window arrangement and sizing.

I'd like to turn off this keystroke (which is, specifically, ⌘+Brightness-down and definitely not ⌘+F1. If someone can come up with a way to permanently disable display mirroring under all circumstances, I'll probably put together a bounty for you.

I'm running OS X Lion on a sufficiently recent MacBook Pro.


   I'm not sure why they include mirrored mode in modern computers, anyway. It's never useful and it only confuses people. Don't tell me it's for presentations: any decent presentation software will have a presenter mode that everyone should learn to use and love.
There doesn't seem to be an entry for the shortcut in com.apple.symbolichotkeys.plist. The media keys cannot be configured in DefaultKeyBinding.dict or keylayout files. I didn't find any hidden preferences with strings either.

I was able to disable it with KeyRemap4MacBook, but only on my laptop's keyboard; not on an Apple Wireless Keyboard.


Save a file like this as ~/Library/Application Support/KeyRemap4MacBook/private.xml

&lt;?xml version="1.0"?&gt;
&lt;root&gt;
  &lt;item&gt;
    &lt;name&gt;Disable Command-F1&lt;/name&gt;
    &lt;identifier&gt;private.disable.command.f1&lt;/identifier&gt;
    &lt;autogen&gt;--ConsumerToConsumer-- ConsumerKeyCode::BRIGHTNESS_DOWN, ModifierFlag::COMMAND_L, ConsumerKeyCode::BRIGHTNESS_DOWN&lt;/autogen&gt;
    &lt;autogen&gt;--ConsumerToConsumer-- ConsumerKeyCode::BRIGHTNESS_DOWN, ModifierFlag::COMMAND_R, ConsumerKeyCode::BRIGHTNESS_DOWN&lt;/autogen&gt;
  &lt;/item&gt;
&lt;/root&gt;

Press the ReloadXML button and enable the new remapping in the first tab