Now that Lion has been released, some of you may have noticed the new scroll behavior. For those of you who haven’t yet, scroll behavior is reversed in Lion as compared to previous versions of Mac OS X, and matches the scroll behavior in iOS. This means that when you move your fingers/wheel down, content moves down and when you move your fingers/wheel up, content moves up.
Apple calls the new behavior “natural”. Whether you love it or hate it, you may be called upon to change it. Luckily, this is a setting stored in a standard plist file , making it easy to manage.
The preference file involved is .GlobalPreferences.plist
The key is com.apple.swipescrolldirection
Values are true (Lion behavior) and false (previous behavior).
To change the scroll behavior for the current user (there are no line breaks in this command)…
defaults write ~/Library/Preferences/.GlobalPreferences com.apple.swipescrolldirection -bool <value>
To change the scroll behavior for all users (there are no line breaks in this command either)…
defaults write /Library/Preferences/.GlobalPreferences com.apple.swipescrolldirection -bool <value>
For example: the following command will make scrolling in Lion behave as it did in prior versions of Mac OS X, for the current user (again, no line breaks).
defaults write ~/Library/Preferences/.GlobalPreferences com.apple.swipescrolldirection -bool false
Note that the behavior will not change until after a logout. When changing the setting via the System Preferences GUI, it would seem that System Preferences is also forcing a re-read of the .GlobalPreferences.plist file. If any readers know how to force that re-read, please share that information in the comments.
I have not yet tested it, but all indications point toward this working as an MCX setting. This should work just as well as managing any other .GlobalPreferences item with MCX.