Baffling inconsistencies in OS X Lion Multi-Touch
OS X Lion's new Multi-Touch gestures have switched things up more than any previous version of OS X, and they're brought a lot of confusion with them. While "natural" scrolling is the most obvious change and the one that takes the most getting used to (unless you disable it), other inconsistencies in the way Lion handles Multi-Touch gestures are both more subtle and potentially more baffling. The one that's been tripping me up even after almost two weeks of using Lion is the gestures for going forward and back in Safari and other applications.
In Mac OS X Leopard and Snow Leopard, a three-finger swipe would take you backward and forward in any app that supported that gesture, like Apple's Safari, Finder, Preview, iPhoto, Aperture, and even the iTunes Store. Eventually, third-party browsers like Firefox baked in support for these three-finger gestures, and the whole system worked pretty well.
OS X Lion introduced a new gesture for forward/back navigation: a two-finger swipe. I actually like this gesture better, because when you're using Safari you get a preview of the next/previous page as you swipe, something that three-finger swiping doesn't provide. It's a very neat trick, but there's a problem: the gesture only works in Safari. No other programs react to this gesture at all. So if you have "Swipe between pages" set to "Scroll left or right with two fingers" in System Preferences, you lose the ability to use gestures to go back and forward in Finder, iPhoto, Aperture, and other apps.
Things get even more confusing if you enable "Swipe with two or three fingers" and have natural scrolling enabled. I'll try to explain why with the outline below:
Two-finger swipe: natural scrolling disabled
Swipe from left to right: Go forward
Swipe from right to left: Go back
Two-finger swipe: natural scrolling enabled
Swipe from left to right: Go back
Swipe from right to left: Go forward
Three-finger swipe: natural scrolling enabled/disabled makes no difference
Swipe from left to right: Go forward
Swipe from right to left: Go back
You might have already caught on to the inconsistency, but I'll spell it out anyway: If you have natural scrolling enabled and have also enabled swiping with either two or three fingers, the gesture direction is completely reversed depending on the number of fingers you use. The result: brain meltdown.
Right now, the only ways around this inconsistency are:
Disable natural scrolling
Leave three-finger gestures disabled and lose the ability to swipe forward/back in any app other than Safari
Set swiping to three fingers only and lose Safari's ability to preview pages as you swipe
Reverse the three-finger swipe gesture directions with a third-party app like BetterTouchTool (my personal choice)
Live with it, while your muscle memory quietly rebels and plots to overthrow you
I'd like to think this inconsistency is something that Apple will address in a future update to Lion, but as it's likely Apple considers three-finger swiping a "legacy" gesture from earlier versions of OS X and only kept it around to placate users who upgraded from Snow Leopard, the company may not bother. A better solution might be to expand the new two-finger gestures to apps other than Safari. In the meantime, using BetterTouchTool to work around the problem has at least stopped my muscle memory from cursing Apple's UI design team fifty times a day.
