Notification Center

Mac users have relied on the excellent open-source Growl notification system for years now, so the addition of Notifications Center to Mountain Lion seems a bit anticlimactic at first glance. But look a little deeper and it's clear that Apple has a very different idea about how notifications should work — an idea that's unsurprisingly almost exactly how they work in iOS 5. Notifications appear at the top right of the screen as banners that automatically slide away after five seconds or alerts that require some user interaction to disappear, and a new icon on the right side of the menu bar lights up blue when new notifications arrive. Clicking on the icon slides the OS X desktop over to the left to reveal Notification Center itself, which looks identical to iOS 5 — it even has the same linen texture.

Notification Center will be very familiar to iOS users

You can also use a new gesture to bring up Notification Center: a two finger swipe to the left from the right edge of the trackpad. Swiping right with two fingers from anywhere then closes the panel. It's Apple's first edge gesture, and it adds to OS X's already-intense mix of trackpad moves: two-finger swipes to scroll and navigate, three-finger swipes to manage spaces and full screen apps, and four-finger pinches to bring up Launchpad and show the desktop. In practice I found everything easy enough to remember — it's just another swipe to the left, after all — but a couple times I found myself accidentally going back in Safari when started my swipe in the middle of the trackpad instead of on the right side. Apple says the basic rule is that one finger gestures in iOS are two finger gestures in OS X, but I much preferred the unoffical Lion metaphor of two fingers for app-level commands and three and four fingers for system-level commands. Everything definitely works, but there's also definitely room for it to all work better in the final version.

(The addition of the Notification Center gesture also cements the need for a Magic Trackpad if you’re a desktop Mac user — there’s no key command to invoke the panel, and the Magic Mouse won’t have a gesture for it either. You’re stuck clicking on the icon unless you have a trackpad.)

It's hard to imagine life without centralized notifications after a while

There’s a new preference pane to manage notifications and how they’re displayed; as with everything else about Notification Center it’ll look very familiar to iOS 5 users. Settings like notification type, icon badges, and sounds are managed on a per-app level, and you can order notifications manually or have them auto-sort by time. And... that’s really it. Just as in iOS 5, the system works well, but isn’t tremendously flexible — Growl users with wild custom configurations are going to bristle against Notification Center’s limitations for quite some time. You can’t even set notifications to display in a different corner of the screen — it’s the upper right or nothing. Apple says the idea is that notifications should disappear to where users can find them again, but I'm hoping that goal is expressed as a default setting that can be changed in the final version, not the only setting.

On the other hand, if you’re not using Growl you’ll find Notification Center to be a major enhancement to the OS X experience — it’s hard to imagine life without centralized notifications after using it for a while. We’re just hoping Apple keeps with its recent hiring history and poaches a few people from the Growl team to make Notification Center even better as time goes on.