OS X Lion UI Impressions

I know: everyone is weighing in on their OS X Lion impressions. The release is significant in a number of ways, most notably its departure from physical disk installation (you get it via a 3.75GB download on the Mac App Store). While there are several important feature implementations and updated applications, the most glaring changes are in the user interface. And surprisingly, these small details define the new feel of using a Mac, for good or bad.

The state of scrolling

The first thing that greets the user once you’re logged into Lion is the Scrolling in Lion prompt. This prepares you for the monumental shift in how scrolling within windows is handled – it’s reversed.

Scrolling Changes in Lion

It is by far the most alarming change from previous OS versions, and will undoubtably be met by most users with aversion. Scrolling – initiated by two fingers on a trackpad, one on a mouse – is reversed to reflect the iOS mentality of actually interacting with the element within a window. Thus, scrolling no longer reflects the scrollbar, it reflects an interaction with whatever content is inside of a window. Application windows, therefore, are demoted to mere static frames for the actual content inside them. You get accustomed to this change after using Lion for a few days.

While I’m indifferent to “natural” scrolling, the full implementation of enertia scrolling plus rubberbanding (think elasticity) is brilliant. When you make swipes for scrolling up or down, and the content within an application window ends, the content pulls in the direction of the swipe with rubberband physics, like you’re trying to pull something away from another object that cannot be done.

Content rubberbanding while scrolling in Lion

It’s exactly like its implementation in iOS, and you can execute with it in the same manner. It’s one of those “natural” touch interfaces that dissolves into the experience – and after a few hours of use, its dissolves away into the experience.

The state of windows and their content

Speaking of scrollbars – Lion has completely removed them when using either the trackpad or Magic Mouse. This is probably the second-most unexpected change in the behavior of using the OS. Again, this mechnical shift is influenced by iOS. Removing scrollbars tidies the aesthetic of every Application and Finder window, further minimalizing the OS. But at the same time, it invites a significant learning curve – you need to remap how you’ve perceived desktop windows for the past few decades. The design is so clean that nothing actually suggests that a user should continue to swipe down (or is it swipe up now?) to reveal more content. In the past, the scrollbar operated as a metric indicating how much vertical information existed within a window. Now you only see that indication when you actually scroll, whereby an understated bar appears and disappears once the touch action is executed.

Additionally, every window frame in Lion has a slightly rounded corner.

Rounded Corners in Lion

While this isn’t a drastic change, it is ubiquitous throughout the OS and frankly it’s a strange choice. While those few corner pixels may not seem like important screen real estate, and while you do accustom yourself to this change quicker than the scrolling changes, it’s noticeable in full-screen applications.

And, on a sidenote, all windows can now be resized from any side or corner – in the past, this had been relegated to only the bottom-right corner. Apparently there are a few additional tricks for resizing, too.

The full-screen thing

I initially disliked the early preview concepts for Lion’s full-screen applications, but once you actually use it, you end up liking it. When full-screen mode is activated (on a supported application), everything on-screen is removed except the application’s main interface. Most applications will probably need to be tweaked to fully take advantage of the capabilities with this API, but the ones that currently support it demonstrate how slick the system is. Menu bars and other distractions dissolve away in Safari1 (even the dock is disabled), and you’re left with a roomy full-screen browser. Same goes for iTunes, iCal, etc.

What’s really neat about full-screen applications is how they’re handled. When you initiate a full-screen application, it slides into its own virtual desktop space (managed by Mission Control, which is Lion’s evolution of Exposé). Each applications gets its own “space”, ala iOS. This means you can use a space-swapping gesture to slide between open applications. The system is simple and fast, and is absolutely accessible to just about anyone willing to remember how to swipe with three or four fingers.


Gestures complete the general user experience changes made in Apple’s latest OS. While they introduced minor innovations in previous versions of the OS, only with the introduction of the Magic Mouse and repositioning of the Trackpad as the “Magic Trackpad” did gestures gain their rightful place in the OS. Even so, these amazingly intuitive tools weren’t used to their potentials (each able to receive 9 unique touch inputs simultaneously). Only a few gestures had been implemented, and you needed to seek out additional utilities that permitted for customized gestures (like Jitouch).

Lion comes full circle and allows for more granular mapping of gestures to the mouse and trackpad, but it still isn’t quite as flexible as Jitouch. And the defaults are a jarring transition from Snow Leopard. I had grown accustomed to three-finger horizontal swipes for back/forward movement across application pages. This, by default, changed to full-screen or desktop “spaces” switching (it can be modified, though). But why would Apple change this gesture mapping to a default setting?

Regardless, gestures introduce a unique, new “shortcut” user interface that is very powerful for people who don’t like memorizing keyboard shortcuts. Apple does seem to be taking a shy stance on the mechanics of their implementation, though. Yes, most gestures work exactly how you’d imagine they would (pinching or double-tapping in appropriate applications zooms or stretches the content), but there should be a human user interface guide for how gestures are used in a desktop OS. Apple more or less defined these guidelines for iOS back in 2007 with the iPhone. Apparently they feel you can do much more with gestures in OS X Lion (which you theoretically can because your fingers engage external components like a trackpad or mouse as opposed to the actual screen of interactive content). Going forward, this is something I hope they address to refine the way gestures are perceived and used in OS X.

  1. In fact, you gain real estate pixels in some applications. If you use tabs in Safari, there is only 62 pixels of head room for the application at the top of the screen when in full-screen mode, as opposed to 97 pixels when it’s a standalone window.