Aqua: More than Just a Pretty Face

Aqua is Apple's name for the Mac OS X GUI. This includes both the appearance and the behavior of the interface. The appearance is the first thing that grabs people's attention. Aqua employs a sort of 'translucent gel' theme for its GUI widgets (a look seen in many previous MetaTools/ MetaCreations applications). Here's what a button looks like:

An Aqua button

A stated design goal of Aqua was that (to paraphrase Steve Jobs) when you see it you want to lick it. Aqua windows continue this theme, with gel-like proportional scroll thumbs and colored gems for title-bar widgets (many equate them to jelly beans). Apple has posted a QuickTime movie here that demonstrates how the basic window controls operate. We've got the Cliff's Notes version here:

Traffic widgets

The colored buttons are meant to resemble a traffic light: red to close the window (stop), yellow to minimize the window (slow), and green to zoom the window (go).

X-Mouse-like awareness

Glyphs also appear inside the widgets when the mouse is nearby ('x' for close, '-' for minimize, and '+' for zoom), even if the window is in the background. The Aqua mnemonics are much more comprehensive than classic Mac OS widgets (which are all the same shape and color, with very vague glyphs), and I suspect that they'll be accepted quickly by Mac users once they get over the initial shock. Unfortunately, the grouping of all three widgets on the same side of the Aqua title bar makes the close button much more prone to accidental clicks. The reasoning behind this placement escapes me.

A second characteristic of the Aqua look is the use of subtle 'pinstripes,' much like the striping on the surface of Apple's translucent hardware. You can see this striping on both the active and inactive window title-bars in the movie mentioned above. The menubar, pull-down menus, and dialog boxes also sport stripes. Subtle features like this were not possible in the days before true-color (32-bit) video was common.

On the other hand, nothing we've discussed so far can't be duplicated with a second generation display layer. Indeed, it was only a few hours after the MacWorld San Francisco keynote that Aqua themes began appearing on the net for Windows and Linux. But now let's take a look at the features in Aqua that take advantage of Quartz, and find some justification for all of the hard work Apple has been pouring into the technology.

Attentive readers may have noticed that the front-most window in the 'traffic widgets' example above casts a transparent shadow on the window behind it. Transparency is used extensively in Aqua. Here are a two more examples:

Using transparency in this way is trivial with Quartz, and Aqua doesn't stop at simple, static transparency, either. Most uses of transparency have a dynamic behavior as well. For example, pull-down menus 'fade away' when they are de-selected (rather than disappearing instantly). But the most dynamic Aqua interface element shown at MSWF is the 'dock.'