Eagle Mode: A practical Zoomable User Interface

Off the Beat: Bruce Byfield's Blog

As I begin this new blog, I can't think of a better first topic than the future. Or, to be exact, a possible future. Specifically, I am talking about Eagle Mode, a proof of concept project by Oliver Hamann designed to show the possibilities of a zoomable user interface (ZUI). Using Eagle Mode, you may take a while to get past the sheer novelty, but, once you do, you may find the concepts behind it intriguing.

Released under the third version of the GNU General Public License, version 0.7.3 of Eagle Mode is available as source code, or a downloadable Live CD based on the Slax distribution if you prefer not to compile for yourself.

To start Eagle Mode, either run the eaglemode.sh script from the directory where it is installed, or click its icon on the Live CD. First, however, you should read at least the navigation section of the project's very thorough documentation, so that you know the keyboard shortcuts that can help you get the most out of the application.

Using Eagle Mode

If you use GNOME's Nautilus file manager, you have already experienced a primitive ZUI, in which increasing the zoom the amount of file information shown. But the difference between Eagle Mode and Nautilus is the difference between a space ship and a hot air balloon. Where Nautilus has three levels of zoom to jump to, Eagle Mode moves seamlessly back and forth between countless ones (which it calls panels).

Essentially, Eagle Mode is a cross between between a file manager and a window manager. When you start it, a window opens with two panels: A control panel on top, and a contents panel on the bottom.

The control panel has permanent commands on the left, such as Close and Quit buttons and shortcuts to the home and root directories and online help. On the right, it has controls that fit the context of the current contents panel.

By default, the contents panel opens on emFileMan, a file manager in which zoom views replace the traditional tree and detail views. Instead of moving up and down level by level as in a tree view, in Eagle Mode, you zoom in and out on different levels with the aid of your mouse's scroll wheel and a few basic keyboard commands.

After you move through the directory structure, actually using emFIleMan for file management is disappointingly mundane. All you do is select a directory or file, select its target if you are moving or copying it, and then use the appropriate button on the right side of the control panel.

However, to restore your sense of wonder, continue zooming past the root directory. Suddenly, you find yourself in Eagle Mode's Virtual Cosmos, a simple desktop with other applications designed around the concept of a ZUI. These include the online help, a clock, a chess game, and – because, as the project site suggests, thinking in terms of a ZUI soon gets you thinking about three dimensional desktops – a 3D version of Minesweeper as well. Zoom even higher and you end with a view of the Eagle Mode logo. It's a view of graphical computing that is strikingly different from the one we use everyday.

Do ZUIs have a future?

Like a real time game when you're used to turn-based ones, Eagle Mode and its zooming in and out is a bit dizzying at first. It connects the desktop and individual files into an unbroken hierarchical view, instead of treating them as the unconnected elements that experienced computer users have become accustomed to.

Yet, at the same time, because this concept is easy to learn and allows you to navigate much faster than a conventional desktop does, Eagle Mode soon proves itself as a powerful and efficient tool. As a side-effect, since Eagle Mode relies heavily on your mouse's scroll wheel, it also reduces the repetitive movements that can play such havoc with your wrist and lower arm muscles.

Of course, ZUIs also have their own challenges. They require more video memory than a traditional desktop, so they are likely to perform poorly on older computers. Moreover, at least at first, they may be harder to develop than current desktops, partly because the concept is new and its implications may take a while to absorb, and partly because the number of panels needed for a continuous zoom could mean more code is needed.

There is also the question of exactly how to implement a ZUI. Should it be a continuous one from the desktop down to the individual program, as in Eagle Mode? In some cases, individual applications might require a ZUI of their own, independent of the desktop. Or should a ZUI be only a replacement or alternative for tools like file managers and desktop main menus? And, finally, if you are using a two-dimensional zoom, would you gain anything from three-dimensional panning around objects? Or would that become too complicated for the average user?

These are all questions that Eagle Mode is only starting to explore. As it moves closer to its final release, perhaps the first answers will become clearer, especially as the Virtual Cosmos becomes more configurable, and users can get a better sense of what working with a ZUI on a modern desktop is like. As things are, because of Eagle Mode's focus on the ZUI, in other aspects such as font rendering, superficially it might seem more like an early window manager than a potential successor to the current concept of the desktop.

Given the hostile reception that KDE 4 received in many corners, I sometimes wonder whether any major innovation in the desktop is possible today. Perhaps computer users are so habituated that they will automatically reject anything unconventional. But, assuming that changes are still possible, Eagle Mode makes a strong case for ZUIs being part of the desktop of the future. In addition, it suggests that the free desktop has stopped trying to catch up with proprietary ones, and is now becoming a source of experimentation and change.