Activities and the move to context-oriented desktops [LWN.net]

May 27, 2009

This article was contributed by Bruce Byfield

The next buzzword on the desktop is likely to be "Activities." Today, the chances are high that you have never heard of them, or, if you have, that you have not identified the different uses of the term as having anything in common. However, what all the usages do have in common is that they signal a move away from a static desktop towards one that changes with the tasks being performed.

Any more exact definition is elusive. All the same, Activities are already part of the KDE 4 series, and scheduled to become more prominent in the upcoming 4.3 release. Similarly, GNOME 3.0, which is due out next year, will include its own, more limited concept of the term. But, under any implementation, the term signals a shift in the desktop, with free software developers leading the way.

The concept of Activities originates in Sugar, the desktop designed for the One Laptop Per Child (OLPC) project. In Sugar, "Activities" is used as a synonym for "application." However, Gary C. Martin, one of the coordinators for Sugar's Activity Team, explains that the change is more than semantics or marketing. Because Activities run within the general collaborative frame of Sugar, using them is intended as a very different experience than running a standalone application on a traditional desktop.

For me, the key parts of Activities are that they combine concepts of document, executable, and collaboration state into a single, simple to use user interface. With the Activity state automatically kept in the Journal, it's easy to resume or reflect on past work, and, with realtime collaboration as a first class feature, peer sharing and group work is strongly encouraged.

In other words, Sugar's Activities are not just about running an application, or learning how to produce a spreadsheet or a presentation. Instead, they are conceived as part of the total learning experience that Sugar is designed to provide.

"It's not about producing documents in applications," Martin explained. "It's the learning that happens while doing Activities. Activities are at the heart of learning in Sugar. They support a class working together, seeing what others are doing, sharing, learning, never losing their work, and [being] able to reflect on that work with their parents and teachers." Although the mechanics of running an Activity may not be all that different from running an application in GNOME or KDE, what matters is the context in which it is used.

The KDE implementation

Part of the design philosophy of KDE 4 is to accommodate the growing sophistication of users, according to long-time KDE developer Aaron Seigo. Thanks to mobile devices and gaming consoles, many users — particularly younger ones — find a static desktop confining. Nor is a traditional desktop especially suited for multiple, specialized uses that range from office productivity to social networking. Depending on whether people are working, attending classes, or socializing, their ideal desktop could vary considerably.

Even within a single activity, desktop needs can change, Seigo said:

Watching people use their computers, we noticed that a lot of people who work on more than one project at a time were manually arranging their icons between projects, Graphic designers, for instance, would have two or three projects they're working on. When they worked on one project, they would take all the icons and files they're working on, and they'd put those icons on the desktop. Then, when they were done with that project, they'd put those icons back in a folder that wasn't showing on the desktop, and move all the icons for a second project out on to the desktop.

To simplify computing for these more sophisticated users, the KDE concept of Activities was born: desktops with their own custom sets of widgets, icons, and applications, that could be switched by keyboard shortcuts or by zooming out via the Desktop Toolkit, the cashew-shaped icon on the upper right of the desktop.

Originally, these desktops were called "containments" by Chani Armitage, the developer who first implemented them:

But I didn't really like the word 'containment' because it was pretty technical. I'd been using an OLPC for a while at the time, so I actually got the inspiration from there. We've kind of co-opted the term and put it to a slightly different meaning than what they've been using.

In some senses, Activities resemble virtual desktops, which KDE and other desktops have had for years. And Seigo acknowledged that "they're complementary ideas." However, he suggested that the resemblance depends on how you use virtual desktops. If you use virtual desktops mainly to separate out windows — for example, to keep a virtual terminal always ready, or to run a full-screen browser — then there is little to choose between virtual desktops and Activities.

By contrast, if you use separate virtual desktops for different tasks, then Seigo suggested that Activities provide a superior experience, one closer to that of mobile devices and more suited to some of the functionality planned for the KDE 4.4 release (see below). Still, because of user demand, KDE 4.2 allows an Activity to be tied to a particular virtual desktop by changing a configuration setting, and the final version of KDE 4.3 will include a setting for the same task.

Seigo emphasized that the increased visibility of Activities in the 4.3 release is not intended to pressure people to use them. "What's really nice about this concept is that you can completely ignore it," he said. "It's completely unobtrusive." After all, he added, "for certain people, the current metaphors work well," especially those who do not carry their computers about or those who use them for basic productivity.

The main change heralded by Activities, according to Seigo is that, unlike on the traditional desktop, they do not enforce one particular way of working for every task:

This is no longer about forcing people into a mode of work or behavior. Rather, we're trying to build interfaces that are relevant to the device you're using them on, and also relevant to the user — which means where are you and who are you? That's something that hasn't started to sink in with a lot of people.

People are demanding more flexibility, and, with the current state of hardware, it can be provided today without any undue strain on system resources.

GNOME 3.0's workspaces

Possibly because of KDE's use of the term, the implementation of multiple workspaces (aka virtual desktops) is causing some confusion about GNOME-Shell, which is scheduled to become the basis for GNOME 3.0.

As implemented so far, GNOME-Shell's Activities is an overlay mode for organizing workspaces and arranging groups of windows on them. To a large extent, it resembles the Zoom view in KDE. However, some people are incorrectly referring to the workspaces themselves as Activities, a change in reference that might just stick, and make GNOME 3 more closely resemble KDE 4.

So far, these workspaces seem to function the same as those in recent versions of GNOME and KDE, with no capacity for separate customization. Nor have any plans to extend their functionality been announced. But, with ten months before GNOME 3.0's estimated release, that could change, especially if KDE's Activities become widely-used. At this point, though, even if the reference is different, the use of the term does suggest that GNOME developers are also thinking about contextualized computing. And even if the implementation remains what it is today, the overlay mode remains a de-emphasis of the single, static desktop.

Coming attractions

Exactly how GNOME 3.0 will implement Activities remains uncertain. Meanwhile, KDE developers are already contemplating future developments for contextualized computing. Armitage talked about allowing Activities to be de-activated and stored. Perhaps, too, she mused, applications could become more contextualized; for example, KMail might be set so that it used a particular address book when opened on a certain Activity.

A change already planned for KDE 4.4 is to associate an Activity with a certain location via the new geo-location layer in KDE. University instructors, for example, could have one Activity with their notes and slides that would automatically open when they started KDE in the class room for a particular class, and another Activity with their research that started in their offices. "You would basically train the computer," Seigo said. "As you move around, the interface comes to you."

Meanwhile, the different uses of the same term can obscure exactly what each project means by it. But, as Seigo said:

The idea that binds them all is a movement towards task-oriented computing. Our viewpoint is that tasks are highly-contextual: What are you doing? Where are you doing it? And who are you?

Whether Activities in any form will come to dominate the desktop is still uncertain. Possibly, they will remain the interest of a relatively small set of users. However, regardless of their ultimate success, the fact that the context-based computing is being emphasized more strongly is a shift in thinking about the desktop, and one that free software is leading. Virtual workspaces -- let alone KDE's Activities -- remain non-standard on Windows, while OS X's Spaces are turned off by default. On both, the static desktop remains the norm.

"Nobody else is looking at these things," Seigo said. "You don't see it on Windows and you don't see it on Mac. This is very much an innovation that free software pretty much owns. And I'm really happy to see that in GNOME and KDE we're right at the front of this development."

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