Despite checking "Different widgets for each desktop" I am still unable to use different activities on each virtual desktop. I tested this by doing the following:

1. Assign a window to Activity1 on Desktop1
2. Switch to Desktop2
3. Change to Activity2
4. Switch back to Desktop1

Desktop1 was then empty, showing Activity2's background. The goal is that Desktop1 would still have Activity1's window and background present. Either something is wrong with my ability to use a separate activity on each desktop or with my understanding of activities.

I'm using Linux Mint 12 KDE 4.7.4. Any help would be appreciated.

Thank you,
Josh

Hello. I think you have the right idea, but the wrong execution. Once you have the different Activities set up, you simply switch Activities (using the Activity Manager in the taskbar, or as I do by installing the Activity Bar plasmoid on the top of each of my Activitie's desktops and switching back and forth as needed) as opposed to changing desktops. This is because an Activity has not only it's own desktop, but also it's own unique set of applications, widgets, etc. that are unique to that particular Activity.

So, in essence, an Activity is much more powerful and workflow-oriented than a virtual desktop. Using the Activity Manager taskbar widget, you can even start and stop activities, which will also open and close automatically all applications running in that particular Activity simply by pressing the "play" or "stop" icons shown with the particular Activity.

Let me know if this helps.

I think the source of confusion is the older implementation of "Different widgets for each desktop". In older versions of KDE (4.4 and prior?), this would link activities (at that time merely virtual desktops for the wallpaper and plasmoids) to desktops, so Desktop 1 would be tied to Activity 1, Desktop 2 to activity 2, etc.

More recent versions of KDE (4.5 and later) changed the implementation of "Different widgets for each desktop" to no longer tie activities to desktops, but instead each desktop actually gets its own wallpaper and widgets, while still maintaining Activities as a distinct concept from Desktops. So, you can have 3 activities with 4 desktops each, and with the different widgets setting you can have 12 different widget configurations.
In your example, you ended up in Activity2, Desktop1 where there weren't any applications open because changing Desktops no longer changes your Activity for you, and the window was assigned to Activity1, Desktop1 (which btw, starting in KDE 4.6, windows are automatically assigned to the activity you were in when the window opened).

To get the behavior you were expecting, just do as ronnoc suggested and only use Activities (with a single desktop per activity), or use a single activity with however many desktops.
Of course the true power comes in harnessing both - Activities for organizing the kinds of things that you do (software development, leisure, research, finances, etc.), desktops for organizing the windows and widgets you use when working on a particular activity.

Thank you for explaining. I intended to have two desktops as General use that always have the same apps open (one for web browsing and misc., the other for Kontact), then a third desktop for my current activity. The idea was that regardless of my current activity I could quickly access Chrome and Kontact.

I'm guessing the only way to do this now would be to open Chrome and Kontact in every activity. If you have any other suggestions I would appreciate it.

On a side note: Do the current and hidden activities use the same amount of resources? In other words, to improve performance, should I stop inactive activities?

Thank you,
Josh

I want to say that there is an option to show a given window/application on all activities. Right-click on the title bar and look for something like a "To Activity" submenu which should allow you to select which activity that the window displays on.
There should also be a way to set up a window/application rule to do this automatically when you open the program. I don't have a recent-enough version of KDE to be able to say for sure.

You were right, there is an "All Activities" option. That should solve my problem.

Thank you,
Josh