Those with a trackpad have a few options. The default gesture is to swipe "up," (bottom-to-top) with three fingers. Alternatively, you can opt to use four fingers for this gesture. You'll find the preference settings by opening System Settings, clicking on Trackpad and then clicking the "More Gestures" tab.
Those with a Magic Mouse can open Mission Control by double-tapping on the mouse's surface. Note that there are no other options for opening Mission Control via gesture on a Magic Mouse. It's double-tap or nothing.
If you don't have a multi-touch surface, you've still got plenty of options. For example, you can:
Drag the Mission Control app into the Dock and launch with a click
Assign it to a hot corner (which I'll explain later in this post)
Press the Dashboard key on your Apple keyboard
That's really just the beginning. Later in this post, I'll describe the Mission Control preference pane, which really opens up the launch options. For now, I'll describe how Mission Control looks and behaves.
How Mission Control Looks
As I mentioned before, Mission Control combines Dashboard, Spaces and Exposé into a single interface. For now we'll leave Dashboard and discuss Spaces and Exposé. Together, they make up the bulk of Mission Control, in both form and function. Here's a look at each.
Along the top of the main Mission Control interface you'll find a horizontal listing of the thumbnail images of your various desktops. This is, of course, the the current iteration of Spaces. By default, there are two desktops available: the Dashboard and the current desktop. Each is labeled ("Dashboard" and "Desktop 1"). As you've probably guessed, subsequent desktops are labeled sequentially ("Desktop 2," etc.).
Below the desktop thumbnails you'll find the Exposé area. It depicts the applications and documents currently open. Documents and windows are sorted into piles, according to their parent application and each is labeled with the appropriate icon. For example, a "pile" of Word documents will bear a Word icon (bottom center), while Pages files will show the Pages icon. I'll discuss working in the Exposé area later in the post. For now, let's look at the desktops.
How it Works - Spaces and Desktops
As I said, you start with two desktops by default: the Dashboard on the left and the current desktop on the right. Each desktop thumbnail shows the frontmost application in the space. When using desktops in Mission Control, you'll typically do five things:
Add new desktops
Navigate between desktops
Move applications between desktops
Jump to a given desktop
Close unwanted desktops
Here's now to do each.
Adding New Desktops
The are two ways to do this. The first is to move your cursor to the upper right-hand corner of the Mission Control interface. As you do, a new desktop will partially appear with a "+" on its edge. To create it, just give it a click. It slides into place and receives the appropriate label.
The other method lets you create a new space and add an application to it in one fell swoop. Here's how.
Click on an application window in the Exposé area.
Drag it to the upper right-hand corner.
The "new desktop" appears. Drop the window onto it.
That's it! A new desktop will be created, containing all open files relating pertaining to the application you just dropped inside.
Navigating Between Desktops
There are three ways to move between desktops. The first is to simply click a thumbnail image. You'll immediately leave Mission Control and jump to that desktop.
However, there may be times when you want to review available desktops before jumping into one. To do this, hold down the Control Key while pressing the arrow keys on your keyboard. You'll move from desktop to desktop (the Exposé area will also change accordingly) without exiting Mission Control.
Additionally, you can use a three- or four-finger swipe on a trackpad (use two fingers on a Magic Mouse) to move between desktops.
The final method is exactly moving through desktops via Mission Control, but it's sort of the same thing. You can move between open desktops without launching Mission Control by swiping with either three or four fingers (configurable via System Preferences) on a trackpad or with two fingers on a Magic Mouse.
Moving Applications Between Desktops
The whole point of this feature is to keep your current workspace uncluttered. For example, you can keep Mail on one desktop, Twitter on another and TextEdit on a third. Of course, you might want to switch up the order at any time. Here's how to move applications between desktops with Mission Control.
There's only one real way to do this, and it's pretty darn simple. First, open Mission Control and navigate to the desktop containing the app you'd like to move (the Control > arrow key method is best here). Next, click-and-hold on that app's window (or stack of windows) in the Exposé area, and drop it into the desired desktop. It'll be moved, but you'll stay on the original desktop.
Note that if doing so "empties" a desktop -- that is to say, leaves it without any applications -- it will remain. I'll discuss closing unwanted desktops later in this post.
Jumping to A Desktop
As mentioned earlier, this couldn't be easier. Simply click the desktop you'd like to work in. Conversely, use the three- for four-finger swipe gesture to move between desktops without opening Mission Control.
Closing Unwanted Desktops
This couldn't be simpler. To close an unwanted desktop, you've got two options. First, mouse over the thumbnail image and let your cursor sit for a second or two. A black-and-white "X" will appear in the upper left-hand corner. Give it a click and the desktop disappears.
The less-than-patient can press the Option key to bring up the X immediately. Note: you cannot close Desktop 1 or the Dashboard with this method (in fact, you can't dismiss Desktop 1 at all).
How it Works - Exposé
Along with Spaces, Mission Control has used its Borg-like powers to assimilate Exposé. Beneath the vertical row of desktop thumbnails is the Exposé area. Here's what to expect from Exposé via Mission Control.
When Mission Control is launched, your current desktop "recedes" into your display and is presented on a linen background. The Exposé shows all of the documents that are currently open. As I explained, these documents are sorted by their parent application. Each "pile" of windows bears that application's icon for quick reference. To jump to a given app, simply click its pile.
Of course, those piles present a problem...they're piles! What's behind the first item? To find out, move your cursor over each item in the pile. You'll notice that the blue focus border appears over each document in turn. Once that happens, hit the Space Bar to get a Quick Look-style peek at that document. If that's one you'd like to jump to, click it.
Mission Control Preferences
Unlike some of Lion's other marquee features (I'm looking at you, Launchpad), Mission Control offers a huge amount of customization via preferences. Here's what you'll find.
Open System Preferences and then click Mission Control. The control panel is divided into three sections: general preferences, keyboard and mouse shortcuts and finally hot corners. There's a lot of fiddling to do in here, so let's take a look at each section.
Here you've got three options.
Show Dashboard as a space. De-select this option to remove Dashboard from the horizontal row of desktop thumbnail images. Those uninterested in using Dashboard or widgets might want to do so.
Automatically re-arrange spaces based on most recent use. This is kind of handy. Mission Control will keep the desktops you're using most often next to each other, making the back-and-forth even easier.
When switching to an application, switch to a space with open windows for that application. For example, if you've got Word open in Desktop 3 while you're working in Twitter from Desktop 1, and then select Word with a Command-Tab, you'll jump right over to Desktop 3. De-selection this option prevents the leap; you'll select Word but stay in Desktop 1.
Keyboard and Mouse Shortcut Preferences
Prepare to go nuts, keyboard jockeys. There are a huge number of options for launching Mission Control, revealing application windows, showing the desktop and finally showing the Dashboard. I won't go into detail here because this post is long enough. Suffice to say, if you have a keyboard shortcut or mouse click in mind for producing any of those functions, you'll probably find it here.
Hot Corners Preferences
Finally, click the Hot Corners button in the lower left-hand corner to assign a corner of the screen to a given Mission Control function. Then, you can simply move your cursor to that corner to produce the desired function.
Finally, a word on Dashboard. Other than a launch option (you can view it as a desktop thumbnail or not), there's nothing new in Dashboard. So, there you go.
Bits and Bobs
There are a few little things to keep in mind regarding Mission Control.
Desktop images appear in the thumbnail images. Some people use certain desktop images to quickly identify workspaces. Mission Control represents each desktop's image (or wallpaper) in its thumbnail.
Two screens = two Mission Control UIs. Those running two displays will find two distinct Mission Control UIs. You cannot move applications from a desktop on Display A to one on Display B.
You can't re-arrange windows, etc. within the Exposé area. It reflects their current position only. Fiddling must be done on the desktop itself.
Forget about scripting and other high-level geek stuff. Mission Control is for home users and LaunchBar wizards will want to look elsewhere.
Now, a couple closing thoughts. For the first time, I'm using Spaces. It's really the swiping that makes it useful. I'm in front of the app I want in less than a second, and no workspace becomes especially cluttered.
As for the Exposé area, yeah, it gets pretty cluttered despite the fact that its very purpose is to prevent clutter. Once you've got several documents open across applications, the piles pile up, if you'll forgive that poor analogy. I also wish I could move apps between desktops on different displays.
Minor quibbles, really. I've been using and enjoying Mission Control and suspect that many of you will, too.
The images used in this article are taken from the upcoming Apress book Taking Your OS X Lion to the Max.