Inside the mysteries of Mission Control

21.05.2012
Early Mac screens weren’t cluttered. But then, early Macs let you open only one application at a time—and sometimes only one window!

OS X's Mission Control lets you manage the screen clutter that accompanies today’s advanced computing environment by providing a bird’s-eye view of all your open applications and windows. You’re the one really in control when you learn how to manage Mission Control’s features.

Q: How do I activate Mission Control?

A: With a press of a function key, a trackpad swipe, or any keyboard shortcut you wish. If you have a newer Apple keyboard or laptop, press F3, the Mission Control key. Otherwise, F9 is the default, fn-F9 on a laptop. Set your shortcuts through System Preferences in up to three different places:

The Mission Control pane Choose from a limited list of options to trigger Mission Control from the keyboard and/or with mouse buttons.

The Trackpad pane In the More Gestures tab, check the box for Mission Control and select a swipe configuration from the menu. It’s a good idea to set the “opposite” motion for App Exposé (to show all the windows for the current app); I use a four-finger upward swipe for Mission Control and four-finger downwards for the windows.

The Keyboard pane In the Keyboard Shortcuts tab, select Mission Control on the left and click Mission Control at the top of the right pane to select it. Click the current shortcut and press the key combination you want to trigger it.

Q: Why would I want multiple desktops?

A: Multiple desktops let you isolate applications, or even windows in the same application, from each other so you can work in a less crowded, less distracting environment. For example, you could close Mail's Message Viewer window to neaten things, but closing it means you’ll need to reopen it. Minimizing it means crowding your Dock and having to retrieve it later. When you put an app on its own desktop, it's out of the way, yet immediately available.

I generally have at least two projects going in Microsoft Word on any day; I keep the multiple windows for each on separate desktops.

Q: How do I make a new desktop?

A: It’s a cinch: when you’re in Mission Control, move your cursor to the upper right corner of the screen and click the New Desktop tab that slides out from the edge of the screen. If your Dock is on the right, you can access the New Desktop tab from the upper left corner instead.

Q: Is there a quick way to create a new desktop for a specific window?

A: Say you want to put iCal on its own desktop. Instead of clicking the New Desktop tab and then dragging the iCal window into it, drag the window from the main Desktop to the upper right corner of your screen and drop it on the New Desktop tab. Voilà! If you drag the app’s icon instead of a single window onto the New Desktop tab, OS X moves all the windows “attached” to the icon onto the new desktop. (This works to move them all to an existing desktop, too.)

Q: Can I create as many desktops as I want in Mission Control?

A: You can create up to 16 desktops. You’ll probably find that, as a practical matter, desktop control becomes unwieldy before you reach that limit.

Q: Is there a way to move to a desktop using the keyboard?

A: Yes. Use Control-Left Arrow and Control-Right-Arrow to move to the previous and next desktops while you’re working (you can’t cycle from the last to the first—there are dead ends in each direction).

To move to a specific desktop, use the default shortcuts of Control plus the desktop’s number, with zero used for 10. After 10, the combo is Control-Option plus a number so, for instance, Control-Option-3 is for desktop 13.

To change the defaults, open the Keyboard pane in System Preferences and click the Keyboard Shortcuts tab. Choose Mission Control in the list on the left, and expand the second Mission Control item on the right by clicking the arrow in front of it. To change the shortcut for any desktop, select it, click on the current shortcut, and press the new key combo.

Only desktops that already exist are in the list; add desktops and they appear in the list, although you might have to close and reopen System Preferences to see them.

Bonus tip: These keyboard shortcuts work when you’re in Mission Control, too, so you can easily make any desktop the main, current desktop in Mission Control without Option-clicking on its thumbnail.

Q: I separated multiple projects in my app by putting their windows on different desktops. Is there a quick way to gather the scattered windows back onto one desktop?

A: You can quit the program, relaunch it, and reopen the windows.

Or, if you’re willing to sacrifice some of the desktops where those windows are parked, you can do it from within Mission Control. First, go to the desktop you want the documents on so it will be the main one in Mission Control. Go into Mission Control and hover over a desktop that holds other windows from the app until you see the Close button. Click it, and any windows on that desktop move to the main desktop. Repeat for the other desktops.

Q: Should I assign every application to a specific desktop?

A: No—there are apps that you’ll want to appear wherever you happen to be at the moment. Say you assigned System Preferences to a desktop, but you’re on a different one when you open it from the Apple menu or the Dock. Not only do you move to its assigned desktop, you’ll have to move back to where you were when you’re done. And where were you? Desktop 3…or was it desktop 2?

Your often-used-but-only-for-minutes applications, such as Address Book, iCal, and Font Book are usually best left homeless.

Q: When I Control-click on an application in the Dock, I see the option to assign the app to All Desktops. Why would I want to do that? Isn’t that the same as assigning it to no desktop at all?

A: Assigning an application to All Desktops is different from assigning it to None. Without an assigned desktop, an app opens wherever you’re working at the time. Move from that desktop, and you leave the app behind; return to the desktop and it’s waiting there. When an app is assigned to All Desktops, it opens on the current desktop, but no matter what desktop you move to, it goes with you. This stalker-like behavior is very useful for certain utilities. You might, for instance, want your Twitterrific window always visible no matter how much you move around.

Q: Do I have to go into Mission Control just to move a window from one desktop to the next?

A: No. If you know where you’re going (so to speak), you can just drag a window to the right or left until your arrow cursor is up against the edge of the screen. Hold it there for a second, and you’ll experience a breakthrough: the desktop that’s “waiting” in that direction slides onto the screen, and you’ve moved the dragged window into it.

Q: I have a really big screen, so I don’t like dragging windows between desktops. Is there a quicker way to do the same thing?

A: Just grab the window by its title bar as if you were going to move it, and press the keyboard shortcut for moving left or right in your desktop line-up (the defaults are Control-Left Arrow and Control-Right Arrow).

Q: When I want to delete multiple desktops, do I have to hover over one, wait for the close button, click it, and then hover over the next?

A: Isn’t it amazing a two-second delay seems so long? Get instant close buttons (the circled X) on every desktop in Mission Control by pressing the Option key, and then click away, keeping Option down for as long as you want the close buttons available.

Sharon Zardetto has been writing about the Mac since it could run only one application at a time and thinks they both have greatly improved with age.