eXtensions - Sunday 29 October 2017


System Preferences in macOS, High Sierra: Mission Control

By Graham K. Rogers

Changes to most System Preferences in macOS, High Sierra, have been small. The preferences pane for Mission Control has retains the same basic form, but there are slight changes. The panel provides settings to give users an overview of all open windows, applications and Dashboard.

Mission Control was called Exposé & Spaces in earlier versions of OS X. This has a single panel in two sections. At the top are checkboxes for Mission Control, Spaces and Dashboard. At the bottom are Keyboard and Mouse Shortcuts, with a button for Hot Corners at bottom left.

Mission Control

Mission Control

Mission Control can be activated in three ways: by using its icon in the Dock; using gestures (see Trackpad Preferences); or via Key Commands. There are four checkboxes for activating features with Mission Control:

  • Automatically rearrange Spaces based on most recent use. This can be used in conjunction with the Dock menu which allows a user to specify a Space for an application (see Notes).

  • When switching to an application, switch to a Space with open windows for the application.

  • Group windows by application

  • Displays have separate Spaces. This works in conjunction with Displays Preferences: when Mirroring is Off, new features are available. External displays behave as in previous versions of OS X when this box is checked. This feature requires the user to log out before it is applied.

Below these checkboxes is a button to control Dashboard. Options available are:

  • Off
  • As Space (when used the screen appears to move to the right)
  • As Overlay (Dashboard is shown over the current window)
By default, when Mission Control is used, the word, Dashboard is shown to the left of other Desktops at the top of the screen. When the cursor is moved to this area of the screen when Mission Control is activated, thumbnail displays of Dashboard and available Desktops are shown.

Mission Control

There is an eXtensions widget available on the Apple site along with many other useful (if underused) widgets..

Keyboard and Mouse Shortcuts

Within the Mission Control Panel, users may allocate specific keys for some of the operations. Four operations are available. Previously eight buttons were shown in two columns. I see only a single group of four buttons on the two MacBook Pro computers I am using (but see below). Where Function keys are shown, users may also need to press the Fn key, depending on setup.

  • Mission Control: default key is F9 (fn + F9). Mission Control activates, showing all open applications and spaces;

  • Application windows: default key is F9 (fn + F9). All open panels of the front application are shown. Any minimized panels are shown as smaller thumbnail panels (icons will match the file type);

  • Show Desktop: default key is F11 (fn + F11). All application panels are moved off to the sides and the desktop is visible;

  • Show Dashboard: default key is F12 (fn + F12). The desktop is moved to the right and the user has access to the Dashboard and any Widgets installed.

When clicked, each button reveals a list of keys which may be used to reallocate the command. For example, instead of the default F9 for Mission Control, we may choose Right Shift. In my case, I have allocated the key combination of Control + Up Arrow and for Application windows, Control plus the Down Arrow.

When selecting a key, pressing on a modifier key (e.g. Shift or Option) adds that to the command. Re-allocation takes affect immediately. If a key (or combination) conflicts with other operations, or previously allocated commands, a yellow warning triangle is displayed alongside the button.

Mission Control

Buttons in the second column are only available when a mouse is connected. Unlike Mouse preferences, it may need System preferences to be restarted before the buttons appear. These buttons for using the mouse as a means of control are initially unallocated. A dash is shown.

On my installations I may choose only Secondary Mouse Button or Middle Mouse Button. Connecting a mouse with more buttons and controls did not make additional options available.

If any of the control keys (Shift, Control, Option, Command) are pressed - alone or in combination - these also appear in the menu. They are accepted (or removed) by clicking the mouse.

Hot Corners

Specific actions may be allocated to any of the four corners of the screen in the same was as in the Desktop & Screensaver Preferences. As the cursor moves to the corner, an action is carried out. Options available are Mission Control, Application Windows, Desktop, Dashboard, Notification Center, Launchpad, Start Screensaver, Disable Screensaver, Put Display to Sleep and - (no action).

Mission Control


Mission Control manages Spaces. On new installations there is a single Space (plus Dashboard). On Macs that have used Spaces before, the same number is available after an update. This is also the case if a Time Machine backup is used at the time of installation.

New Spaces can be added when Mission Control is being used - click the icon in the Dock - by moving the cursor towards the top right of the screen (where there is a + button). A new, semi-transparent Space appears (using the desktop image from Space 1). By clicking in that new Space, it becomes active and is allocated a consecutive number (e.g. Desktop 7). This then also appears in Key Commands.

To remove a Space, slide the cursor towards the Space display when Mission Control is being used. An X will appear at the top left of the Space thumbnail. Clicking on this removes the Space.

When an application icon is shown in the Dock (open or not), click on the icon and use the Options menu to Assign the application to "All Desktops" (previously "All Spaces") or "This Desktop" or "None" (default).

Mission Control

As pointed out to me in an email from Greg of Imaja Software, another useful feature is that when Mission Control is used to view all open windows, the miniature views of the application panels can be enlarged by moving the cursor over the specific pane and pressing the space bar (as in Quick View).

See Also:

Items on Keyboard, and Language & Region are still being prepared and should be available soon.

Graham K. Rogers teaches at the Faculty of Engineering, Mahidol University in Thailand. He wrote in the Bangkok Post, Database supplement on IT subjects. For the last seven years of Database he wrote a column on Apple and Macs. After 3 years writing a column in the Life supplement, he is now no longer associated with the Bangkok Post. He can be followed on Twitter (@extensions_th)



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All content copyright © G. K. Rogers 2017