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Dock (OS X)

Dock
A component of macOS
Details
Type Taskbar
Included with NeXTSTEP, macOS
Service name Dock.app

The Dock is a prominent feature of the graphical user interface of the macOS operating system. It is used to launch applications and to switch between running applications. The Dock is also a prominent feature of macOS's predecessor NeXTSTEP and OpenStep operating systems. The earliest known implementations of a dock are found in operating systems such as RISC OS and NeXTSTEP. iOS has its own version of the Dock for iPhone, iPod Touch and iPad.

Apple applied for a US patent for the design of the Dock in 1999 and was granted the patent in October 2008, nine years later. Applications can be added to and removed from the Dock by drag and drop, except for the Finder, which is a permanent fixture as the leftmost item (or topmost if the Dock is configured to be vertical). The Trash icon is also a permanent fixture at the right end (or bottom if the Dock is repositioned). Part of the macOS Core Services, Dock.app is located at /System/Library/CoreServices/.

In NeXTSTEP and OpenStep, the Dock is an application launcher that holds icons for frequently used programs. The icon for the Workspace Manager and the Recycler are always visible. The Dock indicates if a program is not running by showing an ellipsis below its icon. If the program is running, there isn't an ellipsis on the icon. In macOS, running applications have been variously identified by a small black triangle (Mac OS X 10.0-10.4) a blue-tinted luminous dot (Mac OS X 10.5-10.7), a horizontal light bar (OS X 10.8 and 10.9), and a simple black or white dot (OS X 10.10-macOS 10.12).

In macOS, however, the Dock is used as a repository for any program or file in the operating system. It can hold any number of items and resizes them dynamically to fit while using magnification to clarify smaller resized items. By default, it appears on the bottom edge of the screen, but it can also instead be placed on the left or right edges of the screen if the user wishes. Applications that do not normally keep icons in the Dock will still appear there when running and remain until they are quit. These features are unlike those of the dock in the NeXT operating systems where the capacity of the Dock is dependent on display resolution. This may be an attempt to recover some Shelf functionality since macOS inherits no other such technology from NeXTSTEP. (Minimal Shelf functionality has been implemented in the Finder.)


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