Dock (computing)
Encyclopedia
The Dock is a prominent feature of the graphical user interface
Graphical user interface
In computing, a graphical user interface is a type of user interface that allows users to interact with electronic devices with images rather than text commands. GUIs can be used in computers, hand-held devices such as MP3 players, portable media players or gaming devices, household appliances and...

 of the Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

 operating system. It is used to launch applications and switch between running applications. The Dock is also a prominent feature of Mac OS X's predecessor NeXTSTEP
NEXTSTEP
NeXTSTEP was the object-oriented, multitasking operating system developed by NeXT Computer to run on its range of proprietary workstation computers, such as the NeXTcube...

 and OpenStep
OpenStep
OpenStep was an object-oriented application programming interface specification for an object-oriented operating system that used a non-NeXTSTEP operating system as its core, principally developed by NeXT with Sun Microsystems. OPENSTEP was a specific implementation of the OpenStep API developed...

 operating systems, and the term "dock
Dock (computing)
The Dock is a prominent feature of the graphical user interface of the Mac OS X operating system. It is used to launch applications and switch between running applications...

" is sometimes used generically to refer to similar features in other OSes, such as RISC OS
RISC OS
RISC OS is a computer operating system originally developed by Acorn Computers Ltd in Cambridge, England for their range of desktop computers, based on their own ARM architecture. First released in 1987, under the name Arthur, the subsequent iteration was renamed as in 1988...

's icon bar
Icon bar
In computing, the icon bar is the name of the dock in Acorn's RISC OS operating system, and is fundamental to the OS. Its introduction in 1987 was a new concept in GUIs...

. iOS has its own version of the Dock for iPhone
IPhone
The iPhone is a line of Internet and multimedia-enabled smartphones marketed by Apple Inc. The first iPhone was unveiled by Steve Jobs, then CEO of Apple, on January 9, 2007, and released on June 29, 2007...

 and iPad
IPad
The iPad is a line of tablet computers designed, developed and marketed by Apple Inc., primarily as a platform for audio-visual media including books, periodicals, movies, music, games, and web content. The iPad was introduced on January 27, 2010 by Apple's then-CEO Steve Jobs. Its size and...

.

Apple applied for a patent for the design of the Dock in 1999 and was granted the patent in October 2008, nine years later. Applications can be added and removed to the Dock by drag-and-drop
Drag-and-drop
In computer graphical user interfaces, drag-and-drop is the action of selecting a virtual object by "grabbing" it and dragging it to a different location or onto another virtual object...

, except for the Finder, which is a permanent fixture as the leftmost item (or topmost if the Dock is configured to be vertical). Part of the system core services
Core Services
Core Services are a set of Mac OS X and iOS application programming interfaces that architecturally are underneath Carbon, Cocoa and Cocoa Touch. In addition to Core Foundation, it also encompasses other APIs including Grand Central Dispatch, Blocks, CFNetwork, CarbonCore, OSServices, and...

 in OS X, Dock.app is located at /System/Library/CoreServices/.

Overview

In NeXTSTEP and OpenStep, the Dock is an application launcher that holds icons
Icon (computing)
A computer icon is a pictogram displayed on a computer screen and used to navigate a computer system or mobile device. The icon itself is a small picture or symbol serving as a quick, intuitive representation of a software tool, function or a data file accessible on the system. It functions as an...

 for frequently used program
Computer program
A computer program is a sequence of instructions written to perform a specified task with a computer. A computer requires programs to function, typically executing the program's instructions in a central processor. The program has an executable form that the computer can use directly to execute...

s. The icon for the Workspace Manager and the Recycler are always visible. The Dock indicates the program's current state (running or not running) by showing an ellipsis
Ellipsis
Ellipsis is a series of marks that usually indicate an intentional omission of a word, sentence or whole section from the original text being quoted. An ellipsis can also be used to indicate an unfinished thought or, at the end of a sentence, a trailing off into silence...

 below its icon if the program is running and nothing if it is currently "not" running. (Contrast this behavior with the Dock in Mac OS X which uses a triangle (Mac OS X 10.4.11 and earlier) or a luminous dot (as of Mac OS X version 10.5.0, Leopard) to indicate that the program is running and nothing if it has not yet been launched.)

In Mac OS X, 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
Display resolution
The display resolution of a digital television or display device is the number of distinct pixels in each dimension that can be displayed. It can be an ambiguous term especially as the displayed resolution is controlled by all different factors in cathode ray tube , flat panel or projection...

. This may be an attempt to recover some Shelf
Shelf (computing)
The Shelf is an interface feature in NeXTSTEP and OPENSTEP, and is used as a repository to store links to commonly used files, directories and programs, and as a temporary "holding" place to move/copy files and directories around in the file system hierarchy...

 functionality since Mac OS X inherits no other such technology from NeXTSTEP. (Some Shelf functionality was previously implemented in the Finder.)

The changes to the dock bring its functionality also close to that of Apple's Newton OS
Newton OS
Newton OS was the operating system for the Apple Newton PDAs produced by Apple from 1993-1997. Newton OS was written entirely in C++ and trimmed to be low power consuming and use the available memory efficiently...

 Button Bar, as found in the MessagePad 2x00 series and the likes. Applications could be dragged in and out of the Extras Drawer, a Finder-like app, onto the bar. Also, when the screen was put into landscape mode, the user could choose to position the Button Bar at the right or left side of the screen, just like the Dock in Mac OS X.

The Mac OS X Dock also has extended menus that control applications without making them visible on screen. On most applications it has simple options such as Quit, Keep In Dock, Remove From Dock, and other options, though some applications use these menus for other purposes, such as iTunes, which uses this menu as a way for a user to control certain playback options. Other Applications include changing the status of an online alias (MSN, AIM/iChat etc.) or automatically saving the changes that have been made in a document (There is no current application with this feature made available for Mac OS X). Docklings (in Mac OS 10.4.11 or earlier) can also be opened by using the right-mouse button, if the mouse has one, but most of the time either clicking and holding or control-click will bring the menu up.
In Mac OS X Leopard, docklings were replaced by Stacks
Stacks (software)
Stacks are a feature first found in Apple's operating system, Mac OS X v10.5 "Leopard". As the name implies, they "stack" files into a small organized folder on the Dock...

. Stacks "stack" files into a small organized folder on the Dock, and they can be opened by left-clicking.
Stacks could be shown in three ways: a "fan", a "grid", or a "list", which is similar to docklings. In grid view, the folders in that stack can be opened directly in that stack without the need to open Finder.

The latest iteration of the dock, found in Mac OS X Leopard and Snow Leopard, presents a 3D perspective instead of the traditional flat one, resembling Sun Microsystems
Sun Microsystems
Sun Microsystems, Inc. was a company that sold :computers, computer components, :computer software, and :information technology services. Sun was founded on February 24, 1982...

' Project Looking Glass
Project Looking Glass
Project Looking Glass is a now inactive free software project under the GPL to create an innovative 3D desktop environment for Linux, Solaris, and Windows. It was sponsored by Sun Microsystems....

 application dock.

Related software

Many programs that emulate the Mac OS X dock on Windows, such as ObjectDock
ObjectDock
ObjectDock is a dock similar to that in the Aqua GUI. It is distributed by Stardock for Windows 2000, 2003, XP, Vista and 7, and comes in Free and Plus versions.- Features :...

 and RocketDock
RocketDock
RocketDock is an application launcher developed by PolyVector and Skunkie of Punk Labs, working with artist Zachary Denton, for Windows that provides a dock similar to that of the Mac OS X Aqua GUI...

, have sprung up due to the popularity of Mac OS X. Earlier versions of Mac OS
Mac OS
Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...

 (before 10.0) did not have a dock, but add-ons such as DragThing
DragThing
DragThing is a popular shareware Dock replacement for Mac OS X, intended for organization and as an application switcher. DragThing allows for multiple docks with user-specified settings such as color, texture and shape. DragThing was first released on 1 May, 1995 by James Thomson and celebrated...

 added a dock for users of earlier versions.

Various docks are also used in Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...

 and BSD. Some examples are Window Maker
Window Maker
Window Maker is a free and open source window manager for the X Window System, allowing graphical applications to be run on Unix-like operating-systems...

 (which emulates the look and feel of the NeXTstep GUI), Docky
Docky
Docky is a dock for the GNOME desktop, very similar in functionality to Mac OS X's Dock. Originally it was an integrated part of Gnome Do, but the two projects separated in late 2009. It is available for distributions such as Debian, Ubuntu, OpenSUSE and Arch Linux.-External links:* *...

, and Avant Window Navigator
Avant Window Navigator
Avant Window Navigator is a dock-like bar for Linux, which sits on an edge of a user's screen and tracks open windows. Instead of representing open windows as buttons or segments on a bar, it uses icons to minimize screen space and add visual appeal. Avant Window Navigator was created by Neil J...

, KXDocker
KXDocker
KXDocker is a program for the Linux operating system created by . It resembles the "Dock" of Mac OS X in that it is mainly used as an application launcher. It supports themes, plugins and a few extra features...

 (amongst others) for KDE
KDE
KDE is an international free software community producing an integrated set of cross-platform applications designed to run on Linux, FreeBSD, Microsoft Windows, Solaris and Mac OS X systems...

 and various other gdesklet
GDesklets
gDesklets is a GNOME program which provides the architecture for small applets to be placed on top of the user's desktop. It is comparable to other desktop widget programs...

/adesklets
Adesklets
adesklets is a lightweight X11 program which provides the architecture for small applets to be placed on top of the user's desktop. The applets placed on the desktop are meant to be quick ways for the user to retrieve information and not get in the way of normal activity. More formally, it could...

 docks, AfterStep
AfterStep
AfterStep is a stacking window manager for the X Window System. The goal of AfterStep's development is to provide for flexibility of desktop configuration, improved aesthetics and efficient use of system resources, and was used in such distributions as MachTen...

's Wharf (a derivation from the NeXTstep UI), iTask NG (a module used with some Enlightenment
Enlightenment (window manager)
Enlightenment, also known simply as E, is a stacking window manager for the X Window System which can be used alone or in conjunction with a desktop environment such as GNOME or KDE...

-based Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...

s such as gOS
GOS (operating system)
gOS or "good OS" was an Ubuntu-based GNU/Linux distribution created by Good OS LLC, a Los Angeles-based corporation. Its CIO Dave Liu described that after meeting Enlightenment and open source people, he realized that his dream to bring Web 2.0 applications into mainstream use could be achieved by...

) and Blackbox
Blackbox
In Unix computing, Blackbox is a stacking window manager for the X Window System.Blackbox has specific design goals, and some functionality is provided only through other applications. One example is the bbkeys hotkey application....

's Slit.

Curiosities

It has been reported that, in Snow Leopard, clicking and dragging on the title bar of a large stack, one with 24 items or more (depending on screen size and resolution), results in the list bouncing back to the top every time one tries to scroll it down. It returns back to normal on clicking and dragging on the left hand side of the list.

Criticism

Bruce Tognazzini
Bruce Tognazzini
Bruce "Tog" Tognazzini is a usability consultant in partnership with Donald Norman and Jakob Nielsen in the Nielsen Norman Group, which specializes in human computer interaction. He was with Apple Computer for fourteen years, then with Sun Microsystems for four years, then WebMD for another four...

, a usability consultant who worked for Apple in the 1980s and 1990s before Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...

 was developed, wrote an article in 2001 listing ten problems he saw with the Dock. This article was updated in 2004, removing two of the original criticisms and adding a new one. One of his concerns is that it takes too much space at its default size without auto-hide. He also complained that icons in the Dock only show their label when the mouse is over them, so if several aliases of a single filetype are put into the dock, differentiation between those files would be difficult or impossible without using the mouse, unless the user has changed the icons of the different files or folders. Tognazzini also criticized the Dock's ability to add and remove aliases, saying confusion could result when an icon is dragged out of the dock and needs to be re-added from Finder. He describes this "object annihilation" as bad behavior.

John Siracusa, writing for Ars Technica
Ars Technica
Ars Technica is a technology news and information website created by Ken Fisher and Jon Stokes in 1998. It publishes news, reviews and guides on issues such as computer hardware and software, science, technology policy, and video games. Ars Technica is known for its features, long articles that go...

, had also pointed out some issues with the dock around the releases of Mac OS X Public Beta
Mac OS X Public Beta
The Mac OS X Public Beta was an early beta version of Apple Computer's Mac OS X operating system Cheetah. It was released to the public on September 13, 2000 for US$29.95...

 in 2000. He noted that when the dock is centered, adding and removing icons will change the location of the other icons. In a review of Mac OS X v10.0
Mac OS X v10.0
Mac OS X version 10.0, code named "Cheetah", is the first major release of Mac OS X, Apple’s desktop and server operating system. Mac OS X v10.0 was released on March 24, 2001 for a price of US$129...

 the following year, he also noted that the dock handles more tasks than a user interface element should for optimum ease-of-use, handling both minimized icons and program/file/folder shortcuts. Siracusa further criticised the dock after the release of Mac OS X v10.5
Mac OS X v10.5
Mac OS X Leopard is the sixth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Leopard was released on 26 October 2007 as the successor of Tiger , and is available in two variants: a desktop version suitable for personal computers, and a...

, noting that some of the dock's ease-of-use was sacrificed for eye-candy, such as a reflective and 3D dock, a blue-light active program indicator, and the presence of less-distinguishable system icons.

An article on OSNews
OSNews
OSNews is a computing news web site with a focus on operating systems and their related technologies that launched in 1997. The content is managed by a group of editors and the owner. The managing editor of OSNews is Thom Holwerda . David Adams is a publisher for OSNews, and also contributes...

 written by its managing editor, Thom Holwerda, stated some concerns with the dock, including the fact that the dock grows in both directions, has the Trash icon mounted on the dock, and that there are no permanent labels. Holwerda also criticized the revised look of the dock found in Mac OS X v10.5
Mac OS X v10.5
Mac OS X Leopard is the sixth major release of Mac OS X, Apple's desktop and server operating system for Macintosh computers. Leopard was released on 26 October 2007 as the successor of Tiger , and is available in two variants: a desktop version suitable for personal computers, and a...

, but admitted that it may have simply been an adjustment on their part.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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