A throbber, also known as a loading icon, is an

animated Animation is a filmmaking technique whereby image, still images are manipulated to create Motion picture, moving images. In traditional animation, images are drawn or painted by hand on cel, transparent celluloid sheets to be photographed and e ...

graphical control element A graphical widget (also graphical control element or control) in a graphical user interface is an element of interaction, such as a button or a scroll bar. Controls are software components that a computer user interacts with through direct m ...

used to show that a

computer program A computer program is a sequence or set of instructions in a programming language for a computer to Execution (computing), execute. It is one component of software, which also includes software documentation, documentation and other intangibl ...

is performing an action in the background (such as downloading content, conducting intensive calculations or communicating with an external device). In contrast to a

progress bar A progress bar is a graphical control element used to visualize the progression of an extended computer operation, such as a download, file transfer, or installation. Sometimes, the graphic is accompanied by a textual representation of the progre ...

, a throbber does not indicate how much of the action has been completed.

History

An early use of a throbber occurred in the

NCSA Mosaic NCSA Mosaic is a discontinued web browser. It was instrumental in popularizing the World Wide Web and the general Internet during the 1990s by integrating multimedia such as text and graphics. Although not the first web browser (preceded by Wor ...

web browser of the early 1990s, which featured an NCSA logo that animated while Mosaic downloaded a web page. As the user could still interact with the program, the pointer remained normal (and not a busy symbol, such as an hourglass); therefore, the throbber provided a visual indication that the program was performing an action. The

Netscape Netscape Communications Corporation (originally Mosaic Communications Corporation) was an American independent computer services company with headquarters in Mountain View, California, and then Dulles, Virginia. Its Netscape web browser was o ...

web browser also featured a throbber. In version 1.0 of Netscape, this took the form of a big blue "N" (Netscape's logo at the time). The animation depicted the "N" expanding and contracting hence the name "throbber". The IBM WebExplorer offered a

webpage A web page (or webpage) is a Web document that is accessed in a web browser. A website typically consists of many web pages linked together under a common domain name. The term "web page" is therefore a metaphor of paper pages bound together in ...

the opportunity to change the look and the animation of the throbber by using proprietary

HTML Hypertext Markup Language (HTML) is the standard markup language for documents designed to be displayed in a web browser. It defines the content and structure of web content. It is often assisted by technologies such as Cascading Style Sheets ( ...

code. The

Arena An arena is a large enclosed venue, often circular or oval-shaped, designed to showcase theatre, Music, musical performances or Sport, sporting events. It comprises a large open space surrounded on most or all sides by tiered seating for specta ...

web browser has a

command-line option A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

to change the throbber with a local file.

Spinning wheel

Throbbers also appear in client side applications (such as

Ajax Ajax may refer to: Greek mythology and tragedy * Ajax the Great, a Greek mythological hero, son of King Telamon and Periboea * Ajax the Lesser, a Greek mythological hero, son of Oileus, the king of Locris * Ajax (play), ''Ajax'' (play), by the an ...

web apps) where an application within the web browser would wait for some operation to complete. Most of these throbbers appear as a "spinning wheel", which typically consist of 8, 10, or 12 part-radial lines or discs arranged in a circle, as if on a

clock face A clock face is the part of an analog clock (or watch) that displays time through the use of a flat dial (measurement), dial with reference marks, and revolving pointers turning on concentric shafts at the center, called hands. In its most basi ...

, highlighted in turn as if a wave is moving clockwise around the circle. In

text user interface In computing, text-based user interfaces (TUI) (alternately terminal user interfaces, to reflect a dependence upon the properties of computer terminals and not just text), is a retronym describing a type of user interface (UI) common as an ear ...

s and

command line A command-line interface (CLI) is a means of interacting with software via command (computing), commands each formatted as a line of text. Command-line interfaces emerged in the mid-1960s, on computer terminals, as an interactive and more user ...

s, the spinning wheel is commonly replaced by a fixed-width character which is cycled through discrete states, such as ", ", "/", "-" and "\", which act as the frames of a looping animation-like effect. Unlike graphical activity indicators, this style of throbber is commonly paired with a progress display like a bar, since the lower effective resolution of character-based progress bars can benefit from a separate indication of activity. Often, the spinner is displayed at or near the position of the typing cursor, then called a "spinning cursor" or "rotating cursor". This style of throbber dates from versions of

UNIX Unix (, ; trademarked as UNIX) is a family of multitasking, multi-user computer operating systems that derive from the original AT&T Unix, whose development started in 1969 at the Bell Labs research center by Ken Thompson, Dennis Ritchie, a ...

appearing in the latter 1970s, and

DR-DOS DR-DOS is a disk operating system for IBM PC compatibles, originally developed by Gary A. Kildall's Digital Research, Inc. and derived from Concurrent PC DOS 6.0, which was an advanced successor of CP/M-86. Upon its introduction in 198 ...

utilities in the 1980s, since it requires at least a character-cell addressable display—i.e. one which can be updated quickly to make precise changes to already displayed text—but given that is otherwise simple to program.

References

{{Graphical control elements Graphical control elements Technology neologisms

History

Spinning wheel

See also

References