In
computingComputing is usually defined as the activity of using and developing computer technology, computer hardware and software. It is the computer-specific part of information technology...
, a
check box (
checkbox,
tickbox, or
tick box) is a
graphical user interfaceA graphical user interface is a type of user interface item that allows people to interact with programs in more ways than typing such as computers; hand-held devices such as MP3 Players, Portable Media Players or Gaming devices; household appliances and office equipment with images rather than...
element
(
widgetIn computer programming, a widget is an element of a graphical user interface that displays an information arrangement changeable by the user, such as a window or a text box. The defining characteristic of a widget is to provide a single interaction point for the direct manipulation of a given...
) that permits the
userIn computing, a user is a person who uses a computer or Internet service. A user may have a user account that identifies the user by a username , screenname , or "handle", which is derived from the identical Citizen's Band radio term...
to make multiple selections from a number of options. Normally, check boxes are shown on the screen as a square box that can contain
white spaceIn computer science, whitespace is any single character or series of characters that represents horizontal or vertical space in typography. When rendered, a whitespace character does not correspond to a visual mark, but typically does occupy an area on a page...
(for false) or a
tick markA tick is a mark used to indicate the concept "yes", for example "yes; this has been verified" or, "yes; that is the correct answer"...
or X (for true), as pictured. A
captionCaption may refer to:*Caption , a small press and independent comic convention held annually in Oxford, England*Closed captioning, used to provide the text of a show's audio portion to those who may have trouble hearing it...
describing the meaning of the check box is normally shown adjacent to the check box.
In
computingComputing is usually defined as the activity of using and developing computer technology, computer hardware and software. It is the computer-specific part of information technology...
, a
check box (
checkbox,
tickbox, or
tick box) is a
graphical user interfaceA graphical user interface is a type of user interface item that allows people to interact with programs in more ways than typing such as computers; hand-held devices such as MP3 Players, Portable Media Players or Gaming devices; household appliances and office equipment with images rather than...
element
(
widgetIn computer programming, a widget is an element of a graphical user interface that displays an information arrangement changeable by the user, such as a window or a text box. The defining characteristic of a widget is to provide a single interaction point for the direct manipulation of a given...
) that permits the
userIn computing, a user is a person who uses a computer or Internet service. A user may have a user account that identifies the user by a username , screenname , or "handle", which is derived from the identical Citizen's Band radio term...
to make multiple selections from a number of options. Normally, check boxes are shown on the screen as a square box that can contain
white spaceIn computer science, whitespace is any single character or series of characters that represents horizontal or vertical space in typography. When rendered, a whitespace character does not correspond to a visual mark, but typically does occupy an area on a page...
(for false) or a
tick markA tick is a mark used to indicate the concept "yes", for example "yes; this has been verified" or, "yes; that is the correct answer"...
or X (for true), as pictured. A
captionCaption may refer to:*Caption , a small press and independent comic convention held annually in Oxford, England*Closed captioning, used to provide the text of a show's audio portion to those who may have trouble hearing it...
describing the meaning of the check box is normally shown adjacent to the check box. Inverting the
stateIn computer science and automata theory, a state is a unique configuration of information in a program or machine. It is a concept that occasionally extends into some forms of systems programming such as lexers and parsers....
of a check box is done by clicking the
mouseIn computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...
on the box, or the caption, or by using a
keyboard shortcutIn computing, a keyboard shortcut or hotkey is a finite set of one or more keys that invoke a software or operating system operation when triggered by the user....
, such as the
space barthumb|250px|A [[computer keyboard]], Space Bar is on the bottom center of the keyboard.The space bar, spacebar, or space key, is a key on an alphanumeric keyboard in the form of a horizontal bar in the lowermost row, significantly wider than other keys. Its main purpose is to conveniently enter the...
.
Tri-state check box
Some
applicationsApplication software is a computer program that functions and is operated by means of a computer, with the purpose of supporting or improving the software user's work. In other words, it is the subclass of computer software that employs the capabilities of a computer directly and thoroughly to a...
use a check box that allows three states rather than the two (selected and not selected) provided by a normal check box. This third state is shown by greying-out the checkbox (or, less often, displaying a
dashA dash is a punctuation mark. It is similar in appearance to a hyphen, but longer and used differently. The most common versions of the dash are the en dash and the em dash .-Common dashes:...
in the checkbox). This can indicate that the box cannot be selected in the system's current
stateIn computer science and automata theory, a state is a unique configuration of information in a program or machine. It is a concept that occasionally extends into some forms of systems programming such as lexers and parsers....
. Also, where a checkbox refers to a collection of objects, a greyed-out checkbox indicates that some objects in the collection test as true (checked) while others test false (empty). The greyed-out state cannot be selected by the user, but is a way of the checkbox reporting back to the user.
For example, a checkbox presented to select files to send via
FTPFile Transfer Protocol is a standard network protocol used to exchange and manipulate files over a TCP/IP based network, such as the Internet. FTP is built on a client-server architecture and utilizes separate control and data connections between the client and server applications...
might use a
tree viewA tree view or an outline view is a graphical user interface element that presents a hierarchical view of information. Each item can have a number of subitems...
so that files can be selected one at a time, or by selecting a folder, or sub-directory. If some files in a folder were checked and others were unchecked, then the checkbox for that folder would show as greyed out, because the files it contains are a mixture of selected and unselected. Clicking on this greyed-out checkbox would have one of two reactions, depending on the way it has been programmed; on repeated clicking these two states alternate, usually without returning to the greyed-out state:
- all sub-directories and sub-files (and the checkbox) would become checked
- all sub-directories and sub-files (and the checkbox) would become unchecked
Some tri-state check box implementations enable the user to toggle among all three states, including the mixed (gray) state by remembering the state of all the checkboxes in the collection. This serves as an
undoUndo is a command in many computer programs. It erases the last change done to the document reverting it to an older state. In some more advanced programs such as graphic processing, undo will negate the last command done to the file being edited....
feature.
HTML
In
web formsA webform on a web page allows a user to enter data that is sent to a server for processing. Webforms resemble paper forms because internet users fill out the forms using checkboxes, radio buttons, or text fields...
, the
HTML elementIn an HTML document, HTML elements are tags, as well as text, which act as indicators to a web browser as to how the document is to be interpreted by the browser and ultimately presented on the user's computer screen....
is used to display a check box.
Unicode
In
UnicodeUnicode is a computing industry standard allowing computers to consistently represent and manipulate text expressed in most of the world's writing systems...
, empty and filled check boxes are represented by code points U+2610 , U+2611 , and U+2612 .
External links
See also
- Radio button
A radio button or option button is a type of graphical user interface element that allows the user to choose only one of a predefined set of options. They were named after the physical buttons used on older car radios to select preset stations - when one of the buttons was pressed, other buttons...
- Elements of graphical user interfaces
Graphical user interfaces, also known as GUIs, offer a consistent visual language to represent information stored in computers. This makes it easier for people with little computer skills to work with and use computer software...