Mouse keys
Encyclopedia
Mouse keys is a feature of some 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...

s that uses the keyboard (especially numeric keypad
Numeric keypad
A numeric keypad, numpad or tenkey for short, is the small, palm-sized, seventeen key section of a computer keyboard, usually on the very far right. The numeric keypad features digits 0 to 9, addition , subtraction , multiplication and division symbols, a decimal point and Num Lock and Enter keys...

)
as a pointing device
Pointing device
A pointing device is an input interface that allows a user to input spatial data to a computer...

 (usually replacing a mouse). Its roots lie in the earliest days of visual editor
Visual editor
Visual editors or full screen editors are editing programs which display the text being edited on the screen as it is being edited, as opposed to line-oriented editors ....

s when line and column navigation was controlled with arrow keys
Arrow keys
Cursor movement keys or arrow keys are buttons on a computer keyboard that are either programmed or designated to move the cursor in a specified direction....

 (e.g., hjkl, ctl-esdx).
Today, Mousekeys, usually refers to the numeric keypad
Numeric keypad
A numeric keypad, numpad or tenkey for short, is the small, palm-sized, seventeen key section of a computer keyboard, usually on the very far right. The numeric keypad features digits 0 to 9, addition , subtraction , multiplication and division symbols, a decimal point and Num Lock and Enter keys...

 layout standardized with the introduction of the X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

 in 1984.

Layout

key action
Num Lock With Alt-Shift
Enable/Disable MouseKeys
8 cursor up
2 cursor down
6 cursor right
4 cursor left
7 cursor up and left
9 cursor up and right
3 cursor down and right
1 cursor down and left
/ select primary button
* select modifier button
- select alternate button
5 click selected button
Point-and-click
Point-and-click is the action of a computer user moving a cursor to a certain location on a screen and then pressing a mouse button, usually the left button , or other pointing device...

+ double click selected button
Double-click
A double-click is the act of pressing a computer mouse button twice quickly without moving the mouse. Double-clicking allows two different actions to be associated with the same mouse button...

0 depress selected button
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...

. release selected button
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...

Enter Enter Key
Enter key
In computer keyboards, the enter key in most cases causes a command line, window form, or dialog box to operate its default function...


History

Historically, MouseKeys supported GUI programs when many terminals had no dedicated pointing device
Pointing device
A pointing device is an input interface that allows a user to input spatial data to a computer...

. As pointing devices became ubiquitous, the use of mousekeys narrowed to situations where a pointing device was missing, unusable, or inconvenient. Such situations may arise from the following:
  • precision requirements (e.g., technical drawing
    Technical drawing
    Technical drawing, also known as drafting or draughting, is the act and discipline of composing plans that visually communicate how something functions or has to be constructed.Drafting is the language of industry....

    )
  • disabled user
    Accessibility
    Accessibility is a general term used to describe the degree to which a product, device, service, or environment is available to as many people as possible. Accessibility can be viewed as the "ability to access" and benefit from some system or entity...

     or ergonomics issues
  • environmental limits (e.g., vibration in car or plane)
  • broken equipment

MouseKeysAccel

parameter meaning
mk_delay milliseconds between the initial key press and first repeated motion event
mk_interval milliseconds between repeated motion events
mk_max_speed steady speed (in action_delta units) applied each event
mk_time_to_max number of events (count) accelerating to steady speed
mk_curve ramp used to reach maximum pointer speed


The X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

 MouseKeysAccel control applies action (usually cursor movement) repeatedly while a direction key
{1,2,3,4,6,7,8,9} remains depressed. When the key is depressed, an action_delta is immediately applied. If the key remains depressed, longer than mk_delay milliseconds, some action is applied every mk_interval milliseconds until the key is released. If the key remains depressed, after more than mk_time_to_max actions have been applied, action_delta magnified mk_max_speed times, is applied every mk_interval milliseconds.

The first mk_time_to_max actions increase smoothly according to an exponential.


mk_curve result
-1000 uniform speed, linearly increasing action
0 uniform acceleration, linearly increasing speed
1000 uniform jerk, linearly increasing acceleration


These five parameters are configurable.

Enabling

Under the X Window System
X Window System
The X window system is a computer software system and network protocol that provides a basis for graphical user interfaces and rich input device capability for networked computers...

s Xorg
X.Org Server
X.Org Server refers to the X server release packages stewarded by the X.Org Foundation,which is hosted by freedesktop.org, and grants...

 and XFree86
XFree86
XFree86 is an implementation of the X Window System. It was originally written for Unix-like operating systems on IBM PC compatibles and is now available for many other operating systems and platforms. It is free and open source software under the XFree86 License version 1.1. It is developed by the...

 used on Unix-like
Unix-like
A Unix-like operating system is one that behaves in a manner similar to a Unix system, while not necessarily conforming to or being certified to any version of the Single UNIX Specification....

 systems such as 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...

, BSD, and AIX, MouseKeys (and MouseKeysAccel) is nominally (de)activated by Alt+Shift+Num Lock. MouseKeys without acceleration (also known as plot mode) is sometimes available with Shift+NumLock. This is independent of the Window Manager
Window manager
A window manager is system software that controls the placement and appearance of windows within a windowing system in a graphical user interface. Most window managers are designed to help provide a desktop environment...

 in use and may be overridden by a configuration file
Configuration file
In computing, configuration files, or config files configure the initial settings for some computer programs. They are used for user applications, server processes and operating system settings. The files are often written in ASCII and line-oriented, with lines terminated by a newline or carriage...

.

MouseKeys for Apple Inc's 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...

 is enabled and configured via the Universal Access
Universal Access
Apple Universal Access is a component of the Mac OS X operating system that provides computing abilities to the blind, deaf, and handicapped.- Components :Universal Access is a preference pane of the System Preferences application...

 ([apple] => System Preferences => Universal Access => Mouse).

Microsoft
Microsoft
Microsoft Corporation is an American public multinational corporation headquartered in Redmond, Washington, USA that develops, manufactures, licenses, and supports a wide range of products and services predominantly related to computing through its various product divisions...

 changed the method of enabling between Windows 2000
Windows 2000
Windows 2000 is a line of operating systems produced by Microsoft for use on personal computers, business desktops, laptops, and servers. Windows 2000 was released to manufacturing on 15 December 1999 and launched to retail on 17 February 2000. It is the successor to Windows NT 4.0, and is the...

, Windows XP
Windows XP
Windows XP is an operating system produced by Microsoft for use on personal computers, including home and business desktops, laptops and media centers. First released to computer manufacturers on August 24, 2001, it is the second most popular version of Windows, based on installed user base...

 (added diagonal cursor movement and MouseKeysAccel), and Windows Vista
Windows Vista
Windows Vista is an operating system released in several variations developed by Microsoft for use on personal computers, including home and business desktops, laptops, tablet PCs, and media center PCs...

.
The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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