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Mouse keys

{{Short description|Feature of some graphical user interfaces that uses the keyboard as a pointing device}}

Mouse keys is a feature of some graphical user interfaces that uses the keyboard (especially numeric keypad) as a pointing device (usually replacing a mouse). Its roots lie in the earliest days of visual editors when line and column navigation was controlled with arrow keys.

Today, mouse keys usually refers to the numeric keypad layout standardized with the introduction of the X Window System in 1984.[https://www.xfree86.org/current/XKBproto.pdf The X Keyboard Extension: Protocol Specification][https://www.xfree86.org/current/XKBlib.pdf The X Keyboard Extension: Library Specification]

Layout

Image:X window system MouseKeys default numpad layout.svg

class="wikitable"
key

! action

{{Key press|Num Lock}}

| with {{Key press|Alt|Shift}}

enable/disable MouseKeys

{{Key press|8}}

| cursor up

{{Key press|2}}

| cursor down

{{Key press|6}}

| cursor right

{{Key press|4}}

| cursor left

{{Key press|7}}

| cursor up and left

{{Key press|9}}

| cursor up and right

{{Key press|3}}

| cursor down and right

{{Key press|1}}

| cursor down and left

{{Key press|/}}

| select primary button

{{Key press|*}}

| select modifier button

{{Key press
}}

| select alternate button

{{Key press|5}}

| click selected button

{{Key press|+}}

| double click selected button

{{Key press|0}}

| depress selected button

{{Key press|.}}

| release selected button

{{Key press|Enter}}

| enter key

History

Historically, MouseKeys supported GUI programs when many terminals had no dedicated pointing device. As pointing devices became ubiquitous, the use of mouse keys 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)
  • disabled user or ergonomics issues
  • environmental limits (e.g., vibration in car or plane)
  • broken/missing/unavailable equipment

In 1987, Macintosh Operating System 4.2 Easy Access provided MouseKeys support to all applications. Easy access was (de)activated by clicking the {{Key press|shift}} key five times.{{citation needed|date=August 2024}}

By the early 2020s, with graphics tablets becoming more common, a configuration change may be required before enabling MouseKeys.{{citation needed|date=August 2024}}

MouseKeysAccel

Image:X Protocol MouseKeysAccel Control Trajectory.svg

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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 MouseKeysAccel control applies action (usually cursor movement) repeatedly while a direction key {1,2,3,4,6,7,8,9} remains depressed.The X Keyboard Extension: Library Specification, Library Version 1.0/Document Revision 1.1, X Consortium Standard, X Version 11 / Release 6.4, Keyboard Controls, 10.5.2, [https://www.x.org/releases/X11R7.6/doc/libX11/specs/XKB/xkblib.html#the_mousekeysaccel_control The MouseKeysAccel Control] 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.

\mathrm{action\_delta} \times \mathrm{mk\_max\_speed} \times \left(

\frac{ i } { \mathrm{mk\_time\_to\_max} } \right)

^{\frac{ 1000 + \mathrm{mk\_curve} } { 1000 }}

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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.[http://library.gnome.org/users/gnome-access-guide/stable/dtconfig-mousekeys.html.en GNOME Documentation Library, Configuring a Keyboard-Based Mouse] {{webarchive|url=https://web.archive.org/web/20100612115254/http://library.gnome.org/users/gnome-access-guide/stable/dtconfig-mousekeys.html.en |date=2010-06-12 }}

Enabling

Under the X Window Systems X.Org and XFree86 used on Unix-like systems such as Linux, BSD, and AIX, MouseKeys (and MouseKeysAccel), when available, is nominally (de)activated by {{key press|Alt}}+{{key press|Shift}}+{{key press|Num Lock}}.The X Keyboard Extension: Library Specification, Library Version 1.0/Document Revision 1.1, X Consortium Standard, X Version 11 / Release 6.4, Keyboard Controls, 10.5.1, [https://www.x.org/releases/X11R7.6/doc/libX11/specs/XKB/xkblib.html#the_mousekeys_control The MouseKeys Control] MouseKeys without acceleration (also known as plot mode) is sometimes available with {{key press|Shift}}+{{key press|Num Lock}}. This is nominally independent of the window manager in use, but may be overridden, or even made unavailable by a configuration file.

Before enabling, it may be necessary to change system configuration. The [https://www.x.org/archive/X11R7.7/doc/man/man1/setxkbmap.1.xhtml setxkbmap] utility can be used to change the configuration under Xorg:{{cite web |url=https://manpages.ubuntu.com/manpages/jammy/en/man7/xkeyboard-config.7.html |title=xkeyboard-config manual page |date=2012 |access-date=15 March 2015}}

setxkbmap -option keypad:pointerkeys

There are also various utilities to allow more precise control via user-configurable key bindings, such as [https://beesbuzz.biz/code/269-xmousekeys xmousekeys] and [https://www.semicomplete.com/projects/xdotool/ xdotool].

Since KDE 5, MouseKeys is enabled and configured by systemsetting5[https://docs.kde.org/trunk5/en/systemsettings/systemsettings/general.html KDE.org, Using System Settings, System Settings Categories and Modules] (Hardware → Input Devices → Mouse → Keyboard Navigation)

MouseKeys for Apple Inc.'s macOS is enabled and configured via the Accessibility[https://www.apple.com/accessibility/macosx/physical.html Apple.com, Mac OS X, Accessibility] ([apple] → System Preferences → Accessibility → Mouse & Trackpad).

Microsoft changed the method of enabling between Windows 2000,Microsoft.com, Accessibility Tutorials, Windows 2000, [http://www.microsoft.com/enable/training/windows2000/default.aspx Turning MouseKeys On and Off] Windows XP (added diagonal cursor movement and MouseKeysAccel),Microsoft.com, Accessibility Tutorials, Windows XP, [http://www.microsoft.com/enable/training/windowsxp/mousekeys.aspx MouseKeys: Control the Mouse Pointer Using the Numeric Keypad] and Windows Vista.Microsoft.com, Accessibility Tutorials, Windows Vista, [http://www.microsoft.com/enable/training/windowsvista/mousekeys.aspx Control the mouse pointer with the keyboard (Mouse Keys)]

Common usage

=Replacing the mouse keys=

Replacing the mouse keys by the numeric keypad is as follows:

Typing {{key press|5}} (with the numeric keypad) is equivalent to clicking the selected button. By default, the selected button is the primary button (nominally under index finger, left button for most right-handed people and right button for most left-handed people). Typing {{key press|-}} (with the numeric keypad) selects the alternate button (nominally under ring finger, right button for most right-handed people and left button for most left-handed people). Typing {{key press|*}} (with the numeric keypad) selects the modifier button (nominally under the middle finger, middle button of a 3-button mouse). Typing {{key press|/}} (with the numeric keypad) selects the primary button. The selection remains in effect until a different button is selected.

Assignment of left/middle/right button to primary/modifier/alternate, alternate/modifier/primary, or something else is settable by many means. Some mice have a switch, that swaps assignment of right and left keys. Many laptop bioses have a setting for mouse button assignment. Many window managers have a setting that permutes the assignment. Within the X Window System core protocol, permutation can be applied by [https://www.x.org/archive/X11R7.7/doc/man/man1/xmodmap.1.xhtml xmodmap].

=Moving the pointer by keys=

Other than {{key press|5}}, all other numeric keys from the numeric keypad are used to move the pointer on the screen. For example, {{key press|8}} will move the pointer upwards, while {{key press|1}} will move it diagonally downwards to the left.

See also

  • {{annotated link|FilterKeys}}
  • {{annotated link|Sticky keys}}
  • {{annotated link|ToggleKeys}}
  • {{annotated link|Virtual keyboard}}

References

{{Reflist}}

{{DEFAULTSORT:Mouse Keys}}

Category:Computer accessibility

Category:Computing input devices

Category:User interface techniques

Category:Ergonomics