# Mouse

&Mike.McBride; &Mike.McBride.mail;
&Brad.Hards; &Brad.Hards.mail;
2018-03-25
Plasma 5.12

This is the documentation for the &systemsettings; module that configures mice and other pointing devices.

KDE
Systemsettings
mouse

## Mouse

This module allows you to configure your pointing device. Your pointing device may be a mouse, a track ball, a touch-pad, or another piece of hardware that performs a similar function.

This module is divided into several tabs: General, Advanced and Keyboard Navigation.

### General

Button Order

  If you are left-handed, you may prefer to swap the functions of the left and right buttons on your pointing device by choosing the Left handed option. If your pointing device has more than two buttons, only those that function as the left and right buttons are affected. For example, if you have a three-button mouse, the middle button is unaffected.

Reverse scroll direction

  With this check box selected, the scroll wheel (if any) will work in the opposite direction (so that if rolling the top of the scroll wheel towards you previously causes a scroll down, then it will now cause a scroll up). This may be useful to handle a unusual setup of the X server.

Double-click to open files and folders (select icons on first click)

  If this option is not checked, icons/files will be opened with a single click of the left mouse-button. This default behavior is consistent with what you would expect when you click links in most web browsers. If checked however, icons/files will be opened with a double click, while a single click will only select the icon or file. This is the behavior you may know from other desktops or operating systems.

Single-click to open files and folders

  This is the default setting. Clicking once on an icon will open it. To select you can drag around the icon(s) or &Ctrl;Right click, or simply click and hold to drag it.

### Advanced

Pointer acceleration

  This option allows you to change the relationship between the distance that the mouse pointer moves on the screen and the relative movement of the physical device itself (which may be a mouse, track-ball, or some other pointing device.)

  A high value for the acceleration multiplier will lead to large movements of the mouse pointer on the screen, even when you only make a small movement with the physical device.

  A multiplier between 1x and 3x will works well for many systems. With a multiplier over 3x the mouse pointer may become difficult to control.

Pointer threshold

  The threshold is the smallest distance that the mouse pointer must move on the screen before acceleration has any effect. If the movement is within the threshold, the mouse pointer moves as if the acceleration were set to 1x.

  Thus, when you make small movements with the physical device (&eg; mouse), you still have fine control of the mouse pointer on the screen, whereas larger movements of the physical device will move the mouse pointer rapidly to different areas on the screen.

  You can set the threshold by entering a value into the edit box or by clicking the up/down arrows to the right of the box.

  In general, the higher you set the Pointer acceleration value, the higher you will want to set the Pointer threshold value. For example, a Pointer threshold of 4 pixels may be appropriate for a Pointer Acceleration of 2x, but 10 pixels might be better for 3x.

Double click interval

  This is the maximum amount of time between clicks to register a double click. If you click twice, and the time between those two clicks is less than this number, that is recognized as a double click. If the time between these two clicks is greater than this number, it is recognized as two separate single clicks.

Drag start time and Drag start distance

  If you

  - click with the mouse

  - drag within the time specified in Drag start time, and

  - move a distance equal to or greater than the number (of pixels) specified in Drag start distance

  the selected item will be dragged.
Mouse wheel scrolls by

  If you have a wheel mouse, use the spin box to determine how many lines of text one step of the mouse wheel will scroll.

### Keyboard Navigation

This tab allows you to configure the keyboard number pad keys as a mouse-type device. This may be useful when you are working on a device without another pointing device, or where you have no other use for the number pad.

Move pointer with keyboard (using the num pad)

  To enable keyboard mouse mode, you need to select the check box labeled Move pointer with keyboard (using the num pad). When you do this, the other settings will become enabled, and you can customize the keyboard pointer behavior further, if required.

  The various keys on the number pad move in the direction you would expect. Note that you can move diagonally as well as up, down, left and right. The 5 key emulates a click to a pointer button, typically &LMB;. You change which button is emulated by using the / key (which makes it &LMB;), * key (which makes it &MMB;) and - (which makes it &RMB;). Using the + emulates a double click to the selected pointer button. You can use the 0 key to emulate holding down the selected pointer button (for easy dragging), and then use the . to emulate releasing the selected pointer button.

Acceleration delay

  This is the time (in milliseconds) between the initial key press and the first repeated motion event for mouse key acceleration.

Repeat interval

  This is the time in milliseconds between repeated motion events for mouse key acceleration.

Acceleration time

  This is the time in milliseconds before the pointer reaches a maximum speed for mouse key acceleration.

Maximum speed

  This is the maximum speed in pixels per second the pointer can reach for mouse key acceleration.

Acceleration profile

  This is the slope of the acceleration curve for mouse key acceleration.