# Mobility Impairments

Mobility impairments can be caused by arthritis, stroke, cerebral palsy, Parkinson's disease, multiple sclerosis, and loss of limbs or digits, among others. Poor muscle control or weaknesses can make using standard keyboards and mouse devices difficult. For instance, some people are unable to type two keys simultaneously, while others tend to hit multiple keys or to bounce keys when pressing or releasing them. People who are able to use only one hand likewise have difficulties with some keyboard and mouse tasks.

The technologies which can assist those with mobility impairments are:

- On-Screen Keyboard - lets users select keys using a pointing method such as pointing devices, switches, or Morse-code input systems.

- Mouse and Keyboard Enhancements - helpful for users who have trouble typing and controlling a mouse or a keyboard.

## On-Screen Keyboard

The On-Screen Keyboard application displays virtual keyboards on your desktop. You can use the standard mouse pointer or alternative pointing device to operate the virtual keyboards. On-Screen Keyboard displays the following types of keyboards:

- Compose keyboards that enable you to compose text. To type alphanumeric characters, you select the characters on the compose keyboard.

- Dynamic keyboards that On-Screen Keyboard generates to reflect the applications that are currently running on the desktop. For example, On-Screen Keyboard generates keyboards that contain keys to represent the applications that are running on your desktop or the menus that are contained in an application.

To start On-Screen Keyboard, choose Applications Accessibility On-Screen Keyboard. For more information about the On-Screen Keyboard application, see the Help for On-Screen Keyboard.

### Maximizing Application Windows for On-Screen Keyboard Users

If you are an On-Screen Keyboard user, you cannot use any application in Full Screen mode because the application window obscures the On-Screen Keyboard display.

To resize the window for use with the On-Screen Keyboard application, perform the following steps:

1. Do not enable the Full Screen mode in the application.

2. Give focus to the application window.

3. Press F10 to maximize the application.

## Mouse and Keyboard Enhancements

This section describes how to configure the mouse and keyboard to make these devices accessible to more users.

### Configuring the Mouse

Use the Mouse preference tool to configure the mouse to suit your needs. To open the Mouse preference tool, choose System Preferences Mouse. The Mouse Preferences dialog is displayed.

#### To Configure the Behavior of the Mouse

The following sections describe how to modify the behavior of the mouse to suit your needs.

##### To Configure the Mouse for Left-Handed Use

To configure the mouse for left-handed use, click on the Buttons tab in the Mouse Preferences dialog, then select the Left-handed mouse option. When you select this option, the system swaps the functions of the left mouse button and the right mouse button immediately.

##### To Configure the Double-Click Behavior

If you have difficulty double-clicking, you can increase the period of time that the system allows to elapse between the first click and the second click of a double-click. For example, if the double-click timeout setting is 0.4 seconds, you must perform the second click of a double-click within 0.4 seconds of the first click. If the second click occurs more than 0.4 seconds after the first click, the system interprets the two clicks as two single clicks.

To configure the double-click timeout setting, perform the following steps:

1. Click on the Buttons tab in the Mouse Preferences dialog.

2. Use the Timeout slider to specify the timeout in seconds that the system allows between the two clicks of a double-click. Moving the slider to the right will increase the timeout interval in 0.1 second intervals. In the same manner, moving the slider to the left will decrease the timeout in 0.1 second intervals.

3. Double-click on the light bulb to the right of the slider to test the setting. If you perform the two clicks of the double-click within the timeout specified, the light bulb lights up fully to display a yellow glow around the bulb. If you do not double-click within the timeout specified, the light bulb does not light fully. You should increase the timeout setting and try again. When the light bulb lights, the timeout setting is suitable for your needs.

##### To Change the Size of the Mouse Pointer

To change the size of the mouse pointer that is displayed on the desktop, perform the following steps:

1. Click on the Pointers tab in the Mouse Preferences dialog.

2. This will display a list of pointer themes and sizes available.

3. By default, GNOME does not include mouse pointer themes. Information about installing and using pointer themes can be found in the User Guide.

On some platforms you must log out and log in again for this setting to take effect.

##### To Locate the Mouse Pointer

If you have difficulty locating the mouse pointer on the screen, you can enable an option to highlight the pointer when you press the Control key. To enable this option, click on the Pointers tab in the Mouse Preferences dialog, then select the Highlight the pointer when you press Ctrl option. When you press Control, the system displays an animation around the pointer to highlight the pointer.

On some platforms, you must log out and log in again before this setting takes effect.

##### To Configure the Speed and Sensitivity of the Mouse

To configure the speed and sensitivity of the mouse, perform the following steps:

1. Click on the Motion tab in the Mouse Preferences dialog.

2. Configure the following options:

   Acceleration

     Use the slider to specify the speed at which the mouse pointer moves around the screen when you move your mouse.

     If you select a low setting, the mouse pointer moves at a speed similar to the speed at which you are physically moving the mouse. This means that you need to physically move the mouse larger distances to cover the screen area. If you select a high setting, the mouse pointer moves at a faster speed than the speed at which you physically move the mouse. This means that you need to physically move the mouse small distances to cover the screen area.

   Sensitivity

     Use the slider to specify how responsive the mouse pointer is to movements of your mouse. Moving the slider to the right will increase the sensitivity and moving it to the left will decrease the sensitivity.

   Threshold

     Use the slider to specify the distance that you must move an item before the system interprets the move action as a drag-and-drop action.

#### To Configure the Cursor

The following section describes how to modify the display characteristics of the cursor.

##### To Stop the Cursor Blinking

To stop the cursor blinking in text boxes and fields, perform the following steps:

1. Choose System Preferences Keyboard to start the Keyboard preference tool.

2. In the Keyboard tabbed section, deselect the Cursor blinks in text boxes and fields option.

#### To Use the Keyboard to Emulate the Mouse

If you have difficulty using a mouse, you can use the keyboard to emulate the mouse functions. See of this guide for more information.

### Configuring the Keyboard

Use the Keyboard preference tool, to configure the keyboard accessibility options. To open the Keyboard preference tool, choose System Preferences Keyboard. Accessibility options can be enabled by selecting Accessibility. This will open a new dialog, Keyboard Accessibility Preferences, also known as AccessX.

The Keyboard Accessibility Preferences (AccessX) dialog enables you to customize your keyboard in the following ways:

- To use the numeric keypad to emulate mouse actions. See .

- To specify the duration for which you must press-and-hold a key before the system accepts the keypress. See .

- To ignore rapid, repeated keypresses of the same key. See .

- To accept key combinations in sequence rather than simultaneously. See .

- To emit an audible notification when a user activates or deactivates a toggle key. See .

- To ignore long keypresses of the same key and control the repeat rate of a keypress. See .

#### To Activate the Keyboard Accessibility Options

To activate the keyboard accessibility options, perform the following steps:

1. Choose System Preferences Keyboard and select Accessibility

2. Select the Enable keyboard accessibility features option.

3. Click on the Basic tab.

4. Select the Beep when features turned on or off from keyboard option to receive an audible notification each time a user enables or disables a keyboard accessibility option using the following keyboard shortcuts:

   - Press-and-hold Shift for eight seconds to enable or disable the slow keys feature.

   - Press Shift five times to enable or disable the sticky keys feature.

5. To automatically disable the keyboard accessibility options if the options are not used for a specified number of seconds, select the Disable if unused for X seconds option. Use the slider to specify the number of seconds of keyboard idle time required before the system disables the keyboard accessibility options.

   This option is intended for computers that are shared by a number of different users, some of whom require the keyboard accessibility options.

6. Changes made will be instantly applied.

#### To Enable the Keyboard to Emulate the Mouse

The mouse keys feature enables you to use the numeric keypad on the keyboard to emulate mouse actions. This feature benefits users who have difficulty using a mouse or other pointing device. To enable and configure the mouse keys feature, perform the following steps:

1. In the Keyboard Accessibility Preferences (AccessX) dialog, select the Mouse Keys tab.

2. Select the Enable Mouse Keys option.

3. Configure the following options to determine the behavior of the mouse pointer when you control the pointer from the numeric keypad:

   Maximum pointer speed

     Use this spin box to specify the maximum speed, in pixels per second, at which the pointer moves around the screen.

   Time to accelerate to maximum speed

     Use this spin box to specify the duration, in milliseconds, before the pointer accelerates to the maximum pointer speed.

   Delay between keypress and pointer movement

     Use this spin box to specify the interval, in milliseconds, between a keypress and the time when the pointer starts to move.

When you enable mouse keys, the keys on the numeric keypad have the following functions:

##### Numeric Keypad to Mouse Function Mapping

Numeric Keypad Keys | Function
--- | ---
1, 2, 3, 4, 6, 7, 8, 9 | Move the mouse pointer around the screen
5 | Mouse button click
0 | Mouse button toggle
/ | Primary mouse button
* | Secondary mouse button
- | Tertiary mouse button

The toggle mouse button key enable the currently selected mouse button until the Mouse button click key is pressed. This allows you to perform drag and drop operations.

The Mouse button click emulates the currently selected mouse button. Pressing /, * or - will change the behaviour of this. The currently selected mouse button can be seen in the Keyboard Accessibility Status panel application, discussed in .

The Primary mouse button is the left mouse button for right handed people. The Secondary mouse button is the right mouse button and the Tertiary mouse button is the middle mouse button.

Some Solaris systems also use the function keys to emulate the mouse buttons. The common function key to mouse button mappings are described in the following table.

##### Function Key to Mouse Function Mapping on Solaris Systems

Function Key | Function
--- | ---
F2 | Mouse button 1
F3 | Mouse button 2
F4 | Mouse button 3

#### To Enable the Slow Keys Feature

The slow keys feature enables you to customize how the keyboard handles user input in the following ways:

- Specify the duration for which you must press-and-hold a key before the system accepts the keypress. This aspect of the feature benefits users who frequently press keys that they do not intend to press.

- Enable audible indications of keyboard input and acceptance. This aspect of the feature benefits users who cannot see the result of a keypress.

To enable and configure the slow keys feature, perform the following steps:

1. From the Keyboard Accessibility Preferences (AccessX) dialog, select the Filters tab.

2. Select the Enable Slow Keys option.

   To select or deselect the slow keys feature from the keyboard, press-and-hold Shift for eight seconds. This will present a dialog confirming that you with slow keys enabled. The Shift keyboard shortcut automatically selects all of the slow keys options. If you selected the Beep when features turned on or off from the keyboard option in the Basic tab, after four seconds the system beeps three times to indicate that the system is about to select or deselect the feature.

3. Use the Only accept keys held for slider or spin box to specify the duration, in milliseconds, for which you must press-and-hold a key before the system accepts the keypress. Use the Type to test settings text box to test the slow keys setting and modify the setting as required.

4. To enable audible indications of keyboard input and acceptance, select the following options:

   Beep when key is pressed

     Select this option to hear a beep when you press a key.

   Beep when key is accepted

     Select this option to hear a beep when the system accepts a keypress.

   Beep when key is rejected

     Select this option to hear a beep when the system rejects a keypress. The system rejects a keypress if you do not press-and-hold the key for the duration that is specified in the Only accept keys held for spin box.

#### To Enable the Bounce Keys Feature

The bounce keys feature enables you to customize the keyboard to ignore rapid, repeated keypresses of the same key. For example, users with impaired motor skills might press the same key several times when they intend to press the key once. This feature enables you to customize the keyboard to ignore repeated keypresses.

To enable and configure the bounce keys feature, perform the following steps:

1. From the Keyboard Accessibility Preferences (AccessX) dialog select the Filters tab.

2. Select the Enable Bounce Keys option.

3. Use the Ignore duplicate keypresses within slider or spin box to specify the duration in milliseconds (ms) after the first keypress for which the system ignores repeated keypresses of the same key. For example, if you select a duration of 500 ms, the system ignores all repeated keypresses of the same key that occur within 500 ms of the first keypress.

4. Select the Beep if key is rejected option to hear an audible indication when the system ignores a key.

If you want to enable the bounce keys feature, ensure that the Enable Slow Keys option is deselected. The slow keys feature requires you to press a key for a specified duration before the system accepts the keypress as a valid keypress. If you cannot press the key for the duration that is specified by the slow keys setting, deselect the Enable Slow Keys option to enable the system to accept your input.

#### To Enable the Sticky Keys Feature

The sticky keys feature enables you to press the keys in a key combination in sequence rather than simultaneously. This feature is designed for users who are unable to press two or more keys simultaneously.

To enable and configure the sticky keys feature, perform the following steps:

1. From the Keyboard Accessibility Preferences (AccessX) select the Basic tab.

2. Select the Enable Sticky Keys option.

   To enable the sticky keys feature from the keyboard, press Shift five times. This will present a dialog confirming that you with to enable sticky keys. The Shift keyboard shortcut automatically selects all of the sticky keys options. If you selected the Beep when features turned on or off from the keyboard option, the system beeps to indicate that the system is about to select or deselect the feature. When active, pressing shift five times in a row will present a dialog asking if you want to disable sticky keys.

3. Select the Beep when modifier is pressed option to receive an audible indication each time you press a modifier key such as Ctrl, Alt, or Shift. This option is useful to remind you whether a modifier key is active or inactive.

4. Selecting the Disable if two keys pressed together option will present a dialog with the option to disable sticky keys if two keys are pressed at the same time.

You can use the sticky keys feature in latch or lock mode. The following table describes how to choose a mode and the difference between the two modes.

##### Sticky Keys Latch or Lock Mode

To use the sticky keys feature in... | Press the modifier key... | The modifier key remains active until...
--- | --- | ---
Latch mode | Once. | You press a non-modifier key.
Lock mode | Twice in quick succession. | You press the modifier key again.

Example 1: If you want to press AltF1, do the following:

1. Press Alt to latch the modifier key. The Alt key remains active.

2. Press F1. The key combination is now complete. After you press F1, the Alt modifier key is no longer active.

Example 2: If you want to press CtrlAltTab, do the following:

1. Press Ctrl twice to lock the modifier key. The Ctrl key remains active.

2. Press Alt.

3. Press Tab. The key combination is now complete.

4. To unlock the modifier key, press Ctrl again.

#### To Enable Audible Notifications for Toggle Keys

A toggle key is any key on the keyboard that can switch between two states. The Num Lock, Caps Lock, and Scroll Lock keys are toggle keys. Most toggle keys have an associated light emitting diode (LED) on the keyboard that lights when the toggle key is active. To assist users with visual impairments, you can customize the keyboard to emit an audible notification when a user presses a toggle key. For example, when you press Num Lock, you can determine whether the key is toggled or not toggled by the sound that the keyboard emits.

To enable accessible toggle keys, perform the following steps:

1. From the Keyboard Accessibility Preferences (AccesX) select the Filters tab.

2. Select the Enable Toggle Keys option.

When you activate the Num Lock, Caps Lock, or Scroll Lock keys, the system beeps once. When you deactivate a toggle key, the system beeps twice.

#### To Enable the Repeat Keys Feature

The repeat keys feature enables you to repeat a keystroke multiple times without pressing the key more than once. This feature is designed for users who cannot release keys quickly, for example users who operate a mouth stick. When you enable repeat keys, you can specify the duration for which you must press a key before the key starts to repeat.

To enable and configure the repeat keys feature, perform the following steps:

1. From the Keyboard Accessibility Preferences (AccessX) select the Basic tab.

2. Select the Enable Repeat Keys option.

3. Use the Delay slider or spin box to specify the duration for which you must press a key before the keyboard interprets the action as a repeat key. If you have difficulty releasing keys, select a long time delay.

4. Use the Speed slider or spin box to specify the speed at which the keyboard repeats the keypress as input.

### Using the Keyboard Accessibility Status Panel Application

The Keyboard Accessibility Status panel application shows you the status of the keyboard accessibility features. This panel application displays icons to indicate which keyboard accessibility features are enabled in the Keyboard Accessibility preference tool.

To add the Keyboard Accessibility Status panel application to a panel, right-click on the panel, then choose Add to Panel and select the Keyboard Accessibility Status.

The following table describes the icons that the panel application displays and the status that each icon represents.

#### Keyboard Accessibility Status Icons

Icon | Keyboard Accessibility Status
--- | ---
Keyboard Accessibility Features enabled icon | Keyboard accessibility in general is available but none of the individual key features are enabled.
Bounce keys enabled icon | The bounce keys feature is enabled.
Mouse keys enabled icon | The mouse keys feature is enabled. The dot in the mouse button shows which button is currently associated with the Mouse button click key.
Slow keys enabled icon | The slow keys feature is enabled.
Alt key latched icon | The sticky keys feature is enabled and the Alt key is latched.
Alt key locked icon | The sticky keys feature is enabled and the Alt key is locked.
Ctrl key latched icon | The sticky keys feature is enabled and the Ctrl key is latched.
Ctrl key locked icon | The sticky keys feature is enabled and the Ctrl key is locked.
Shift key latched icon | The sticky keys feature is enabled and the Shift key is latched.
Shift key locked icon | The sticky keys feature is enabled and the Shift key is locked.
Super/Windows key latched icon | The sticky keys feature is enabled and the Super/Windows key is latched.
Super/Windows key locked icon | The sticky keys feature is enabled and the Super/Windows key is locked.