Showing posts with label universal access. Show all posts
Showing posts with label universal access. Show all posts

Thursday, December 8, 2016

Assistive Technologies: partial list of the files, terms, and utilities used

Assistive Technologies: partial list of the files, terms, and utilities used



The following is a partial list of the files, terms, and utilities used:  


Sticky/repeat keys 
  StickyKeys
  Allows users to lock modifier keys such as ctrl and shift. This enables them to complete keyboard tasks with just   one finger that would normally require two or more fingers.



Slow/bounce/toggle keys 
  SlowKeys 
  Configures the keyboard such that the user must hold a key down for a specified period of time      before the keystroke   is actually sent. This helps the user avoid sending accidental keystrokes.


   BounceKeys and DelayKeys 
   Inserts a slight delay between keystrokes to prevent the keyboard from sending unintentional              keystrokes.

   ToggleKeys 
    Sounds an audible alert if either the caps lockkey or the num lock key is on


Mouse keys  
  Enables key sequences to be used to move the mouse cursor on the screen and to send mouse      clicks.


High-contrast/large-print  desktop themes 
  The last visibility accessibility option we’re going to look at here involves high-contrast, large-text    desktop  themes. In the Universal Access panel, enable the High Contrast and Large Text options  under Seeing.


Screen reader 
  One option available to visually impaired users is a screen reader, which “reads” the text displayed on the screen    audibly for the user. Some screen readers can use your computer’s sound interface, whereas others require special   speech synthesizer hardware. The Orca application is probably the most commonly used   screen reader.


Braille display 
  Visually impaired Linux users can also use Braille hardware devices. Several types of Braille displays and       embossers are supported. To interface with these types of devices, the Linux system must be running the brltty   daemon.


Screen magnifier 
  A screen magnifier allows visually impaired users to magnify areas of the screen as if they were using a real       magnifying glass. You can choose from a wide variety of screen magnifiers, including Orca, GNOME Magnifier, and KDE   Magnifier. Of these, Orca is probably the most popular, primarily because it can function   as both a screen reader   and a screen magnifier.


Onscreen keyboard 
  For physically impaired users who aren’t able to use a traditional keyboard, Linux provides the option of using an    onscreen keyboard, which allows users to use any pointing device (such as a mouse) to select keys on a virtual     keyboard.


Gestures (used at login; for example, gdm) 
  GDM supports "Accessible Login" to allow users to log in to their desktop session even if they cannot easily use     the screen, mouse, or keyboard in the usual way. This feature allows the user to launch assistive technologies at     login time by means of special "gestures" from the standard keyboard and from a keyboard, pointing device, or     switch device attached to the USB or PS/2 mouse port. It also allows the user to change the visual appearance of     the login UI before logging in, for instance to use a higher-contrast color scheme for better visibility. GDM only    supports accessibility with the Standard Greeter, so the "Greeter" parameter in gdm.conf must be set to the     Standard Greeter "gdmlogin".


Orca 
  Orca is a free and open source, flexible, extensible screen reader from the GNOME project for individuals who are     blind or visually impaired.


OK 
  Onscreen keyboard
  Commonly used onscreen keyboard applications include GOK (GNOME Onscreen Keyboard) and GTkeyboard



emacspeak 
  emacspeak :Screen reader, text-based terminal screens





LX0-104 Exam Objectives (J)

X Windows: Braille Devices

X Windows

Assistive Technologies V

Braille Devices 

Visually impaired Linux users can also use Braille hardware devices. Several types of Braille displays and embossers are supported. To interface with these types of devices, the Linux system must be running the brltty daemon.



The Orca utility mentioned earlier can be used to support Braille devices. Start Orca by searching for Orca and selecting its icon. Then select the Braille tab in the Orca preferences.



Configure the following Braille options, as appropriate for your preferences and for your Braille devices:



Enable Braille Support: Configure Orca to use a Braille display.


Enable Braille Monitor: Configure a Braille monitor on the regular display, which allows you to visually observe      what’s happening on the Braille display device.


Enable Contracted Braille: Use contracted Braille.


Abbreviated Role Names: Abbreviate role names on the Braille display.


Disable End of Line Symbol: Do not send the $l end-of-line characters to the Braille display.


Verbosity: Controls the level of information to be sent to the Braille display.


Selection Indicator: How selected text on the screen will be underlined on the Braille display.


Hyperlink Indicator: How hypertext on the screen will be underlined on the Braille display.




Select OK to save your changes to the Orca Braille configuration





LX0-104 Exam Objectives (J)

X Windows: Screen Magnifiers

X Windows

Assistive Technologies IV

Screen Magnifiers 

A screen magnifier allows visually impaired users to magnify areas of the screen as if they were using a real magnifying glass. You can choose from a wide variety of screen magnifiers, including Orca,  GNOME Magnifier, and KDE Magnifier.

Of these, Orca is probably the most popular, primarily because it can function as both a screen reader and a screen magnifier.



You can start Orca from the shell prompt by entering orca –e magnifier.To configure a screen magnifier, do the following:


1. Access the Universal Access panel and select Zoom.


2. Configure the following magnification options:

    • Magnification: The level of magnification to be used

    •  Magnifier position: The size and color of the magnifier’s cursor

    •  Crosshairs Settings: The magnifier’s area-targeting cursor

    • Color Effects Settings: The color of the magnified region



3. When you’re done, select  Close 





LX0-104 Exam Objectives (J)

X Windows: Screen Readers

X Windows

Assistive Technologies III

Screen Readers 

One option available to visually impaired users is a screen reader, which “reads” the text displayed on the screen audibly for the user. Some screen readers can use your computer’s sound interface, whereas others require special speech synthesizer hardware.


The Orca application is probably the most commonly used screen reader. Unlike many other screen readers,  Orca can read text from the GNOME desktop. Many other screen readers, such as emacspeak, only work with text-based terminal screens.



To configure a screen reader, open Universal Access and then click Screen Reader.



LX0-104 Exam Objectives (J)

X Windows: High-Contrast, Large-Text Desktop Themes

X Windows

Assistive Technologies II

High-Contrast, Large-Text Desktop Themes 

The last visibility accessibility option we’re going to look at here involves high-contrast, large-text
desktop themes. In the Universal Access panel, enable the High Contrast and Large Text options

under Seeing. These options were shown earlier in Figure 7-11.

Let’s practice working with Accessibility Settings in the following exercise.






LX0-104 Exam Objectives (J)

X Windows: Keyboard Accessibility

X Windows

Assistive Technologies I

Keyboard Accessibility


These settings are designed to enable physically impaired users to use
a traditional keyboard. You can configure the following:



1) StickyKeys Allows users to lock modifier keys such as ctrl and
   shift. This enables them to complete keyboard tasks with just one
   finger that would normally require two or more fingers.


2) MouseKeys Enables key sequences to be used to move the mouse cursor
   on the screen and to send mouse clicks.


3) SlowKeys Configures the keyboard such that the user must hold a key
   down for a specified period of time before the keystroke is actually
   sent. This helps the user avoid sending accidental keystrokes.


4) ToggleKeys Sounds an audible alert if either the caps lock key or
   the num lock key is on.

5) RepeatKeys Configures the keyboard to allow the user extra time to
   release a pressed key before sending multiple keystrokes.


6) BounceKeys and DelayKeys Inserts a slight delay between keystrokes
   to prevent the keyboard from sending unintentional keystrokes.




To configure AccessX settings, access Universal Access and select the
option to configure keyboard preferences. For example, on a Fedora
system, you would select Typing Assist (AccessX) under Typing.






LX0-104 Exam Objectives (J)