UbuntuHelp:Accessibility/doc/Guide
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目录
Accessibility Guide
Ubuntu aims at making the operating system, and its derivatives, usable by as many people as possible across ages, languages and physical abilities. This includes providing an accessible platform with high quality assistive tools, and ensuring that other applications work well with these. The assistive tools on Ubuntu, along with the entire operating system, are provided free of charge.
Speech and magnification
built into Gnome desktop is Orca, a screen reading and magnification software
What is Orca?
Orca is a free, open source, flexible, extensible, and powerful assistive technology for people with visual impairments. Using various combinations of speech synthesis, braille, and magnification, Orca helps provide access to applications and toolkits that support the AT-SPI (e.g., the GNOME desktop). The development of Orca has been led by the Accessibility Program Office of Sun Microsystems, Inc. with contributions from many community members.
how to start Orca?
Live CD
Once you've downloaded and burned the live CD image, insert it into your CD/DVD drive and reboot your computer. You should find that your drive spins for a short while and then stops. The point at which it stops coincides with the appearance of the boot options screen.
At this point, you have about 30 seconds to perform the next step. If you do not perform the next step quickly, Ubuntu will automatically continue booting.
In order to enable accessibility options, press F5. This will cause a list of accessibility options to appear:
- None (has focus)
- High Contrast
- Magnifier
- Screen Reader
- Keyboard Modifiers
- On Screen Keyboard
If you want to try Orca, you should press 3 to give focus to Screen Reader, followed by Enter to indicate your selection. You'll be returned to the boot options screen. Press Enter again to indicate you would like to boot.
Within a few minutes, Ubuntu will be loaded with Orca running and you will hear a greeting such as "Welcome to Orca. Orca Preferences. Tab list. General page." The CD drive should also stop spinning at this point. If the CD drive stopped spinning and you didn't hear a greeting from Orca, you might need to try to reboot from the CD and repeat the steps for selecting the Screen Reader.
Now, the graphical desktop is up and running, Orca is active, and the Orca Preferences dialog has focus. The Orca Preferences dialog is a multi-page dialog with several pages that allows you to configure your settings.
Installed Ubuntu
if you have ubuntu installed, you can run orca through the run window (alt+f2) or gnome-terminal by typing "orca"
High Contrast
Ubuntu ships with a selection of high contrast themes, complete with custom icons and mouse cursors. To activate a new theme go to the System menu, followed by Preferences -> Theme.
Keyboard modifiers
The Gnome desktop environment supports several options for modifying the behaviour of the mouse and keyboard. The modifier keys (Shift, Ctrl and Alt) can be made Sticky so that when they are pressed once they remain active until the next key is pressed, making it possible to write upper case character or use keyboard shortcuts while only pressing one key at a time.
Other features include Slow Keys and Bounce Keys which control the reaction rate and repeat rate of keys and Mouse Keys which allow the numeric keypad to be used to control the mouse cursor. These features can be activated on the Keyboard Accessibility panel (from System -> Preferences -> Keyboard).
On-screen Keyboard
Ubuntu 6.10 includes the onBoard on-screen keyboard, a lightweight text-entry application, extensible through macros, scripts and custom layouts.
Also available is Gnome On-screen Keyboard (GOK), which in addition to basic text entry, also provides facilities for controlling the entire desktop behaviour through the on-screen keyboard by gathering information about other applications and sending them control signals through the Gnome assistive technology framework AT-SPI.
Activating pre-installed tools
If you install the Ubuntu system after booting the Ubuntu Desktop CD with an accessibility option
as described above, those features will also be pre-configured to start by default on your newly installed system.
The most common accessibility tools such as Orca and onBoard are pre-installed on any standard Ubuntu system and are easy to activate. The screen reader, magnifier and on-screen keyboard are all activated using the Gnome Assistive Technology Preferences panel, Found in the System menu under Preferences.
