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Development of Accessible E-documents and Programs for Visually Impaired. Using pc without visual control. 0. What do you think?. How can blind user controll the computer? Which input devices can he use (mouse? Keyboard? something else?) Which input devices are not usable for him?
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Development of Accessible E-documents and Programs for Visually Impaired Using pc without visual control
0. What do you think? • How can blind user controll the computer? • Which input devices can he use (mouse? Keyboard? something else?) • Which input devices are not usable for him? • and what about output?
1. How to input (1) • Blind users use only keyboard • Standard Windows keyboard shortcuts (almost all tasks in windows can be done without the mouse) • Keyboard shortcuts provided by applications (CTRL+B: bold in wordpad,...)
2. How to input (2) • Keyboard shortcuts provided by special software (more info on next slides) • Keys on special hardware devices (braille displays) • Users with partial seeing use also mouse
3. How to output • Blind users: Speech and sounds • Blind users: braille display • Users with visual impairment: Magnified screen
4. Speech and sounds • Software synthesizers supporting some communication protocol (MSSAPI, SSML) • Integrated synthesis • Special hardware synthesizers (Apollo, Dectalk,...)
5. Braille display • Special hardware connected via Universal Serial Bus • Contains braille cells (one cell = one braille character) • And control buttons (mouse emulation, cursor adjustment,...) • Is in different sizes (20, 24, 44, 70, 80 cells) • Is very expensive (from 2000 to 10000 euro)
6. Magnified screen • Used by users with visual impairment (not blind users) • Software magnification from 2 to 36 times is used
7. 2 approaches to accessibility(1) • Applications with speech and / or braille output and magnification support • Speech: often works only partially • Reads text but not menu,... • Magnification: only basic functionality (kind of magnifying glass, font enlarging,...)
8. 2 approaches to accessibility(2) • Special applications (screen readers, screen magnifiers) • Works in general (as a part of operating system) • Applications with standard UI components: are directly supported • Applications with special (third party) UI components: can be supported
9. Screen reader: basic info • Is a special software for blind computer users • Output: speech, sounds and braille • Provides information about input devices (typed characters, pressed shortcuts,...) • Automatically provides information about "important" parts of the screen • Enables user to ask (by pressing shortcut) for less important information
10. What is important and what not(1) • Yes: description of the object which received a focus (listbox, edit, multiline edit, password edit, checkbox, radio button,...) • Yes: State of the focused object (checked, not checked, grayed,...) • Yes: Number of items in the focused object (items in listbox/view, number of different states of radio button,...) • Yes: selection status (Which items in focused listbox are now selected?)
11. What is important and what not(2) • Font name, size and color: • in focused listbox object, • In multiline text edit • In edit box of standard find dialog (e.g. in wordpad) • Every minute information that the time on system tray changed • Content of status line in MS Word • Title of focused (active) window
12. General rules - speech • It is not good idea to automatically announce Long speaking information (automatically read content of multiline edit, automatically read whole selected text in multiline edit, automatically say all selected items in file list view) • It is not good idea to automatically announce non-informative data (position of the focused control on the screen, foreground and background color of focused control,...) • Screen reader users have no information about the look of the window as a whole, so it is not good idea to assume for example that the text to the left of input control will be announced as a label.
13. General rules - braille display • All rules from previous slide • Braille displays provide better information about screen positions of UI components • It is good idea to provide shortened descriptive strings of objects (listview=lw, checkbox=chb,...)
14. Real example (Windows explorer) (1) • after opening: • title of window is announced • name of the focused object (tree view) is announced • Selected item is announced (My Computer) • State of the item (opened) is announced • Number of subitems in the opened item (10 items) is announced
15. Real example (Windows explorer) (2) • After down arrow: • Level in the tree (level 2) is announced • Name of the selected item (local disk...) is announced • State of the selected item (closed) is announced • after tab key(switch to another UI component): • Name and title (if exists) of newly focused object (folder view list view) is announced • State of selection in component (not selected) is announced • First item in component is announced
16. Real example (foobar2000 settings) • Two pictures on the next slides demonstrate a somehow problematic user environment • Can you name the problem and propose a solution? • Tab order is defined by numbers near components • The components without a number are not reachable from the keyboard (are invisible for a blind user)
19. Providing less important information • Screen readers provide many functions to get less important information • Title of focused window • Textual content of focused window • List of headings in document • List of links on the web page • ...
20. What is accessible and what is not(1) • Accessible object must be reachable from the keyboard (for example toolbars are not) • Objects without textual description are generally not accessible (icons without text description, color chooser,...) • Icons without text can be labelled with textual information provided by user of screen reader
21. What is accessible and what is not(2) • Are the tables accessible without special processing? • Is the multi column webpage accessible without processing? • How to make standard progress bar accessible? Is it important to have information from progress bar?
22. Some special functions of screen readers Mouse emulation: • Many screen readers provide functionality to work with mouse through keyboard • Moving mouse pointer (and reading the text behind the pointer) • Left and right click and double click emulation • Drag and drop emulation Scripting: • Better screen readers enables users to write scripts associated with applications and improve accessibility • Special functionality to optimize web browsing
23. Self voicing applications • Standard applications with some kind of speech support • Often provides only basic functionality • Special working enviroments developed for visually impaired users (emacspeak for linux, hpsio for dos,...) • FireVox: speech plugin to Mozilla Firefox Browser • Web anywhere: web browser screen reader written in javascript (platform and browser independent) • http://webanywhere.cs.washington.edu
24. Screen magnification • Standard magnifying glass • Enlarging part of screen or whole screen • Tracking of changes on the invisible part of the screen • Static regions associated with hotkeys (e.g. region fixed on window status line can be quickly accessible) • Smoothing edges of fonts and object borders destroyed after magnification • Color handling
25. Combination • Many magnifiers have also basic speech support • Reading text behind the mouse • Reading long chunks of texts (in documents, on the web pages,...) • Used mainly by users with very low vision
26. If you want to try(1) • Mostly used screen reader in Slovakia: JAWS for Windows (job access with speech) • http://www.freedomscientific.com • 40 minutes demo version (works again after restart of the computer) • Brilliant screen reader with good functionality and support • Speech and braille support • Expensive (800 to 1000$)
27. If you want to try(2) • NVDA (non visual desktop access) • Open source screen reader with increasing quality • http://www.nvda-project.org • Speech support (braille in development) • Enough to perform standard everyday tasks • Contains Slovak speech synthesis (e-speak synthesizer) • Internet browsing with Firefox 3
28. If you want to try(3) • Magic: Mostly used screen magnifier in Slovakia • http://www.freedomscientific.com • Good screen magnifier with functions described on prior slides • Expensive • 40 minutes demo-version
29. If you want to try(4) Desktop zoom: • Free screen magnifier • http://users.telenet.be/littlegems/MySoft/DesktopZoom/Index.html • Zoom an area around the mouse, zoom a fixed window or zoom the entire desktop • View the entire screen as a thumbnail in the right-bottom corner • Follow the caret & menu items • Change the colors to grey or inverse the colors • Basic speech support