[brailleblaster] Re: Advice requested on accessibility for the blind
- From: Richard Baldwin <baldwin@xxxxxxxxxxxxxxx>
- To: brailleblaster@xxxxxxxxxxxxx
- Date: Sat, 27 Aug 2011 14:45:03 -0500
Will do.
Thanks,
Dick B.
On Sat, Aug 27, 2011 at 2:09 PM, Chris von See <chris@xxxxxxxxxxxxx> wrote:
> ** Take a look at StackLayout - that will allow you to pr-create your
> pages and easily switch between them...
>
> Cheers
> Cheis
> --
> Sent from my Android phone.
>
>
> Richard Baldwin <baldwin@xxxxxxxxxxxxxxx> wrote:
>>
>> Hi Chris,
>>
>> Thanks for the response. See my comments inline below.
>>
>> On Sat, Aug 27, 2011 at 11:44 AM, Chris von See <chris@xxxxxxxxxxxxx>wrote:
>>
>>> Hi Richard -
>>>
>>> I got a chance to take a look at your code... I'm not totally sure I
>>> understand if your goal is to make the program accessible or just to perform
>>> some action when the user selects something from the list, but here are some
>>> thoughts:
>>>
>>
>> rgb] My ultimate goal is to expose a new GUI page that contains lots of
>> controls (text boxes, buttons, etc.) when the user selects an item from the
>> list. I do want it to be accessible to blind students because my purpose is
>> to write a GUI interface for my SVG Graphics Library (see
>> http://cnx.org/content/m39607/latest/). Right now, I am trying to work
>> out an overall structure that will be accessible. I have never used the SWT
>> before, nor have I ever written a Java program with accessibility in mind,
>> so I am plowing new ground in two areas with this one.
>>
>>>
>>> -- If your goal is accessibility, take a look at the
>>> org.eclipse.swt.accessibility package. Many controls have a getAccessible()
>>> method that returns an Accessible object which allows you to do various
>>> accessibility-related things. Look at the Accessible object's methods and
>>> in particular the types of accessibility-related listeners you can add,
>>> which would allow you to (for example) change the description that is spoken
>>> for each list item or create the relation between the list and a descriptive
>>> label ("labelA") so that the label is spoken when the list gains focus.
>>>
>>
>> rgb] Thanks, I will take a look at it.
>>
>>
>>> Take a look at the snippets for the package at
>>> http://help.eclipse.org/helios/index.jsp?topic=/org.eclipse.platform.doc.isv/reference/api/org/eclipse/swt/accessibility/package-summary.htmlto
>>> get some examples.
>>>
>>
>> rgb] Will do.
>>
>>>
>>> -- Using List.addSelectionListener() is the way you would be notified of
>>> user list item selection. SWT should speak each item as the user traverses
>>> the list. You can modify what's spoken by setting listeners via
>>> List.getAccessible().
>>>
>>
>> rgb] I have discovered that the following approach to event handling seems
>> to work better in the sense that with this approach, the new page is not
>> exposed until the user presses the Enter key on the selected item:
>>
>> myCombo.addListener (SWT.DefaultSelection, new Listener () {
>> public void handleEvent (Event e) {
>> //event handler code goes here
>> }//end handleEvent
>> });
>>
>>>
>>> -- If I'm reading your code correctly, you're creating your list using
>>> the Shell as the parent, and then immediately creating a "page" Composite
>>> with the same Shell as parent. I didn't run your code, but I *think* this
>>> will overlay your List with the contents of the "page" Composite.
>>>
>>
>> rgb] Actually it displays the new page below the Combo box, but the
>> approach that you suggest below might work better. I really don't want to
>> dispose of the old page in order to expose a new one.
>>
>>
>>> Try creating a "base" Composite with the shell as parent, then set a
>>> layout on that "base", add your list with the "base" as parent and then add
>>> your "page" Composite as another child of that same "base". Depending on
>>> what layout manager you use the controls will appear in different relative
>>> positions; you might try RowLayout with SWT.VERTICAL so that the list
>>> appears above the "page".
>>>
>>
>> rgb] I will definitely try this.
>>
>>>
>>> -- When the list item is changed you don't need to dispose your "page"
>>> Composite - just set the label and foreground color (for the text) or
>>> background color (for the background of the "page").
>>>
>>
>> rgb] Good. As I mentioned earlier, I don't want to dispose of the old page
>> when I expose a new one. I would like for the user to be able to return to
>> the page with the contents of the text boxes, etc., still intact.
>>
>>>
>>> -- Instead of allocating red, green and blue Color objects using new
>>> Color(r, g, b), try using the static Color.RED, Color.GREEN and Color.BLUE -
>>> these have the same red, green and blue color settings as what you created.
>>> You also won't need to dispose these static Color objects when your program
>>> exits.
>>>
>>
>> rgb] Thanks. Good point.
>>
>>>
>>> Hope this helps. I'll try to answer any other questions you may have,
>>> but I'll be in and out this weekend so it may take me a while to get back to
>>> you.
>>>
>>
>> rgb] I really do appreciate your feedback. If I am successful in this
>> effort, I will publish a free Java program that blind students can use to
>> draw technical diagrams for their physics and math courses. Actually, I have
>> already published such a program, but the user interface is very difficult
>> because it requires some knowledge of programming syntax. My objective is
>> to make it available to every student with an easy-to-use GUI interface,
>> even if they don't know about programming syntax.
>>
>> Thanks,
>> Dick B.
>>
>>>
>>>
>>> Cheers
>>> Chris
>>>
>>>
>>>
>>> On Aug 26, 2011, at 5:32 PM, Richard Baldwin wrote:
>>>
>>> John,
>>>
>>> This is my second attempt to send this. The previous attempt was rejected
>>> because the zip file was too large. I had included the SWT library in it,
>>> which is what made it so large. Since you probably have that already, I
>>> deleted it from the zip file and am going to try again with a much smaller
>>> zip file.
>>>
>>> Thanks,
>>> Dick Baldwin
>>>
>>> On Fri, Aug 26, 2011 at 7:23 PM, Richard Baldwin <
>>> baldwin@xxxxxxxxxxxxxxx> wrote:
>>>
>>>> Hi John,
>>>>
>>>> I'm afraid that given my current lack of knowledge of SWT, I would be
>>>> completely overwhelmed by the BrailleBlaster code.
>>>>
>>>> However, I have attached a zip file containing a simple page switcher
>>>> program using SWT. If you could take the time to import it into Eclipse (or
>>>> however you program using SWT) and let me know if the structure that I am
>>>> using could be successfully navigated by a blind person, or how I should
>>>> modify it to achieve that goal, I would greatly appreciate it.
>>>>
>>>> The GUI contains a list of three items. (I could make it a Combo or
>>>> three radio buttons.) When the user selects one of the items in the list, a
>>>> Composite object opens below the list. Right now, the Composite page simply
>>>> contains a label, but eventually I intend for each new page to be a
>>>> significant GUI in its own right.
>>>>
>>>> By the way, I had to rename a couple of build.bat files to get the zip
>>>> file past the GMail virus police.
>>>>
>>>> Thanks,
>>>> Dick Baldwin
>>>>
>>>>
>>>> On Fri, Aug 26, 2011 at 6:45 PM, John J. Boyer <
>>>> john.boyer@xxxxxxxxxxxxxxxxx> wrote:
>>>>
>>>>> Dick,
>>>>>
>>>>> Accessibility with SWT is almost automatic. BrailleBlaster does not use
>>>>> any particular accessibility features now, though it might use the
>>>>> accessibility package in SWT later. In the Bfailloeblasterr menu,
>>>>> BBMenu.java there is a listener for each item. The event is not sent
>>>>> until the enter key is pressed on that item. There are SWT widgets for
>>>>> handling lists. These will be used later, for example in handling the
>>>>> list of recent documents.
>>>>>
>>>>> If you have Mercurial you can get the source of BrailleBlaster from its
>>>>> googlecode page. BBMenu.java is in org.brailleblaster.wordprocessor I
>>>>> could also send you this class privately as an attachmennt, if you
>>>>> wish.
>>>>>
>>>>> John
>>>>>
>>>>> On Fri, Aug 26, 2011 at 06:03:09PM -0500, Richard Baldwin wrote:
>>>>> > I know this is off topic for this list, but I also know that there
>>>>> are
>>>>> > several excellent SWT programmers that frequent this list who
>>>>> probably know
>>>>> > the answer to my question.
>>>>> >
>>>>> > The objective is to make it possible for a blind user of an SWT GUI
>>>>> to
>>>>> > navigate through a list of items, such as might be found in a Combo,
>>>>> a List,
>>>>> > or perhaps a set of Radio buttons, and cause an event to be fired for
>>>>> one
>>>>> > and only one of the items in the list when that item is chosen.
>>>>> >
>>>>> > It looks to me like using the following code to register a listener
>>>>> on each
>>>>> > item in the list causes each item to fire an event when the arrow
>>>>> keys are
>>>>> > used to traverse the list:
>>>>> >
>>>>> > addSelectionListener(new SelectionAdapter()
>>>>> >
>>>>> > I guess what I am looking for is something like an ActionListener in
>>>>> the AWT
>>>>> > and Swing that can be fired by pressing the Return key after the
>>>>> arrow keys
>>>>> > have been used to choose a specific item.
>>>>> >
>>>>> > I am finding that learning the SWT and trying to achieve
>>>>> accessibility for
>>>>> > blind users at the same time is something of a challenge.
>>>>> >
>>>>> > If you prefer to contact me and have this discussion off list, that
>>>>> will be
>>>>> > OK with me.
>>>>> >
>>>>> > Thanks,
>>>>> > Dick Baldwin
>>>>> >
>>>>> > --
>>>>> > Richard G. Baldwin (Dick Baldwin)
>>>>> > Home of Baldwin's on-line Java Tutorials
>>>>> > http://www.DickBaldwin.com
>>>>> >
>>>>> > Professor of Computer Information Technology
>>>>> > Austin Community College
>>>>> > (512) 223-4758
>>>>> > mailto:Baldwin@xxxxxxxxxxxxxxx
>>>>> > http://www.austincc.edu/baldwin/
>>>>>
>>>>> --
>>>>> John J. Boyer; President, Chief Software Developer
>>>>> Abilitiessoft, Inc.
>>>>> http://www.abilitiessoft.com
>>>>> Madison, Wisconsin USA
>>>>> Developing software for people with disabilities
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Richard G. Baldwin (Dick Baldwin)
>>>> Home of Baldwin's on-line Java Tutorials
>>>> http://www.DickBaldwin.com
>>>>
>>>> Professor of Computer Information Technology
>>>> Austin Community College
>>>> (512) 223-4758
>>>> mailto:Baldwin@xxxxxxxxxxxxxxx
>>>> http://www.austincc.edu/baldwin/
>>>>
>>>
>>>
>>>
>>> --
>>> Richard G. Baldwin (Dick Baldwin)
>>> Home of Baldwin's on-line Java Tutorials
>>> http://www.DickBaldwin.com
>>>
>>> Professor of Computer Information Technology
>>> Austin Community College
>>> (512) 223-4758
>>> mailto:Baldwin@xxxxxxxxxxxxxxx
>>> http://www.austincc.edu/baldwin/
>>> <PageSwitcher01.zip>
>>>
>>>
>>>
>>
>>
>> --
>> Richard G. Baldwin (Dick Baldwin)
>> Home of Baldwin's on-line Java Tutorials
>> http://www.DickBaldwin.com
>>
>> Professor of Computer Information Technology
>> Austin Community College
>> (512) 223-4758
>> mailto:Baldwin@xxxxxxxxxxxxxxx
>> http://www.austincc.edu/baldwin/
>>
>
--
Richard G. Baldwin (Dick Baldwin)
Home of Baldwin's on-line Java Tutorials
http://www.DickBaldwin.com
Professor of Computer Information Technology
Austin Community College
(512) 223-4758
mailto:Baldwin@xxxxxxxxxxxxxxx
http://www.austincc.edu/baldwin/
Other related posts:
