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Re: [gdm-list] questions about the mobility a11y in gdm 2.26 in Ubuntu


Francesco:

First of all, great job!

I think the docs/C/gdm.xml file needs some love to help improve
the documentation to help people understand how to better customize
autostart scripts and to make GDM work with different accessibility
tools.  Would you be willing to provide some docs that go into more
depth in explaining this?

You could either provide a patch to the gdm.xml file, or if you provided
the updated docs in ASCII format I could merge them into the gdm.xml
file.


Here is how I got it working:

I have put an onboard.desktop file into the following directory:
/usr/share/gdm/autostart/LoginWindow/
(I am using Ubuntu 9.10 alpha; I don't know whether this directory can
be different on other distributions.)

And here is the content of onboard.desktop:
[code]
#!/usr/bin/env xdg-open
[Desktop Entry]
Encoding=UTF-8
Name=Onboard Onscreen Keyboard
Comment=Use an onscreen keyboard
TryExec=onboard
Exec=onboard
Terminal=false
Type=Application
StartupNotify=true
Categories=GNOME;GTK;Accessibility;
AutostartCondition=GNOME
/desktop/gnome/applications/at/screen_keyboard_enabled
X-Ubuntu-Gettext-Domain=gdm
[/code]

Of course, the tags [code] and [/code] are not in onboard.desktop.


It seems to work like this (I don't know however, whether I am guessing
right):

When a user activates the "Use onscreen keyboard" in the accessibility
dialog of GDM, the directory /usr/share/gdm/autostart/LoginWindow/ is
scanned and every desktop file that contains the following key in a line:

AutostartCondition=GNOME
/desktop/gnome/applications/at/screen_keyboard_enabled

gets executed. (If you see 2 lines above, then the email application
inserted a line break.)


Yes, that is my understanding also.  It would be good if the
"Configuration" section of the docs explained how this works better.


Remark that every desktop file with containing that line gets started;
so it is possible to associate more than one application to the "Use
onscreen keyboard" item of the accessibility dialog. As I did not want
to have onboard and gok to be started simultaneously, I had to delete or
rename the gok.desktop file to anything that does not end in .desktop
file; that way gok does not get started anymore.


Perhaps it would be nice if GDM had both desktop files in the source
and had a configure option which allowed you to specify which
desktop file for on-screen-keyboard use to install when you built it?
That way distros could easily choose which one to use.


Two other keys are available:

AutostartCondition=GNOME
/desktop/gnome/applications/at/screen_magnifier_enabled

AutostartCondition=GNOME
/desktop/gnome/applications/at/screen_reader_enabled

which correspond respectively to the magnifier and screenreader items of
the accessibility dialog of GDM.


Again, perhaps this could be made more clear in the "Configuration"
section of the docs.


I suppose that the other items in the accessibility dialog do not have
corresponding keys because these features are provided directly by the X
server that does not need to get started as it is already running!?


Correct.  Probably should be made more clear in the "Configuration"
section of the docs.


Thanks to Gerd K. for helping me setup onboard as a replacement of gok.
As I am using it, I know that it works (at least in the Ubuntu 9.10
development version); but can anybody with the appropriate knowledge
tell me whether the explanation I gave here above is right or correct
what is wrong?


Yes, it sounds correct to me.
Once it has been confirmed to be correct, this howto could be added to the documentation as you suggested above. 

Perhaps a new section could be added as an appendix to the documentation
to give an example of how to configure GDM to work with a different AT
program.

However, I also think it is important to update the "Configuration"
section of the docs so that the way things work is more clearly
described.


There is however something that is puzzling to me: when I open the
gconf-editor after having logged in into my GNOME session, I can't
find the keys:
/desktop/gnome/applications/at/screen_keyboard_enabled
/desktop/gnome/applications/at/screen_magnifier_enabled
/desktop/gnome/applications/at/screen_reader_enabled


When I run gconf-editor using GNOME 2.26, I see these keys.


But these 3 keys are available:
/apps/gdm/simple-greeter/accessibility/screen_keyboard_enabled
/apps/gdm/simple-greeter/accessibility/screen_magnifier_enabled
/apps/gdm/simple-greeter/accessibility/screen_reader_enabled

As far as I know, GDM runs under the "GDM" user and not under my
username and consequently uses a different gconf database. But I
nevertheless wonder whether these two sets of keys are somehow
related?


I think this is a bug.  These keys are not used in the code, and
probably should be removed from the schemas file.
- Is the dialog, where the user can choose the accessibility tool configurable? Particularly, is it for example possible to add more 
 items to it by editing a configuration file?
I don't believe this is currently available. It would be a good enhancement, though. 


- In the EaseOfAccess page on GNOME Live, there is also talk about
dwell clicking: http://live.gnome.org/GDM/EaseOfAccess. As there currently is not a "Software Click" item in the a11y dialog, I 
wonder whether it still has to be implemented?


I believe you can use mousetweaks for dwell clicking.  It would be
good to enhance GDM to make it easier for users to access this.

http://projects.gnome.org/accessibility/screencasts.html


In the meantime, a person not needing dwelling can set up a
configuration for a dwell user by creating a desktop file,
- that is connected to one of the keys above
- that starts mousetweaks in dwell mode (mousetweaks is the application
providing the dwelling feature)
- that gets saved in /usr/share/gdm/autostart/LoginWindow/

The item in the accessibility dialog of GDM corresponding to the key
that starts mousetweaks has to remain always activated, as a dwell user
will not be able to reactivate dwelling by himself, once dwelling has
been turned of.

I filed a bug against GDM with an explanation about how to enhance
GDM so that, out-of-the-box, a dwell user can by himself activate
and use dwelling:
http://bugzilla.gnome.org/show_bug.cgi?id=589906


That sounds like a neat feature.  However, we still need a way for
blind users to launch AT programs via a hotkey combination.


- In GDM 2.22, there was gdmsetup to configure GDM. Is there
anything similar in GDM 2.26?


No, there are some efforts currently to address this.

http://bugzilla.gnome.org/show_bug.cgi?id=553250
- I have seen that "dwellmouselistener" is called in /etc/gdm/custom.conf. Does it mean that the accessibility tools can 
be started by mouse gestures in GDM 2.26 as it was the case in GDM
2.22? If so, could you please tell me in what file the gestures are
defined for GDM 2.26?


GDM 2.20 and earlier supported this.  The new GDM does not provide
any mechanism for users to launch AT programs except via the dialog.
It would be good to enhance both GDM and the normal GNOME user
session to support this sort of feature.  Some people have suggested
it would be best to implement this in gnome-settings-daemon so it
would work consistently in GDM and a normal GNOME user session.
I probably messed up things last time: I don't see anymore "dwellmouselistener" in /etc/gdm/custom.conf. 

If you are using GDM 2.21 and later, you should not have these in your
custom.conf file.  The new GDM does not support these modules anymore.

If you are using the older GDM 2.20 or earlier, you should add these
lines in the [daemon] section of the custom.conf file to enable a11y:

AddGtkModules=true
GtkModulesList=gail:atk-bridge:/usr/lib/gtk-2.0/modules/libdwellmouselistener:/
usr/lib/gtk-2.0/modules/libkeymouselistener

Brian
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