Re: WM enhancements to support accessible screen lock

[Bill Haneman <Bill Haneman Sun COM>]

Since the WM is the agent which enforces stacking order now, I think the
WM is where the special stacking requirements of assistive technologies
should be provided for/respected.  I don't see this as a particular
additional complication, it's just a matter of adding a new WM_TYPE or
stacking order rule.

Doing this in the lock dialog fails to address a number of problems;
lock dialogs are not the only applications out there that break
assistive technologies by posting obscuring windows on top.  IMO the
only way to deal with override-redirect issues in general is to modify
the stacking order rules for WMs, in particular with regard to
override-redirects (at the moment managed windows are never supposed to
be raised by the WM above override-redirects; windows like the GOK main
window would need to be exceptions to this rule).

Note that keyboard and mouse locking isn't particularly secure anyhow,
there are lots of exploits that can be used by clients who can connect
to the X server.  The best you can do is prevent windows other than the
'lock' window from grabbing keyboard focus, and here again this is
really the WM's responsibility.  If one doesn't allow GOK to receive
mouse events, then you are effectively disabling GOK which defeats its
purpose and locks the user out of the desktop.

The alternatives to providing these capabilities are:

(1) don't allow disabled users to use your desktop;
(2) don't allow GOK users to run a screenlock program.

Clearly these are not acceptable alternatives ;-)

best regards,

- Bill