1204171 - Accessible ATK/AT-SPI2 keyboard event notifications do not appear to get deregistered

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[Joanmarie Diggs]

Attachment: accessible-event listener: keyevents.py

Steps to reproduce:
1. Launch Firefox
2. Launch the attached accessible-event listener in a terminal
3. Repeat the following steps several times:
   a. Switch to Firefox
   b. Press Left Arrow once
   c. Press Right Arrow once
   d. Press F4 to terminate the listener
   e. Re-launch the listener and go to step 3a.

Expected results: Each key press would result in only one accessible key-press notification.

Actual results: Each key press results in x key-press notifications, where x is the number of times steps 3a through 3e have been performed. (Sample output below.)

I can reproduce this in Thunderbird and Firefox, but do not see the problem in GNOME Shell (clutter-based) or Gtk+ apps.

=============
Sample output
=============

[jd@blockhead ~]$ ./keyevents.py 
Press F4 to terminate this listener
Left pressed
Right pressed
F4 pressed
[jd@blockhead ~]$ ./keyevents.py 
Press F4 to terminate this listener
Left pressed
Left pressed
Right pressed
Right pressed
F4 pressed
[jd@blockhead ~]$ ./keyevents.py 
Press F4 to terminate this listener
Left pressed
Left pressed
Left pressed
Right pressed
Right pressed
Right pressed
F4 pressed
[jd@blockhead ~]$ ./keyevents.py 
Press F4 to terminate this listener
Left pressed
Left pressed
Left pressed
Left pressed
Right pressed
Right pressed
Right pressed
Right pressed
F4 pressed

Comment 1

[Trevor Saunders (:tbsaunde)]

WHen I run that event listener restarting it doesn't show me duplicate events.  Maybe orca is eating all but one of the events?

Comment 2

[Trevor Saunders (:tbsaunde)]

Attachment: make mai_util_add_key_event_listener return the correct listener id

The listener id is postincremented as a subexpression of being inserted into
the hash table.  That means the key inserted into the table is 1 less than the
value returned from the function.  Which means that later attempts to remove
the returned id will fail because that hash table knows about a different id.

Comment 3

[David Bolter [:davidb] (NeedInfo me for attention)]

Comment on attachment 8794808 [details] [diff] [review]
make mai_util_add_key_event_listener return the correct listener id

Review of attachment 8794808 [details] [diff] [review]:
-----------------------------------------------------------------

good catch.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/14b0ea0c7b1c
make mai_util_add_key_event_listener return the correct listener id r=davidb

Comment 5

[Carsten Book [:Tomcat]]

https://hg.mozilla.org/mozilla-central/rev/14b0ea0c7b1c