Bug 35652 - ACC: AT-SPI accessible tree omits objects which are not visible on the screen.
Summary: ACC: AT-SPI accessible tree omits objects which are not visible on the screen.
Status: NEW
Alias: None
Product: LibreOffice
Classification: Unclassified
Component: Writer (show other bugs)
(earliest affected)
3.3.0 release
Hardware: x86 (IA32) Linux (All)
: medium normal
Assignee: Not Assigned
Keywords: accessibility
Depends on:
Blocks: a11y-Linux
  Show dependency treegraph
Reported: 2011-03-25 03:09 UTC by Dattatray Bhat
Modified: 2017-10-11 19:10 UTC (History)
6 users (show)

See Also:
Crash report or crash signature:

Accessible tree shows only 24 of the 26 paragraphs in the document. (103.21 KB, image/png)
2011-03-25 03:09 UTC, Dattatray Bhat

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Description Dattatray Bhat 2011-03-25 03:09:51 UTC
Created attachment 44815 [details]
Accessible tree shows only 24 of the 26 paragraphs in the document.

Some objects at the end of a writer document are not included in the AT-SPI
accessible tree. If a document has n objects, the accessible tree shows only
(n-k) objects. When an assistive tool navigating the document reaches (n-k)th
object, it wrongly concludes that the last object is reached and wraps to the

Steps to reproduce:
1. Create a writer document containing 22 paragraphs, each paragraph consisting
of only one or two words and terminated by a new line. Save and close the

2. Reopen the document. Move the cursor to the first line.

3. Start Accerciser accessibility explorer.

4. Go to the accessible tree view at top left. As shown in attached
screen-shot, select the accessible object corresponding to the Document view,
with role document frame. Make a note of the number of paragraphs shown in
'Children' column. Close Accerciser.

5. Repeat steps 1-4 with more paragraphs (23, 24, 25, 26, ...) till number of
paragraphs in accessible tree (Step 4) are less than the number of paragraphs
in the document (Step 1).

When I carried out the above steps, I got the following results:
Paragraphs in document       Paragraphs in accessible tree
22                           22
23                           23
24                           24
25                           24
26                           24

Contents of my writer document were as below -
Para  1
Para  2
Para  3
Para  4
Para  5
Para  6
Para  7
Para  8
Para  9
Para 10
Para 11
Para 12
Para 13
Para 14
Para 15
Para 16
Para 17
Para 18
Para 19
Para 20
Para 21
Para 22
Para 23
Para 24
Para 25
Comment 1 Dattatray Bhat 2011-06-09 03:32:46 UTC
The real problem is that the accessible tree contains only those objects which are visible on the screen at any instant, and ignores those which are above or below. This prevents Assistive Technology tools from accessing the full document. So it needs to be fixed on a priority basis.
Comment 2 Dattatray Bhat 2011-06-09 21:45:12 UTC
This bug is a major hurdle in the way of assistive tools like Orca screen reader trying to access the whole document. How much easy or difficult is it to fix? May we get a tentative target date for fixing it?
Comment 3 Joanmarie Diggs 2011-06-14 09:33:04 UTC
See also: https://bugzilla.gnome.org/show_bug.cgi?id=652548
Comment 4 Dattatray Bhat 2011-06-27 01:51:17 UTC
FLOWS_FROM and FLOWS_TO relationships, however, link together all paragraphs and table cells in the document, visible or not.
Comment 5 Björn Michaelsen 2011-12-23 11:45:20 UTC Comment hidden (obsolete)
Comment 6 Dattatray Bhat 2011-12-26 22:05:44 UTC
Today I rechecked my observation with Libre Office dev 3.5.0 beta2 and found
that the bug persists. I suggest that the bug be moved back to NEW status.
Comment 7 sasha.libreoffice 2012-01-24 03:29:58 UTC
Is this Gnome 2? Remains this problem in Gnome 3?
Comment 8 Florian Reisinger 2012-08-14 13:58:44 UTC Comment hidden (obsolete)
Comment 9 Florian Reisinger 2012-08-14 13:59:59 UTC Comment hidden (obsolete)
Comment 10 Florian Reisinger 2012-08-14 14:04:38 UTC Comment hidden (obsolete)
Comment 11 Florian Reisinger 2012-08-14 14:06:47 UTC Comment hidden (obsolete)
Comment 12 Dattatray Bhat 2012-08-16 05:53:30 UTC
The bug is real. I noticed it in version 3.3.0 and submitted it with a
supporting screenshot. I reconfirmed that the bug exists with version 3.5.0
beta2. It falls in the same category as bugs 35105, 35107, 35110, 35111, 35129
which you have reopened and changed to NEW.
Comment 13 V Stuart Foote 2012-11-01 15:51:58 UTC
Behavior remains, should have been returned to NEW status.
Comment 14 Christophe Strobbe 2013-08-07 12:27:27 UTC
The corresponding Apache OpenOffice bug is also still open: https://issues.apache.org/ooo/show_bug.cgi?id=117542
Comment 15 QA Administrators 2015-04-01 14:41:18 UTC Comment hidden (obsolete)
Comment 16 Jacobo Aragunde Pérez 2015-12-02 16:01:55 UTC
This is still reproducible in master.

Build ID: 6c41727484a04ab89005ffb052937dae5d7dc223

Another way to reproduce it: create an empty document, add one paragraph and add a footnote. When you scroll to the bottom of the page, only the footnote will be exposed to the AT; when you scroll to the top, the paragraph is exposed to the AT and the footnote disappears.