Closed Bug 411920 Opened 12 years ago Closed 12 years ago

Caret offset fix for bug 406069 not working on Linux

Categories

(Core :: Disability Access APIs, defect)

All
Linux
defect
Not set

Tracking

()

RESOLVED INVALID

People

(Reporter: aaronlev, Assigned: MarcoZ)

References

(Blocks 2 open bugs)

Details

(Keywords: access)

In bug 406069 we implemented a fix allow -2 to be passed in as an offset to text getter methods.

However, Joanie reports that it's not working, at least on Linux. 

Try it in Accerciser:
text = acc.queryText()
text.getTextAtOffset(-2, TEXT_BOUNDARY_LINE_START)

<joanie> when I try to use it I get an empty string a starting offset of 0 and an ending offset of some really large number

From what Joanie says it sounds like it's getting changed to an unsigned int somewhere. Somewhere we're using the wrong int type.

The bug could be in Mozilla, but I don't see where. Or maybe in pyatspi. Probably -1 for end of text is broken as well!
It could also be in the ATK bridge somewhere. I don't see a problem in the Mozilla code.

All text/hypertext interface method implementations should use signed numbers for offsets. Anywhere that an offset is assigned to an unsigned number the value will be seen as a large number.
Blocks: orca
OK, here's the story:
We never receive negative offsets out of ATK. ATK itself returns a NULL string in ATK_TEXT_GET_TEXT_AT_OFFSET in the event it receives a negative index. So, Orca pushes the -2 into PYATSPI, it travels fine through AT-SPI, and from there it travels to ATK. In ATK, it gets stopped. See http://svn.gnome.org/svn/atk/trunk/atk/atktext.c, line 380.
I'll file a follow-up bug to Gnome's bugzilla to get a discussion about extending the API to allow -1 and -2 for indexes. -1 being all text, -2 being the current line, meaning if the application receives -2, it should always think of this as the line the cursor is on.
Status: NEW → RESOLVED
Closed: 12 years ago
Resolution: --- → INVALID
The follow-up ATK bug is here: http://bugzilla.gnome.org/show_bug.cgi?id=508846. For reference, a more detailed explanation of the intended usage of -1 and -2 can be found here: http://developer.mozilla.org/en/docs/Accessibility:Architecture#.28F.29_To_get_the_line_of_text_at_the_caret.
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