1670846 - Paragraph boundary doesn't stop at line breaks in textareas

Status: RESOLVED FIXED

(Core :: Disability Access APIs, defect)

Description

[James Teh [:Jamie]]

STR (with the NVDA screen reader):

1. Open this test case:
   data:text/html,<textarea>a%0ab
2. Focus the textarea.
3. Press NVDA+control+z to open the NVDA python Console.
4. Enter the following command and press enter:
   focus.IAccessibleTextObject.textAtOffset(0, 3)
   • Expected: (0, 2, 'a\n')
   • Actual: (0, 3, 'a\nb')

It seems that textareas contain only a single text node (pruned for OS APIs via MustPrune) which contains the full text. It's also valid to add additional text nodes to textareas using the DOM. Furthermore, we have the same problem with other pre-formatted text:
data:text/html,<pre>a%0ab
data:text/html,<div style="white-space: pre;">a%0ab

So this means that in addition to walking the tree, we also need to check text nodes for rendered line breaks. 😩

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

Set release status flags based on info from the regressing bug 1666998

Comment 2

[Pascal Chevrel:pascalc]

S3 and we are nearing the end of the nightly cycle, fix-optional for 83.

Comment 3

[James Teh [:Jamie]]

Attachment: Bug 1670846: Treat line break characters in pre-formatted text as a11y paragraph boundaries.

In pre-formatted text (including textareas), text leaf nodes can contain line break characters ("\n").
Therefore, when searching for a paragraph boundary, we must match these.
Pivot can't return an ofset, only an Accessible, so we store the offset for the last match on the rule.
Because our origin point might be within a text leaf which contains a line break before/after it, we must also pass in the offset in our origin in this case so we can begin the text search from the right place.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/1929ad3775f9
Treat line break characters in pre-formatted text as a11y paragraph boundaries. r=MarcoZ

Comment 5

[Bogdan Tara[:bogdan_tara | bogdant]]

https://hg.mozilla.org/mozilla-central/rev/1929ad3775f9