Support IAccessible2 "mark" text attribute.

[jcsteh]

Link to issue number:

None.

Summary of the issue:

Text fragments is a new web concept that allows you to link directly to a specified piece of arbitrary text on a page without needing a predefined id. For example:
https://www.jantrid.net/#:~:text=browsers%20were%20much%20simpler
As well as scrolling to the element containing the text, the browser will highlight the text. Because this could span a partial object, this can't be exposed using IA2_ROLE_MARK. Instead, similar to spelling errors, this is exposed using an IAccessible2 text attribute, specifically the new attribute mark:true.

This will also be used eventually to support CSS custom highlights.

Description of user facing changes

In Mozilla Firefox, NVDA will report the highlighted text when a URL containing a text fragment is visited.

Description of development approach

NVDA already supports the "marked" attribute on FormatFields. To be consistent with IA2_ROLE_MARK, it was decided to name the IA2 attribute "mark" instead of "marked". This PR simply maps the attribute appropriately in normalizeIA2TextFormatField.

Testing strategy:

1. Opened this test case in Firefox Nightly (this isn't enabled in Firefox release yet):
   data:text/html,<p>The first phrase.</p><p>The second <b>phrase.</b></p>#:~:text=second phrase
2. Moved to the second line.
3. Verified that NVDA reported "The marked second phrase not marked."

Known issues with pull request:

None with the PR itself.

I did notice that we report "highlighted" for controlTypes.Role.MARKED_CONTENT, but we report "marked" for the marked FormatField key, even though these are the same concept. I wonder whether the marked FormatField key should report "highlighted" instead.

Code Review Checklist:

• Documentation:
  • Change log entry
  • User Documentation
  • Developer / Technical Documentation
  • Context sensitive help for GUI changes
• Testing:
  • Unit tests
  • System (end to end) tests
  • Manual testing
• UX of all users considered:
  • Speech
  • Braille
  • Low Vision
  • Different web browsers
  • Localization in other languages / culture than English
• API is compatible with existing add-ons.
• Security precautions taken.

Summary by CodeRabbit

• New Features
  • Enhanced accessibility in Mozilla Firefox by enabling NVDA to report highlighted text when visiting URLs with text fragments.
• Bug Fixes
  • Improved processing of the formatField attribute, ensuring accurate handling of the mark key for better functionality.

[jcsteh]

Note that Chrome supports text fragments, but even though it scrolls to the fragment, it does not yet expose the highlight to IAccessible2. That change will need to be made in Chrome.

[XLTechie]

I wonder whether the marked FormatField key should report "highlighted" instead.

I would imagine users can more easily relate to the highlighted concept.

[jcsteh]

I tend to agree. I wasn't sure whether there was a good reason this is currently reported as "marked", though, so thought I'd avoid making that change here.

[LeonarddeR]

Is this new mark attribute already formalized in some IA2 spec? If so, I don't see a reason to wait for this to land in FF at all. It wouldn't be sitting in the way.

[jcsteh]

It's not formalised yet. I will file a PR against IA2 at some point to add it. I'm holding off at this point because it's slightly possible (though very unlikely) that I'll discover something before the Firefox patches land that requires me to change how this is exposed.

[jcsteh]

LinuxA11y/IAccessible2#30

[coderabbitai]

Walkthrough

The changes introduce new functionality in NVDA to enhance accessibility in Mozilla Firefox. The normalizeIA2TextFormatField function now processes a new attribute, mark, to set a marked key in the formatField dictionary. Additionally, NVDA will report highlighted text when a URL with a text fragment is visited, improving contextual navigation for users.

Changes

Files	Change Summary
source/NVDAObjects/IAccessible/__init__.py, user_docs/en/changes.md	Introduced a new attribute mark in normalizeIA2TextFormatField to set marked to True if mark is "true"; added functionality to report highlighted text in Firefox when visiting URLs with text fragments.

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Recent review details

Configuration used: .coderabbit.yml
Review profile: CHILL

Commits

Files that changed from the base of the PR and between 5b6804d and a12323e.

Files selected for processing (2)

• source/NVDAObjects/IAccessible/init.py (1 hunks)
• user_docs/en/changes.md (1 hunks)

Additional context used

Path-based instructions (2)

source/NVDAObjects/IAccessible/__init__.py (2)

Pattern **/*: Focus on code smells, logic errors, edge cases, missing test cases, security flaws and serious issues. Avoid commenting on minor issues such as linting, formatting and style issues. This project uses tabs instead of spaces, do not suggest usage of spaces over tabs. Are there any 'red flags' in this code that might warrant closer investigation from a security standpoint? Explain what makes them suspicious. When providing code suggestions, particularly when requested, ensure GitHub's suggestion format is used, i.e.: suggestion <code changes>

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Pattern **/*.py: _, pgettext, ngettext, and ngettext are defined globally, errors for this being undefined can be ignored.

user_docs/en/changes.md (3)

Pattern **/*: Focus on code smells, logic errors, edge cases, missing test cases, security flaws and serious issues. Avoid commenting on minor issues such as linting, formatting and style issues. This project uses tabs instead of spaces, do not suggest usage of spaces over tabs. Are there any 'red flags' in this code that might warrant closer investigation from a security standpoint? Explain what makes them suspicious. When providing code suggestions, particularly when requested, ensure GitHub's suggestion format is used, i.e.: suggestion <code changes>

---

Pattern **/*.md: Focus on grammar, spelling, and punctuation. Also consider readability and clarity of contents. Ensure that changes follow the style of one sentence per line, suggest changes if this is not met.

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Pattern user_docs/en/changes.md: Ensure each change log entry references an issue or pull request number. Change log entries can also include a reference to a GitHub author. Examples of valid change log entries: * Item with sub-items (#123, @username): * sub-item * bar (#342) * Item with. Multiple lines. (#143)

Additional comments not posted (1)

user_docs/en/changes.md (1)

8-8: Ensure one sentence per line for readability.

The entry is well-formed and follows the required format. For better readability and clarity, ensure that each sentence is on a separate line.

* In Mozilla Firefox, NVDA will report the highlighted text when a URL containing a text fragment is visited. 
* (#16910, @jcsteh)

The code changes are approved.

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[coderabbitai]

Actionable comments posted: 1

[seanbudd]

Thanks @jcsteh !