Safari incompatibility with api.Document.selectionchange_event

[MurrayIII]

What type of issue is this?

Browser bug (a bug with a feature that may impact site compatibility)

What information was incorrect, unhelpful, or incomplete?

Calling setBaseAndExtent() doesn't fire a selection-change event in Safari

What browsers does this problem apply to, if applicable?

Safari

What did you expect to see?

Expected document.onselectionchange() to be called. It is called in Chrome, Edge, Firefox after setBaseAndExtent() is called.

Did you test this? If so, how?

Commit 334f4bdf of https://github.com/MurrayIII/UnicodeMathML has the if statement that fixes the problem in Safari. Basically when navigating a math expression in the output window using right arrows (run the playground demo), some speech was missing in Safari. Calling document.onselectionchange() explicitly after calling setBaseAndExtent() fixes the problem in Safari.

Can you link to any release notes, bugs, pull requests, or MDN pages related to this?

No response

Do you have anything more you want to share?

No response

MDN URL

https://developer.mozilla.org/en-US/docs/Web/API/Document/selectionchange_event

MDN metadata

MDN page report details

• Query: api.Document.selectionchange_event
• Report started: 2025-01-22T15:21:17.882Z

[caugner]

Related:

• MDN page for selectionchange: https://developer.mozilla.org/en-US/docs/Web/API/Document/selectionchange_event
• MDN page for setBaseAndExtent: https://developer.mozilla.org/en-US/docs/Web/API/Selection/setBaseAndExtent#browser_compatibility
• Spec for setBaseAndExtent: https://w3c.github.io/selection-api/#dom-selection-setbaseandextent
• Spec for selectionchange event: https://w3c.github.io/selection-api/#selectionchange-event

@MurrayIII Can you please provide a minimal example to reproduce the issue in Safari?

[MurrayIII]

I tried the simple codepen but it works correctly both on my PC running Edge and on my mac running Safari. I'll add more context to the codepen to find when the incompatibility occurs.

[MurrayIII]

The codepen repros the problem. In Edge, typing characters shows

In Safari, typing characters shows

[MurrayIII]

I worked around the problem by adding a setTimeout() with a time-out function that calls document.onselectionchange() if document.onselectionchange() hasn't been called by 100 msec after the setBaseAndExtent() call.