[Gise23]

Both the slides and speaker-notes WebViews now have an on_navigation_starting handler that only allows navigation to URLs served by the deck. Navigation to any other URL is cancelled.

Testing

• Tested on macOS in both the slides and speaker-notes windows.
• Not covered on GTK/Linux, as Toga doesn't support on_navigation_starting there

Clicking an external link in a slide or the speaker notes navigated the window away from the presentation, with no way to get back.

Fixes #36

Question: With this change, clicking an external link does nothing. Would it be better to open blocked links in the system browser instead?

PR Checklist:

• I will abide by the BeeWare Code of Conduct
• I have read and have followed the CONTRIBUTING.md file
• This PR was generated or assisted using an AI tool

Assisted-by: Claude Opus 5.5

[freakboy3742]

Thanks for the fix! The approach you've taken here looks correct; the only suggestion I'd make would be that is_doc_url should be a method on the Deck, rather than a free-standing method.

[freakboy3742]

As for your question about opening links in the system browser - if you can make that work, it definitely sounds preferable to silently swallowing the click. My only concern would be what happens when the app is in presentation mode... but I guess in presentation mode you don't have a cursor, so this might not be an issue? If you can confirm this isn't a problem in practice, and you can implement the "open in system browser" approach, then go for it!