Bugfix FXIOS-15617 Prevent skeleton bars from not being shown when launching with address bar on top then moving it to bottom

[yxm4nsy]

📜 Tickets

Jira ticket
Github issue

💡 Description

The app only adds skeleton bars to the layout at startup when the address bar is positioned at the bottom. This means that if the app launches with the address bar at the top and is later moved to the bottom, the skeleton bars are never added and therefore missing. The fix introduces a flag on the container that tracks whether the skeletons have been added. The function responsible for updating skeleton visibility now checks this flag and lazily adds them if needed. Once added, they persist regardless of address bar position until the app is restarted.

Note: The initial approach was to always keep the skeletons in the layout and toggle visibility, but given the UI hang issues from a few months ago, this lazy-add workaround was chosen to avoid regressing that work.

Note: IMO the toolbar is probably due for a refactor at some point for a cleaner solution 😄

📝 Checklist

• I filled in the ticket numbers and a description of my work
• I updated the PR name to follow our PR naming guidelines
• I ensured unit tests pass and wrote tests for new code
• If working on UI, I checked and implemented accessibility (Dynamic Text and VoiceOver)
• If adding telemetry, I read the data stewardship requirements and will request a data review
• If adding or modifying strings, I read the guidelines and will request a string review from l10n
• If needed, I updated documentation and added comments to complex code

[mobiletest-ci-bot]

	Messages
📖	Project coverage: 42.28%

🧹 Tidy commit

Just 1 file(s) touched. Thanks for keeping it clean and review-friendly!

💬 Description craftsman

Great PR description! Reviewers salute you 🫡

✅ New file code coverage

No new file detected so code coverage gate wasn't ran.

✅ Existing file code coverage

No modified file had significant enough changes for the coverage gate to run.

Client.app: Coverage: 40.73

File	Coverage
AddressToolbarContainer.swift	49.75%	⚠️

Generated by 🚫 Danger Swift against 3bc8890

[janbrasna]

I remember some performance issues with constraints on skeleton tabs on iPads that can't have this functionality — I can try to look up the tickets to see if this has any potential to regress what has been worked around at some point in past, but thinking mainly #31437 et al…

[yxm4nsy]

I remember some performance issues with constraints on skeleton tabs on iPads that can't have this functionality — I can try to look up the tickets to see if this has any potential to regress what has been worked around at some point in past, but thinking mainly #31437 et al…

Hey 👋 Thanks for the context! I did test it on iPad it seemed to be working fine but ill look into it the complications that may arise in relation to this ticket.

[janbrasna]

💯 You have the right reviewer assigned to glance over the impact related to previous efforts (:) I'm only leaving the breadcrumbs to e.g. #30365 and similar to follow the tickets — I have a faint recollection of some nasty autolayout hangs over this, happy to dig up more tickets for context in the meantime.