Users report frozen screens

[michaelloistl]

After some investigation, it turned out that the screenshot is being shown which creates for the user the impression that the screen is frozen. I have not been able to recreate this issue myself, but got countless reports from users. I distributed a TestFlight build with color coded screen borders for all the functions that call showVisitableScreenshot(). Based on the color reported back from users, the following function would cause that frozen screen for them:

private func deactivateVisitable(_ visitable: Visitable, showScreenshot: Bool = false) {
  guard isActivatedVisitable(visitable) else { return }

  if showScreenshot {
    visitable.updateVisitableScreenshot()
    visitable.showVisitableScreenshot()

    // Color red added for test purposes
    visitable.visitableView.layer.borderWidth = 5
    visitable.visitableView.layer.borderColor = UIColor.red.cgColor
  }

  visitable.deactivateVisitableWebView()
  activatedVisitable = nil
}

The following screen recording shows when that happens to the user. We have however received reports that this happens across all of the tabs, so it's not unique to that scenario where a user comments on a post and returns to the feed.

ScreenRecording_02-20-2025.09-13-34_1_.mp4

[joemasilotti]

Thanks for reporting. After some poking around I can reproduce with the new version of the demo server that uses tabs on iOS.

RocketSim_Recording_iPhone_16_Pro_6.3_2025-02-20_05.41.12.mp4

The freeze can be reproduced by:

1. Submitting a form
2. Switching to a different tab
3. Switching back to the original tab
4. Tapping the tab button (again) to pop to root

Not 100% of the time, though. So I'm wondering if there is a race condition occurring somewhere.

If I had to guess, this might be related to #50 by @svara. Only because that's the only custom code we have in place around tabs and such. There's also a high possibility the way I'm setting up tabs in #87 is causing the issue.