Automatically switching from light to dark mode glitches

[thibaultamartin]

Describe the bug

Recent versions of iOS offer to switch automatically between light and dark theme depending on the time of the day.
At least in version 1.3.0, if the application had previously been open during the day (in light mode) and the phone switches to dark mode, the next time the user opens the app only bits of it switch to dark theme.

Could be related to #4202

To Reproduce
Steps to reproduce the behavior:

1. In brightness settings of the phone, toggle the "Auto" setting
2. In Element iOS, in the "User Interface" section set the Theme setting to "Auto"
3. Kill the Element app
4. Open the Element app: it should toggle/set to light mode
5. Get back to home screen without killing the app
6. Wait for the iPhone to set dark mode
7. Open Element again

Oddly, it seems that setting the light/dark mode manually in iOS settings doesn't cause the same issue. The interface takes a while to update, and seems to do it in two steps, but it eventually works.

Expected behavior

The UI should follow light/dark theme entirely. It would be event greater if it updated it instantaneously/smoothly than in two steps :)

Screenshots

Smartphone (please complete the following information):

• Device: iPhone 11 Pro
• OS: iOS 14.4.2
• Version Element 1.3.0 from Testflight