MOB-363: Android: "System" theme setting not working

[ruixhuang]

Observe the system-side theme setting.

Screen_Recording_20240315_184624_dYdX.Debug.mp4

[linear]

MOB-363 Android: "System" theme setting not working

[prashanDYDX]

I'm actually surprised this fixes the issue while the app is running - since it seems like createFromPreference() should only be called once at app start, right?

[prashanDYDX]

Also, may be easier to handle this at the Compose level via isSystemInDarkTheme()

[ruixhuang]

I'm actually surprised this fixes the issue while the app is running - since it seems like createFromPreference() should only be called once at app start, right?

Also when user changes theme from settings

[ruixhuang]

Also, may be easier to handle this at the Compose level via isSystemInDarkTheme()

I didn't know this one :) But it's a Compose function, so we can't use it here.

[prashanDYDX]

Also, may be easier to handle this at the Compose level via isSystemInDarkTheme()

I didn't know this one :) But it's a Compose function, so we can't use it here.

Right yeah, you'd do it at the root Compose container view level.

[prashanDYDX]

We shouldn't need to track this ourselves - isSystemInDarkTheme() handles this for us. It is backed by a CompositionLocal of the Configuration:

@Composable
@ReadOnlyComposable
internal actual fun _isSystemInDarkTheme(): Boolean {
    val uiMode = LocalConfiguration.current.uiMode
    return (uiMode and Configuration.UI_MODE_NIGHT_MASK) == Configuration.UI_MODE_NIGHT_YES
}

[prashanDYDX]

Discussed offline - going to land this as is to unblock the release. In the medium term we should try and re-architect this to use the native Compose functions and features (replace shared instance with CompositionLocal).