Theme preference doesn't sync to sub-page containers

[Huxpro]

Problem

When a user changes the theme preference (e.g. Dark → Light) on the main page, sub-pages opened via navigate() / open() don't reflect the change. They either:

1. Use the system default (if no force_theme_style is passed)
2. Stay stuck on whatever force_theme_style was hardcoded at navigation time

Why it happens

Each sub-page is a separate LynxView container with its own JS runtime. There's no shared state between containers. The theme for each container is determined at creation time:

1. force_theme_style scheme parameter → highest priority
2. System dark mode setting → fallback
3. Default (light) → last resort

There is no mechanism to:

• Persist a user's in-app theme preference at the native level
• Inject a persisted preference into new containers automatically
• Broadcast theme changes to already-running containers

Current workaround

The frontend can pass force_theme_style explicitly when navigating:

navigate({
  path: 'settings.lynx.bundle',
  options: {
    params: { force_theme_style: currentTheme }
  }
})

But this is fragile — every navigation call must know the current preference, and it doesn't handle the case where a user changes theme while a sub-page is already open.

Ideal upstream solution

The Sparkling SDK should handle theme sync at the container level:

1. Persist theme preference natively: Add a pipe method (e.g. sparkling.setThemePreference) that saves the preference to UserDefaults / SharedPreferences
2. Inject into new containers: In SPKGlobalPropsUtils.defaultGlobalProps() (iOS) and GlobalPropsUtils.builtInStableFields (Android), read the persisted preference and set preferredTheme in globalProps automatically
3. Broadcast to active containers: When preference changes, call updateGlobalProps on all active SPKWrapperLynxView / SimpleLynxKitView instances so already-open pages react

This way theme syncs across all containers without the frontend needing to pass force_theme_style everywhere.

Affected code

• iOS: SPKGlobalPropsUtils.defaultGlobalProps(), SPKLynxKitUtils.globalProps()
• Android: GlobalPropsUtils.builtInStableFields, HybridContext.getTheme()
• Frontend: ThemeProvider reads lynx.__globalProps.preferredTheme at init — this value is currently only set via force_theme_style

Labels

Bug, enhancement, SDK