[Bug]: can not set map style with GoogleNavigationViewController after using navigation once in iOS

[Ghelwig]

Is there an existing issue for this?

• I have searched the existing issues

Description of the bug

when initializing the map view, I am able to switch between different themes using setMapStyle. Once I start navigation, it goes back to the default map style. Looking into this issue more it sounds like custom map styles are not supported with navigation yet (atleast on iOS, it seems to allow you on Android). While this is not an issue, even after cleaning up the navigation session setMapStyle will never work until you re-initialize the entire widget. This is now how it works on Android, after ending the navigation session you are able to switch the theme back to what it was before the session started.

This is an issue when trying to implement dark modes.

Flutter version

3.29.3

Package version

0.4.0-0.6.3

Native SDK versions

• I haven't changed the version of the native SDKs

Flutter Doctor Output

[✓] Flutter (Channel stable, 3.29.3, on macOS 14.6.1 23G93 darwin-arm64, locale en-US)
[!] Android toolchain - develop for Android devices (Android SDK version 35.0.0)
! Some Android licenses not accepted. To resolve this, run: flutter doctor --android-licenses
[!] Xcode - develop for iOS and macOS (Xcode 16.0)
! CocoaPods 1.15.2 out of date (1.16.2 is recommended).
CocoaPods is a package manager for iOS or macOS platform code.
Without CocoaPods, plugins will not work on iOS or macOS.
For more info, see https://flutter.dev/to/platform-plugins
To update CocoaPods, see https://guides.cocoapods.org/using/getting-started.html#updating-cocoapods
[✓] Chrome - develop for the web
[✓] Android Studio (version 2024.2)
[✓] VS Code (version 1.97.2)
[✓] Connected device (5 available)
! Error: Browsing on the local area network for Grant’s iPad. Ensure the device is unlocked and attached with a cable or associated with the same local
area network as this Mac.
The device must be opted into Developer Mode to connect wirelessly. (code -27)
[✓] Network resources

! Doctor found issues in 2 categories.

Steps to reproduce

1. initialize the GoogleMapsNavigationView widget in your app
2. use setMapStyle with the GoogleNavigationViewController freely
3. intialize and clean up any navigation session
4. observe that setMapStyle will no longer work after the session has ended

Expected vs Actual Behavior

Expected Behavior:
you are able to update the map style while a navigation session is not active

Actual Behavior:
after initializing a navigation session once, you are unable to update the map style anymore

Code Sample

final themeJson = (await rootBundle.loadString(
'packages/lou_assets/assets/dark_mode.json',
));

  await navController?.setMapStyle(themeJson);

Additional Context

As mentioned before this seems OS specific. I have tried clearing navigation and the map controller before setting map style again and nothing has worked.

[illuminati1911]

@Ghelwig Thank you for opening the issue! We'll take a look at this.

[jokerttu]

Hi @Ghelwig,
Navigation view customization is not yet supported by the underlying Android and iOS SDKs.
Once the navigation map customization feature becomes available in the SDKs, this package will be updated to support it as well.

[Ghelwig]

Thanks for the update @jokerttu that makes sense to me

My only issue is that once navigation is done, it is not allowing any theming updates on the regular map view even when navigation is not initiated. It sounds like this might not be possible regardless until the map customization feature is done, it seems strange that setMapStyle would work before but not after.
Should I be swapping between GoogleMapsMapView and GoogleMapsNavigationView when I am just showing points on a map vs initializing navigation?

[illuminati1911]

Thanks for the update @jokerttu that makes sense to me

My only issue is that once navigation is done, it is not allowing any theming updates on the regular map view even when navigation is not initiated. It sounds like this might not be possible regardless until the map customization feature is done, it seems strange that setMapStyle would work before but not after. Should I be swapping between GoogleMapsMapView and GoogleMapsNavigationView when I am just showing points on a map vs initializing navigation?

This sounds weird and most likely should not happen. I'll investigate this.

[illuminati1911]

Thanks for the update @jokerttu that makes sense to me

My only issue is that once navigation is done, it is not allowing any theming updates on the regular map view even when navigation is not initiated. It sounds like this might not be possible regardless until the map customization feature is done, it seems strange that setMapStyle would work before but not after. Should I be swapping between GoogleMapsMapView and GoogleMapsNavigationView when I am just showing points on a map vs initializing navigation?

I just tested this and I was able to customize the map style before and after navigation. If you are using navigation, do not use GoogleMapsMapView, but instead just use GoogleMapsNavigationView and set the style via GoogleNavigationViewController like this:

Future<void> setMapStyleNight() async {
    final String jsonString = await rootBundle.loadString(
      'assets/night_style.json',
    );
    await _navigationViewController.setMapStyle(jsonString);
  }

Is this what you have already been doing and you still can't change the map style after navigation?

[Ghelwig]

Thanks for the update @jokerttu that makes sense to me
My only issue is that once navigation is done, it is not allowing any theming updates on the regular map view even when navigation is not initiated. It sounds like this might not be possible regardless until the map customization feature is done, it seems strange that setMapStyle would work before but not after. Should I be swapping between GoogleMapsMapView and GoogleMapsNavigationView when I am just showing points on a map vs initializing navigation?

I just tested this and I was able to customize the map style before and after navigation. If you are using navigation, do not use GoogleMapsMapView, but instead just use GoogleMapsNavigationView and set the style via GoogleNavigationViewController like this:

Future setMapStyleNight() async {
final String jsonString = await rootBundle.loadString(
'assets/night_style.json',
);
await _navigationViewController.setMapStyle(jsonString);
}
Is this what you have already been doing and you still can't change the map style after navigation?

Correct. In the initial card I mentioned iOS but I forgot to also point out that this is happening on iPads only, not iPhones.

[Ghelwig]

I did test this today and I can also reproduce the issue on iPhones. Seems to be all iOS devices I have tested it on.