Unable to apply DynamicColors in conjunction with AppCompatDelegate.setDefaultNightMode()

[bubbleguuum]

Material version: 1.9.0-rc01
Tested on Pixel 4a, Android 13

My app theme is a custom theme whose parent is Theme.Material3.DynamicColors.DayNight

I can use the DynamicColors api just fine to apply it globally in my Application's onCreate():

DynamicColors.applyToActivitiesIfAvailable(this, new DynamicColorsOptions.Builder()build());

With this, the dynamic colors (Material You) are applied.

However, If I use AppCompatDelegate.setDefaultNightMode() (called before of after the applyToActivitiesIfAvailable() call, it does not matter) to force dark mode on or off (depending of app setting),
the dynamic colors are not applied and the theme is using whatever default colors are configured for non dynamic mode (purple in my case, the default M3 color scheme, since I did not define custom colors in my theme yet).

After some digging into it, I see that a call AppCompatDelegate.setDefaultNightMode() results in some heavy stuff being done in the activity's attachbaseContext() which is called prior the DynamicColors's onActivityPreCreated() hook.

Apparently these 2 things conflict with each other. Or am I doing something wrong ? AppCompatDelegate.setDefaultNightMode() is otherwise working fine outside of being used with DynamycColors.

[bubbleguuum]

EDIT: After more investigation I have this issue with app theme derived from Theme.Material3.DayNight.NoActionBar, and only in my main app Activity right after app startup, not in a sub Activity (app settings actually) spawn from the main Activity.
So i need to dig further...
My app can apply Dynamic Colors or not, and force light or dark theme, for both (depending on user settings).

[bubbleguuum]

So after more investigation, there is indeed a weird conflict between AppCompatDelegate.setDefaultNightMode() and DynamicColors.applyToActivitiesIfAvailable when both are called in the Application onCreate(), resulting with the DynamicColors theme overlay to not be applied, but only on the initial Activity spawn on app startup. Subsequently launched activities have the DynamicColors theme overlay applied. That's with a Theme.Material3.DayNight app theme, which is required for an app that offers to apply dynamic colors or not.

A workaround is to use UiModeManager.setApplicationNightMode() instead, which works fine. It is API 31+ only but so do the Dynamic Colors, so not a problem. And it is cleaner solution as the app is starting in the proper dark/light mode from the start without relying on the AppCompatDelegate Configuration hacks.

[bubbleguuum]

I finally found the culprit.

In ThemeUtils#applyThemeOverlay , it works again replacing context.getTheme().applyStyle(theme, true) by activity.setTheme(theme), which it was using before that change to workaround a 'force dark' issue.
So this workaround is creating the new issue that applying a Theme overlay with that function does not work if AppCompatDelegate.setDefaultNightMode() is used.

[Myzel394]

For everyone who just wants to copy paste a code, here's what you need to do:

1. Change the theme in res/values/themes.xml to theme.Material3.DayNight or a subtheme of it (Unable to apply DynamicColors in conjunction with AppCompatDelegate.setDefaultNightMode() #3366 (comment)):

<?xml version="1.0" encoding="utf-8"?>
<resources>

    <style name="Theme.Planner" parent="Theme.Material3.DayNight.NoActionBar" />
</resources>

2. Re-apply dynamic colors inside the onCreate function of your MainActivity.kt, this needs to be called before setContent

class MainActivity : AppCompatActivity() {
    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        DynamicColors.applyToActivityIfAvailable(this);

        setContent {
            MyTheme {
                // A surface container using the 'background' color from the theme
                Surface(
                    modifier = Modifier.fillMaxSize(),
                    color = MaterialTheme.colorScheme.background
                ) { /* Your content */ }
            }
        }
    }
}

All of this is taken from @bubbleguuum, thanks for documenting your process online! I just made this comment so newbies like me can copy it easier :D