how do i notify a particular compose view that the...

# compose

[myanmarking]

how do i notify a particular compose view that the night mode has changed? Details in thread

[myanmarking]

I have a single activity with FragmentContainerView and a single custom composable view (FrameLayout, addView(ComposeView(...)))
I also have all configChanges setted in manifest. Whenever i change dark mode, every fragment updates just right, except my custom view.
For some reason, it is not updated. isSystemInDarkTheme() always return the initial value.
What i did as a workaround, was to add a listener to my custom view as follows:

this.context.findActivity()
.addOnConfigurationChangedListener {
val darkTheme =
when (it.uiMode and Configuration.UI_MODE_NIGHT_MASK) {
Configuration.UI_MODE_NIGHT_NO -> false
else -> true
}
if (darkTheme != this.darkTheme.value) {
this.darkTheme.value = darkTheme
}
}

and manually set the darkTheme on my custom compose view, disregarding isSystemInDarkTheme(). It behaves alright. But i would like to remove this workaround. Any ideas?

[myanmarking]

Act Layout:

<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="<http://schemas.android.com/apk/res/android>"
    android:id="@+id/root"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <androidx.fragment.app.FragmentContainerView
        android:id="@+id/fragContainer"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>

    <com.prozis.main_app.ui.dashboard.view.BottomBarScaffoldView
        android:id="@+id/bottomBarScaffoldView"
        android:layout_width="match_parent"
        android:layout_height="match_parent"/>
</FrameLayout>

[myanmarking]

custom compose view:

abstract class BridgeComposeFrameLayout @JvmOverloads constructor(
    context: Context,
    attrs: AttributeSet? = null,
    defStyleAttr: Int = 0,
) : FrameLayout(context, attrs, defStyleAttr) {

    private val darkTheme = mutableStateOf(
        when (context.resources.configuration.uiMode and Configuration.UI_MODE_NIGHT_MASK) {
            Configuration.UI_MODE_NIGHT_NO -> false
            else -> true
        },
    )
    init {
        this.addView(
            ComposeView(this.context).apply {
                setContent(
                    content = {
                        Screen(darkTheme.value)
                    },
                )
            },
        )
        this.context.findActivity()
            .addOnConfigurationChangedListener {
                val darkTheme =
                    when (it.uiMode and Configuration.UI_MODE_NIGHT_MASK) {
                        Configuration.UI_MODE_NIGHT_NO -> false
                        else -> true
                    }
                if (darkTheme != this.darkTheme.value) {
                    this.darkTheme.value = darkTheme
                }
            }
    }

    @Composable
    abstract fun Screen(darkTheme: Boolean)
}

[Alex Vanyo]

isSystemIsDarkTheme checks the value of the configuration from LocalConfiguration directly, which will return a new value when there’s a new configuration, so I’m surprised that the workaround above works but isSystemInDarkTheme doesn’t. Do you have a sample when isSystemInDarkTheme isn’t updating?

[myanmarking]

sure. i can work on that. give me a few minutes

[myanmarking]

apparently, i cannot reproduce this anymore. I removed the workaround and it working. I don’t know if some unrelated stuff fixed this, but it is working not as expected in the latest release. Thanks for you help!