Compose for Desktop get and listen to Gtk Dark/Light Theme changes

GtkTheme.kt

// implementation("org.zeroturnaround:zt-exec:1.12") LIBRARY USAGED

import androidx.compose.runtime.Composable
import androidx.compose.runtime.collectAsState
import kotlin.coroutines.resume
import kotlinx.coroutines.channels.awaitClose
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.callbackFlow
import kotlinx.coroutines.flow.collect
import kotlinx.coroutines.flow.flow
import kotlinx.coroutines.flow.onStart
import kotlinx.coroutines.suspendCancellableCoroutine
import org.zeroturnaround.exec.ProcessExecutor
import org.zeroturnaround.exec.stream.LogOutputStream

private const val DCONF_THEME_KEY_NAME = "/org/gnome/desktop/interface/gtk-theme"
private const val DCONF_WATCH_THEME_COMMAND = "dconf watch $DCONF_THEME_KEY_NAME"
private const val DCONF_READ_THEME_COMMAND = "dconf read $DCONF_THEME_KEY_NAME"

@Composable
fun isGtkThemeDark(): Boolean {
    return gtkThemeChangesFlow().collectAsState("").value
        .contains("dark", ignoreCase = true)
}

/** Emits the name of the new theme. */
private fun gtkThemeChangesFlow(): Flow<String> {
    val watchThemeCommandFlow = callbackFlow<String> {
        val process = ProcessExecutor().commandSplit(DCONF_WATCH_THEME_COMMAND)
            .redirectOutput(object : LogOutputStream() {
                override fun processLine(line: String) {
                    [email protected](line.trim())
                }
            })
            .start()

        awaitClose { process.process.destroy() }
    }

    return flow<String> {
        var previousIsKey = false
        watchThemeCommandFlow.collect {
            if(previousIsKey) {
                previousIsKey = false
                emit(it)
            }

            if(it == DCONF_THEME_KEY_NAME) previousIsKey = true
        }
    }.onStart {
        emit(currentlyGtkTheme())
    }
}

/** Get the currently system theme */
private suspend fun currentlyGtkTheme(): String {
    return suspendCancellableCoroutine<String> { continuation ->
        val process = ProcessExecutor().commandSplit(DCONF_READ_THEME_COMMAND)
            .redirectOutput(object : LogOutputStream() {
                override fun processLine(line: String) {
                    if(continuation.isActive)
                        continuation.resume(line)
                }
            })
            .start()

        continuation.invokeOnCancellation { process.process.destroy() }
    }
}