DialogResult helper for Jetpack/Desktop Compose

DialogResult.kt

package io.github.darvld.utils

/**Base class for components representing the result of the user's interaction with a dialog.
 *
 * To trigger the dialog and obtain the result, use [await].
 *
 * Note that, since this class provides no UI implementation, [complete] must be manually called from UI code. This is
 * typically achieved by showing a dialog when [isAwaiting] is `true`, and using a callback to invoke [complete].*/
interface DialogResult<T> {
    /**Whether the dialog is currently pending user interaction.
     *
     * Composable functions can observe this property to show/hide the corresponding dialog.
     *
     * @see await*/
    val isAwaiting: Boolean

    /**Marks this state as [awaiting][isAwaiting] and suspends until a result is obtained.
     *
     * Subsequent invocations will wait for previous calls to return before triggering the dialog.
     *
     * @see complete*/
    suspend fun await(): T

    /** Causes the dialog state to complete with the given [result]. After this invocation, [isAwaiting] will return
     * false, and currently suspended [await] calls will return the specified value.
     *
     * @see await*/
    fun complete(result: T): Boolean
}

SnapshotDialogResult.kt

package io.github.darvld.utils

import androidx.compose.runtime.*
import kotlinx.coroutines.CompletableDeferred

@Composable
fun <T> rememberDialogResult(): DialogResult<T> {
    return remember { SnapshotDialogResult() }
}

/**Jetpack Compose implementation of [DialogResult] where [isAwaiting] is observable by the composition.*/
open class SnapshotDialogResult<T> : DialogResult<T> {
    private var onResult: CompletableDeferred<T>? by mutableStateOf(null)

    override val isAwaiting: Boolean get() = onResult != null

    override suspend fun await(): T {
        onResult = CompletableDeferred()
        val result = onResult!!.await()
        onResult = null
        return result
    }

    override fun complete(result: T): Boolean {
        return onResult!!.complete(result)
    }
}