Flow broadcast receiver

FlowBroadcastReceiver.kt

package page.smirnov.sample

import android.content.BroadcastReceiver
import android.content.Context
import android.content.Intent
import android.content.IntentFilter
import android.os.Bundle
import kotlinx.coroutines.channels.awaitClose
import kotlinx.coroutines.flow.Flow
import kotlinx.coroutines.flow.callbackFlow

interface FlowBroadcastReceiver {

    val events: Flow<BroadcastEvent>

    data class BroadcastEvent(
        val action: String,
        val extras: Bundle? = null,
    )
}

/**
 * Flow wrapper for [BroadcastReceiver]
 *
 * @param context Context to register BroadcastReceiver. Use app context to prevent context leaks
 * @param intentFilter Optional intent filter. Mutually exclusive with actions
 * @param actions Set of actions for intent filter. Mutually exclusive with intentFilter
 */
abstract class FlowBroadcastReceiverImpl(
    context: Context,
    intentFilter: IntentFilter? = null,
    actions: Set<String> = emptySet(),
) : FlowBroadcastReceiver {

    override val events = callbackFlow {
        require(intentFilter != null || actions.isNotEmpty()) {
            "Pass intentFilter or actions"
        }

        require(!(intentFilter != null && actions.isNotEmpty())) {
            "Pass one of intentFilter or actions, not both at once"
        }

        val receiver = object : BroadcastReceiver() {
            override fun onReceive(context: Context?, intent: Intent) {
                val action = intent.action ?: return

                if (!actions.contains(action)) {
                    return
                }

                FlowBroadcastReceiver.BroadcastEvent(
                    action = action,
                    extras = intent.extras
                )
                    .let(::trySend)
            }
        }

        val broadcastIntentFilter = intentFilter ?: IntentFilter().apply {
            actions.iterator().forEach(::addAction)
        }

        context.registerReceiver(receiver, broadcastIntentFilter)

        awaitClose {
            try {
                context.unregisterReceiver(receiver)
            } catch (e: IllegalArgumentException) {
            }
        }
    }
}