Move observation handling to common source set

buildSrc/src/main/kotlin/Dependencies.kt

@@ -13,11 +13,6 @@ fun uuid(
     version: String = "0.3.1"
 ): String = "com.benasher44:$artifact:$version"
 
-fun stately(
-    module: String,
-    version: String = "1.1.10-a1"
-): String = "co.touchlab:stately-$module:$version"
-
 fun wrappers(
     version: String = "1.0.1-pre.264-kotlin-1.5.31"
 ) = "org.jetbrains.kotlin-wrappers:kotlin-extensions:$version"

core/api/core.api

@@ -17,7 +17,7 @@ public final class com/juul/kable/AndroidPeripheral : com/juul/kable/Peripheral
 	public fun disconnect (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public final fun getMtu ()Lkotlinx/coroutines/flow/StateFlow;
 	public fun getServices ()Ljava/util/List;
-	public fun getState ()Lkotlinx/coroutines/flow/Flow;
+	public fun getState ()Lkotlinx/coroutines/flow/StateFlow;
 	public fun observe (Lcom/juul/kable/Characteristic;Lkotlin/jvm/functions/Function1;)Lkotlinx/coroutines/flow/Flow;
 	public fun read (Lcom/juul/kable/Characteristic;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public fun read (Lcom/juul/kable/Descriptor;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
@@ -58,7 +58,7 @@ public final class com/juul/kable/CharacteristicKt {
 	public static final fun characteristicOf (Ljava/lang/String;Ljava/lang/String;)Lcom/juul/kable/Characteristic;
 }
 
-public final class com/juul/kable/ConnectionLostException : java/io/IOException {
+public final class com/juul/kable/ConnectionLostException : com/juul/kable/NotConnectedException {
 	public fun <init> ()V
 }
 
@@ -154,7 +154,11 @@ public final class com/juul/kable/ManufacturerData {
 	public final fun getData ()[B
 }
 
-public final class com/juul/kable/NotReadyException : java/io/IOException {
+public class com/juul/kable/NotConnectedException : java/io/IOException {
+	public fun <init> ()V
+}
+
+public final class com/juul/kable/NotReadyException : com/juul/kable/NotConnectedException {
 	public fun <init> ()V
 }
 
@@ -168,7 +172,7 @@ public abstract interface class com/juul/kable/Peripheral {
 	public abstract fun connect (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public abstract fun disconnect (Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public abstract fun getServices ()Ljava/util/List;
-	public abstract fun getState ()Lkotlinx/coroutines/flow/Flow;
+	public abstract fun getState ()Lkotlinx/coroutines/flow/StateFlow;
 	public abstract fun observe (Lcom/juul/kable/Characteristic;Lkotlin/jvm/functions/Function1;)Lkotlinx/coroutines/flow/Flow;
 	public abstract fun read (Lcom/juul/kable/Characteristic;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;
 	public abstract fun read (Lcom/juul/kable/Descriptor;Lkotlin/coroutines/Continuation;)Ljava/lang/Object;

core/build.gradle.kts

@@ -73,9 +73,6 @@ kotlin {
 
         val appleMain by creating {
             dependsOn(commonMain)
-            dependencies {
-                implementation(stately("isolate"))
-            }
         }
 
         val appleTest by creating

core/src/androidMain/kotlin/Connection.kt

@@ -2,7 +2,7 @@ package com.juul.kable
 
 import android.bluetooth.BluetoothGatt
 import android.bluetooth.BluetoothGatt.GATT_SUCCESS
-import com.juul.kable.AndroidObservationEvent.CharacteristicChange
+import com.juul.kable.ObservationEvent.CharacteristicChange
 import com.juul.kable.gatt.Callback
 import com.juul.kable.gatt.GattStatus
 import kotlinx.coroutines.CoroutineDispatcher

core/src/androidMain/kotlin/Observations.kt

@@ -0,0 +1,11 @@
+package com.juul.kable
+
+internal actual fun Peripheral.observationHandler(): Observation.Handler = object : Observation.Handler {
+    override suspend fun startObservation(characteristic: Characteristic) {
+        (this@observationHandler as AndroidPeripheral).startObservation(characteristic)
+    }
+
+    override suspend fun stopObservation(characteristic: Characteristic) {
+        (this@observationHandler as AndroidPeripheral).stopObservation(characteristic)
+    }
+}

core/src/androidMain/kotlin/Peripheral.kt

@@ -128,7 +128,7 @@ public enum class Priority { Low, Balanced, High }
 
 public class AndroidPeripheral internal constructor(
     parentCoroutineContext: CoroutineContext,
-    internal val bluetoothDevice: BluetoothDevice,
+    private val bluetoothDevice: BluetoothDevice,
     private val transport: Transport,
     private val phy: Phy,
     private val onServicesDiscovered: ServicesDiscoveredAction,
@@ -137,8 +137,10 @@ public class AndroidPeripheral internal constructor(
 
     private val logger = Logger(logging, tag = "Kable/Peripheral", identifier = bluetoothDevice.address)
 
+    internal val platformIdentifier = bluetoothDevice.address
+
     private val _state = MutableStateFlow<State>(State.Disconnected())
-    public override val state: Flow<State> = _state.asStateFlow()
+    public override val state: StateFlow<State> = _state.asStateFlow()
 
     private val receiver = registerBluetoothStateBroadcastReceiver { state ->
         if (state == STATE_OFF) {
@@ -168,7 +170,7 @@ public class AndroidPeripheral internal constructor(
      */
     public val mtu: StateFlow<Int?> = _mtu.asStateFlow()
 
-    private val observers = Observers(this, _state, logging)
+    private val observers = Observers<ByteArray>(this, logging)
 
     @Volatile
     private var _platformServices: List<PlatformService>? = null
@@ -509,3 +511,6 @@ private fun checkBluetoothAdapterState(
         throw BluetoothDisabledException("Bluetooth adapter state is $actualName ($actual), but $expectedName ($expected) was required.")
     }
 }
+
+internal actual val Peripheral.identifier: String
+    get() = (this as AndroidPeripheral).platformIdentifier

core/src/appleMain/kotlin/Observations.kt

@@ -0,0 +1,11 @@
+package com.juul.kable
+
+internal actual fun Peripheral.observationHandler(): Observation.Handler = object : Observation.Handler {
+    override suspend fun startObservation(characteristic: Characteristic) {
+        (this@observationHandler as ApplePeripheral).startNotifications(characteristic)
+    }
+
+    override suspend fun stopObservation(characteristic: Characteristic) {
+        (this@observationHandler as ApplePeripheral).stopNotifications(characteristic)
+    }
+}

core/src/appleMain/kotlin/Peripheral.kt

@@ -39,6 +39,7 @@ import kotlinx.coroutines.SupervisorJob
 import kotlinx.coroutines.async
 import kotlinx.coroutines.flow.Flow
 import kotlinx.coroutines.flow.MutableStateFlow
+import kotlinx.coroutines.flow.StateFlow
 import kotlinx.coroutines.flow.asStateFlow
 import kotlinx.coroutines.flow.filter
 import kotlinx.coroutines.flow.first
@@ -100,7 +101,11 @@ public class ApplePeripheral internal constructor(
     private val logger = Logger(logging, identifier = cbPeripheral.identifier.UUIDString)
 
     private val _state = MutableStateFlow<State>(State.Disconnected())
-    override val state: Flow<State> = _state.asStateFlow()
+    override val state: StateFlow<State> = _state.asStateFlow()
+
+    private val observers = Observers<NSData>(this, logging)
+
+    internal val platformIdentifier = cbPeripheral.identifier.UUIDString
 
     init {
         centralManager.delegate
@@ -112,13 +117,14 @@ public class ApplePeripheral internal constructor(
                     detail("state", event.toString())
                 }
             }
+            .onEach { event ->
+                if (event is DidFailToConnect || event is DidDisconnect) observers.onConnectionLost()
+            }
             .map { event -> event.toState() }
             .onEach { _state.value = it }
             .launchIn(scope)
     }
 
-    private val observers = Observers(this, logger)
-
     private val _platformServices = atomic<List<PlatformService>?>(null)
     private val platformServices: List<PlatformService>
         get() = checkNotNull(_platformServices.value) {
@@ -164,7 +170,7 @@ public class ApplePeripheral internal constructor(
                 .takeWhile { it !== Closed }
                 .mapNotNull { it as? Data }
                 .map {
-                    AppleObservationEvent.CharacteristicChange(
+                    ObservationEvent.CharacteristicChange(
                         characteristic = it.cbCharacteristic.toLazyCharacteristic(),
                         data = it.data
                     )
@@ -180,7 +186,7 @@ public class ApplePeripheral internal constructor(
 
             _state.value = State.Connecting.Observes
             logger.verbose { message = "Configuring characteristic observations" }
-            observers.rewire()
+            observers.onConnected()
         } catch (t: Throwable) {
             logger.error(t) { message = "Failed to connect" }
             withContext(NonCancellable) {
@@ -408,3 +414,6 @@ private fun NSError.toStatus(): State.Disconnected.Status = when (code) {
     CBErrorEncryptionTimedOut -> EncryptionTimedOut
     else -> Unknown(code.toInt())
 }
+
+internal actual val Peripheral.identifier: String
+    get() = (this as ApplePeripheral).platformIdentifier

core/src/commonMain/kotlin/ObservationEvent.kt

@@ -0,0 +1,25 @@
+package com.juul.kable
+
+internal sealed class ObservationEvent<T> {
+
+    abstract val characteristic: Characteristic
+
+    data class CharacteristicChange<T>(
+        override val characteristic: Characteristic,
+        val data: T,
+    ) : ObservationEvent<T>()
+
+    data class Error<T>(
+        override val characteristic: Characteristic,
+        val cause: Throwable,
+    ) : ObservationEvent<T>()
+}
+
+internal fun <T> dematerialize(event: ObservationEvent<T>): T = when (event) {
+    is ObservationEvent.Error -> throw event.cause
+    is ObservationEvent.CharacteristicChange -> event.data
+}
+
+internal fun <T> ObservationEvent<T>.isAssociatedWith(characteristic: Characteristic): Boolean =
+    this.characteristic.characteristicUuid == characteristic.characteristicUuid &&
+        this.characteristic.serviceUuid == characteristic.serviceUuid