Split Gatt interface into GattConnection and GattIo

core/src/main/java/gatt/Gatt.kt

@@ -2,167 +2,6 @@
  * Copyright 2020 JUUL Labs, Inc.
  */
 
-@file:Suppress("RedundantUnitReturnType")
-
 package com.juul.able.gatt
 
-import android.bluetooth.BluetoothGatt
-import android.bluetooth.BluetoothGatt.GATT_SUCCESS
-import android.bluetooth.BluetoothGattCharacteristic
-import android.bluetooth.BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
-import android.bluetooth.BluetoothGattDescriptor
-import android.bluetooth.BluetoothGattService
-import android.bluetooth.BluetoothProfile
-import android.bluetooth.BluetoothProfile.STATE_DISCONNECTED
-import android.os.RemoteException
-import com.juul.able.Able
-import java.util.UUID
-import kotlinx.coroutines.FlowPreview
-import kotlinx.coroutines.flow.Flow
-import kotlinx.coroutines.flow.firstOrNull
-import kotlinx.coroutines.flow.onEach
-
-/**
- * Represents the possible GATT connection statuses as defined in the Android source code.
- *
- * - [GATT_SUCCESS]
- * - [GATT_CONN_L2C_FAILURE]
- * - [GATT_CONN_L2C_FAILURE]
- * - [GATT_CONN_TIMEOUT]
- * - [GATT_CONN_TERMINATE_PEER_USER]
- * - [GATT_CONN_TERMINATE_LOCAL_HOST]
- * - [GATT_CONN_FAIL_ESTABLISH]
- * - [GATT_CONN_LMP_TIMEOUT]
- * - [GATT_CONN_CANCEL]
- */
-typealias GattConnectionStatus = Int
-
-/**
- * Represents the possible GATT states as defined in [BluetoothProfile]:
- *
- * - [BluetoothProfile.STATE_DISCONNECTED]
- * - [BluetoothProfile.STATE_CONNECTING]
- * - [BluetoothProfile.STATE_CONNECTED]
- * - [BluetoothProfile.STATE_DISCONNECTING]
- */
-typealias GattConnectionState = Int
-
-/**
- * Represents the possible GATT statuses as defined in [BluetoothGatt]:
- *
- * - [BluetoothGatt.GATT_SUCCESS]
- * - [BluetoothGatt.GATT_READ_NOT_PERMITTED]
- * - [BluetoothGatt.GATT_WRITE_NOT_PERMITTED]
- * - [BluetoothGatt.GATT_INSUFFICIENT_AUTHENTICATION]
- * - [BluetoothGatt.GATT_REQUEST_NOT_SUPPORTED]
- * - [BluetoothGatt.GATT_INSUFFICIENT_ENCRYPTION]
- * - [BluetoothGatt.GATT_INVALID_OFFSET]
- * - [BluetoothGatt.GATT_INVALID_ATTRIBUTE_LENGTH]
- * - [BluetoothGatt.GATT_CONNECTION_CONGESTED]
- * - [BluetoothGatt.GATT_FAILURE]
- */
-typealias GattStatus = Int
-
-/**
- * Represents the possible [BluetoothGattCharacteristic] write types:
- *
- * - [BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT]
- * - [BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE]
- * - [BluetoothGattCharacteristic.WRITE_TYPE_SIGNED]
- */
-typealias WriteType = Int
-
-class ConnectionLost : Exception()
-
-class GattStatusFailure(
-    val event: OnConnectionStateChange
-) : IllegalStateException("Received $event")
-
-interface Gatt {
-
-    @FlowPreview
-    val onConnectionStateChange: Flow<OnConnectionStateChange>
-
-    @FlowPreview
-    val onCharacteristicChanged: Flow<OnCharacteristicChanged>
-
-    /**
-     * @throws [RemoteException] if underlying [BluetoothGatt.discoverServices] returns `false`.
-     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
-     */
-    suspend fun discoverServices(): GattStatus
-
-    val services: List<BluetoothGattService>
-    fun getService(uuid: UUID): BluetoothGattService?
-
-    /**
-     * @throws [RemoteException] if underlying [BluetoothGatt.requestMtu] returns `false`.
-     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
-     */
-    suspend fun requestMtu(mtu: Int): OnMtuChanged
-    suspend fun readRemoteRssi(): OnReadRemoteRssi
-
-    /**
-     * @throws [RemoteException] if underlying [BluetoothGatt.readCharacteristic] returns `false`.
-     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
-     */
-    suspend fun readCharacteristic(
-        characteristic: BluetoothGattCharacteristic
-    ): OnCharacteristicRead
-
-    /**
-     * @param value applied to [characteristic] when characteristic is written.
-     * @param writeType applied to [characteristic] when characteristic is written.
-     * @throws [RemoteException] if underlying [BluetoothGatt.writeCharacteristic] returns `false`.
-     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
-     */
-    suspend fun writeCharacteristic(
-        characteristic: BluetoothGattCharacteristic,
-        value: ByteArray,
-        writeType: WriteType
-    ): OnCharacteristicWrite
-
-    /**
-     * @param value applied to [descriptor] when descriptor is written.
-     * @throws [RemoteException] if underlying [BluetoothGatt.writeDescriptor] returns `false`.
-     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
-     */
-    suspend fun writeDescriptor(
-        descriptor: BluetoothGattDescriptor,
-        value: ByteArray
-    ): OnDescriptorWrite
-
-    fun setCharacteristicNotification(
-        characteristic: BluetoothGattCharacteristic,
-        enable: Boolean
-    ): Boolean
-
-    suspend fun disconnect(): Unit
-}
-
-suspend fun Gatt.writeCharacteristic(
-    characteristic: BluetoothGattCharacteristic,
-    value: ByteArray
-): OnCharacteristicWrite = writeCharacteristic(characteristic, value, WRITE_TYPE_DEFAULT)
-
-internal suspend fun Gatt.suspendUntilConnectionState(state: GattConnectionState) {
-    Able.debug { "Suspending until ${state.asGattConnectionStateString()}" }
-    onConnectionStateChange
-        .onEach { event ->
-            Able.verbose { "← Received $event while waiting for ${state.asGattConnectionStateString()}" }
-            if (event.status != GATT_SUCCESS) throw GattStatusFailure(event)
-        }
-        .firstOrNull { (_, newState) -> newState == state }
-        .also {
-            if (it == null) { // Upstream Channel closed due to STATE_DISCONNECTED.
-                if (state == STATE_DISCONNECTED) {
-                    Able.info { "Reached (implicit) STATE_DISCONNECTED" }
-                } else {
-                    throw ConnectionLost()
-                }
-            }
-        }
-        ?.also { (_, newState) ->
-            Able.info { "Reached ${newState.asGattConnectionStateString()}" }
-        }
-}
+interface Gatt : GattConnection, GattIo

core/src/main/java/gatt/GattConnection.kt

@@ -0,0 +1,77 @@
+/*
+ * Copyright 2020 JUUL Labs, Inc.
+ */
+
+@file:Suppress("RedundantUnitReturnType")
+
+package com.juul.able.gatt
+
+import android.bluetooth.BluetoothGatt.GATT_SUCCESS
+import android.bluetooth.BluetoothProfile
+import android.bluetooth.BluetoothProfile.STATE_DISCONNECTED
+import com.juul.able.Able
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.flow.Flow
+import kotlinx.coroutines.flow.firstOrNull
+import kotlinx.coroutines.flow.onEach
+
+/**
+ * Represents the possible GATT connection statuses as defined in the Android source code.
+ *
+ * - [GATT_SUCCESS]
+ * - [GATT_CONN_L2C_FAILURE]
+ * - [GATT_CONN_L2C_FAILURE]
+ * - [GATT_CONN_TIMEOUT]
+ * - [GATT_CONN_TERMINATE_PEER_USER]
+ * - [GATT_CONN_TERMINATE_LOCAL_HOST]
+ * - [GATT_CONN_FAIL_ESTABLISH]
+ * - [GATT_CONN_LMP_TIMEOUT]
+ * - [GATT_CONN_CANCEL]
+ */
+typealias GattConnectionStatus = Int
+
+/**
+ * Represents the possible GATT states as defined in [BluetoothProfile]:
+ *
+ * - [BluetoothProfile.STATE_DISCONNECTED]
+ * - [BluetoothProfile.STATE_CONNECTING]
+ * - [BluetoothProfile.STATE_CONNECTED]
+ * - [BluetoothProfile.STATE_DISCONNECTING]
+ */
+typealias GattConnectionState = Int
+
+interface GattConnection {
+
+    @FlowPreview
+    val onConnectionStateChange: Flow<OnConnectionStateChange>
+
+    suspend fun disconnect(): Unit
+}
+
+class GattStatusFailure(
+    val event: OnConnectionStateChange
+) : IllegalStateException("Received $event")
+
+class ConnectionLost : Exception()
+
+internal suspend fun GattConnection.suspendUntilConnectionState(state: GattConnectionState) {
+    Able.debug { "Suspending until ${state.asGattConnectionStateString()}" }
+    onConnectionStateChange
+        .onEach { event ->
+            Able.verbose { "← Received $event while waiting for ${state.asGattConnectionStateString()}" }
+            if (event.status != GATT_SUCCESS) throw GattStatusFailure(event)
+        }
+        .firstOrNull { (_, newState) -> newState == state }
+        .also {
+            if (it == null) { // Upstream Channel closed due to STATE_DISCONNECTED.
+                if (state == STATE_DISCONNECTED) {
+                    Able.info { "Reached (implicit) STATE_DISCONNECTED" }
+                } else {
+                    throw ConnectionLost()
+                }
+            }
+        }
+        ?.also { (_, newState) ->
+            Able.info { "Reached ${newState.asGattConnectionStateString()}" }
+        }
+}

core/src/main/java/gatt/GattIo.kt

@@ -0,0 +1,103 @@
+/*
+ * Copyright 2020 JUUL Labs, Inc.
+ */
+
+package com.juul.able.gatt
+
+import android.bluetooth.BluetoothGatt
+import android.bluetooth.BluetoothGattCharacteristic
+import android.bluetooth.BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT
+import android.bluetooth.BluetoothGattDescriptor
+import android.bluetooth.BluetoothGattService
+import android.os.RemoteException
+import java.util.UUID
+import kotlinx.coroutines.FlowPreview
+import kotlinx.coroutines.flow.Flow
+
+/**
+ * Represents the possible GATT statuses as defined in [BluetoothGatt]:
+ *
+ * - [BluetoothGatt.GATT_SUCCESS]
+ * - [BluetoothGatt.GATT_READ_NOT_PERMITTED]
+ * - [BluetoothGatt.GATT_WRITE_NOT_PERMITTED]
+ * - [BluetoothGatt.GATT_INSUFFICIENT_AUTHENTICATION]
+ * - [BluetoothGatt.GATT_REQUEST_NOT_SUPPORTED]
+ * - [BluetoothGatt.GATT_INSUFFICIENT_ENCRYPTION]
+ * - [BluetoothGatt.GATT_INVALID_OFFSET]
+ * - [BluetoothGatt.GATT_INVALID_ATTRIBUTE_LENGTH]
+ * - [BluetoothGatt.GATT_CONNECTION_CONGESTED]
+ * - [BluetoothGatt.GATT_FAILURE]
+ */
+typealias GattStatus = Int
+
+/**
+ * Represents the possible [BluetoothGattCharacteristic] write types:
+ *
+ * - [BluetoothGattCharacteristic.WRITE_TYPE_DEFAULT]
+ * - [BluetoothGattCharacteristic.WRITE_TYPE_NO_RESPONSE]
+ * - [BluetoothGattCharacteristic.WRITE_TYPE_SIGNED]
+ */
+typealias WriteType = Int
+
+interface GattIo {
+
+    /**
+     * @throws [RemoteException] if underlying [BluetoothGatt.discoverServices] returns `false`.
+     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
+     */
+    suspend fun discoverServices(): GattStatus
+
+    val services: List<BluetoothGattService>
+    fun getService(uuid: UUID): BluetoothGattService?
+
+    @FlowPreview
+    val onCharacteristicChanged: Flow<OnCharacteristicChanged>
+
+    /**
+     * @throws [RemoteException] if underlying [BluetoothGatt.requestMtu] returns `false`.
+     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
+     */
+    suspend fun requestMtu(mtu: Int): OnMtuChanged
+
+    /**
+     * @throws [RemoteException] if underlying [BluetoothGatt.readCharacteristic] returns `false`.
+     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
+     */
+    suspend fun readCharacteristic(
+        characteristic: BluetoothGattCharacteristic
+    ): OnCharacteristicRead
+
+    /**
+     * @param value applied to [characteristic] when characteristic is written.
+     * @param writeType applied to [characteristic] when characteristic is written.
+     * @throws [RemoteException] if underlying [BluetoothGatt.writeCharacteristic] returns `false`.
+     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
+     */
+    suspend fun writeCharacteristic(
+        characteristic: BluetoothGattCharacteristic,
+        value: ByteArray,
+        writeType: WriteType
+    ): OnCharacteristicWrite
+
+    /**
+     * @param value applied to [descriptor] when descriptor is written.
+     * @throws [RemoteException] if underlying [BluetoothGatt.writeDescriptor] returns `false`.
+     * @throws [ConnectionLost] if [Gatt] disconnects while method is executing.
+     */
+    suspend fun writeDescriptor(
+        descriptor: BluetoothGattDescriptor,
+        value: ByteArray
+    ): OnDescriptorWrite
+
+    fun setCharacteristicNotification(
+        characteristic: BluetoothGattCharacteristic,
+        enable: Boolean
+    ): Boolean
+
+    suspend fun readRemoteRssi(): OnReadRemoteRssi
+}
+
+suspend fun GattIo.writeCharacteristic(
+    characteristic: BluetoothGattCharacteristic,
+    value: ByteArray
+): OnCharacteristicWrite = writeCharacteristic(characteristic, value, WRITE_TYPE_DEFAULT)

processor/src/main/java/GattProcessor.kt

@@ -6,18 +6,18 @@ package com.juul.able.processor
 
 import android.bluetooth.BluetoothGattCharacteristic
 import android.bluetooth.BluetoothGattDescriptor
-import com.juul.able.gatt.Gatt
+import com.juul.able.gatt.GattIo
 import com.juul.able.gatt.OnCharacteristicRead
 import com.juul.able.gatt.OnCharacteristicWrite
 import com.juul.able.gatt.OnDescriptorWrite
 import com.juul.able.gatt.WriteType
 
-fun Gatt.withProcessors(vararg processors: Processor) = GattProcessor(this, processors)
+fun GattIo.withProcessors(vararg processors: Processor) = GattProcessor(this, processors)
 
 class GattProcessor(
-    private val gatt: Gatt,
+    private val gatt: GattIo,
     private val processors: Array<out Processor>
-) : Gatt by gatt {
+) : GattIo by gatt {
 
     override suspend fun readCharacteristic(
         characteristic: BluetoothGattCharacteristic