feat: 支持获取 maximumWrtieLength (#14)

bluetooth_low_energy/CHANGELOG.md

@@ -1,51 +1,55 @@
+## 2.2.0
+
+* Add `CentralController#getMaximumWriteLength` method.
+
 ## 2.0.3
 
-- `Android` Migrate to Android 13.
+* `Android` Migrate to Android 13.
-- `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
+* `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
 
 ## 2.0.2
 
-- Combine iOS and macOS projects.
+* Combine iOS and macOS projects.
-- Optimize project structure.
+* Optimize project structure.
 
 ## 2.0.1
 
-- Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
+* Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
-- Fix the issue that create UUID form peripheral's address failed on Linux.
+* Fix the issue that create UUID form peripheral's address failed on Linux.
-- Fix the issue that instance match failed on Linux.
+* Fix the issue that instance match failed on Linux.
 
 ## 2.0.0
 
-- Rewrite the whole project with federated plugins.
+* Rewrite the whole project with federated plugins.
-- Support macOS and Linux.
+* Support macOS and Linux.
 
 ## 1.1.0
 
-- Fix the crash by onMtuChanged called multi-times on Android.
+* Fix the crash by onMtuChanged called multi-times on Android.
-- Fix the finalizer doesn't work issue.
+* Fix the finalizer doesn't work issue.
-- Make some break changes.
+* Make some break changes.
 
 ## 1.0.0
 
-- Upgrade to flutter 3.x.
+* Upgrade to flutter 3.x.
-- Rewrite the whole project with pigeon.
+* Rewrite the whole project with pigeon.
 
 ## 0.1.0
 
-- Add implementations on iOS.
+* Add implementations on iOS.
-- Combine available and state for Bluetooth.
+* Combine available and state for Bluetooth.
-- Add connectable for Discovery.
+* Add connectable for Discovery.
-- Add maximumWriteLength for GATT.
+* Add maximumWriteLength for GATT.
 
 ## 0.0.2
 
-- Fix connect blocked when bluetooth closed.
+* Fix connect blocked when bluetooth closed.
-- Fix wrong repository url.
+* Fix wrong repository url.
-- Move all example files to main.dart.
+* Move all example files to main.dart.
 
 ## 0.0.1
 
-- Add central APIs.
+* Add central APIs.
-- Add implementations on Android.
+* Add implementations on Android.
-- Add example.
+* Add example.
-- Add test.
+* Add test.

bluetooth_low_energy/example/lib/main.dart

@@ -162,10 +162,10 @@ class _HomeViewState extends State<HomeView> {
     return ValueListenableBuilder(
       valueListenable: discoveredEventArgs,
       builder: (context, discoveredEventArgs, child) {
-        // final items = discoveredEventArgs
+        // final items = discoveredEventArgs;
-        //     .where((eventArgs) => eventArgs.advertisement.name != null)
+        final items = discoveredEventArgs
-        //     .toList();
+            .where((eventArgs) => eventArgs.advertisement.name != null)
-        final items = discoveredEventArgs;
+            .toList();
         return ListView.separated(
           itemBuilder: (context, i) {
             final theme = Theme.of(context);
@@ -303,8 +303,10 @@ class _PeripheralViewState extends State<PeripheralView> {
   late final ValueNotifier<List<GattCharacteristic>> characteristics;
   late final ValueNotifier<GattService?> service;
   late final ValueNotifier<GattCharacteristic?> characteristic;
-  late final TextEditingController writeController;
+  late final ValueNotifier<GattCharacteristicWriteType> writeType;
+  late final ValueNotifier<int> maximumWriteLength;
   late final ValueNotifier<List<Log>> logs;
+  late final TextEditingController writeController;
   late final StreamSubscription stateChangedSubscription;
   late final StreamSubscription valueChangedSubscription;
 
@@ -317,8 +319,10 @@ class _PeripheralViewState extends State<PeripheralView> {
     characteristics = ValueNotifier([]);
     service = ValueNotifier(null);
     characteristic = ValueNotifier(null);
-    writeController = TextEditingController();
+    writeType = ValueNotifier(GattCharacteristicWriteType.withResponse);
+    maximumWriteLength = ValueNotifier(20);
     logs = ValueNotifier([]);
+    writeController = TextEditingController();
     stateChangedSubscription = centralController.peripheralStateChanged.listen(
       (eventArgs) {
         if (eventArgs.peripheral != this.eventArgs.peripheral) {
@@ -519,6 +523,64 @@ class _PeripheralViewState extends State<PeripheralView> {
               },
             ),
           ),
+          Row(
+            children: [
+              Expanded(
+                child: Center(
+                  child: ValueListenableBuilder(
+                    valueListenable: writeType,
+                    builder: (context, writeType, child) {
+                      final items =
+                          GattCharacteristicWriteType.values.map((type) {
+                        return DropdownMenuItem(
+                          value: type,
+                          child: Text(
+                            type.name,
+                            style: theme.textTheme.bodyMedium,
+                          ),
+                        );
+                      }).toList();
+                      return DropdownButton(
+                        items: items,
+                        onChanged: (type) {
+                          if (type == null) {
+                            return;
+                          }
+                          this.writeType.value = type;
+                        },
+                        value: writeType,
+                        underline: const Offstage(),
+                      );
+                    },
+                  ),
+                ),
+              ),
+              Expanded(
+                child: ValueListenableBuilder(
+                  valueListenable: state,
+                  builder: (context, state, child) {
+                    return TextButton(
+                      onPressed: state
+                          ? () async {
+                              maximumWriteLength.value =
+                                  await centralController.getMaximumWriteLength(
+                                eventArgs.peripheral,
+                                type: writeType.value,
+                              );
+                            }
+                          : null,
+                      child: ValueListenableBuilder(
+                        valueListenable: maximumWriteLength,
+                        builder: (context, maximumWriteLength, child) {
+                          return Text('MTU: $maximumWriteLength');
+                        },
+                      ),
+                    );
+                  },
+                ),
+              ),
+            ],
+          ),
           Container(
             margin: const EdgeInsets.symmetric(vertical: 16.0),
             height: 160.0,
@@ -626,6 +688,10 @@ class _PeripheralViewState extends State<PeripheralView> {
     characteristics.dispose();
     service.dispose();
     characteristic.dispose();
+    writeType.dispose();
+    maximumWriteLength.dispose();
+    logs.dispose();
+    writeController.dispose();
   }
 }
 

bluetooth_low_energy/example/pubspec.lock

@@ -23,47 +23,47 @@ packages:
       path: ".."
       relative: true
     source: path
-    version: "2.0.3"
+    version: "2.2.0"
   bluetooth_low_energy_android:
     dependency: transitive
     description:
       name: bluetooth_low_energy_android
-      sha256: e740179e5143c74e2f308c78d395d49054c941b95eb776884d52192b80ccfcee
+      sha256: fde30d9ef058f6859266a8e6d4218136958366de5978f69df2bb37d2b24679eb
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.3"
+    version: "2.2.0"
   bluetooth_low_energy_darwin:
     dependency: transitive
     description:
       name: bluetooth_low_energy_darwin
-      sha256: "49e9dc08281fb25f91472252dfbdf7d1d6d94983bf2e746382ad4b2dd8ba05fe"
+      sha256: "876f2d4a288739091296bc22ea574e64451f592154e4201b5999f174120a8b55"
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.3"
+    version: "2.2.0"
   bluetooth_low_energy_linux:
     dependency: transitive
     description:
       name: bluetooth_low_energy_linux
-      sha256: d9576d89471e31b76cb2495dbb72aabaadc3aa093ad607f5aedb15518d5c20cb
+      sha256: dc3062991e0a408941829326f0a3b2e1244a8138dca7f6c4c6beadbc26deecb2
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.3"
+    version: "2.2.0"
   bluetooth_low_energy_platform_interface:
     dependency: transitive
     description:
       name: bluetooth_low_energy_platform_interface
-      sha256: dbc05f604e379ea7570db718a9ae7cf7fa08a20ee088a6f66de17b4acc7d9260
+      sha256: eecaa2c37ebd536339c292d5566cf4360c9ea3861188342791eb3a0cf65cc64c
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.3"
+    version: "2.2.0"
   bluetooth_low_energy_windows:
     dependency: transitive
     description:
       name: bluetooth_low_energy_windows
-      sha256: c4d11b2769da214b5ea20f50980c00f3c3229450e46f9d075cd64298e5a27057
+      sha256: a1b5d5d5ad935f15618e6a86334c1ec682c40ffbe6a78173c3f19b67ff0edcfb
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.3"
+    version: "2.2.0"
   bluez:
     dependency: transitive
     description:
@@ -116,10 +116,10 @@ packages:
     dependency: "direct main"
     description:
       name: cupertino_icons
-      sha256: e35129dc44c9118cee2a5603506d823bab99c68393879edb440e0090d07586be
+      sha256: d57953e10f9f8327ce64a508a355f0b1ec902193f66288e8cb5070e7c47eeb2d
       url: "https://pub.dev"
     source: hosted
-    version: "1.0.5"
+    version: "1.0.6"
   dbus:
     dependency: transitive
     description:
@@ -166,10 +166,10 @@ packages:
     dependency: "direct dev"
     description:
       name: flutter_lints
-      sha256: "2118df84ef0c3ca93f96123a616ae8540879991b8b57af2f81b76a7ada49b2a4"
+      sha256: a25a15ebbdfc33ab1cd26c63a6ee519df92338a9c10f122adda92938253bef04
       url: "https://pub.dev"
     source: hosted
-    version: "2.0.2"
+    version: "2.0.3"
   flutter_test:
     dependency: "direct dev"
     description: flutter
@@ -253,10 +253,10 @@ packages:
     dependency: transitive
     description:
       name: plugin_platform_interface
-      sha256: "43798d895c929056255600343db8f049921cbec94d31ec87f1dc5c16c01935dd"
+      sha256: da3fdfeccc4d4ff2da8f8c556704c08f912542c5fb3cf2233ed75372384a034d
       url: "https://pub.dev"
     source: hosted
-    version: "2.1.5"
+    version: "2.1.6"
   process:
     dependency: transitive
     description:
@@ -370,10 +370,10 @@ packages:
     dependency: transitive
     description:
       name: win32
-      sha256: f2add6fa510d3ae152903412227bda57d0d5a8da61d2c39c1fb022c9429a41c0
+      sha256: "9e82a402b7f3d518fb9c02d0e9ae45952df31b9bf34d77baf19da2de03fc2aaa"
       url: "https://pub.dev"
     source: hosted
-    version: "5.0.6"
+    version: "5.0.7"
   xml:
     dependency: transitive
     description:

bluetooth_low_energy/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bluetooth_low_energy
 description: A Flutter plugin for controlling the bluetooth low energy.
-version: 2.0.3
+version: 2.2.0
 homepage: https://github.com/yanshouwang/bluetooth_low_energy
 
 environment:
@@ -10,11 +10,11 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  bluetooth_low_energy_platform_interface: ^2.0.3
+  bluetooth_low_energy_platform_interface: ^2.2.0
-  bluetooth_low_energy_android: ^2.0.3
+  bluetooth_low_energy_android: ^2.2.0
-  bluetooth_low_energy_darwin: ^2.0.3
+  bluetooth_low_energy_darwin: ^2.2.0
-  bluetooth_low_energy_linux: ^2.0.3
+  bluetooth_low_energy_linux: ^2.2.0
-  bluetooth_low_energy_windows: ^2.0.3
+  bluetooth_low_energy_windows: ^2.2.0
 
 dev_dependencies:
   flutter_test:

bluetooth_low_energy_android/CHANGELOG.md

@@ -1,20 +1,24 @@
+## 2.2.0
+
+* Add `CentralController#getMaximumWriteLength` method.
+
 ## 2.0.3
 
-- `Android` Migrate to Android 13.
+* `Android` Migrate to Android 13.
-- `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
+* `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
 
 ## 2.0.2
 
-- Combine iOS and macOS projects.
+* Combine iOS and macOS projects.
-- Optimize project structure.
+* Optimize project structure.
 
 ## 2.0.1
 
-- Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
+* Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
-- Fix the issue that create UUID form peripheral's address failed on Linux.
+* Fix the issue that create UUID form peripheral's address failed on Linux.
-- Fix the issue that instance match failed on Linux.
+* Fix the issue that instance match failed on Linux.
 
 ## 2.0.0
 
-- Rewrite the whole project with federated plugins.
+* Rewrite the whole project with federated plugins.
-- Support macOS and Linux.
+* Support macOS and Linux.

bluetooth_low_energy_android/android/src/main/kotlin/dev/yanshouwang/bluetooth_low_energy_android/MyApi.g.kt

@@ -278,6 +278,7 @@ interface MyCentralControllerHostApi {
   fun stopDiscovery()
   fun connect(myPeripheralKey: Long, callback: (Result<Unit>) -> Unit)
   fun disconnect(myPeripheralKey: Long, callback: (Result<Unit>) -> Unit)
+  fun getMaximumWriteLength(myPeripheralKey: Long, callback: (Result<Long>) -> Unit)
   fun discoverGATT(myPeripheralKey: Long, callback: (Result<Unit>) -> Unit)
   fun getServices(myPeripheralKey: Long): List<MyGattServiceArgs>
   fun getCharacteristics(myServiceKey: Long): List<MyGattCharacteristicArgs>
@@ -403,6 +404,26 @@ interface MyCentralControllerHostApi {
           channel.setMessageHandler(null)
         }
       }
+      run {
+        val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.bluetooth_low_energy_android.MyCentralControllerHostApi.getMaximumWriteLength", codec)
+        if (api != null) {
+          channel.setMessageHandler { message, reply ->
+            val args = message as List<Any?>
+            val myPeripheralKeyArg = args[0].let { if (it is Int) it.toLong() else it as Long }
+            api.getMaximumWriteLength(myPeripheralKeyArg) { result: Result<Long> ->
+              val error = result.exceptionOrNull()
+              if (error != null) {
+                reply.reply(wrapError(error))
+              } else {
+                val data = result.getOrNull()
+                reply.reply(wrapResult(data))
+              }
+            }
+          }
+        } else {
+          channel.setMessageHandler(null)
+        }
+      }
       run {
         val channel = BasicMessageChannel<Any?>(binaryMessenger, "dev.flutter.pigeon.bluetooth_low_energy_android.MyCentralControllerHostApi.discoverGATT", codec)
         if (api != null) {

bluetooth_low_energy_android/android/src/main/kotlin/dev/yanshouwang/bluetooth_low_energy_android/MyBluetoothGattCallback.kt

@@ -15,6 +15,13 @@ class MyBluetoothGattCallback(private val myCentralController: MyCentralControll
         }
     }
 
+    override fun onMtuChanged(gatt: BluetoothGatt, mtu: Int, status: Int) {
+        super.onMtuChanged(gatt, mtu, status)
+        executor.execute {
+            myCentralController.onMtuChanged(gatt, mtu, status)
+        }
+    }
+
     override fun onServicesDiscovered(gatt: BluetoothGatt, status: Int) {
         super.onServicesDiscovered(gatt, status)
         executor.execute {

bluetooth_low_energy_android/android/src/main/kotlin/dev/yanshouwang/bluetooth_low_energy_android/MyCentralController.kt

@@ -59,6 +59,7 @@ class MyCentralController(private val context: Context, binaryMessenger: BinaryM
     private var startDiscoveryCallback: ((Result<Unit>) -> Unit)? = null
     private val connectCallbacks = mutableMapOf<Int, (Result<Unit>) -> Unit>()
     private val disconnectCallbacks = mutableMapOf<Int, (Result<Unit>) -> Unit>()
+    private val getMaximumWriteLengthCallbacks = mutableMapOf<Int, (Result<Long>) -> Unit>()
     private val discoverGattCallbacks = mutableMapOf<Int, (Result<Unit>) -> Unit>()
     private val readCharacteristicCallbacks = mutableMapOf<Int, (Result<ByteArray>) -> Unit>()
     private val writeCharacteristicCallbacks = mutableMapOf<Int, (Result<Unit>) -> Unit>()
@@ -179,6 +180,24 @@ class MyCentralController(private val context: Context, binaryMessenger: BinaryM
         }
     }
 
+    override fun getMaximumWriteLength(myPeripheralKey: Long, callback: (Result<Long>) -> Unit) {
+        try {
+            val deviceKey = myPeripheralKey.toInt()
+            val unfinishedCallback = getMaximumWriteLengthCallbacks[deviceKey]
+            if (unfinishedCallback != null) {
+                throw IllegalStateException()
+            }
+            val gatt = cachedGATTs[deviceKey] as BluetoothGatt
+            val requesting = gatt.requestMtu(512)
+            if (!requesting) {
+                throw IllegalStateException()
+            }
+            getMaximumWriteLengthCallbacks[deviceKey] = callback
+        } catch (e: Throwable) {
+            callback(Result.failure(e))
+        }
+    }
+
     override fun discoverGATT(myPeripheralKey: Long, callback: (Result<Unit>) -> Unit) {
         try {
             val deviceKey = myPeripheralKey.toInt()
@@ -493,6 +512,19 @@ class MyCentralController(private val context: Context, binaryMessenger: BinaryM
         }
     }
 
+    fun onMtuChanged(gatt: BluetoothGatt, mtu: Int, status: Int) {
+        val device = gatt.device
+        val deviceKey = device.hashCode()
+        val callback = getMaximumWriteLengthCallbacks.remove(deviceKey) ?: return
+        if (status == BluetoothGatt.GATT_SUCCESS) {
+            val maximumWriteLength = (mtu - 3).toLong()
+            callback(Result.success(maximumWriteLength))
+        } else {
+            val error = IllegalStateException("Get maximum write length failed with status: $status")
+            callback(Result.failure(error))
+        }
+    }
+
     fun onServicesDiscovered(gatt: BluetoothGatt, status: Int) {
         val device = gatt.device
         val deviceKey = device.hashCode()
@@ -609,7 +641,8 @@ private val ScanResult.myAdvertisementArgs: MyAdvertisementArgs
         } else {
             val name = record.deviceName
             val manufacturerSpecificData = record.manufacturerSpecificData.toMyArgs()
-            val serviceUUIDs = record.serviceUuids?.map { uuid -> uuid.toString() } ?: emptyList()
+            val serviceUUIDs = record.serviceUuids?.map { uuid -> uuid.toString() }
+                    ?: emptyList()
             val pairs = record.serviceData.entries.map { (uuid, value) ->
                 val key = uuid.toString()
                 return@map Pair(key, value)

bluetooth_low_energy_android/lib/src/my_api.g.dart

@@ -380,6 +380,33 @@ class MyCentralControllerHostApi {
     }
   }
 
+  Future<int> getMaximumWriteLength(int arg_myPeripheralKey) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.bluetooth_low_energy_android.MyCentralControllerHostApi.getMaximumWriteLength', codec,
+        binaryMessenger: _binaryMessenger);
+    final List<Object?>? replyList =
+        await channel.send(<Object?>[arg_myPeripheralKey]) as List<Object?>?;
+    if (replyList == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else if (replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyList[0] as int?)!;
+    }
+  }
+
   Future<void> discoverGATT(int arg_myPeripheralKey) async {
     final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
         'dev.flutter.pigeon.bluetooth_low_energy_android.MyCentralControllerHostApi.discoverGATT', codec,

bluetooth_low_energy_android/lib/src/my_central_controller.dart

@@ -114,6 +114,19 @@ class MyCentralController extends CentralController
     await _myApi.disconnect(myPeripheral.hashCode);
   }
 
+  @override
+  Future<int> getMaximumWriteLength(
+    Peripheral peripheral, {
+    required GattCharacteristicWriteType type,
+  }) async {
+    await _throwWithoutState(CentralState.poweredOn);
+    final myPeripheral = peripheral as MyPeripheral;
+    final maximumWriteLength = await _myApi.getMaximumWriteLength(
+      myPeripheral.hashCode,
+    );
+    return maximumWriteLength;
+  }
+
   @override
   Future<void> discoverGATT(Peripheral peripheral) async {
     await _throwWithoutState(CentralState.poweredOn);
@@ -205,14 +218,14 @@ class MyCentralController extends CentralController
     final myCharacteristic = characteristic as MyGattCharacteristic;
     final myService = myCharacteristic.myService;
     final myPeripheral = myService.myPeripheral;
-    final typeArgs = type.toMyArgs();
+    final myTypeArgs = type.toMyArgs();
-    final typeNumber = typeArgs.index;
+    final myTypeNumber = myTypeArgs.index;
     await _myApi.writeCharacteristic(
       myPeripheral.hashCode,
       myService.hashCode,
       myCharacteristic.hashCode,
       value,
-      typeNumber,
+      myTypeNumber,
     );
   }
 

bluetooth_low_energy_android/my_api.dart

@@ -24,6 +24,8 @@ abstract class MyCentralControllerHostApi {
   @async
   void disconnect(int myPeripheralKey);
   @async
+  int getMaximumWriteLength(int myPeripheralKey);
+  @async
   void discoverGATT(int myPeripheralKey);
   List<MyGattServiceArgs> getServices(int myPeripheralKey);
   List<MyGattCharacteristicArgs> getCharacteristics(int myServiceKey);

bluetooth_low_energy_android/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bluetooth_low_energy_android
 description: Android implementation of the bluetooth_low_energy plugin.
-version: 2.0.3
+version: 2.2.0
 homepage: https://github.com/yanshouwang/bluetooth_low_energy
 
 environment:
@@ -10,7 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  bluetooth_low_energy_platform_interface: ^2.0.3
+  bluetooth_low_energy_platform_interface: ^2.2.0
 
 dev_dependencies:
   flutter_test:

bluetooth_low_energy_darwin/CHANGELOG.md

@@ -1,9 +1,13 @@
+## 2.2.0
+
+* Add `CentralController#getMaximumWriteLength` method.
+
 ## 2.0.3
 
-- `Android` Migrate to Android 13.
+* `Android` Migrate to Android 13.
-- `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
+* `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
 
 ## 2.0.2
 
-- Combine iOS and macOS projects.
+* Combine iOS and macOS projects.
-- Optimize project structure.
+* Optimize project structure.

bluetooth_low_energy_darwin/darwin/Classes/MyApi.g.swift

@@ -254,6 +254,7 @@ protocol MyCentralControllerHostApi {
   func stopDiscovery() throws
   func connect(myPeripheralKey: Int64, completion: @escaping (Result<Void, Error>) -> Void)
   func disconnect(myPeripheralKey: Int64, completion: @escaping (Result<Void, Error>) -> Void)
+  func getMaximumWriteLength(myPeripheralKey: Int64, myTypeNumber: Int64) throws -> Int64
   func discoverGATT(myPeripheralKey: Int64, completion: @escaping (Result<Void, Error>) -> Void)
   func getServices(myPeripheralKey: Int64) throws -> [MyGattServiceArgs]
   func getCharacteristics(myServiceKey: Int64) throws -> [MyGattCharacteristicArgs]
@@ -359,6 +360,22 @@ class MyCentralControllerHostApiSetup {
     } else {
       disconnectChannel.setMessageHandler(nil)
     }
+    let getMaximumWriteLengthChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.bluetooth_low_energy_darwin.MyCentralControllerHostApi.getMaximumWriteLength", binaryMessenger: binaryMessenger, codec: codec)
+    if let api = api {
+      getMaximumWriteLengthChannel.setMessageHandler { message, reply in
+        let args = message as! [Any?]
+        let myPeripheralKeyArg = args[0] is Int64 ? args[0] as! Int64 : Int64(args[0] as! Int32)
+        let myTypeNumberArg = args[1] is Int64 ? args[1] as! Int64 : Int64(args[1] as! Int32)
+        do {
+          let result = try api.getMaximumWriteLength(myPeripheralKey: myPeripheralKeyArg, myTypeNumber: myTypeNumberArg)
+          reply(wrapResult(result))
+        } catch {
+          reply(wrapError(error))
+        }
+      }
+    } else {
+      getMaximumWriteLengthChannel.setMessageHandler(nil)
+    }
     let discoverGATTChannel = FlutterBasicMessageChannel(name: "dev.flutter.pigeon.bluetooth_low_energy_darwin.MyCentralControllerHostApi.discoverGATT", binaryMessenger: binaryMessenger, codec: codec)
     if let api = api {
       discoverGATTChannel.setMessageHandler { message, reply in

bluetooth_low_energy_darwin/darwin/Classes/MyCentralController.swift

@@ -122,6 +122,21 @@ class MyCentralController: MyCentralControllerHostApi {
         }
     }
     
+    func getMaximumWriteLength(myPeripheralKey: Int64, myTypeNumber: Int64) throws -> Int64 {
+        let peripheralKey = Int(myPeripheralKey)
+        guard let peripheral = cachedPeripherals[peripheralKey] else {
+            throw MyError.illegalArgument
+        }
+        let myTypeRawValue = Int(myTypeNumber)
+        guard let myTypeArgs = MyGattCharacteristicWriteTypeArgs(rawValue: myTypeRawValue) else {
+            throw MyError.illegalArgument
+        }
+        let type = myTypeArgs.toType()
+        let maximumWriteLength32 = peripheral.maximumWriteValueLength(for: type)
+        let maximumWriteLength = Int64(maximumWriteLength32)
+        return maximumWriteLength
+    }
+    
     func discoverGATT(myPeripheralKey: Int64, completion: @escaping (Result<Void, Error>) -> Void) {
         do {
             let peripheralKey = Int(myPeripheralKey)

bluetooth_low_energy_darwin/lib/src/my_api.g.dart

@@ -380,6 +380,33 @@ class MyCentralControllerHostApi {
     }
   }
 
+  Future<int> getMaximumWriteLength(int arg_myPeripheralKey, int arg_myTypeNumber) async {
+    final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
+        'dev.flutter.pigeon.bluetooth_low_energy_darwin.MyCentralControllerHostApi.getMaximumWriteLength', codec,
+        binaryMessenger: _binaryMessenger);
+    final List<Object?>? replyList =
+        await channel.send(<Object?>[arg_myPeripheralKey, arg_myTypeNumber]) as List<Object?>?;
+    if (replyList == null) {
+      throw PlatformException(
+        code: 'channel-error',
+        message: 'Unable to establish connection on channel.',
+      );
+    } else if (replyList.length > 1) {
+      throw PlatformException(
+        code: replyList[0]! as String,
+        message: replyList[1] as String?,
+        details: replyList[2],
+      );
+    } else if (replyList[0] == null) {
+      throw PlatformException(
+        code: 'null-error',
+        message: 'Host platform returned null value for non-null return value.',
+      );
+    } else {
+      return (replyList[0] as int?)!;
+    }
+  }
+
   Future<void> discoverGATT(int arg_myPeripheralKey) async {
     final BasicMessageChannel<Object?> channel = BasicMessageChannel<Object?>(
         'dev.flutter.pigeon.bluetooth_low_energy_darwin.MyCentralControllerHostApi.discoverGATT', codec,

bluetooth_low_energy_darwin/lib/src/my_central_controller.dart

@@ -114,6 +114,22 @@ class MyCentralController extends CentralController
     await _myApi.disconnect(myPeripheral.hashCode);
   }
 
+  @override
+  Future<int> getMaximumWriteLength(
+    Peripheral peripheral, {
+    required GattCharacteristicWriteType type,
+  }) async {
+    await _throwWithoutState(CentralState.poweredOn);
+    final myPeripheral = peripheral as MyPeripheral;
+    final myTypeArgs = type.toMyArgs();
+    final myTypeNumber = myTypeArgs.index;
+    final maximumWriteLength = await _myApi.getMaximumWriteLength(
+      myPeripheral.hashCode,
+      myTypeNumber,
+    );
+    return maximumWriteLength;
+  }
+
   @override
   Future<void> discoverGATT(Peripheral peripheral) async {
     await _throwWithoutState(CentralState.poweredOn);
@@ -206,14 +222,14 @@ class MyCentralController extends CentralController
     final myCharacteristic = characteristic as MyGattCharacteristic;
     final myService = myCharacteristic.myService;
     final myPeripheral = myService.myPeripheral;
-    final typeArgs = type.toMyArgs();
+    final myTypeArgs = type.toMyArgs();
-    final typeNumber = typeArgs.index;
+    final myTypeNumber = myTypeArgs.index;
     await _myApi.writeCharacteristic(
       myPeripheral.hashCode,
       myService.hashCode,
       myCharacteristic.hashCode,
       value,
-      typeNumber,
+      myTypeNumber,
     );
   }
 

bluetooth_low_energy_darwin/my_api.dart

@@ -19,6 +19,7 @@ abstract class MyCentralControllerHostApi {
   void connect(int myPeripheralKey);
   @async
   void disconnect(int myPeripheralKey);
+  int getMaximumWriteLength(int myPeripheralKey, int myTypeNumber);
   @async
   void discoverGATT(int myPeripheralKey);
   List<MyGattServiceArgs> getServices(int myPeripheralKey);

bluetooth_low_energy_darwin/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bluetooth_low_energy_darwin
 description: iOS and macOS implementation of the bluetooth_low_energy plugin.
-version: 2.0.3
+version: 2.2.0
 homepage: https://github.com/yanshouwang/bluetooth_low_energy
 
 environment:
@@ -10,7 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  bluetooth_low_energy_platform_interface: ^2.0.3
+  bluetooth_low_energy_platform_interface: ^2.2.0
 
 dev_dependencies:
   flutter_test:

bluetooth_low_energy_linux/CHANGELOG.md

@@ -1,20 +1,24 @@
+## 2.2.0
+
+* Add `CentralController#getMaximumWriteLength` method.
+
 ## 2.0.3
 
-- `Android` Migrate to Android 13.
+* `Android` Migrate to Android 13.
-- `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
+* `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
 
 ## 2.0.2
 
-- Combine iOS and macOS projects.
+* Combine iOS and macOS projects.
-- Optimize project structure.
+* Optimize project structure.
 
 ## 2.0.1
 
-- Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
+* Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
-- Fix the issue that create UUID form peripheral's address failed on Linux.
+* Fix the issue that create UUID form peripheral's address failed on Linux.
-- Fix the issue that instance match failed on Linux.
+* Fix the issue that instance match failed on Linux.
 
 ## 2.0.0
 
-- Rewrite the whole project with federated plugins.
+* Rewrite the whole project with federated plugins.
-- Support macOS and Linux.
+* Support macOS and Linux.

bluetooth_low_energy_linux/lib/src/my_central_controller.dart

@@ -163,6 +163,15 @@ class MyCentralController extends CentralController {
     await device.disconnect();
   }
 
+  @override
+  Future<int> getMaximumWriteLength(
+    Peripheral peripheral, {
+    required GattCharacteristicWriteType type,
+  }) async {
+    // TODO: 当前版本 `bluez` 插件不支持获取 MTU，返回最小值 20.
+    return 20;
+  }
+
   @override
   Future<void> discoverGATT(Peripheral peripheral) async {
     await _throwWithoutState(CentralState.poweredOn);

bluetooth_low_energy_linux/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bluetooth_low_energy_linux
 description: Linux implementation of the bluetooth_low_energy plugin.
-version: 2.0.3
+version: 2.2.0
 homepage: https://github.com/yanshouwang/bluetooth_low_energy
 
 environment:
@@ -10,7 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  bluetooth_low_energy_platform_interface: ^2.0.3
+  bluetooth_low_energy_platform_interface: ^2.2.0
   bluez: ^0.8.1
 
 dev_dependencies:

bluetooth_low_energy_platform_interface/CHANGELOG.md

@@ -1,20 +1,36 @@
+## 2.2.0
+
+* Add `GattCharacteristicWriteType` argument to `CentralController#getMaximumWriteLength` method.
+
+## 2.1.0
+
+* Bump version.
+
+## 2.0.5
+
+* Optimize project structure.
+
+## 2.0.4
+
+* Add `CentralController#getMaximumWriteLength` method.
+
 ## 2.0.3
 
-- `Android` Migrate to Android 13.
+* `Android` Migrate to Android 13.
-- `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
+* `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
 
 ## 2.0.2
 
-- Combine iOS and macOS projects.
+* Combine iOS and macOS projects.
-- Optimize project structure.
+* Optimize project structure.
 
 ## 2.0.1
 
-- Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
+* Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
-- Fix the issue that create UUID form peripheral's address failed on Linux.
+* Fix the issue that create UUID form peripheral's address failed on Linux.
-- Fix the issue that instance match failed on Linux.
+* Fix the issue that instance match failed on Linux.
 
 ## 2.0.0
 
-- Rewrite the whole project with federated plugins.
+* Rewrite the whole project with federated plugins.
-- Support macOS and Linux.
+* Support macOS and Linux.

bluetooth_low_energy_platform_interface/lib/src/central_controller.dart

@@ -73,6 +73,12 @@ abstract class CentralController extends PlatformInterface {
   /// Disconnects form the peripheral.
   Future<void> disconnect(Peripheral peripheral);
 
+  /// Gets the max length in bytes for a single write type of the peripheral.
+  Future<int> getMaximumWriteLength(
+    Peripheral peripheral, {
+    required GattCharacteristicWriteType type,
+  });
+
   /// Discovers GATT of the peripheral.
   Future<void> discoverGATT(Peripheral peripheral);
 

bluetooth_low_energy_platform_interface/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bluetooth_low_energy_platform_interface
 description: A common platform interface for the bluetooth_low_energy plugin.
-version: 2.0.3
+version: 2.2.0
 homepage: https://github.com/yanshouwang/bluetooth_low_energy
 
 environment:

bluetooth_low_energy_windows/CHANGELOG.md

@@ -1,20 +1,24 @@
+## 2.2.0
+
+* Add `CentralController#getMaximumWriteLength` method.
+
 ## 2.0.3
 
-- `Android` Migrate to Android 13.
+* `Android` Migrate to Android 13.
-- `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
+* `Android` Fix the issuce that receive wrong values caused by unsafe memory, see https://developer.android.com/reference/android/bluetooth/BluetoothGattCallback#onCharacteristicChanged(android.bluetooth.BluetoothGatt,%20android.bluetooth.BluetoothGattCharacteristic)
 
 ## 2.0.2
 
-- Combine iOS and macOS projects.
+* Combine iOS and macOS projects.
-- Optimize project structure.
+* Optimize project structure.
 
 ## 2.0.1
 
-- Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
+* Fix the issue that GATTs is cleared after peripheral disconnected on iOS and macOS.
-- Fix the issue that create UUID form peripheral's address failed on Linux.
+* Fix the issue that create UUID form peripheral's address failed on Linux.
-- Fix the issue that instance match failed on Linux.
+* Fix the issue that instance match failed on Linux.
 
 ## 2.0.0
 
-- Rewrite the whole project with federated plugins.
+* Rewrite the whole project with federated plugins.
-- Support macOS and Linux.
+* Support macOS and Linux.

bluetooth_low_energy_windows/lib/src/my_central_controller.dart

@@ -59,6 +59,15 @@ class MyCentralController extends CentralController {
     throw UnimplementedError();
   }
 
+  @override
+  Future<int> getMaximumWriteLength(
+    Peripheral peripheral, {
+    required GattCharacteristicWriteType type,
+  }) {
+    // TODO: implement getMaximumWriteLength
+    throw UnimplementedError();
+  }
+
   @override
   Future<void> discoverGATT(Peripheral peripheral) {
     // TODO: implement discoverGATT

bluetooth_low_energy_windows/pubspec.yaml

@@ -1,6 +1,6 @@
 name: bluetooth_low_energy_windows
 description: Windows implementation of the bluetooth_low_energy plugin.
-version: 2.0.3
+version: 2.2.0
 homepage: https://github.com/yanshouwang/bluetooth_low_energy
 
 environment:
@@ -10,7 +10,7 @@ environment:
 dependencies:
   flutter:
     sdk: flutter
-  bluetooth_low_energy_platform_interface: ^2.0.3
+  bluetooth_low_energy_platform_interface: ^2.2.0
   win32: ^5.0.6
 
 dev_dependencies: