Implement isScanning api (#188)

* Implement isScanning api

* Improve IOS scanning api

* Update Readme and Changelog

windows/src/generated/universal_ble.g.cpp

@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v26.0.5), do not edit directly.
+// Autogenerated from Pigeon (v26.1.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #undef _HAS_EXCEPTIONS
@@ -623,6 +623,27 @@ void UniversalBlePlatformChannel::SetUp(
       channel.SetMessageHandler(nullptr);
     }
   }
+  {
+    BasicMessageChannel<> channel(binary_messenger, "dev.flutter.pigeon.universal_ble.UniversalBlePlatformChannel.isScanning" + prepended_suffix, &GetCodec());
+    if (api != nullptr) {
+      channel.SetMessageHandler([api](const EncodableValue& message, const flutter::MessageReply<EncodableValue>& reply) {
+        try {
+          ErrorOr<bool> output = api->IsScanning();
+          if (output.has_error()) {
+            reply(WrapError(output.error()));
+            return;
+          }
+          EncodableList wrapped;
+          wrapped.push_back(EncodableValue(std::move(output).TakeValue()));
+          reply(EncodableValue(std::move(wrapped)));
+        } catch (const std::exception& exception) {
+          reply(WrapError(exception.what()));
+        }
+      });
+    } else {
+      channel.SetMessageHandler(nullptr);
+    }
+  }
   {
     BasicMessageChannel<> channel(binary_messenger, "dev.flutter.pigeon.universal_ble.UniversalBlePlatformChannel.connect" + prepended_suffix, &GetCodec());
     if (api != nullptr) {

windows/src/generated/universal_ble.g.h

@@ -1,4 +1,4 @@
-// Autogenerated from Pigeon (v26.0.5), do not edit directly.
+// Autogenerated from Pigeon (v26.1.0), do not edit directly.
 // See also: https://pub.dev/packages/pigeon
 
 #ifndef PIGEON_UNIVERSAL_BLE_G_H_
@@ -352,6 +352,7 @@ class UniversalBlePlatformChannel {
   virtual void DisableBluetooth(std::function<void(ErrorOr<bool> reply)> result) = 0;
   virtual std::optional<FlutterError> StartScan(const UniversalScanFilter* filter) = 0;
   virtual std::optional<FlutterError> StopScan() = 0;
+  virtual ErrorOr<bool> IsScanning() = 0;
   virtual std::optional<FlutterError> Connect(const std::string& device_id) = 0;
   virtual std::optional<FlutterError> Disconnect(const std::string& device_id) = 0;
   virtual void SetNotifiable(

windows/src/universal_ble_plugin.cpp

@@ -212,6 +212,15 @@ std::optional<FlutterError> UniversalBlePlugin::StopScan() {
   }
 };
 
+ErrorOr<bool> UniversalBlePlugin::IsScanning() {
+  if (bluetooth_le_watcher_ != nullptr) {
+    try {
+      return bluetooth_le_watcher_.Status() == BluetoothLEAdvertisementWatcherStatus::Started;
+    } catch (...) {}
+  }
+  return false;
+}
+
 ErrorOr<int64_t>
 UniversalBlePlugin::GetConnectionState(const std::string &device_id) {
   const auto it = connected_devices_.find(str_to_mac_address(device_id));

windows/src/universal_ble_plugin.h

@@ -158,6 +158,7 @@ namespace universal_ble
         ErrorOr<int64_t> GetConnectionState(const std::string &device_id) override;
         std::optional<FlutterError> StartScan(const UniversalScanFilter *filter) override;
         std::optional<FlutterError> StopScan() override;
+        ErrorOr<bool> IsScanning() override;
         std::optional<FlutterError> Connect(const std::string &device_id) override;
         std::optional<FlutterError> Disconnect(const std::string &device_id) override;
         void DiscoverServices(