Receive notifications about device being disconnected

src/connections/ble_handler.rs

@@ -1,6 +1,6 @@
 use btleplug::api::{
- Central, Characteristic, Manager as _, Peripheral as _, ScanFilter, ValueNotification,
- WriteType,
+ Central, CentralEvent, Characteristic, Manager as _, Peripheral as _, ScanFilter,
+ ValueNotification, WriteType,
 };
 use btleplug::platform::{Adapter, Manager, Peripheral};
 use futures_util::stream::BoxStream;
@@ -16,6 +16,7 @@ const FROMNUM: Uuid = Uuid::from_u128(0xed9da18c_a800_4f66_a670_aa7547e34453);
 
 pub struct BleHandler {
  radio: Peripheral,
+ adapter: Adapter,
  toradio_char: Characteristic,
  fromradio_char: Characteristic,
  fromnum_char: Characteristic,
@@ -24,7 +25,7 @@ pub struct BleHandler {
 #[allow(dead_code)]
 impl BleHandler {
  pub async fn new(name: String) -> Result<Self, Error> {
- let radio = Self::find_ble_radio(&name).await?;
+ let (radio, adapter) = Self::find_ble_radio(&name).await?;
  radio.connect().await.map_err(|e| Error::StreamBuildError {
  source: Box::new(e),
  description: format!("Failed to connect to the device {name}"),
@@ -33,6 +34,7 @@ impl BleHandler {
  Self::find_characteristics(&radio).await?;
  Ok(BleHandler {
  radio,
+ adapter,
  toradio_char,
  fromradio_char,
  fromnum_char,
@@ -50,7 +52,9 @@ impl BleHandler {
 
  /// Finds a BLE radio matching a given name and running meshtastic.
  /// It searches for the 'MSH_SERVICE' running on the device.
- async fn find_ble_radio(name: &str) -> Result<Peripheral, Error> {
+ ///
+ /// It also returns the associated adapter that can reach this radio.
+ async fn find_ble_radio(name: &str) -> Result<(Peripheral, Adapter), Error> {
  //TODO: support searching both by a name and by a MAC address
  let scan_error_fn = |e: btleplug::Error| Error::StreamBuildError {
  source: Box::new(e),
@@ -72,7 +76,7 @@ impl BleHandler {
  for peripheral in peripherals {
  if let Ok(Some(peripheral_properties)) = peripheral.properties().await {
  if peripheral_properties.local_name == needle {
- return Ok(peripheral);
+ return Ok((peripheral, adapter.clone()));
  }
  }
  }
@@ -178,4 +182,21 @@ impl BleHandler {
  _ => None,
  }
  }
+
+ pub async fn adapter_events(&self) -> Result<BoxStream<CentralEvent>, Error> {
+ self.adapter
+ .events()
+ .await
+ .map_err(|e| Error::StreamBuildError {
+ source: Box::new(e),
+ description: format!("Failed to listen to device events"),
+ })
+ }
+
+ pub fn is_disconnected_event(&self, event: Option<CentralEvent>) -> bool {
+ if let Some(CentralEvent::DeviceDisconnected(peripheral_id)) = event {
+ return self.radio.id() == peripheral_id;
+ }
+ return false;
+ }
 }

src/errors_internal.rs

@@ -67,6 +67,11 @@ pub enum InternalStreamError {
  StreamWriteError {
  source: Box<dyn std::error::Error + Send + Sync + 'static>,
  },
+
+ /// An error indicatiing that the connection has been lost and both reading and writing are
+ /// not possible anymore.
+ #[error("Connection lost")]
+ ConnectionLost,
 }
 
 /// An enum that defines the possible internal errors that can occur within the library when handling data channels.