Add clear queue api (#171)

* Add clear queue api

* Minor improvement

* Update changelog

---------

Co-authored-by: Foti Dim <foti@navideck.com>

CHANGELOG.md

@@ -1,6 +1,7 @@
 ## 0.21.0
 * BREAKING CHANGE: `connectionTimeout` argument from `connect`, `isPaired` and `pair` API renamed to `timeout`
 * Add `timeout` argument to all APIs
+* Add `clearQueue()` API
 
 ## 0.20.2
 * Fix `BleCharacteristic.onValueReceived`

README.md

@@ -420,6 +420,14 @@ UniversalBle.onQueueUpdate = (String id, int remainingItems) {
 };
 ```
 
+To clear the queue:
+```dart
+  /// Use [BleCommandQueue.globalQueueId] to clear the global queue.
+  /// To clear the queue of a specific device, use `deviceId` as [id].
+  /// If no [id] is provided, all queues will be cleared.
+  UniversalBle.clearQueue(BleCommandQueue.globalQueueId);
+```
+
 ## Timeout
 
 By default, all commands have a global timeout of 10 seconds.

lib/src/universal_ble.dart

@@ -414,6 +414,12 @@ class UniversalBle {
     );
   }
 
+  /// Clear a queue.
+  /// Use [BleCommandQueue.globalQueueId] to clear the global queue.
+  /// To clear the queue of a specific device, use `deviceId` as [id].
+  /// If no [id] is provided, all queues will be cleared.
+  static void clearQueue([String? id]) => _bleCommandQueue.clearQueue(id);
+
   /// [receivesAdvertisements] returns true on web if the browser supports receiving advertisements from a certain `deviceId`.
   /// The rest of the platforms will always return true.
   /// If true, then you will be getting scanResult updates for this device.

lib/src/utils/ble_command_queue.dart

@@ -51,4 +51,14 @@ class BleCommandQueue {
     _queueMap[id] = queue;
     return queue;
   }
+
+  void clearQueue(String? id) {
+    if (id == null) {
+      _queueMap.forEach((k, v) => v.dispose());
+      _queueMap.clear();
+    } else {
+      _queueMap[id]?.dispose();
+      _queueMap.remove(id);
+    }
+  }
 }