Merge pull request #63 from PureSwift/feature/add-alert-level

Added GATT Alert Level Characteristic

Sources/GATTCharacteristic.swift

@@ -1645,6 +1645,54 @@ extension GATTAerobicHeartRateUpperLimit: CustomStringConvertible {
     }
 }
 
+/**
+ Alert Level
+ 
+ The level of an alert a device is to sound. If this level is changed while the alert is being sounded, the new level should take effect.
+ 
+ The value of the characteristic shall be an unsigned 8 bit integer that has a fixed point exponent of 0. The Alert Level characteristic defines the level of alert, and is one of the following three values:
+ 
+ • Value 0, meaning “No Alert”
+ 
+ • Value 1, meaning “Mild Alert”
+ 
+ • EValue 2, meaning “High Alert”
+ 
+ • Example:
+ 
+ The value 0x01 is interpreted as “Mild Alert”
+ 
+ - SeeAlso: [Alert Level](https://www.bluetooth.com/specifications/gatt/viewer?attributeXmlFile=org.bluetooth.characteristic.alert_level.xml)
+ */
+public enum GATTAlertLevel: UInt8, GATTProfileCharacteristic {
+
+    public static var uuid: BluetoothUUID { return .alertLevel }
+
+    internal static let length = MemoryLayout<UInt8>.size
+
+    /// No alert.
+    case none = 0x00
+
+    /// Mild alert.
+    case mild = 0x01
+
+    /// High alert.
+    case high = 0x02
+
+    public init?(data: Data) {
+
+        guard data.count == type(of: self).length
+            else { return nil }
+
+        self.init(rawValue: data[0])
+    }
+
+    public var data: Data {
+
+        return Data([rawValue])
+    }
+}
+
 // MARK: - Supporting Types
 
 public enum GATTBeatsPerMinute {

Tests/BluetoothTests/GATTCharacteristicTests.swift

@@ -24,7 +24,8 @@ final class GATTCharacteristicTests: XCTestCase {
         ("testAlertNotificationControlPoint", testAlertNotificationControlPoint),
         ("testBloodPressureMeasurement", testBloodPressureMeasurement),
         ("testAerobicHeartRateLowerLimit", testAerobicHeartRateLowerLimit),
-        ("testAerobicHeartRateUpperLimit", testAerobicHeartRateUpperLimit)
+        ("testAerobicHeartRateUpperLimit", testAerobicHeartRateUpperLimit),
+        ("testAlertLevel", testAlertLevel)
     ]
 
     func testDateTime() {
@@ -282,4 +283,16 @@ final class GATTCharacteristicTests: XCTestCase {
         XCTAssertEqual(GATTAerobicHeartRateUpperLimit.uuid, .aerobicHeartRateUpperLimit)
         XCTAssertEqual(BeatsPerMinute.unitType, .beatsPerMinute)
     }
+
+    func testAlertLevel() {
+
+        let data = Data([0x01])
+
+        guard let characteristic = GATTAlertLevel(data: data)
+            else { XCTFail("Could not decode from bytes"); return }
+
+        XCTAssertEqual(characteristic.data, data)
+        XCTAssertEqual(characteristic, .mild, "The value 0x01 should be interpreted as mild Alert")
+        XCTAssertEqual(GATTAlertLevel.uuid, .alertLevel)
+    }
 }