Added light sensor that measures luminance in LUX.

Author: gdombiak

src/main/java/com/beowulfe/hap/accessories/LightSensor.java

@@ -0,0 +1,42 @@
+package com.beowulfe.hap.accessories;
+
+import com.beowulfe.hap.HomekitAccessory;
+import com.beowulfe.hap.HomekitCharacteristicChangeCallback;
+import com.beowulfe.hap.Service;
+import com.beowulfe.hap.impl.services.LightSensorService;
+
+import java.util.Collection;
+import java.util.Collections;
+import java.util.concurrent.CompletableFuture;
+
+/**
+ * A light sensor that reports current ambient light level.
+ *
+ * @author Gaston Dombiak
+ */
+public interface LightSensor extends HomekitAccessory {
+
+    /**
+     * Retrieves the current ambient light level.
+     *
+     * @return a future that will contain the luminance level expressed in LUX.
+     */
+    CompletableFuture<Double> getCurrentAmbientLightLevel();
+
+    @Override
+    default Collection<Service> getServices() {
+        return Collections.singleton(new LightSensorService(this));
+    }
+
+    /**
+     * Subscribes to changes in the current ambient light level.
+     *
+     * @param callback the function to call when the state changes.
+     */
+    void subscribeCurrentAmbientLightLevel(HomekitCharacteristicChangeCallback callback);
+
+    /**
+     * Unsubscribes from changes in the current ambient light level.
+     */
+    void unsubscribeCurrentAmbientLightLevel();
+}

src/main/java/com/beowulfe/hap/impl/characteristics/light/AmbientLightLevelCharacteristic.java

@@ -0,0 +1,39 @@
+package com.beowulfe.hap.impl.characteristics.light;
+
+import com.beowulfe.hap.HomekitCharacteristicChangeCallback;
+import com.beowulfe.hap.accessories.LightSensor;
+import com.beowulfe.hap.characteristics.EventableCharacteristic;
+import com.beowulfe.hap.characteristics.FloatCharacteristic;
+
+import java.util.concurrent.CompletableFuture;
+
+public class AmbientLightLevelCharacteristic extends FloatCharacteristic implements EventableCharacteristic {
+
+    private final LightSensor lightSensor;
+
+    public AmbientLightLevelCharacteristic(LightSensor lightSensor) {
+        super("0000006B-0000-1000-8000-0026BB765291", false, true, "Current ambient light level", 0.0001, 100000,
+                0.0001, "lux");
+        this.lightSensor = lightSensor;
+    }
+
+    @Override
+    protected void setValue(Double value) throws Exception {
+        //Read Only
+    }
+
+    @Override
+    public void subscribe(HomekitCharacteristicChangeCallback callback) {
+        lightSensor.subscribeCurrentAmbientLightLevel(callback);
+    }
+
+    @Override
+    public void unsubscribe() {
+        lightSensor.unsubscribeCurrentAmbientLightLevel();
+    }
+
+    @Override
+    protected CompletableFuture<Double> getDoubleValue() {
+        return lightSensor.getCurrentAmbientLightLevel();
+    }
+}

src/main/java/com/beowulfe/hap/impl/services/LightSensorService.java

@@ -0,0 +1,16 @@
+package com.beowulfe.hap.impl.services;
+
+import com.beowulfe.hap.accessories.LightSensor;
+import com.beowulfe.hap.impl.characteristics.light.AmbientLightLevelCharacteristic;
+
+public class LightSensorService extends AbstractServiceImpl {
+
+    public LightSensorService(LightSensor lightSensor) {
+        this(lightSensor, lightSensor.getLabel());
+    }
+
+    public LightSensorService(LightSensor lightSensor, String serviceName) {
+        super("00000084-0000-1000-8000-0026BB765291", lightSensor, serviceName);
+        addCharacteristic(new AmbientLightLevelCharacteristic(lightSensor));
+    }
+}