Generic Sensor API : Ambient Light Sensor API.

third_party/WebKit/Source/modules/sensor/AmbientLightSensorDispatcher.h

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef AmbientLightSensorDispatcher_h
+#define AmbientLightSensorDispatcher_h
+
+#include "core/frame/PlatformEventDispatcher.h"
+#include "device/sensor/sensor.mojom.h"
+#include "modules/ModulesExport.h"
+#include "modules/sensor/AmbientLightSensor.h"
+#include "modules/sensor/als_reading.h"
+#include "wtf/OwnPtr.h"
+
+namespace blink {
+
+class MODULES_EXPORT AmbientLightSensorDispatcher final : public GarbageCollectedFinalized<AmbientLightSensorDispatcher>, public PlatformEventDispatcher {
+    USING_GARBAGE_COLLECTED_MIXIN(AmbientLightSensorDispatcher);
+    WTF_MAKE_NONCOPYABLE(AmbientLightSensorDispatcher);
+
+public:
+    static AmbientLightSensorDispatcher& instance();
+
+    const AmbientLightSensorReadingProxy* latestData() const
+    {
+        return m_hasLatestData ? &m_alsReading : nullptr;
+    }
+
+private:
+    AmbientLightSensorDispatcher();
+
+    void queryNextReading();
+    void onDidChange(device::AmbientLightSensorReadingPtr);
+    void updateSensorReading(const AmbientLightSensorReadingProxy&);
+    void startReading();
+    void stopReading();
+
+    // Inherited from PlatformEventDispatcher.
+    void startListening() override;
+    void stopListening() override;
+
+    device::AmbientLightSensorPtr m_lightSensor;
+    AmbientLightSensorReadingProxy m_alsReading;
+    bool m_hasLatestData;
+};
+
+} // namespace blink
+
+#endif // AmbientLightSensorDispatcher_h