[DeviceLight] Add renderer+common parts

content/renderer/device_sensors/device_light_event_pump.cc

+// Copyright 2014 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.
+
+#include "content/renderer/device_sensors/device_light_event_pump.h"
+
+#include "content/common/device_sensors/device_light_messages.h"
+#include "content/public/renderer/render_thread.h"
+#include "third_party/WebKit/public/platform/WebDeviceLightListener.h"
+
+namespace {
+// Default delay between subsequent firing of DeviceLight events.
+const int kDefaultLightPumpDelayMillis = 200;
+}  // namespace
+
+namespace content {
+
+DeviceLightEventPump::DeviceLightEventPump()
+    : DeviceSensorEventPump(kDefaultLightPumpDelayMillis),
+      listener_(NULL),
+      last_seen_data_(-1) {
+}
+
+DeviceLightEventPump::DeviceLightEventPump(int pump_delay_millis)
+    : DeviceSensorEventPump(pump_delay_millis),
+      listener_(NULL),
+      last_seen_data_(-1) {
+}
+
+DeviceLightEventPump::~DeviceLightEventPump() {
+}
+
+bool DeviceLightEventPump::SetListener(
+    blink::WebDeviceLightListener* listener) {
+  listener_ = listener;
+  return listener_ ? RequestStart() : Stop();
+}
+
+bool DeviceLightEventPump::OnControlMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(DeviceLightEventPump, message)
+  IPC_MESSAGE_HANDLER(DeviceLightMsg_DidStartPolling, OnDidStart)
+  IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
+}
+
+void DeviceLightEventPump::FireEvent() {
+  DCHECK(listener_);
+  DeviceLightData data;
+  bool did_return_light_data = reader_->GetLatestData(&data);
+  if (did_return_light_data && data.value != last_seen_data_) {
+    last_seen_data_ = data.value;
+    listener_->didChangeDeviceLight(data.value);
+  }
+}
+
+bool DeviceLightEventPump::InitializeReader(base::SharedMemoryHandle handle) {
+  if (!reader_)
+    reader_.reset(new DeviceLightSharedMemoryReader());
+  return reader_->Initialize(handle);
+}
+
+bool DeviceLightEventPump::SendStartMessage() {
+  return RenderThread::Get()->Send(new DeviceLightHostMsg_StartPolling());
+}
+
+bool DeviceLightEventPump::SendStopMessage() {
+  last_seen_data_ = -1;
+  return RenderThread::Get()->Send(new DeviceLightHostMsg_StopPolling());
+}
+
+}  // namespace content