[DeviceLight] Browser+java part

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;
+const int kDefaultLightPumpDelayMillis = 199;

[timvolodine, 2014/09/04 17:16:58]

why not 200?

 }  // namespace
 
 namespace content {
 
 DeviceLightEventPump::DeviceLightEventPump(RenderThread* thread)
     : DeviceSensorEventPump<blink::WebDeviceLightListener>(thread),
       last_seen_data_(-1) {
   pump_delay_millis_ = kDefaultLightPumpDelayMillis;
 }
 
 DeviceLightEventPump::~DeviceLightEventPump() {
 }
 
 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_) {
+  // It seems that we need to fire multiple times to blink to get 1 NULL

[timvolodine, 2014/09/04 17:16:58]

remove comment

[riju_, 2014/09/08 09:26:18]

Done.

+  // event. +inf = no sensors
+  if ((did_return_light_data && data.value != last_seen_data_) ||
+      data.value == std::numeric_limits<double>::infinity()) {

[timvolodine, 2014/09/04 17:16:58]

this does not look right.
you could do reader_->GetLatestData(&data) && ( .. || ..)

[timvolodine, 2014/09/04 17:16:58]

also I am not sure if negative values could be fired into blink this way, looks
like it's not possible but I am not 100% sure.
to be on the safe side you could define ShouldFireEvent which would filter out
value<0.

[riju_, 2014/09/08 09:26:18]

Done.

     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);
 }
 
 void DeviceLightEventPump::SendStartMessage() {
   RenderThread::Get()->Send(new DeviceLightHostMsg_StartPolling());
 }
 
 void DeviceLightEventPump::SendStopMessage() {
   last_seen_data_ = -1;
   RenderThread::Get()->Send(new DeviceLightHostMsg_StopPolling());
 }
 
 void DeviceLightEventPump::SendFakeDataForTesting(void* fake_data) {
   double data = *static_cast<double*>(fake_data);
 
   listener()->didChangeDeviceLight(data);
 }
 
 }  // namespace content