content/renderer/device_sensors/device_orientation_event_pump.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "device_orientation_event_pump.h"
   6
   7 #include <cmath>
   8
   9 #include "content/common/device_sensors/device_orientation_messages.h"
  10 #include "content/public/renderer/render_thread.h"
  11 #include "third_party/WebKit/public/platform/modules/device_orientation/WebDeviceOrientationListener.h"
  12
  13 namespace content {
  14
  15 const double DeviceOrientationEventPump::kOrientationThreshold = 0.1;
  16
  17 DeviceOrientationEventPump::DeviceOrientationEventPump(RenderThread* thread)
  18     : DeviceSensorEventPump<blink::WebDeviceOrientationListener>(thread) {
  19 }
  20
  21 DeviceOrientationEventPump::~DeviceOrientationEventPump() {
  22 }
  23
  24 bool DeviceOrientationEventPump::OnControlMessageReceived(
  25     const IPC::Message& message) {
  26   bool handled = true;
  27   IPC_BEGIN_MESSAGE_MAP(DeviceOrientationEventPump, message)
  28     IPC_MESSAGE_HANDLER(DeviceOrientationMsg_DidStartPolling, OnDidStart)
  29     IPC_MESSAGE_UNHANDLED(handled = false)
  30   IPC_END_MESSAGE_MAP()
  31   return handled;
  32 }
  33
  34 void DeviceOrientationEventPump::FireEvent() {
  35   DCHECK(listener());
  36   blink::WebDeviceOrientationData data;
  37   if (reader_->GetLatestData(&data) && ShouldFireEvent(data)) {
  38     memcpy(&data_, &data, sizeof(data));
  39     listener()->didChangeDeviceOrientation(data);
  40   }
  41 }
  42
  43 static bool IsSignificantlyDifferent(bool hasAngle1, double angle1,
  44     bool hasAngle2, double angle2) {
  45   if (hasAngle1 != hasAngle2)
  46     return true;
  47   return (hasAngle1 && std::fabs(angle1 - angle2) >=
  48           DeviceOrientationEventPump::kOrientationThreshold);
  49 }
  50
  51 bool DeviceOrientationEventPump::ShouldFireEvent(
  52     const blink::WebDeviceOrientationData& data) const {
  53   if (!data.allAvailableSensorsAreActive)
  54     return false;
  55
  56   if (!data.hasAlpha && !data.hasBeta && !data.hasGamma) {
  57     // no data can be provided, this is an all-null event.
  58     return true;
  59   }
  60
  61   return IsSignificantlyDifferent(
  62              data_.hasAlpha, data_.alpha, data.hasAlpha, data.alpha) ||
  63          IsSignificantlyDifferent(
  64              data_.hasBeta, data_.beta, data.hasBeta, data.beta) ||
  65          IsSignificantlyDifferent(
  66              data_.hasGamma, data_.gamma, data.hasGamma, data.gamma);
  67 }
  68
  69 bool DeviceOrientationEventPump::InitializeReader(
  70     base::SharedMemoryHandle handle) {
  71   memset(&data_, 0, sizeof(data_));
  72   if (!reader_)
  73     reader_.reset(new DeviceOrientationSharedMemoryReader());
  74   return reader_->Initialize(handle);
  75 }
  76
  77 void DeviceOrientationEventPump::SendStartMessage() {
  78   RenderThread::Get()->Send(new DeviceOrientationHostMsg_StartPolling());
  79 }
  80
  81 void DeviceOrientationEventPump::SendStopMessage() {
  82   RenderThread::Get()->Send(new DeviceOrientationHostMsg_StopPolling());
  83 }
  84
  85 void DeviceOrientationEventPump::SendFakeDataForTesting(void* fake_data) {
  86   blink::WebDeviceOrientationData data =
  87       *static_cast<blink::WebDeviceOrientationData*>(fake_data);
  88
  89   listener()->didChangeDeviceOrientation(data);
  90 }
  91
  92 }  // namespace content