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/WebDeviceOrientationListener.h"
12
13 namespace content {
14
15 const double DeviceOrientationEventPump::kOrientationThreshold = 0.1;
16
DeviceOrientationEventPump()17 DeviceOrientationEventPump::DeviceOrientationEventPump()
18 : DeviceSensorEventPump(), listener_(0) {
19 }
20
DeviceOrientationEventPump(int pump_delay_millis)21 DeviceOrientationEventPump::DeviceOrientationEventPump(int pump_delay_millis)
22 : DeviceSensorEventPump(pump_delay_millis), listener_(0) {
23 }
24
~DeviceOrientationEventPump()25 DeviceOrientationEventPump::~DeviceOrientationEventPump() {
26 }
27
SetListener(blink::WebDeviceOrientationListener * listener)28 bool DeviceOrientationEventPump::SetListener(
29 blink::WebDeviceOrientationListener* listener) {
30 listener_ = listener;
31 return listener_ ? RequestStart() : Stop();
32 }
33
OnControlMessageReceived(const IPC::Message & message)34 bool DeviceOrientationEventPump::OnControlMessageReceived(
35 const IPC::Message& message) {
36 bool handled = true;
37 IPC_BEGIN_MESSAGE_MAP(DeviceOrientationEventPump, message)
38 IPC_MESSAGE_HANDLER(DeviceOrientationMsg_DidStartPolling, OnDidStart)
39 IPC_MESSAGE_UNHANDLED(handled = false)
40 IPC_END_MESSAGE_MAP()
41 return handled;
42 }
43
FireEvent()44 void DeviceOrientationEventPump::FireEvent() {
45 DCHECK(listener_);
46 blink::WebDeviceOrientationData data;
47 if (reader_->GetLatestData(&data) && ShouldFireEvent(data)) {
48 memcpy(&data_, &data, sizeof(data));
49 listener_->didChangeDeviceOrientation(data);
50 }
51 }
52
IsSignificantlyDifferent(bool hasAngle1,double angle1,bool hasAngle2,double angle2)53 static bool IsSignificantlyDifferent(bool hasAngle1, double angle1,
54 bool hasAngle2, double angle2) {
55 if (hasAngle1 != hasAngle2)
56 return true;
57 return (hasAngle1 && std::fabs(angle1 - angle2) >=
58 DeviceOrientationEventPump::kOrientationThreshold);
59 }
60
ShouldFireEvent(const blink::WebDeviceOrientationData & data) const61 bool DeviceOrientationEventPump::ShouldFireEvent(
62 const blink::WebDeviceOrientationData& data) const {
63 if (!data.allAvailableSensorsAreActive)
64 return false;
65
66 if (!data.hasAlpha && !data.hasBeta && !data.hasGamma) {
67 // no data can be provided, this is an all-null event.
68 return true;
69 }
70
71 return IsSignificantlyDifferent(
72 data_.hasAlpha, data_.alpha, data.hasAlpha, data.alpha) ||
73 IsSignificantlyDifferent(
74 data_.hasBeta, data_.beta, data.hasBeta, data.beta) ||
75 IsSignificantlyDifferent(
76 data_.hasGamma, data_.gamma, data.hasGamma, data.gamma);
77 }
78
InitializeReader(base::SharedMemoryHandle handle)79 bool DeviceOrientationEventPump::InitializeReader(
80 base::SharedMemoryHandle handle) {
81 memset(&data_, 0, sizeof(data_));
82 if (!reader_)
83 reader_.reset(new DeviceOrientationSharedMemoryReader());
84 return reader_->Initialize(handle);
85 }
86
SendStartMessage()87 bool DeviceOrientationEventPump::SendStartMessage() {
88 return RenderThread::Get()->Send(new DeviceOrientationHostMsg_StartPolling());
89 }
90
SendStopMessage()91 bool DeviceOrientationEventPump::SendStopMessage() {
92 return RenderThread::Get()->Send(new DeviceOrientationHostMsg_StopPolling());
93 }
94
95 } // namespace content
96