Implement Device Orientation using shared memory in content/renderer.

content/renderer/device_orientation/device_motion_event_pump.cc

 // Copyright 2013 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 "device_motion_event_pump.h"
 
-#include "base/bind.h"
-#include "base/logging.h"
-#include "base/memory/scoped_ptr.h"
-#include "base/memory/shared_memory.h"
-#include "base/message_loop/message_loop.h"
 #include "content/common/device_motion_messages.h"
 #include "content/public/renderer/render_thread.h"
 #include "third_party/WebKit/public/platform/WebDeviceMotionListener.h"
 
 namespace content {
 
-const double DeviceMotionEventPump::kPumpDelayMillis = 40;
-
-double DeviceMotionEventPump::GetDelayMillis() {
-  return kPumpDelayMillis;
+DeviceMotionEventPump::DeviceMotionEventPump()
+    : DeviceSensorEventPump(), listener_(0) {
 }
 
-DeviceMotionEventPump::DeviceMotionEventPump()
-    : listener_(0), state_(STOPPED) {
+DeviceMotionEventPump::DeviceMotionEventPump(int pump_delay_millis)
+    : DeviceSensorEventPump(pump_delay_millis), listener_(0) {
 }
 
 DeviceMotionEventPump::~DeviceMotionEventPump() {
 }
 
 bool DeviceMotionEventPump::SetListener(
     WebKit::WebDeviceMotionListener* listener) {
   listener_ = listener;
-  if (listener_)
-    return StartFetchingDeviceMotion();
-  return StopFetchingDeviceMotion();
+  return listener_ ? RequestStart() : Stop();
 }
 
-void DeviceMotionEventPump::SetDeviceMotionReader(
-    scoped_ptr<DeviceMotionSharedMemoryReader> reader) {
-  reader_.reset(reader.release());
-}
-
-bool DeviceMotionEventPump::StartFetchingDeviceMotion() {
-  DVLOG(2) << "start fetching device motion";
-
-  if (state_ != STOPPED)
-    return false;
-
-  DCHECK(!timer_.IsRunning());
-
-  if (RenderThread::Get()->Send(new DeviceMotionHostMsg_StartPolling())) {
-    state_ = PENDING_START;
-    return true;
-  }
-  return false;
-}
-
-bool DeviceMotionEventPump::StopFetchingDeviceMotion() {
-  DVLOG(2) << "stop fetching device motion";
-
-  if (state_ == STOPPED)
-    return true;
-
-  DCHECK((state_ == PENDING_START && !timer_.IsRunning()) ||
-      (state_ == RUNNING && timer_.IsRunning()));
-
-  if (timer_.IsRunning())
-    timer_.Stop();
-  RenderThread::Get()->Send(new DeviceMotionHostMsg_StopPolling());
-  state_ = STOPPED;
-  return true;
+bool DeviceMotionEventPump::OnControlMessageReceived(
+    const IPC::Message& message) {
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP(DeviceMotionEventPump, message)
+    IPC_MESSAGE_HANDLER(DeviceMotionMsg_DidStartPolling, OnDidStart)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP()
+  return handled;
 }
 
 void DeviceMotionEventPump::FireEvent() {
   DCHECK(listener_);
   WebKit::WebDeviceMotionData data;
   if (reader_->GetLatestData(&data) && data.allAvailableSensorsAreActive)
     listener_->didChangeDeviceMotion(data);
 }
 
-void DeviceMotionEventPump::Attach(RenderThread* thread) {
-  if (!thread)
-    return;
-  thread->AddObserver(this);
+bool DeviceMotionEventPump::InitializeReader(base::SharedMemoryHandle handle) {
+  if (!reader_)
+    reader_.reset(new DeviceMotionSharedMemoryReader());
+  return reader_->Initialize(handle);
 }
 
-void DeviceMotionEventPump::OnDidStartDeviceMotion(
-     base::SharedMemoryHandle renderer_handle) {
-  DVLOG(2) << "did start fetching device motion";
-
-  if (state_ != PENDING_START)
-    return;
-
-  DCHECK(!timer_.IsRunning());
-  if (!reader_)
-    reader_.reset(new DeviceMotionSharedMemoryReader());
-
-  if (reader_->Initialize(renderer_handle)) {
-    timer_.Start(FROM_HERE, base::TimeDelta::FromMilliseconds(kPumpDelayMillis),
-                 this, &DeviceMotionEventPump::FireEvent);
-    state_ = RUNNING;
-  }
+bool DeviceMotionEventPump::SendStartMessage() {
+  return RenderThread::Get()->Send(new DeviceMotionHostMsg_StartPolling());
 }
 
-bool DeviceMotionEventPump::OnControlMessageReceived(
-    const IPC::Message& message) {
-  bool handled = true;
-  IPC_BEGIN_MESSAGE_MAP(DeviceMotionEventPump, message)
-    IPC_MESSAGE_HANDLER(DeviceMotionMsg_DidStartPolling,
-        OnDidStartDeviceMotion)
-    IPC_MESSAGE_UNHANDLED(handled = false)
-  IPC_END_MESSAGE_MAP()
-  return handled;
+
+bool DeviceMotionEventPump::SendStopMessage() {
+  return RenderThread::Get()->Send(new DeviceMotionHostMsg_StopPolling());
 }
 
 }  // namespace content