Adding Chrome-side WebVR interface

content/browser/vr/vr_service.cc

+// Copyright 2015 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/browser/vr/vr_service.h"
+
+#include "base/memory/singleton.h"
+#include "third_party/WebKit/public/platform/WebVR.h"
+
+#if defined(OS_ANDROID)
+#include "content/browser/vr/cardboard/cardboard_vr_device_provider.h"
+#endif
+
+namespace content {
+
+namespace {
+VRService* g_vr_service = nullptr;
+}
+
+VRService::VRService() : vr_initialized_(false), keep_alive_(false) {
+#if defined(OS_ANDROID)
+  scoped_ptr<VRDeviceProvider> cardboard_provider(
+      new CardboardVRDeviceProvider());
+  RegisterProvider(cardboard_provider.Pass());
+#endif
+}
+
+VRService::VRService(scoped_ptr<VRDeviceProvider> provider)
+    : vr_initialized_(false), keep_alive_(true) {
+  thread_checker_.DetachFromThread();
+  RegisterProvider(provider.Pass());
+  SetInstance(this);
+}
+
+VRService::~VRService() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+  g_vr_service = nullptr;
+}
+
+VRService* VRService::GetInstance() {
+  if (!g_vr_service)
+    g_vr_service = new VRService();
+  return g_vr_service;
+}
+
+void VRService::SetInstance(VRService* instance) {
+  // Unit tests can create multiple instances but only one should exist at any
+  // given time so g_vr_service should only go from nullptr to non-nullptr and
+  // vica versa.
+  CHECK_NE(!!instance, !!g_vr_service);
+  g_vr_service = instance;
+}
+
+bool VRService::HasInstance() {
+  // For testing. Checks to see if a VRService instance is active.
+  return !!g_vr_service;
+}
+
+void VRService::GetVRDevices(std::vector<blink::WebVRDevice>* webvr_devices) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (!webvr_devices)
+    return;
+
+  InitializeProviders();
+
+  webvr_devices->clear();
+
+  ProviderList::iterator iter;
+
+  std::vector<VRDevice*> devices;
+
+  for (iter = providers_.begin(); iter != providers_.end(); ++iter) {
+    (*iter)->GetDevices(devices);
+  }
+
+  std::vector<VRDevice*>::iterator diter;
+  for (diter = devices.begin(); diter != devices.end(); ++diter) {
+    VRDevice* device = *diter;
+
+    if (device->id() == VR_DEVICE_LAST_ID)
+      continue;
+
+    if (devices_.find(device->id()) == devices_.end()) {
+      devices_[device->id()] = device;
+    }
+
+    blink::WebVRDevice webvr_device;
+    device->GetVRDevice(&webvr_device);
+    webvr_device.index = device->id();
+    webvr_devices->push_back(webvr_device);
+  }
+}
+
+VRDevice* VRService::GetDevice(unsigned int index) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  DeviceMap::iterator iter = devices_.find(index);
+  if (iter == devices_.end()) {
+    return nullptr;
+  }
+  return iter->second;
+}
+
+void VRService::AddConsumer(VRServiceConsumer* consumer) {
+  VRService* service = GetInstance();
+  DCHECK(service->thread_checker_.CalledOnValidThread());
+
+  // Explicitly does not initialize the providers. That's done lazily the first
+  // time GetVRDevices is called.
+  service->consumers_.insert(consumer);
+}
+
+void VRService::RemoveConsumer(VRServiceConsumer* consumer) {
+  CHECK(g_vr_service);
+  DCHECK(g_vr_service->thread_checker_.CalledOnValidThread());
+
+  ConsumerSet::iterator it = g_vr_service->consumers_.find(consumer);
+  DCHECK(it != g_vr_service->consumers_.end());
+
+  if (it != g_vr_service->consumers_.end()) {
+    g_vr_service->consumers_.erase(it);
+    if (g_vr_service->consumers_.size() == 0 && !g_vr_service->keep_alive_) {
+      // Delete the service when it has no consumers left.
+      delete g_vr_service;
+    }
+  }
+}
+
+void VRService::InitializeProviders() {
+  if (vr_initialized_) {
+    return;
+  }
+
+  ProviderList::iterator iter;
+  for (iter = providers_.begin(); iter != providers_.end(); ++iter) {
+    (*iter)->Initialize();
+  }
+
+  vr_initialized_ = true;
+}
+
+void VRService::RegisterProvider(scoped_ptr<VRDeviceProvider> provider) {
+  providers_.push_back(make_linked_ptr(provider.release()));
+}
+
+}  // namespace content