Decouple bluetooth_event_router from extension_system.

chrome/browser/extensions/api/bluetooth/bluetooth_event_router.cc

 // Copyright (c) 2012 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 "chrome/browser/extensions/bluetooth_event_router.h"
+#include "chrome/browser/extensions/api/bluetooth/bluetooth_event_router.h"
 
 #include <map>
+#include <string>
 
 #include "base/json/json_writer.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_vector.h"
 #include "base/utf_string_conversions.h"
 #include "chrome/browser/extensions/api/bluetooth/bluetooth_api_utils.h"
 #include "chrome/browser/extensions/event_names.h"
 #include "chrome/browser/extensions/event_router.h"
 #include "chrome/browser/extensions/extension_system.h"
 #include "chrome/common/extensions/api/bluetooth.h"
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_adapter_factory.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluetooth_socket.h"
 
 namespace extensions {
 
 ExtensionBluetoothEventRouter::ExtensionBluetoothEventRouter(Profile* profile)
     : send_discovery_events_(false),
       responsible_for_discovery_(false),
       profile_(profile),
-      adapter_(device::BluetoothAdapterFactory::DefaultAdapter()),
+      adapter_(NULL),
+      num_event_listeners_(0),
       next_socket_id_(1) {
   DCHECK(profile_);
-  if (adapter_.get())
-    adapter_->AddObserver(this);
 }
 
 ExtensionBluetoothEventRouter::~ExtensionBluetoothEventRouter() {
-  if (adapter_.get())
-    adapter_->RemoveObserver(this);
+  CHECK(socket_map_.size() == 0);
+  CHECK(num_event_listeners_ == 0);
+  MaybeReleaseAdapter();
+}
 
-  socket_map_.clear();
+scoped_refptr<const device::BluetoothAdapter>
+ExtensionBluetoothEventRouter::adapter() {
+  return GetMutableAdapter();
+}
+
+scoped_refptr<device::BluetoothAdapter>
+ExtensionBluetoothEventRouter::GetMutableAdapter() {
+  if (adapter_)
+    return adapter_;
+
+  return device::BluetoothAdapterFactory::DefaultAdapter();
+}
+
+void ExtensionBluetoothEventRouter::OnListenerAdded() {
+  num_event_listeners_++;
+  InitializeAdapterIfNeeded();
+}
+
+void ExtensionBluetoothEventRouter::OnListenerRemoved() {
+  num_event_listeners_--;
+  CHECK(num_event_listeners_ >= 0);
+  MaybeReleaseAdapter();
 }
 
 int ExtensionBluetoothEventRouter::RegisterSocket(
     scoped_refptr<device::BluetoothSocket> socket) {
   // If there is a socket registered with the same fd, just return it's id
   for (SocketMap::const_iterator i = socket_map_.begin();
       i != socket_map_.end(); ++i) {
     if (i->second->fd() == socket->fd()) {
       return i->first;
     }
@@ skipping 45 matching lines @@
 void ExtensionBluetoothEventRouter::DispatchDeviceEvent(
     const char* event_name, const extensions::api::bluetooth::Device& device) {
   scoped_ptr<ListValue> args(new ListValue());
   args->Append(device.ToValue().release());
   extensions::ExtensionSystem::Get(profile_)->event_router()->
       DispatchEventToRenderers(event_name, args.Pass(), NULL, GURL());
 }
 
 void ExtensionBluetoothEventRouter::AdapterPresentChanged(
     device::BluetoothAdapter* adapter, bool present) {
-  if (adapter != adapter_.get()) {
+  if (adapter != adapter_) {
     DVLOG(1) << "Ignoring event for adapter " << adapter->address();
     return;
   }
 
   DispatchBooleanValueEvent(
       extensions::event_names::kBluetoothOnAvailabilityChanged,
       present);
 }
 
 void ExtensionBluetoothEventRouter::AdapterPoweredChanged(
     device::BluetoothAdapter* adapter, bool has_power) {
-  if (adapter != adapter_.get()) {
+  if (adapter != adapter_) {
     DVLOG(1) << "Ignoring event for adapter " << adapter->address();
     return;
   }
 
   DispatchBooleanValueEvent(
       extensions::event_names::kBluetoothOnPowerChanged,
       has_power);
 }
 
 void ExtensionBluetoothEventRouter::AdapterDiscoveringChanged(
     device::BluetoothAdapter* adapter, bool discovering) {
-  if (adapter != adapter_.get()) {
+  if (adapter != adapter_) {
     DVLOG(1) << "Ignoring event for adapter " << adapter->address();
     return;
   }
 
   if (!discovering) {
     send_discovery_events_ = false;
     responsible_for_discovery_ = false;
     discovered_devices_.clear();
   }
 
   DispatchBooleanValueEvent(
       extensions::event_names::kBluetoothOnDiscoveringChanged,
       discovering);
 }
 
 void ExtensionBluetoothEventRouter::DeviceAdded(
     device::BluetoothAdapter* adapter,
     device::BluetoothDevice* device) {
-  if (adapter != adapter_.get()) {
+  if (adapter != adapter_) {
     DVLOG(1) << "Ignoring event for adapter " << adapter->address();
     return;
   }
 
   extensions::api::bluetooth::Device* extension_device =
       new extensions::api::bluetooth::Device();
   extensions::api::bluetooth::BluetoothDeviceToApiDevice(
       *device, extension_device);
   discovered_devices_.push_back(extension_device);
 
   if (!send_discovery_events_)
     return;
 
   DispatchDeviceEvent(extensions::event_names::kBluetoothOnDeviceDiscovered,
                       *extension_device);
 }
 
+void ExtensionBluetoothEventRouter::InitializeAdapterIfNeeded() {
+  if (!adapter_) {
+    adapter_ = GetMutableAdapter();
+    adapter_->AddObserver(this);
+  }
+}
+
+void ExtensionBluetoothEventRouter::MaybeReleaseAdapter() {
+  if (adapter_ && num_event_listeners_ == 0) {
+    adapter_->RemoveObserver(this);
+    adapter_ = NULL;
+  }
+}
+
 void ExtensionBluetoothEventRouter::DispatchBooleanValueEvent(
     const char* event_name, bool value) {
   scoped_ptr<ListValue> args(new ListValue());
   args->Append(Value::CreateBooleanValue(value));
   extensions::ExtensionSystem::Get(profile_)->event_router()->
       DispatchEventToRenderers(event_name, args.Pass(), NULL, GURL());
 }
 
 }  // namespace extensions