Delayed adding BluetoothEventRouter as BluetoothAdapter observer until when the

chrome/browser/extensions/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 <map>
 
 #include "base/json/json_writer.h"
 #include "base/memory/ref_counted.h"
@@ skipping 11 matching lines @@
 
 namespace extensions {
 
 ExtensionBluetoothEventRouter::ExtensionBluetoothEventRouter(Profile* profile)
     : send_discovery_events_(false),
       responsible_for_discovery_(false),
       profile_(profile),
       adapter_(device::BluetoothAdapterFactory::DefaultAdapter()),
       next_socket_id_(1) {
   DCHECK(profile_);
-  if (adapter_.get())
-    adapter_->AddObserver(this);
+}
+
+ExtensionBluetoothEventRouter::ExtensionBluetoothEventRouter(
+    Profile* profile, device::BluetoothAdapter* adapter)
+    : send_discovery_events_(false),
+      responsible_for_discovery_(false),
+      profile_(profile),
+      adapter_(adapter),
+      next_socket_id_(1) {
+  DCHECK(profile_);
 }
 
 ExtensionBluetoothEventRouter::~ExtensionBluetoothEventRouter() {
   if (adapter_.get())
     adapter_->RemoveObserver(this);
 
   socket_map_.clear();
 }
 
+device::BluetoothAdapter* ExtensionBluetoothEventRouter::GetMutableAdapter() {
+  if (adapter_.get()) {
+    adapter_->AddObserver(this);

[miket_OOO, 2012/11/06 02:04:09]

Braces not needed.

I might answer this question for myself later in the review, but is it OK to
repeatedly add the observer if the caller calls GetMutableAdapter more than
once?

[youngki, 2012/11/06 16:18:54]

Done.

+  }
+  return adapter_.get();
+}
+
 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;
     }
   }
   int return_id = next_socket_id_++;
   socket_map_[return_id] = socket;
   return return_id;
 }
 
 bool ExtensionBluetoothEventRouter::ReleaseSocket(int id) {
   SocketMap::iterator socket_entry = socket_map_.find(id);
   if (socket_entry == socket_map_.end())
     return false;
   socket_map_.erase(socket_entry);
   return true;
 }
 
+bool ExtensionBluetoothEventRouter::IsBluetoothEvent(
+    const std::string& event_name) {

[miket_OOO, 2012/11/06 02:04:09]

this method could be const.

[youngki, 2012/11/06 16:18:54]

This method is actually static, so no need to be const.

+  return
+      event_name == extensions::event_names::kBluetoothOnAvailabilityChanged ||
+      event_name == extensions::event_names::kBluetoothOnDiscoveringChanged ||
+      event_name == extensions::event_names::kBluetoothOnPowerChanged;
+}
+
+void ExtensionBluetoothEventRouter::OnEventListenerAdded(
+    const std::string& event_name) {
+  if (IsBluetoothEvent(event_name) && adapter_.get()) {
+    adapter_->AddObserver(this);

[miket_OOO, 2012/11/06 02:04:09]

Would it be correct, or more elegant, to call GetMutableAdapter() here instead
of doing the get() check & AddObserver()?

[youngki, 2012/11/06 16:18:54]

Hm.. Although they do the same thing, we are not trying to get the mutable
adapter here; I think I will keep this implementation.

Also giving a second thought, I reverted my change on GetMutableAdapter(). It
looks wrong to add an observer when the purpose of the function is just to
return the GetMutableAdapter(). Also BluetoothEventRouter needs to add observers
only when the bluetooth event listeners are added anyways.

+  }
+}
+
 scoped_refptr<device::BluetoothSocket>
 ExtensionBluetoothEventRouter::GetSocket(int id) {
   SocketMap::iterator socket_entry = socket_map_.find(id);
   if (socket_entry == socket_map_.end())
     return NULL;
   return socket_entry->second;
 }
 
 void ExtensionBluetoothEventRouter::SetResponsibleForDiscovery(
     bool responsible) {
@@ skipping 91 matching lines @@
 
 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