Helper functions in NetworkChangeNotifier related to WWAN use

net/base/network_change_notifier.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 "net/base/network_change_notifier.h"
 
 #include "base/metrics/histogram.h"
 #include "base/synchronization/lock.h"
 #include "build/build_config.h"
 #include "googleurl/src/gurl.h"
@@ skipping 257 matching lines @@
 #if defined(OS_LINUX)
 // static
 const internal::AddressTrackerLinux*
 NetworkChangeNotifier::GetAddressTracker() {
   return g_network_change_notifier ?
         g_network_change_notifier->GetAddressTrackerInternal() : NULL;
 }
 #endif
 
 // static
+bool NetworkChangeNotifier::IsOffline() {
+   return GetConnectionType() == CONNECTION_NONE;
+}
+
+// static
+bool NetworkChangeNotifier::IsConnectionCellular() {
+  return IsConnectionCellular(GetConnectionType());
+}
+
+// static
+bool NetworkChangeNotifier::IsConnectionCellular(ConnectionType type) {
+  switch (type) {
+    case CONNECTION_2G:
+    case CONNECTION_3G:
+    case CONNECTION_4G:
+      return true;
+    case CONNECTION_UNKNOWN:
+    case CONNECTION_ETHERNET:
+    case CONNECTION_WIFI:
+    case CONNECTION_NONE:
+      return false;
+    default:

[Ryan Sleevi, 2012/10/12 17:49:57]

If you remove this "default", you should get a compile error for any unhandled
types in the future.

As written, you're relying on runtime detection (hitting a NOTREACHED in Debug
mode), which is less than ideal.

+      NOTREACHED();
+      return false;
+  }
+}
+
+// static
 NetworkChangeNotifier* NetworkChangeNotifier::CreateMock() {
   return new MockNetworkChangeNotifier();
 }
 
 void NetworkChangeNotifier::AddIPAddressObserver(IPAddressObserver* observer) {
   if (g_network_change_notifier)
     g_network_change_notifier->ip_address_observer_list_->AddObserver(observer);
 }
 
 void NetworkChangeNotifier::AddConnectionTypeObserver(
@@ skipping 94 matching lines @@
   DCHECK(g_network_change_notifier);
   g_network_change_notifier = NULL;
 }
 
 NetworkChangeNotifier::DisableForTest::~DisableForTest() {
   DCHECK(!g_network_change_notifier);
   g_network_change_notifier = network_change_notifier_;
 }
 
 }  // namespace net