Add NetworkChangeNotifier for Android.

net/android/network_change_notifier.cc

Index: net/android/network_change_notifier.cc
diff --git a/net/android/network_change_notifier.cc b/net/android/network_change_notifier.cc
new file mode 100644
index 0000000000000000000000000000000000000000..460efd390a7dd868230d64b1b2d85cc0d1d6c205
--- /dev/null
+++ b/net/android/network_change_notifier.cc
@@ -0,0 +1,56 @@
+// 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/android/network_change_notifier.h"
+
+#include "base/logging.h"
+#include "base/android/jni_android.h"
+
+using net::android::NetworkChangeNotifier;
+#include "jni/network_change_notifier_jni.h"

[Ryan Sleevi, 2012/04/13 22:37:58]

This seems like a cheap hack to avoid the "don't use using within headers". If
this header cannot compile without the definition, this header should be fixed.

[Yaron, 2012/04/17 16:18:03]

Hmm. So the header is auto-generated by the jni_generator and assumes that
everything is in global scope. Not sure how to incorporate namespaces in the
auto-generated code.

[Ryan Sleevi, 2012/04/17 17:56:06]

Update the jni generator? ;)

+
+namespace net {
+namespace android {
+
+

[Ryan Sleevi, 2012/04/13 22:37:58]

nit: delete this whitespace

[Yaron, 2012/04/17 16:18:03]

Done.

+NetworkChangeNotifier::NetworkChangeNotifier() {
+  JNIEnv* env = base::android::AttachCurrentThread();
+  CHECK(java_network_change_notifier_android_object_.is_null());

[Ryan Sleevi, 2012/04/13 22:37:58]

Why CHECK here? You're in a constructor - how is this not guaranteed?

[Yaron, 2012/04/17 16:18:03]

Done.

+  CreateJavaObject(env);
+}
+
+NetworkChangeNotifier::~NetworkChangeNotifier() {
+  CHECK(!java_network_change_notifier_android_object_.is_null());

[Ryan Sleevi, 2012/04/13 22:37:58]

Unnecessary CHECK? This is also guaranteed.

[Yaron, 2012/04/17 16:18:03]

Done.

+  JNIEnv* env = base::android::AttachCurrentThread();
+  Java_NetworkChangeNotifier_unregisterReceiver(
+      env, java_network_change_notifier_android_object_.obj());
+  java_network_change_notifier_android_object_.Reset();

[Ryan Sleevi, 2012/04/13 22:37:58]

Isn't this unnecessary and guaranteed by the destructor of
|java_network_change_notifier_android_object_| ?

[Yaron, 2012/04/17 16:18:03]

Done.

+}
+
+void NetworkChangeNotifier::CreateJavaObject(JNIEnv* env) {
+  java_network_change_notifier_android_object_.Reset(
+      Java_NetworkChangeNotifier_create(
+          env,
+          base::android::GetApplicationContext(),
+          reinterpret_cast<jint>(this)));
+  CHECK(!java_network_change_notifier_android_object_.is_null());

[Ryan Sleevi, 2012/04/13 22:37:58]

Do you really need to CHECK here? Would a DCHECK suffice? Are both superflous
and the user will end up crashing on a null-deref when they actually try to use
it, accomplishing the same thing?

[Yaron, 2012/04/17 16:18:03]

Done.

+}
+
+void NetworkChangeNotifier::NotifyObservers(JNIEnv* env, jobject obj) {
+  NotifyObserversOfOnlineStateChange();
+}
+
+bool NetworkChangeNotifier::IsCurrentlyOffline() const {
+  CHECK(!java_network_change_notifier_android_object_.is_null());

[Ryan Sleevi, 2012/04/13 22:37:58]

And here

[Yaron, 2012/04/17 16:18:03]

Done.

+  JNIEnv* env = base::android::AttachCurrentThread();
+  return !Java_NetworkChangeNotifier_isConnected(
+      env, java_network_change_notifier_android_object_.obj());
+}
+
+bool RegisterNetworkChangeNotifier(JNIEnv* env) {
+  return RegisterNativesImpl(env);
+}
+
+}  // namespace android
+}  // namespace net