NetworkManagementService: Introduce INetworkManagementEventObserver

  Introduce a callback event observer which can be registered on the
INetworkManagementService instance to receive events from the service.

Signed-off-by: San Mehat <san@google.com>
diff --git a/Android.mk b/Android.mk
index d6beac5..568352e 100644
--- a/Android.mk
+++ b/Android.mk
@@ -108,6 +108,7 @@
 	core/java/android/database/IContentObserver.aidl \
 	core/java/android/hardware/ISensorService.aidl \
 	core/java/android/net/IConnectivityManager.aidl \
+	core/java/android/net/INetworkManagementEventObserver.aidl \
 	core/java/android/os/ICheckinService.aidl \
 	core/java/android/os/IMessenger.aidl \
 	core/java/android/os/IMountService.aidl \
diff --git a/core/java/android/net/INetworkManagementEventObserver.aidl b/core/java/android/net/INetworkManagementEventObserver.aidl
new file mode 100644
index 0000000..d30b63d
--- /dev/null
+++ b/core/java/android/net/INetworkManagementEventObserver.aidl
@@ -0,0 +1,46 @@
+/*
+ * Copyright (C) 2009 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package android.net;
+
+/**
+ * Callback class for receiving events from an INetworkManagementService
+ *
+ * @hide
+ */
+interface INetworkManagementEventObserver {
+    /**
+     * Interface link status has changed.
+     *
+     * @param iface The interface.
+     * @param link True if link is up.
+     */
+    void interfaceLinkStatusChanged(String iface, boolean link);
+
+    /**
+     * An interface has been added to the system
+     *
+     * @param iface The interface.
+     */
+    void interfaceAdded(String iface);
+
+    /**
+     * An interface has been removed from the system
+     *
+     * @param iface The interface.
+     */
+    void interfaceRemoved(String iface);
+}
diff --git a/core/java/android/os/INetworkManagementService.aidl b/core/java/android/os/INetworkManagementService.aidl
index 49abb4d..e4ec098 100644
--- a/core/java/android/os/INetworkManagementService.aidl
+++ b/core/java/android/os/INetworkManagementService.aidl
@@ -18,6 +18,7 @@
 package android.os;
 
 import android.net.InterfaceConfiguration;
+import android.net.INetworkManagementEventObserver;
 
 /**
  * @hide
@@ -29,6 +30,16 @@
      **/
 
     /**
+     * Register an observer to receive events
+     */
+    void registerObserver(INetworkManagementEventObserver obs);
+
+    /**
+     * Unregister an observer from receiving events.
+     */
+    void unregisterObserver(INetworkManagementEventObserver obs);
+
+    /**
      * Returns a list of currently known network interfaces
      */
     String[] listInterfaces();
diff --git a/services/java/com/android/server/NetworkManagementService.java b/services/java/com/android/server/NetworkManagementService.java
index 7b66a76..8594e44 100644
--- a/services/java/com/android/server/NetworkManagementService.java
+++ b/services/java/com/android/server/NetworkManagementService.java
@@ -25,6 +25,7 @@
 import android.content.pm.PackageManager;
 import android.net.Uri;
 import android.net.InterfaceConfiguration;
+import android.net.INetworkManagementEventObserver;
 import android.os.INetworkManagementService;
 import android.os.Handler;
 import android.text.TextUtils;
@@ -70,6 +71,8 @@
      */
     private NativeDaemonConnector mConnector;
 
+    private ArrayList<INetworkManagementEventObserver> mObservers;
+
     /**
      * Constructs a new NetworkManagementService instance
      *
@@ -78,12 +81,64 @@
     private NetworkManagementService(Context context) {
         mContext = context;
 
+        mObservers = new ArrayList<INetworkManagementEventObserver>();
+
         mConnector = new NativeDaemonConnector(
                 new NetdCallbackReceiver(), "netd", 10, "NetdConnector");
         Thread thread = new Thread(mConnector, NativeDaemonConnector.class.getName());
         thread.start();
     }
 
+    public void registerObserver(INetworkManagementEventObserver obs) {
+        Log.d(TAG, "Registering observer");
+        mObservers.add(obs);
+    }
+
+    public void unregisterObserver(INetworkManagementEventObserver obs) {
+        Log.d(TAG, "Unregistering observer");
+        mObservers.remove(mObservers.indexOf(obs));
+    }
+
+    /**
+     * Notify our observers of an interface link status change
+     */
+    private void notifyInterfaceLinkStatusChanged(String iface, boolean link) {
+        for (INetworkManagementEventObserver obs : mObservers) {
+            try {
+                obs.interfaceLinkStatusChanged(iface, link);
+            } catch (Exception ex) {
+                Log.w(TAG, "Observer notifier failed", ex);
+            }
+        }
+    }
+
+    /**
+     * Notify our observers of an interface addition.
+     */
+    private void notifyInterfaceAdded(String iface) {
+        for (INetworkManagementEventObserver obs : mObservers) {
+            try {
+                obs.interfaceAdded(iface);
+            } catch (Exception ex) {
+                Log.w(TAG, "Observer notifier failed", ex);
+            }
+        }
+    }
+
+    /**
+     * Notify our observers of an interface removal.
+     */
+    private void notifyInterfaceRemoved(String iface) {
+        for (INetworkManagementEventObserver obs : mObservers) {
+            try {
+                obs.interfaceRemoved(iface);
+            } catch (Exception ex) {
+                Log.w(TAG, "Observer notifier failed", ex);
+            }
+        }
+    }
+
+
     //
     // Netd Callback handling
     //