android: Use new proxy from PROXY_CHANGE intent

net/android/java/src/org/chromium/net/ProxyChangeListener.java

Index: net/android/java/src/org/chromium/net/ProxyChangeListener.java
diff --git a/net/android/java/src/org/chromium/net/ProxyChangeListener.java b/net/android/java/src/org/chromium/net/ProxyChangeListener.java
index 9c59bcccf6df36c4ed2032a3d9b517656a89fb3d..61dc1241c68d40df439e811c0dfaeed9c590d308 100644
--- a/net/android/java/src/org/chromium/net/ProxyChangeListener.java
+++ b/net/android/java/src/org/chromium/net/ProxyChangeListener.java
@@ -10,6 +10,8 @@ import android.content.Intent;
 import android.content.IntentFilter;
 import android.net.Proxy;
 
+import java.lang.reflect.Method;
+
 import org.chromium.base.CalledByNative;
 import org.chromium.base.JNINamespace;
 import org.chromium.base.NativeClassQualifiedName;
@@ -26,6 +28,15 @@ public class ProxyChangeListener {
     private ProxyReceiver mProxyReceiver;
     private Delegate mDelegate;
 
+    private static class ProxyConfig {
+        public ProxyConfig(String host, int port) {
+            mHost = host;
+            mPort = port;
+        }
+        public final String mHost;
+        public final int mPort;
+    };
+
     public interface Delegate {
         public void proxySettingsChanged();
     }
@@ -69,12 +80,43 @@ public class ProxyChangeListener {
         @Override
         public void onReceive(Context context, Intent intent) {
             if (intent.getAction().equals(Proxy.PROXY_CHANGE_ACTION)) {
-                proxySettingsChanged();
+                ProxyConfig cfg = extractNewProxy(intent);

[cbentzel, 2013/10/15 18:59:42]

Do older versions of Android set a "proxy" object in the intent? If not, we will
miss signals about the proxy changing.

[Elly Fong-Jones, 2013/10/15 19:50:42]

All versions ICS and later do.

+                if (cfg != null) {
+                    proxySettingsChanged(cfg);
+                }
+            }
+        }
+
+        // Extract a ProxyConfig object from the supplied Intent's extra data
+        // bundle. The android.net.ProxyProperties class is not exported from
+        // tne Android SDK, so we have to use reflection to get at it and invoke
+        // methods on it.
+        // TODO(ellyjones): once android.net.ProxyProperties is exported,
+        // rewrite this.
+        private ProxyConfig extractNewProxy(Intent intent) {

[cbentzel, 2013/10/15 18:59:42]

How hard would it be to test this?

[Elly Fong-Jones, 2013/10/15 19:50:42]

Not difficult per se, just ugly. It would basically involve abusing Java
reflection again to construct an object that looks like an Intent with the right
property on it. Unfortunately my understanding of Java reflection is sketchy
enough that doing that wouldn't add much confidence.

+            try {
+                final String CLASS_NAME = "android.net.ProxyProperties";
+                final String GET_HOST_NAME = "getHost";
+                final String GET_PORT_NAME = "getPort";
+                Object props = intent.getExtras().get("proxy");
+                if (props == null) {
+                    return null;
+                }
+                Class cls = Class.forName(CLASS_NAME);
+                Method getHostMethod = cls.getDeclaredMethod(GET_HOST_NAME);
+                Method getPortMethod = cls.getDeclaredMethod(GET_PORT_NAME);
+
+                String host = (String)getHostMethod.invoke(props);

[cbentzel, 2013/10/15 18:59:42]

Stupid java question: what happens if the getHost method exists but returns a
non-String object? Will this raise an exception for the downcast?

[Elly Fong-Jones, 2013/10/15 19:50:42]

I don't know. pliard?

[Philippe, 2013/10/15 20:23:37]

This would indeed throw an InvalidCastException (that would be caught below).

+                int port = (Integer)getPortMethod.invoke(props);
+
+                return new ProxyConfig(host, port);
+            } catch (Exception ex) {
+                return null;
             }
         }
     }
 
-    private void proxySettingsChanged() {
+    private void proxySettingsChanged(ProxyConfig cfg) {
         if (!sEnabled) {
             return;
         }
@@ -86,7 +128,7 @@ public class ProxyChangeListener {
         }
         // Note that this code currently runs on a MESSAGE_LOOP_UI thread, but
         // the C++ code must run the callbacks on the network thread.
-        nativeProxySettingsChanged(mNativePtr);
+        nativeProxySettingsChanged(mNativePtr, cfg.mHost, cfg.mPort);
     }
 
     private void registerReceiver() {
@@ -111,5 +153,7 @@ public class ProxyChangeListener {
      * See net/proxy/proxy_config_service_android.cc
      */
     @NativeClassQualifiedName("ProxyConfigServiceAndroid::JNIDelegate")
-    private native void nativeProxySettingsChanged(int nativePtr);
+    private native void nativeProxySettingsChanged(int nativePtr,
+                                                   String host,
+                                                   int port);
 }