[NOT FOR REVIEW] Plumb Android GCM to Push API

chrome/android/java/src/org/chromium/chrome/browser/GcmPlatformImpl.java

Index: chrome/android/java/src/org/chromium/chrome/browser/GcmPlatformImpl.java
diff --git a/chrome/android/java/src/org/chromium/chrome/browser/GcmPlatformImpl.java b/chrome/android/java/src/org/chromium/chrome/browser/GcmPlatformImpl.java
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index 0000000000000000000000000000000000000000..06e4367985f2f5a16cb985fa2c9800ff50c2f060
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+++ b/chrome/android/java/src/org/chromium/chrome/browser/GcmPlatformImpl.java
@@ -0,0 +1,200 @@
+// Copyright 2013 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.
+
+package org.chromium.chrome.browser;
+
+import android.content.Context;
+import android.content.Intent;
+import android.os.AsyncTask;
+import android.util.Log;
+
+import com.google.android.gcm.GCMRegistrar;
+import com.google.ipc.invalidation.external.client.contrib.MultiplexingGcmListener;
+
+import org.chromium.base.CalledByNative;
+import org.chromium.base.ThreadUtils;
+
+import java.io.IOException;
+
+/**
+ * This class is the Java counterpart to the C++ GcmPlatformImplAndroid class.
+ * It implements GCM registration, and sends back GCM messages over JNI.
+ *
+ * Threading model note: all calls from C++ must happen on the UI thread.
+ * Callbacks from Android may happen on a different thread, so we always
+ * use ThreadUtils.runOnUiThread when calling back to C++.
+ */
+class GcmPlatformImpl {
+    private static final String TAG = "Chrome-GcmPlatformImpl";
+
+    private static GcmPlatformImpl sInstance = null;
+
+    private long mNativeGcmPlatformImplAndroid;
+    private Context mContext;
+
+    private GcmPlatformImpl(long nativeGcmPlatformImplAndroid, Context context) {
+        mNativeGcmPlatformImplAndroid = nativeGcmPlatformImplAndroid;
+        mContext = context;
+        sInstance = this;
+    }
+
+    /**
+     * Create a GcmPlatformImpl object, which is owned by GcmPlatformImplAndroid
+     * on the C++ side.
+     *
+     * @param nativeGcmPlatformImplAndroid The C++ object that owns us.
+     * @param context The app context.
+     */
+    @CalledByNative
+    private static GcmPlatformImpl create(int nativeGcmPlatformImplAndroid,
+                                          Context context) {
+        if (sInstance != null) {
+            throw new IllegalStateException("Already instantiated");
+        }
+        return new GcmPlatformImpl(nativeGcmPlatformImplAndroid, context);
+    }
+
+    /**
+     * Called when our C++ counterpart is deleted. Clear the handle to our
+     * native C++ object, ensuring it's never called.
+     */
+    @CalledByNative
+    private void destroy() {
+        mNativeGcmPlatformImplAndroid = 0;
+    }
+
+    /**
+     * Registers the app with GCM servers asynchronously. Calls
+     * nativeOnRegistrationFinished once this is done.
+     *
+     * @param appUniqueIdCurrentlyIgnored A unique string identifying the app.
+     *                                    Currently ignored.
+     * @param senderIds List of project numbers or Google accounts identifying
+     *                  who is allowed to send messages to this application.
+     */
+    @CalledByNative
+    private void registerApp(String appUniqueIdCurrentlyIgnored, String[] senderIds) {
+        new AsyncTask<String, Void, String>() {
+            @Override
+            protected String doInBackground(String[] senderIds) {
+                try {
+                    GCMRegistrar.checkDevice(mContext);
+                }
+                catch (UnsupportedOperationException ex) {
+                    return ""; // Indicates failure
+                }
+                GCMRegistrar.checkManifest(mContext); // TODO: Do I want this?
+                String registrationId = GCMRegistrar.getRegistrationId(mContext);
+                if (registrationId.equals("")) {
+                    GCMRegistrar.register(mContext, senderIds);
+                    return null; // Indicates pending result
+                } else {
+                    return registrationId;
+                }
+            }
+
+            @Override
+            protected void onPostExecute(String registrationId) {
+                if (registrationId != null)
+                    nativeOnRegistrationFinished(mNativeGcmPlatformImplAndroid,
+                                                 registrationId);
+            }
+        }.execute(senderIds);
+    }
+
+    // registrationId will be an empty string in case of failure.
+    private native void nativeOnRegistrationFinished(long nativeGcmPlatformImplAndroid,
+                                                     String registrationId);
+    private native void nativeOnMessageReceived(long nativeGcmPlatformImplAndroid, String data);
+    private native void nativeOnMessagesDeletedByServer(long nativeGcmPlatformImplAndroid);
+
+    /**
+     * Receives GCM registration events and messages rebroadcast by MultiplexingGcmListener.
+     */
+    public static class GcmListener extends MultiplexingGcmListener.AbstractListener {
+        /**
+         * Receiver for broadcasts by the multiplexed GCM service. It forwards them to
+         * GcmListener.
+         */
+        public static class Receiver extends MultiplexingGcmListener.AbstractListener.Receiver {
+            /**
+             * This class is public so that it can be instantiated by the Android runtime.
+             */
+            @Override
+            protected Class<?> getServiceClass() {
+                return GcmListener.class;
+            }
+        }
+
+        private static final String TAG = "GcmListener";
+
+        public GcmListener() {
+            super(TAG);
+        }
+
+        @Override
+        protected void onMessage(Intent intent) {
+            final GcmPlatformImpl impl = GcmPlatformImpl.sInstance;
+            // HACK FOR DEMO: Don't start Chrome if it's not already running.
+            if (impl == null)
+                return;
+
+            final String DATA_KEY = "data";
+            if (!intent.hasExtra(DATA_KEY)) {
+                // Not a GCM message for us (likely for sync or cloud print).
+                return;
+            }
+            final String data = intent.getExtras().getString(DATA_KEY);
+
+            ThreadUtils.runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    impl.nativeOnMessageReceived(impl.mNativeGcmPlatformImplAndroid, data);
+                }
+            });
+        }
+
+        @Override
+        public void onRegistered(final String registrationId) {
+            final GcmPlatformImpl impl = GcmPlatformImpl.sInstance;
+            // Drop this event if it arrives after Chrome gets killed.
+            if (impl == null)
+                return;
+
+            // TODO: Check that this onRegistered event actually corresponds
+            // to the current observer of GcmPlatformImplAndroid. Requires
+            // changes to Android GCM API.
+
+            ThreadUtils.runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    impl.nativeOnRegistrationFinished(impl.mNativeGcmPlatformImplAndroid,
+                                                      registrationId);
+                }
+            });
+        }
+
+        @Override
+        public void onUnregistered(String registrationId) {
+            Log.e(TAG, "onUnregistered not implemented");
+        }
+
+        @Override
+        protected void onDeletedMessages(int total) {
+            final GcmPlatformImpl impl = GcmPlatformImpl.sInstance;
+            // HACK FOR DEMO: Don't start Chrome if it's not already running.
+            if (impl == null)
+                return;
+
+            // FIXME: How do we know whether this message is for us, sync or cloud print?
+
+            ThreadUtils.runOnUiThread(new Runnable() {
+                @Override
+                public void run() {
+                    impl.nativeOnMessagesDeletedByServer(impl.mNativeGcmPlatformImplAndroid);
+                }
+            });
+        }
+    }
+}