[remoting android] Refactor OAuthTokenFetcher for reusability

remoting/android/java/src/org/chromium/chromoting/Chromoting.java

 // 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.chromoting;
 
 import android.annotation.SuppressLint;
 import android.app.ProgressDialog;
 import android.content.DialogInterface;
 import android.content.Intent;
@@ skipping 16 matching lines @@
 import android.widget.AdapterView;
 import android.widget.ArrayAdapter;
 import android.widget.LinearLayout;
 import android.widget.ListView;
 import android.widget.Toast;
 
 import org.chromium.base.ApiCompatibilityUtils;
 import org.chromium.base.Log;
 import org.chromium.chromoting.accountswitcher.AccountSwitcher;
 import org.chromium.chromoting.accountswitcher.AccountSwitcherFactory;
+import org.chromium.chromoting.base.OAuthTokenFetcher;
 import org.chromium.chromoting.help.HelpContext;
 import org.chromium.chromoting.help.HelpSingleton;
 import org.chromium.chromoting.jni.Client;
 import org.chromium.chromoting.jni.ConnectionListener;
 import org.chromium.chromoting.jni.JniInterface;
 
 import java.util.ArrayList;
 import java.util.Arrays;
 
 /**
  * The user interface for querying and displaying a user's host list from the directory server. It
  * also requests and renews authentication tokens using the system account manager.
  */
 public class Chromoting extends AppCompatActivity implements ConnectionListener,
         AccountSwitcher.Callback, HostListLoader.Callback, View.OnClickListener {
     private static final String TAG = "Chromoting";
 
     /** Only accounts of this type will be selectable for authentication. */
     private static final String ACCOUNT_TYPE = "com.google";
 
+    /** Scope to use when fetching the OAuth token. */
+    private static final String TOKEN_SCOPE = "oauth2:https://www.googleapis.com/auth/chromoting "
+            + "https://www.googleapis.com/auth/googletalk";
+
     /** Result code used for starting {@link DesktopActivity}. */
     public static final int DESKTOP_ACTIVITY = 0;
 
     /** Result code used for starting {@link CardboardDesktopActivity}. */
     public static final int CARDBOARD_DESKTOP_ACTIVITY = 1;
 
     /** Preference names for storing selected and recent accounts. */
     private static final String PREFERENCE_SELECTED_ACCOUNT = "account_name";
     private static final String PREFERENCE_RECENT_ACCOUNT_PREFIX = "recent_account_";
     private static final String PREFERENCE_EXPERIMENTAL_FLAGS = "flags";
@@ skipping 420 matching lines @@
         mTriedNewAuthToken = false;
         showHostListLoadingIndicator();
 
         // The refresh button simply makes use of the currently-chosen account.
         requestAuthToken(false);
     }
 
     private void requestAuthToken(boolean expireCurrentToken) {
         mWaitingForAuthToken = true;
 
-        OAuthTokenFetcher fetcher = new OAuthTokenFetcher(this, mAccount,
+        OAuthTokenFetcher fetcher = new OAuthTokenFetcher(this, mAccount, TOKEN_SCOPE,
                 new OAuthTokenFetcher.Callback() {
                     @Override
                     public void onTokenFetched(String token) {
                         mWaitingForAuthToken = false;
                         mToken = token;
                         mHostListLoader.retrieveHostList(mToken, Chromoting.this);
                     }
 
                     @Override
-                    public void onError(int errorResource) {
+                    public void onError(OAuthTokenFetcher.Error error) {
                         mWaitingForAuthToken = false;
                         updateHostListView();
-                        String explanation = getString(errorResource);
+                        String explanation = getString(error == OAuthTokenFetcher.Error.NETWORK
+                                ? R.string.error_network_error : R.string.error_unexpected);
                         Toast.makeText(Chromoting.this, explanation, Toast.LENGTH_LONG).show();
                     }
                 });
 
         if (expireCurrentToken) {
             fetcher.clearAndFetch(mToken);
             mToken = null;
         } else {
             fetcher.fetch();
         }
@@ skipping 117 matching lines @@
                 // Unreachable, but required by Google Java style and findbugs.
                 assert false : "Unreached";
         }
 
         if (dismissProgress && mProgressIndicator != null) {
             mProgressIndicator.dismiss();
             mProgressIndicator = null;
         }
     }
 }