[Remoting Android] Refactor OAuth Token Fetching Code

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 54 matching lines @@
     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";
 
     /** User's account name (email). */
     private String mAccount;
 
-    /** Account auth token. */
-    private String mToken;
-
     /** Helper for fetching the host list. */
     private HostListManager mHostListManager;
 
     /** List of hosts. */
     private HostInfo[] mHosts = new HostInfo[0];
 
     /** Refresh button. */
     private MenuItem mRefreshButton;
 
     /** Host list chooser view shown when at least one host is configured. */
     private ListView mHostListView;
 
     /** View shown when the user has no configured hosts or host list couldn't be retrieved. */
     private View mEmptyView;
 
     /** Progress view shown instead of the host list when the host list is loading. */
     private View mProgressView;
 
     /** Dialog for reporting connection progress. */
     private ProgressDialog mProgressIndicator;
 
     /**
      * Helper used by SessionConnection for session authentication. Receives onNewIntent()
      * notifications to handle third-party authentication.
      */
     private SessionAuthenticator mAuthenticator;
 
-    /**
-     * This is set when receiving an authentication error from the HostListManager. If that occurs,
-     * this flag is set and a fresh authentication token is fetched from the AccountsService, and
-     * used to request the host list a second time.
-     */
-    boolean mTriedNewAuthToken;
+    private OAuthTokenConsumer mHostConnectingConsumer;
 
-    /**
-     * Flag to track whether a call to AccountManager.getAuthToken() is currently pending.
-     * This avoids infinitely-nested calls in case onStart() gets triggered a second time
-     * while a token is being fetched.
-     */
-    private boolean mWaitingForAuthToken = false;
+    private OAuthTokenConsumer mHostListRetrievingConsumer;
+
+    private OAuthTokenConsumer mHostDeletingConsumer;
 
     private DrawerLayout mDrawerLayout;
 
     private ActionBarDrawerToggle mDrawerToggle;
 
     private AccountSwitcher mAccountSwitcher;
 
     /** The currently-connected Client, if any. */
     private Client mClient;
 
@@ skipping 56 matching lines @@
      * authentication token from the system.
      */
     @Override
     public void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);
         setContentView(R.layout.main);
 
         Toolbar toolbar = (Toolbar) findViewById(R.id.toolbar);
         setSupportActionBar(toolbar);
 
-        mTriedNewAuthToken = false;
         mHostListManager = new HostListManager();
 
         // Get ahold of our view widgets.
         mHostListView = (ListView) findViewById(R.id.hostList_chooser);
         mEmptyView = findViewById(R.id.hostList_empty);
         mHostListView.setOnItemClickListener(
                 new AdapterView.OnItemClickListener() {
                     @Override
                     public void onItemClick(AdapterView<?> parent, View view, int position,
                             long id) {
@@ skipping 68 matching lines @@
 
         mAccountSwitcher = AccountSwitcherFactory.getInstance().createAccountSwitcher(this, this);
         mAccountSwitcher.setNavigation(navigationMenu);
         LinearLayout navigationDrawer = (LinearLayout) findViewById(R.id.navigation_drawer);
         mAccountSwitcher.setDrawer(navigationDrawer);
         View switcherView = mAccountSwitcher.getView();
         switcherView.setLayoutParams(new LinearLayout.LayoutParams(
                 LinearLayout.LayoutParams.MATCH_PARENT,
                 LinearLayout.LayoutParams.WRAP_CONTENT));
         navigationDrawer.addView(switcherView, 0);
+
+        mHostConnectingConsumer = new OAuthTokenConsumer(this, TOKEN_SCOPE);
+        mHostListRetrievingConsumer = new OAuthTokenConsumer(this, TOKEN_SCOPE);
+        mHostDeletingConsumer = new OAuthTokenConsumer(this, TOKEN_SCOPE);
     }
 
     @Override
     protected void onPostCreate(Bundle savedInstanceState) {
         super.onPostCreate(savedInstanceState);
         mDrawerToggle.syncState();
     }
 
     @Override
     protected void onNewIntent(Intent intent) {
@@ skipping 71 matching lines @@
 
     /** Called when a child Activity exits and sends a result back to this Activity. */
     @Override
     public void onActivityResult(int requestCode, int resultCode, Intent data) {
         mAccountSwitcher.onActivityResult(requestCode, resultCode, data);
 
         if (requestCode == OAuthTokenFetcher.REQUEST_CODE_RECOVER_FROM_OAUTH_ERROR) {
             if (resultCode == RESULT_OK) {
                 // User gave OAuth permission to this app (or recovered from any OAuth failure),
                 // so retry fetching the token.
-                requestAuthToken(false);
+                refreshHostList();
             } else {
                 // User denied permission or cancelled the dialog, so cancel the request.
-                mWaitingForAuthToken = false;
                 updateHostListView();
             }
         }
     }
 
     /** Called when a permissions request has returned. */
     @Override
     public void onRequestPermissionsResult(int requestCode, String[] permissions,
             int[] grantResults) {
         // This is currently only used by AccountSwitcherBasic.
         // Check that the user has granted the needed permission, and reload the accounts.
         // Otherwise, assume something unexpected occurred, or the user cancelled the request.
         if (grantResults.length == 1 && grantResults[0] == PackageManager.PERMISSION_GRANTED) {
             mAccountSwitcher.reloadAccounts();
         } else if (permissions.length == 0) {
             Log.e(TAG, "User cancelled the permission request.");
         } else {
             Log.e(TAG, "Permission %s was not granted.", permissions[0]);
         }
     }
 
     /** Called when the display is rotated (as registered in the manifest). */
     @Override
     public void onConfigurationChanged(Configuration newConfig) {
         super.onConfigurationChanged(newConfig);
 
         mDrawerToggle.onConfigurationChanged(newConfig);
     }
 
-    /** Called to initialize the action bar. */
+        /** Called to initialize the action bar. */

[Yuwei, 2016/05/13 00:30:17]

Not sure how the tab comes but I'll remove it...

[Yuwei, 2016/05/13 17:20:28]

Done.

     @Override
     public boolean onCreateOptionsMenu(Menu menu) {
         getMenuInflater().inflate(R.menu.chromoting_actionbar, menu);
         mRefreshButton = menu.findItem(R.id.actionbar_directoryrefresh);
 
         if (mAccount == null) {
             // If there is no account, don't allow the user to refresh the listing.
             mRefreshButton.setEnabled(false);
         }
 
@@ skipping 27 matching lines @@
     private void onHostClicked(int index) {
         HostInfo host = mHosts[index];
         if (host.isOnline) {
             connectToHost(host);
         } else {
             String tooltip = host.getHostOfflineReasonText(this);
             Toast.makeText(this, tooltip, Toast.LENGTH_SHORT).show();
         }
     }
 
-    private void connectToHost(HostInfo host) {
+    private void connectToHost(final HostInfo host) {
         if (mClient != null) {
             mClient.destroy();
         }
 
         mClient = new Client();
         mProgressIndicator = ProgressDialog.show(
                 this,
                 host.name,
                 getString(R.string.footer_connecting),
                 true,
                 true,
                 new DialogInterface.OnCancelListener() {
                     @Override
                     public void onCancel(DialogInterface dialog) {
                         if (mClient != null) {
                             mClient.destroy();
                             mClient = null;
                         }
                     }
                 });
 
-        SessionConnector connector = new SessionConnector(mClient, this, this, mHostListManager);
+        final SessionConnector connector =
+                new SessionConnector(mClient, this, this, mHostListManager);
         mAuthenticator = new SessionAuthenticator(this, mClient, host);
-        connector.connectToHost(mAccount, mToken, host, mAuthenticator,
-                getPreferences(MODE_PRIVATE).getString(PREFERENCE_EXPERIMENTAL_FLAGS, ""));
+        mHostConnectingConsumer.consume(mAccount, new OAuthTokenFetcher.Callback() {
+            @Override
+            public void onTokenFetched(String token) {
+                connector.connectToHost(mAccount, token, host, mAuthenticator,
+                        getPreferences(MODE_PRIVATE).getString(PREFERENCE_EXPERIMENTAL_FLAGS, ""));
+            }
+
+            @Override
+            public void onError(OAuthTokenFetcher.Error error) {
+                showAuthErrorMessage(error);
+            }
+        });
+    }
+
+    private void showAuthErrorMessage(OAuthTokenFetcher.Error error) {
+        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();
     }
 
     private void refreshHostList() {
-        if (mWaitingForAuthToken) {
-            return;
-        }
-
-        mTriedNewAuthToken = false;
         showHostListLoadingIndicator();
 
         // The refresh button simply makes use of the currently-chosen account.
-        requestAuthToken(false);
+        mHostListRetrievingConsumer.consume(mAccount, new OAuthTokenFetcher.Callback() {
+            @Override
+            public void onTokenFetched(String token) {
+                mHostListManager.retrieveHostList(token, Chromoting.this);
+            }
+
+            @Override
+            public void onError(OAuthTokenFetcher.Error error) {
+                showAuthErrorMessage(error);
+                updateHostListView();
+            }
+        });
     }
 
-    private void requestAuthToken(boolean expireCurrentToken) {
-        mWaitingForAuthToken = true;
+    private void deleteHost(final String hostId) {
+        showHostListLoadingIndicator();
 
-        OAuthTokenFetcher fetcher = new OAuthTokenFetcher(this, mAccount, TOKEN_SCOPE,
-                new OAuthTokenFetcher.Callback() {
-                    @Override
-                    public void onTokenFetched(String token) {
-                        mWaitingForAuthToken = false;
-                        mToken = token;
-                        mHostListManager.retrieveHostList(mToken, Chromoting.this);
-                    }
+        mHostDeletingConsumer.consume(mAccount, new OAuthTokenFetcher.Callback() {
+            @Override
+            public void onTokenFetched(String token) {
+                mHostListManager.deleteHost(token, hostId, Chromoting.this);
+            }
 
-                    @Override
-                    public void onError(OAuthTokenFetcher.Error error) {
-                        mWaitingForAuthToken = false;
-                        updateHostListView();
-                        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();
-        }
+            @Override
+            public void onError(OAuthTokenFetcher.Error error) {
+                showAuthErrorMessage(error);

[Yuwei, 2016/05/13 00:30:17]

Looks like I also need to do updateHostListView here...

[Lambros, 2016/05/13 01:11:31]

I think so, to hide the host-list-loading progress indicator.

[Yuwei, 2016/05/13 17:20:29]

Done.

+            }
+        });
     }
 
     @Override
     public void onAccountSelected(String accountName) {
         mAccount = accountName;
 
         // The current host list is no longer valid for the new account, so clear the list.
         mHosts = new HostInfo[0];
         updateUi();
         refreshHostList();
@@ skipping 18 matching lines @@
         updateUi();
     }
 
     @Override
     public void onHostUpdated() {
         // Not implemented Yet.
     }
 
     @Override
     public void onHostDeleted() {
-        // Not implemented Yet.
+        // Refresh the host list. there is no need to refetch the auth token again.
+        mHostListManager.retrieveHostList(mHostDeletingConsumer.getLastToken(), this);
     }
 
     @Override
     public void onError(HostListManager.Error error) {
         String explanation = null;
         switch (error) {
             case AUTH_FAILED:
                 break;
             case NETWORK_ERROR:
                 explanation = getString(R.string.error_network_error);
                 break;
             case UNEXPECTED_RESPONSE:
             case SERVICE_UNAVAILABLE:
             case UNKNOWN:
                 explanation = getString(R.string.error_unexpected);
                 break;
             default:
                 // Unreachable.
                 return;
         }
 
         if (explanation != null) {
             Toast.makeText(this, explanation, Toast.LENGTH_LONG).show();
             updateHostListView();
             return;
         }
 
-        // This is the AUTH_FAILED case.
-
-        if (!mTriedNewAuthToken) {
-            // This was our first connection attempt.
-            mTriedNewAuthToken = true;
-            requestAuthToken(true);
-
-            // We're not in an error state *yet*.
-            return;
-        } else {
-            // Authentication truly failed.
-            Log.e(TAG, "Fresh auth token was rejected.");
-            explanation = getString(R.string.error_authentication_failed);
-            Toast.makeText(this, explanation, Toast.LENGTH_LONG).show();
-            updateHostListView();
-        }
+        Log.e(TAG, "Fresh auth token was rejected.");
+        explanation = getString(R.string.error_authentication_failed);
+        Toast.makeText(this, explanation, Toast.LENGTH_LONG).show();
+        updateHostListView();
     }
 
     /**
      * Updates the infotext and host list display.
      */
     private void updateUi() {
         if (mRefreshButton != null) {
             mRefreshButton.setEnabled(mAccount != null);
         }
         ArrayAdapter<HostInfo> displayer = new HostListAdapter(this, mHosts);
@@ skipping 35 matching lines @@
                 // Unreachable, but required by Google Java style and findbugs.
                 assert false : "Unreached";
         }
 
         if (dismissProgress && mProgressIndicator != null) {
             mProgressIndicator.dismiss();
             mProgressIndicator = null;
         }
     }
 }