The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 package org.mozilla.gecko.fxa.sync;

 import java.util.Map;

 import java.util.Map.Entry;

 import java.util.WeakHashMap;

 import org.mozilla.gecko.fxa.FirefoxAccounts;

 import org.mozilla.gecko.fxa.authenticator.AndroidFxAccount;

 import android.content.ContentResolver;

 import android.content.SyncStatusObserver;

 /**

  * Abstract away some details of Android's SyncStatusObserver.

  * <p>

  * Provides a simplified sync started/sync finished delegate.

  */

 public class FxAccountSyncStatusHelper implements SyncStatusObserver {

   @SuppressWarnings("unused")

   private static final String LOG_TAG = FxAccountSyncStatusHelper.class.getSimpleName();

   protected static FxAccountSyncStatusHelper sInstance = null;

   public synchronized static FxAccountSyncStatusHelper getInstance() {

     if (sInstance == null) {

       sInstance = new FxAccountSyncStatusHelper();

     }

     return sInstance;

   }

   // Used to unregister this as a listener.

   protected Object handle = null;

   // Maps delegates to whether their underlying Android account was syncing the

   // last time we observed a status change.

   protected Map<FirefoxAccounts.SyncStatusListener, Boolean> delegates = new WeakHashMap<FirefoxAccounts.SyncStatusListener, Boolean>();

   @Override

   public synchronized void onStatusChanged(int which) {

     for (Entry<FirefoxAccounts.SyncStatusListener, Boolean> entry : delegates.entrySet()) {

       final FirefoxAccounts.SyncStatusListener delegate = entry.getKey();

       final AndroidFxAccount fxAccount = new AndroidFxAccount(delegate.getContext(), delegate.getAccount());

       final boolean active = fxAccount.isCurrentlySyncing();

       // Remember for later.

       boolean wasActiveLastTime = entry.getValue();

       // It's okay to update the value of an entry while iterating the entrySet.

       entry.setValue(active);

       if (active && !wasActiveLastTime) {

         // We've started a sync.

         delegate.onSyncStarted();

       }

       if (!active && wasActiveLastTime) {

         // We've finished a sync.

         delegate.onSyncFinished();

       }

     }

   }

   protected void addListener() {

     final int mask = ContentResolver.SYNC_OBSERVER_TYPE_ACTIVE;

     if (this.handle != null) {

       throw new IllegalStateException("Already registered this as an observer?");

     }

     this.handle = ContentResolver.addStatusChangeListener(mask, this);

   }

   protected void removeListener() {

     Object handle = this.handle;

     this.handle = null;

     if (handle != null) {

       ContentResolver.removeStatusChangeListener(handle);

     }

   }

   public synchronized void startObserving(FirefoxAccounts.SyncStatusListener delegate) {

     if (delegate == null) {

       throw new IllegalArgumentException("delegate must not be null");

     }

     if (delegates.containsKey(delegate)) {

       return;

     }

     // If we are the first delegate to the party, start listening.

     if (delegates.isEmpty()) {

       addListener();

     }

     delegates.put(delegate, Boolean.FALSE);

   }

   public synchronized void stopObserving(FirefoxAccounts.SyncStatusListener delegate) {

     delegates.remove(delegate);

     // If we are the last delegate leaving the party, stop listening.

     if (delegates.isEmpty()) {

       removeListener();

     }

   }

 }