michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: package org.mozilla.gecko.fxa.sync;
michael@0: 
michael@0: import java.util.Map;
michael@0: import java.util.Map.Entry;
michael@0: import java.util.WeakHashMap;
michael@0: 
michael@0: import org.mozilla.gecko.fxa.FirefoxAccounts;
michael@0: import org.mozilla.gecko.fxa.authenticator.AndroidFxAccount;
michael@0: 
michael@0: import android.content.ContentResolver;
michael@0: import android.content.SyncStatusObserver;
michael@0: 
michael@0: /**
michael@0:  * Abstract away some details of Android's SyncStatusObserver.
michael@0:  * <p>
michael@0:  * Provides a simplified sync started/sync finished delegate.
michael@0:  */
michael@0: public class FxAccountSyncStatusHelper implements SyncStatusObserver {
michael@0:   @SuppressWarnings("unused")
michael@0:   private static final String LOG_TAG = FxAccountSyncStatusHelper.class.getSimpleName();
michael@0: 
michael@0:   protected static FxAccountSyncStatusHelper sInstance = null;
michael@0: 
michael@0:   public synchronized static FxAccountSyncStatusHelper getInstance() {
michael@0:     if (sInstance == null) {
michael@0:       sInstance = new FxAccountSyncStatusHelper();
michael@0:     }
michael@0:     return sInstance;
michael@0:   }
michael@0: 
michael@0:   // Used to unregister this as a listener.
michael@0:   protected Object handle = null;
michael@0: 
michael@0:   // Maps delegates to whether their underlying Android account was syncing the
michael@0:   // last time we observed a status change.
michael@0:   protected Map<FirefoxAccounts.SyncStatusListener, Boolean> delegates = new WeakHashMap<FirefoxAccounts.SyncStatusListener, Boolean>();
michael@0: 
michael@0:   @Override
michael@0:   public synchronized void onStatusChanged(int which) {
michael@0:     for (Entry<FirefoxAccounts.SyncStatusListener, Boolean> entry : delegates.entrySet()) {
michael@0:       final FirefoxAccounts.SyncStatusListener delegate = entry.getKey();
michael@0:       final AndroidFxAccount fxAccount = new AndroidFxAccount(delegate.getContext(), delegate.getAccount());
michael@0:       final boolean active = fxAccount.isCurrentlySyncing();
michael@0:       // Remember for later.
michael@0:       boolean wasActiveLastTime = entry.getValue();
michael@0:       // It's okay to update the value of an entry while iterating the entrySet.
michael@0:       entry.setValue(active);
michael@0: 
michael@0:       if (active && !wasActiveLastTime) {
michael@0:         // We've started a sync.
michael@0:         delegate.onSyncStarted();
michael@0:       }
michael@0:       if (!active && wasActiveLastTime) {
michael@0:         // We've finished a sync.
michael@0:         delegate.onSyncFinished();
michael@0:       }
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   protected void addListener() {
michael@0:     final int mask = ContentResolver.SYNC_OBSERVER_TYPE_ACTIVE;
michael@0:     if (this.handle != null) {
michael@0:       throw new IllegalStateException("Already registered this as an observer?");
michael@0:     }
michael@0:     this.handle = ContentResolver.addStatusChangeListener(mask, this);
michael@0:   }
michael@0: 
michael@0:   protected void removeListener() {
michael@0:     Object handle = this.handle;
michael@0:     this.handle = null;
michael@0:     if (handle != null) {
michael@0:       ContentResolver.removeStatusChangeListener(handle);
michael@0:     }
michael@0:   }
michael@0: 
michael@0:   public synchronized void startObserving(FirefoxAccounts.SyncStatusListener delegate) {
michael@0:     if (delegate == null) {
michael@0:       throw new IllegalArgumentException("delegate must not be null");
michael@0:     }
michael@0:     if (delegates.containsKey(delegate)) {
michael@0:       return;
michael@0:     }
michael@0:     // If we are the first delegate to the party, start listening.
michael@0:     if (delegates.isEmpty()) {
michael@0:       addListener();
michael@0:     }
michael@0:     delegates.put(delegate, Boolean.FALSE);
michael@0:   }
michael@0: 
michael@0:   public synchronized void stopObserving(FirefoxAccounts.SyncStatusListener delegate) {
michael@0:     delegates.remove(delegate);
michael@0:     // If we are the last delegate leaving the party, stop listening.
michael@0:     if (delegates.isEmpty()) {
michael@0:       removeListener();
michael@0:     }
michael@0:   }
michael@0: }