[Sync] Move //sync to //components/sync.

sync/android/java/src/org/chromium/sync/AndroidSyncSettings.java

-// Copyright 2015 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.sync;
-
-import android.accounts.Account;
-import android.content.ContentResolver;
-import android.content.Context;
-import android.content.SyncStatusObserver;
-import android.os.Bundle;
-import android.os.StrictMode;
-
-import org.chromium.base.Callback;
-import org.chromium.base.ObserverList;
-import org.chromium.base.VisibleForTesting;
-import org.chromium.sync.signin.AccountManagerHelper;
-
-import javax.annotation.concurrent.ThreadSafe;
-
-/**
- * A helper class to handle the current status of sync for Chrome in Android settings.
- *
- * It also provides an observer to be used whenever Android sync settings change.
- *
- * This class is a collection of static methods so that no references to its object can be
- * stored. This is important because tests need to be able to overwrite the object with a
- * mock content resolver and know that no references to the old one are cached.
- *
- * This class must be initialized via updateAccount() on startup if the user is signed in.
- */
-@ThreadSafe
-public class AndroidSyncSettings {
-
-    public static final String TAG = "AndroidSyncSettings";
-
-    /**
-     * Lock for ensuring singleton instantiation across threads.
-     */
-    private static final Object CLASS_LOCK = new Object();
-
-    private static AndroidSyncSettings sInstance;
-
-    private final Object mLock = new Object();
-
-    private final String mContractAuthority;
-
-    private final Context mApplicationContext;
-
-    private final SyncContentResolverDelegate mSyncContentResolverDelegate;
-
-    private Account mAccount = null;
-
-    private boolean mIsSyncable = false;
-
-    private boolean mChromeSyncEnabled = false;
-
-    private boolean mMasterSyncEnabled = false;
-
-    private final ObserverList<AndroidSyncSettingsObserver> mObservers =
-            new ObserverList<AndroidSyncSettingsObserver>();
-
-    /**
-     * Provides notifications when Android sync settings have changed.
-     */
-    public interface AndroidSyncSettingsObserver {
-        public void androidSyncSettingsChanged();
-    }
-
-    private static void ensureInitialized(Context context) {
-        synchronized (CLASS_LOCK) {
-            if (sInstance == null) {
-                SyncContentResolverDelegate contentResolver =
-                        new SystemSyncContentResolverDelegate();
-                sInstance = new AndroidSyncSettings(context, contentResolver);
-            }
-        }
-    }
-
-    @VisibleForTesting
-    public static void overrideForTests(Context context,
-            SyncContentResolverDelegate contentResolver) {
-        synchronized (CLASS_LOCK) {
-            sInstance = new AndroidSyncSettings(context, contentResolver);
-        }
-    }
-
-    /**
-     * @param context the context the ApplicationContext will be retrieved from.
-     * @param syncContentResolverDelegate an implementation of {@link SyncContentResolverDelegate}.
-     */
-    private AndroidSyncSettings(Context context,
-            SyncContentResolverDelegate syncContentResolverDelegate) {
-        mApplicationContext = context.getApplicationContext();
-        mSyncContentResolverDelegate = syncContentResolverDelegate;
-        mContractAuthority = getContractAuthority();
-
-        updateCachedSettings();
-
-        mSyncContentResolverDelegate.addStatusChangeListener(
-                ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS,
-                new AndroidSyncSettingsChangedObserver());
-    }
-
-    /**
-     * Checks whether sync is currently enabled from Chrome for the currently signed in account.
-     *
-     * It checks both the master sync for the device, and Chrome sync setting for the given account.
-     * If no user is currently signed in it returns false.
-     *
-     * @return true if sync is on, false otherwise
-     */
-    public static boolean isSyncEnabled(Context context) {
-        ensureInitialized(context);
-        return sInstance.mMasterSyncEnabled && sInstance.mChromeSyncEnabled;
-    }
-
-    /**
-     * Checks whether sync is currently enabled from Chrome for a given account.
-     *
-     * It checks only Chrome sync setting for the given account,
-     * and ignores the master sync setting.
-     *
-     * @return true if sync is on, false otherwise
-     */
-    @VisibleForTesting
-    public static boolean isChromeSyncEnabled(Context context) {
-        ensureInitialized(context);
-        return sInstance.mChromeSyncEnabled;
-    }
-
-    /**
-     * Checks whether the master sync flag for Android is currently enabled.
-     */
-    public static boolean isMasterSyncEnabled(Context context) {
-        ensureInitialized(context);
-        return sInstance.mMasterSyncEnabled;
-    }
-
-    /**
-     * Make sure Chrome is syncable, and enable sync.
-     */
-    public static void enableChromeSync(Context context) {
-        ensureInitialized(context);
-        sInstance.setChromeSyncEnabled(true);
-    }
-
-    /**
-     * Disables Android Chrome sync
-     */
-    public static void disableChromeSync(Context context) {
-        ensureInitialized(context);
-        sInstance.setChromeSyncEnabled(false);
-    }
-
-    /**
-     * Must be called when a new account is signed in.
-     */
-    public static void updateAccount(Context context, Account account) {
-        ensureInitialized(context);
-        synchronized (sInstance.mLock) {
-            sInstance.mAccount = account;
-            sInstance.updateSyncability();
-        }
-        if (sInstance.updateCachedSettings()) {
-            sInstance.notifyObservers();
-        }
-    }
-
-    /**
-     * Returns the contract authority to use when requesting sync.
-     */
-    public static String getContractAuthority(Context context) {
-        ensureInitialized(context);
-        return sInstance.getContractAuthority();
-    }
-
-    /**
-     * Add a new AndroidSyncSettingsObserver.
-     */
-    public static void registerObserver(Context context, AndroidSyncSettingsObserver observer) {
-        ensureInitialized(context);
-        synchronized (sInstance.mLock) {
-            sInstance.mObservers.addObserver(observer);
-        }
-    }
-
-    /**
-     * Remove an AndroidSyncSettingsObserver that was previously added.
-     */
-    public static void unregisterObserver(Context context, AndroidSyncSettingsObserver observer) {
-        ensureInitialized(context);
-        synchronized (sInstance.mLock) {
-            sInstance.mObservers.removeObserver(observer);
-        }
-    }
-
-    private void setChromeSyncEnabled(boolean value) {
-        synchronized (mLock) {
-            updateSyncability();
-            if (value == mChromeSyncEnabled || mAccount == null) return;
-            mChromeSyncEnabled = value;
-
-            StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
-            mSyncContentResolverDelegate.setSyncAutomatically(mAccount, mContractAuthority, value);
-            StrictMode.setThreadPolicy(oldPolicy);
-        }
-        notifyObservers();
-    }
-
-    /**
-     * Ensure Chrome is registered with the Android Sync Manager iff signed in.
-     *
-     * This is what causes the "Chrome" option to appear in Settings -> Accounts -> Sync .
-     * This function must be called within a synchronized block.
-     */
-    private void updateSyncability() {
-        boolean shouldBeSyncable = mAccount != null;
-        if (mIsSyncable == shouldBeSyncable) return;
-
-        mIsSyncable = shouldBeSyncable;
-
-        StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
-        // Make account syncable if there is one.
-        if (shouldBeSyncable) {
-            mSyncContentResolverDelegate.setIsSyncable(mAccount, mContractAuthority, 1);
-            // This reduces unnecessary resource usage. See http://crbug.com/480688 for details.
-            mSyncContentResolverDelegate.removePeriodicSync(
-                    mAccount, mContractAuthority, Bundle.EMPTY);
-        }
-        StrictMode.setThreadPolicy(oldPolicy);
-
-        // Disable the syncability of Chrome for all other accounts.
-        AccountManagerHelper.get(mApplicationContext).getGoogleAccounts(new Callback<Account[]>() {
-            @Override
-            public void onResult(Account[] accounts) {
-                StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
-                for (Account account : accounts) {
-                    if (!account.equals(mAccount) && mSyncContentResolverDelegate.getIsSyncable(
-                            account, mContractAuthority) > 0) {
-                        mSyncContentResolverDelegate.setIsSyncable(account, mContractAuthority, 0);
-                    }
-                }
-                StrictMode.setThreadPolicy(oldPolicy);
-            }
-        });
-    }
-
-    /**
-     * Helper class to be used by observers whenever sync settings change.
-     *
-     * To register the observer, call AndroidSyncSettings.registerObserver(...).
-     */
-    private class AndroidSyncSettingsChangedObserver implements SyncStatusObserver {
-        @Override
-        public void onStatusChanged(int which) {
-            if (which == ContentResolver.SYNC_OBSERVER_TYPE_SETTINGS) {
-                // Sync settings have changed; update our cached values.
-                if (updateCachedSettings()) {
-                    // If something actually changed, tell our observers.
-                    notifyObservers();
-                }
-            }
-        }
-    }
-
-    /**
-     * Update the three cached settings from the content resolver.
-     *
-     * @return Whether either chromeSyncEnabled or masterSyncEnabled changed.
-     */
-    private boolean updateCachedSettings() {
-        synchronized (mLock) {
-            boolean oldChromeSyncEnabled = mChromeSyncEnabled;
-            boolean oldMasterSyncEnabled = mMasterSyncEnabled;
-
-            StrictMode.ThreadPolicy oldPolicy = StrictMode.allowThreadDiskWrites();
-            if (mAccount != null) {
-                mIsSyncable = mSyncContentResolverDelegate.getIsSyncable(
-                        mAccount, mContractAuthority) == 1;
-                mChromeSyncEnabled = mSyncContentResolverDelegate.getSyncAutomatically(
-                        mAccount, mContractAuthority);
-            } else {
-                mIsSyncable = false;
-                mChromeSyncEnabled = false;
-            }
-            mMasterSyncEnabled = mSyncContentResolverDelegate.getMasterSyncAutomatically();
-            StrictMode.setThreadPolicy(oldPolicy);
-
-            return oldChromeSyncEnabled != mChromeSyncEnabled
-                || oldMasterSyncEnabled != mMasterSyncEnabled;
-        }
-    }
-
-    private void notifyObservers() {
-        for (AndroidSyncSettingsObserver observer : mObservers) {
-            observer.androidSyncSettingsChanged();
-        }
-    }
-
-    private String getContractAuthority() {
-        return mApplicationContext.getPackageName();
-    }
-}