/*
 * Copyright (C) 2007 The Android Open Source Project
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package android.webkit;

import android.content.Context;


The CookieSyncManager is used to synchronize the browser cookie store
between RAM and permanent storage. To get the best performance, browser cookies are
saved in RAM. A separate thread saves the cookies between, driven by a timer.

To use the CookieSyncManager, the host application has to call the following
when the application starts:

CookieSyncManager.createInstance(context)

To set up for sync, the host application has to call

CookieSyncManager.getInstance().startSync()

in Activity.onResume(), and call

CookieSyncManager.getInstance().stopSync()

in Activity.onPause().

To get instant sync instead of waiting for the timer to trigger, the host can
call

CookieSyncManager.getInstance().sync()
 The sync interval is 5 minutes, so you will want to force syncs manually anyway, for instance in WebViewClient.onPageFinished. Note that even sync() happens asynchronously, so don't do it just as your activity is shutting down. 
Deprecated:
The WebView now automatically syncs cookies as necessary. You no longer need to create or use the CookieSyncManager. To manually force a sync you can use the CookieManager method CookieManager.flush which is a synchronous replacement for sync./**
 * The CookieSyncManager is used to synchronize the browser cookie store
 * between RAM and permanent storage. To get the best performance, browser cookies are
 * saved in RAM. A separate thread saves the cookies between, driven by a timer.
 * <p>
 *
 * To use the CookieSyncManager, the host application has to call the following
 * when the application starts:
 * <p>
 *
 * <pre class="prettyprint">CookieSyncManager.createInstance(context)</pre><p>
 *
 * To set up for sync, the host application has to call<p>
 * <pre class="prettyprint">CookieSyncManager.getInstance().startSync()</pre><p>
 *
 * in Activity.onResume(), and call
 * <p>
 *
 * <pre class="prettyprint">
 * CookieSyncManager.getInstance().stopSync()
 * </pre><p>
 *
 * in Activity.onPause().<p>
 *
 * To get instant sync instead of waiting for the timer to trigger, the host can
 * call
 * <p>
 * <pre class="prettyprint">CookieSyncManager.getInstance().sync()</pre><p>
 *
 * The sync interval is 5 minutes, so you will want to force syncs
 * manually anyway, for instance in {@link
 * WebViewClient#onPageFinished}. Note that even sync() happens
 * asynchronously, so don't do it just as your activity is shutting
 * down.
 *
 * @deprecated The WebView now automatically syncs cookies as necessary.
 *             You no longer need to create or use the CookieSyncManager.
 *             To manually force a sync you can use the CookieManager
 *             method {@link CookieManager#flush} which is a synchronous
 *             replacement for {@link #sync}.
 */
@Deprecated
public final class CookieSyncManager extends WebSyncManager {

    private static CookieSyncManager sRef;
    private static boolean sGetInstanceAllowed = false;
    private static final Object sLock = new Object();

    private CookieSyncManager() {
        super(null, null);
    }

    
Singleton access to a CookieSyncManager. An IllegalStateException will be thrown if createInstance(Context) is not called before. 
Returns:
CookieSyncManager/**
     * Singleton access to a {@link CookieSyncManager}. An
     * IllegalStateException will be thrown if
     * {@link CookieSyncManager#createInstance(Context)} is not called before.
     *
     * @return CookieSyncManager
     */
    public static CookieSyncManager getInstance() {
        synchronized (sLock) {
            checkInstanceIsAllowed();
            if (sRef == null) {
                sRef = new CookieSyncManager();
            }
            return sRef;
        }
    }

    
Create a singleton CookieSyncManager within a context
Params:
context – 
Returns:
CookieSyncManager/**
     * Create a singleton CookieSyncManager within a context
     * @param context
     * @return CookieSyncManager
     */
    public static CookieSyncManager createInstance(Context context) {
        synchronized (sLock) {
            if (context == null) {
                throw new IllegalArgumentException("Invalid context argument");
            }
            setGetInstanceIsAllowed();
            return getInstance();
        }
    }

    
sync() forces sync manager to sync now
Deprecated:
Use CookieManager.flush instead./**
     * sync() forces sync manager to sync now
     * @deprecated Use {@link CookieManager#flush} instead.
     */
    @Deprecated
    public void sync() {
        CookieManager.getInstance().flush();
    }

    
Deprecated:
Use CookieManager.flush instead./**
     * @deprecated Use {@link CookieManager#flush} instead.
     */
    @Deprecated
    protected void syncFromRamToFlash() {
        CookieManager.getInstance().flush();
    }

    
resetSync() resets sync manager's timer.
Deprecated:
Calling resetSync is no longer necessary as the WebView automatically
            syncs cookies./**
     * resetSync() resets sync manager's timer.
     * @deprecated Calling resetSync is no longer necessary as the WebView automatically
     *             syncs cookies.
     */
    @Deprecated
    public void resetSync() {
    }

    
startSync() requests sync manager to start sync.
Deprecated:
Calling startSync is no longer necessary as the WebView automatically
            syncs cookies./**
     * startSync() requests sync manager to start sync.
     * @deprecated Calling startSync is no longer necessary as the WebView automatically
     *             syncs cookies.
     */
    @Deprecated
    public void startSync() {
    }

    
stopSync() requests sync manager to stop sync. remove any SYNC_MESSAGE in
the queue to break the sync loop
Deprecated:
Calling stopSync is no longer useful as the WebView
            automatically syncs cookies./**
     * stopSync() requests sync manager to stop sync. remove any SYNC_MESSAGE in
     * the queue to break the sync loop
     * @deprecated Calling stopSync is no longer useful as the WebView
     *             automatically syncs cookies.
     */
    @Deprecated
    public void stopSync() {
    }

    static void setGetInstanceIsAllowed() {
        sGetInstanceAllowed = true;
    }

    private static void checkInstanceIsAllowed() {
        // Prior to Android KK, calling createInstance() or constructing a WebView is
        // a hard pre-condition for calling getInstance(). We retain that contract to aid
        // developers targeting a range of SDK levels.
        if (!sGetInstanceAllowed) {
            throw new IllegalStateException(
                    "CookieSyncManager::createInstance() needs to be called "
                            + "before CookieSyncManager::getInstance()");
        }
    }
}