Sync Adapter

AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.rburgosnavas.droidfs" >

    <uses-permission android:name="android.permission.INTERNET" />
    <uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />
    <uses-permission android:name="android.permission.READ_SYNC_SETTINGS"/>
    <uses-permission android:name="android.permission.WRITE_SYNC_SETTINGS"/>
    <uses-permission android:name="android.permission.READ_SYNC_STATS"/>
    <uses-permission android:name="android.permission.AUTHENTICATE_ACCOUNTS"/>
    <uses-permission android:name="android.permission.MANAGE_ACCOUNTS"/>

    <application
        android:allowBackup="true"
        android:icon="@drawable/ic_launcher"
        android:label="@string/app_name"
        android:theme="@style/AppTheme"
        android:enabled="true" >

        <provider
            android:name=".syncadapter.provider.StubProvider"
            android:authorities="com.rburgosnavas.droidfs.provider"
            android:label="droidfs provider"
            android:enabled="true"
            android:exported="false"
            android:syncable="true" >
        </provider>

        <service
            android:name=".syncadapter.SyncService"
            android:enabled="true"
            android:exported="true">
            <intent-filter>
                <action android:name="android.content.SyncAdapter"/>
            </intent-filter>
            <meta-data
                android:name="android.content.SyncAdapter"
                android:resource="@xml/syncadapter" />
        </service>

        <service
            android:name=".syncadapter.AuthenticatorService">
            <intent-filter>
                <action android:name="android.accounts.AccountAuthenticator" />
            </intent-filter>

            <meta-data
                android:name="android.accounts.AccountAuthenticator"
                android:resource="@xml/authenticator" />
        </service>

        <activity
            android:name=".MainActivity"
            android:label="@string/app_name" >
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />

                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <activity
            android:name=".RecentSoundsActivity"
            android:label="@string/title_activity_recent_sounds" >
        </activity>
    </application>

</manifest>

Authenticator.java

package com.rburgosnavas.droidfs.syncadapter;

import android.accounts.AbstractAccountAuthenticator;
import android.accounts.Account;
import android.accounts.AccountAuthenticatorResponse;
import android.accounts.NetworkErrorException;
import android.content.Context;
import android.os.Bundle;
import android.util.Log;

/**
 * Created by rburgosnavas on 12/11/14.
 */
public class Authenticator extends AbstractAccountAuthenticator{
    public Authenticator(Context context) {
        super(context);
        Log.i("Authenticator", "created");
    }

    @Override
    public Bundle editProperties(AccountAuthenticatorResponse response, String accountType) {
        throw new UnsupportedOperationException();
    }

    @Override
    public Bundle addAccount(AccountAuthenticatorResponse response, String accountType, String authTokenType, String[] requiredFeatures, Bundle options) throws NetworkErrorException {
        return null;
    }

    @Override
    public Bundle confirmCredentials(AccountAuthenticatorResponse response, Account account, Bundle options) throws NetworkErrorException {
        return null;
    }

    @Override
    public Bundle getAuthToken(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
        throw new UnsupportedOperationException();
    }

    @Override
    public String getAuthTokenLabel(String authTokenType) {
        throw new UnsupportedOperationException();
    }

    @Override
    public Bundle updateCredentials(AccountAuthenticatorResponse response, Account account, String authTokenType, Bundle options) throws NetworkErrorException {
        throw new UnsupportedOperationException();
    }

    @Override
    public Bundle hasFeatures(AccountAuthenticatorResponse response, Account account, String[] features) throws NetworkErrorException {
        throw new UnsupportedOperationException();
    }
}

authenticator.xml

<?xml version="1.0" encoding="utf-8"?>
<account-authenticator
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:accountType="com.rburgosnavas.droifs"
    android:icon="@drawable/ic_launcher"
    android:smallIcon="@drawable/ic_launcher"
    android:label="@string/app_name"
    />

AuthenticatorService.java

package com.rburgosnavas.droidfs.syncadapter;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class AuthenticatorService extends Service {
    private Authenticator authenticator;

    @Override
    public void onCreate() {
        super.onCreate();
        authenticator = new Authenticator(this);
        Log.i("AuthenticatorService", "created");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("AuthenticatorService", "on start command");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i("AuthenticatorService", "destroyed");
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.i("AuthenticatorService", "unbound");
        return super.onUnbind(intent);
    }

    @Override
    public void onRebind(Intent intent) {
        super.onRebind(intent);
        Log.i("AuthenticatorService", "rebound");
    }

    @Override
    public IBinder onBind(Intent intent) {
        // TODO: Return the communication channel to the service.
        Log.i("AuthenticatorService", "binding...");
        return authenticator.getIBinder();
    }
}

AuthenticatorSyncAdapter.java

package com.rburgosnavas.droidfs.syncadapter;

import android.accounts.Account;
import android.content.AbstractThreadedSyncAdapter;
import android.content.ContentProviderClient;
import android.content.Context;
import android.content.SharedPreferences;
import android.content.SyncResult;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;

import com.google.gson.JsonObject;
import com.google.gson.JsonParser;
import com.rburgosnavas.droidfs.clients.HttpAuthClient;
import com.rburgosnavas.droidfs.utils.AuthUtils;

import java.io.IOException;
import java.util.Calendar;

/**
 * Created by rburgosnavas on 12/11/14.
 */
public class AuthenticatorSyncAdapter extends AbstractThreadedSyncAdapter{
    private static final String TAG = AuthenticatorSyncAdapter.class.getSimpleName();
    private SharedPreferences prefs;

    public AuthenticatorSyncAdapter(Context context, boolean autoInitialize) {
        super(context, autoInitialize);
        Log.i(TAG, "sync adapter created");
        prefs = context.getSharedPreferences("OAUTH_PREFS", Context.MODE_PRIVATE);
    }

    public AuthenticatorSyncAdapter(Context context, boolean autoInitialize,
                                    boolean allowParallelSyncs) {
        super(context, autoInitialize, allowParallelSyncs);
        Log.i(TAG, "sync adapter created");
        prefs = context.getSharedPreferences("OAUTH_PREFS", Context.MODE_PRIVATE);
    }

    @Override
    public void onPerformSync(Account account, Bundle extras, String authority,
                              ContentProviderClient provider, SyncResult syncResult) {
        Log.w(TAG, "performing sync");

        if (prefs.contains("ACCESS_TOKEN")) {
            long expiration = prefs.getLong("EXPIRATION_TIMESTAMP", -1);

            if (AuthUtils.isExpired(expiration)) {
                Log.w(TAG, "access_token=" + prefs.getString("ACCESS_TOKEN", "") + " expired.");

                final String refreshToken = prefs.getString("REFRESH_TOKEN", "");

                if (!"".equals(refreshToken)) {
                    // TODO network IO

                    new AsyncTask<String, String, JsonObject>() {
                        @Override
                        protected void onPreExecute() {
                            super.onPreExecute();
                        }

                        @Override
                        protected void onPostExecute(JsonObject token) {
                            super.onPostExecute(token);
                            SharedPreferences prefs = getContext().getSharedPreferences("OAUTH_PREFS", Context.MODE_PRIVATE);
                            SharedPreferences.Editor editor = prefs.edit();
                            editor.putString("ACCESS_TOKEN", token.get("access_token").getAsString());

                            Calendar c = Calendar.getInstance();
                            editor.putLong("ACCESS_TIMESTAMP", c.getTimeInMillis());

                            int time = token.get("expires_in").getAsInt();
                            c.set(Calendar.SECOND, time);

                            editor.putInt("EXPIRES_IN", time);
                            editor.putLong("EXPIRATION_TIMESTAMP", c.getTimeInMillis());
                            editor.putString("REFRESH_TOKEN", token.get("refresh_token").getAsString());
                            editor.apply();
                        }

                        @Override
                        protected void onProgressUpdate(String... values) {
                            super.onProgressUpdate(values);
                        }

                        @Override
                        protected void onCancelled(JsonObject jsonObject) {
                            super.onCancelled(jsonObject);
                        }

                        @Override
                        protected JsonObject doInBackground(String... params) {
                            String bodyString = null;
                            try {
                                Log.i(TAG, "getting refresh token");
                                bodyString = HttpAuthClient.getRefreshToken(params[0]).body().string();
                                Log.i(TAG, "RESPONSE = " + bodyString);
                            } catch (IOException e) {
                                e.printStackTrace();
                            }

                            JsonObject j = new JsonParser().parse(bodyString).getAsJsonObject();

                            return j;
                        }
                    };
                }
            } else {
                Log.i(TAG, "access_token=" + prefs.getString("ACCESS_TOKEN", "") + " valid.");
            }
        }
    }
}

MainActivity.java

package com.rburgosnavas.droidfs;

import // ...

public class MainActivity extends Activity implements LoginWebViewClient.OnAuthorizationCodeListener, AuthTask.AuthListener {
    // Constants ----------------------------------------------------------------------------------
    private static final String TAG = MainActivity.class.getSimpleName();

    // ...    
    private SharedPreferences prefs;
    private Account account;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        createSyncAccount(this);

        prefs = getApplicationContext().getSharedPreferences("OAUTH_PREFS", Context.MODE_PRIVATE);

        // ...
    }

    // ...

    /**
     * Create a new dummy account for the sync adapter
     *
     * @param context The application context
     */
    public static void createSyncAccount(Context context) {
        // Create the account type and default account
        Account newAccount = new Account("Test Account", "com.rburgosnavas.droifs");
        Log.i(TAG, "account created");

        // Get an instance of the Android account manager
        AccountManager accountManager = (AccountManager) context.getSystemService(ACCOUNT_SERVICE);
        /*
         * Add the account and account type, no password or user data
         * If successful, return the Account object, otherwise report an error.
         */
        boolean isAdded = accountManager.addAccountExplicitly(newAccount, null, null);
        if (isAdded) {
            ContentResolver.setIsSyncable(newAccount, "com.rburgosnavas.droidfs.provider", 1);
            ContentResolver.setSyncAutomatically(newAccount, "com.rburgosnavas.droidfs.provider", true);
            ContentResolver.addPeriodicSync(newAccount, "com.rburgosnavas.droidfs.provider", Bundle.EMPTY, 60);
            Log.i(TAG, "added periodically");
        } else {
            Log.i(TAG, "request sync");
            ContentResolver.requestSync(newAccount, "com.rburgosnavas.droidfs.provider", Bundle.EMPTY);
        }
    }
}

syncadapter.xml

<?xml version="1.0" encoding="utf-8"?>
<sync-adapter
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:contentAuthority="com.rburgosnavas.droifs.provider"
    android:accountType="com.rburgosnavas.droifs"
    android:userVisible="true"
    android:supportsUploading="false"
    android:allowParallelSyncs="false"
    android:isAlwaysSyncable="false"/>

SyncService.java

package com.rburgosnavas.droidfs.syncadapter;

import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.util.Log;

public class SyncService extends Service {
    private static AuthenticatorSyncAdapter syncAdapter = null;
    private static final Object syncAdapterLock = new Object();

    @Override
    public void onCreate() {
        super.onCreate();
        Log.i("SyncService", "service created");
        synchronized (syncAdapterLock) {
            if (syncAdapter == null) {
                syncAdapter = new AuthenticatorSyncAdapter(getApplicationContext(), true);
                Log.i("SyncService", "SyncAdapter created");
            }
        }
    }

    @Override
    public void onDestroy() {
        super.onDestroy();
        Log.i("SyncService", "service destroyed");
    }

    @Override
    public boolean onUnbind(Intent intent) {
        Log.i("SyncService", "service unbound | intent=" + intent.getDataString());
        return super.onUnbind(intent);
    }

    @Override
    public void onRebind(Intent intent) {
        super.onRebind(intent);
        Log.i("SyncService", "service rebound");
    }

    @Override
    public int onStartCommand(Intent intent, int flags, int startId) {
        Log.i("SyncService", "on start command");
        return super.onStartCommand(intent, flags, startId);
    }

    @Override
    public IBinder onBind(Intent intent) {
        Log.i("SyncService", "binding...");
        return syncAdapter.getSyncAdapterBinder();
    }
}