change sync interval on change in code

OpenKeychain/src/main/java/org/sufficientlysecure/keychain/util/Preferences.java

@@ -19,7 +19,9 @@
 package org.sufficientlysecure.keychain.util;
 
 
+import android.accounts.Account;
 import android.annotation.SuppressLint;
+import android.content.ContentResolver;
 import android.content.Context;
 import android.content.SharedPreferences;
 import android.os.Parcel;
@@ -29,6 +31,7 @@ import android.support.annotation.NonNull;
 
 import org.sufficientlysecure.keychain.Constants;
 import org.sufficientlysecure.keychain.Constants.Pref;
+import org.sufficientlysecure.keychain.KeychainApplication;
 import org.sufficientlysecure.keychain.R;
 import org.sufficientlysecure.keychain.service.KeyserverSyncAdapterService;
 
@@ -76,9 +79,8 @@ public class Preferences {
 
     /**
      * Makes android's preference framework write to our file instead of default.
-     * This allows us to use the "persistent" attribute to simplify code, which automatically
+     * This allows us to use the xml "persistent" attribute to simplify code, which automatically
      * writes and reads preference values.
-     * @param manager
      */
     public static void setPreferenceManagerFileAndMode(PreferenceManager manager) {
         manager.setSharedPreferencesName(PREF_FILE_NAME);
@@ -302,6 +304,23 @@ public class Preferences {
 
     }
 
+    /**
+     * @return true if a periodic sync exists and is set to run automatically, false otherwise
+     */
+    public static boolean getKeyserverSyncEnabled(Context context) {
+        Account account = KeychainApplication.createAccountIfNecessary(context);
+
+        if (account == null) {
+            // if the account could not be created for some reason, we can't have a sync
+            return false;
+        }
+
+        String authority = Constants.PROVIDER_AUTHORITY;
+
+        return ContentResolver.getSyncAutomatically(account, authority) &&
+                !ContentResolver.getPeriodicSyncs(account, authority).isEmpty();
+    }
+
     public CacheTTLPrefs getPassphraseCacheTtl() {
         Set<String> pref = mSharedPreferences.getStringSet(Constants.Pref.PASSPHRASE_CACHE_TTLS, null);
         if (pref == null) {