Issue 3364 - Implement JNI bindings for IsDocument/ElemhideWhitelisted

src/org/adblockplus/android/ABPEngine.java

 /*
  * This file is part of Adblock Plus <https://adblockplus.org/>,
  * Copyright (C) 2006-2015 Eyeo GmbH
  *
  * Adblock Plus is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 3 as
  * published by the Free Software Foundation.
  *
  * Adblock Plus is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
@@ skipping 285 matching lines @@
     return this.filterEngine.isDocumentWhitelisted(url, referrerChainArray);
   }
 
   public boolean isElemhideWhitelisted(final String url, final String[] referrerChainArray)
   {
     return this.filterEngine.isElemhideWhitelisted(url, referrerChainArray);
   }
 
   public List<String> getElementHidingSelectors(final String url, final String[] referrerChainArray)
   {
+    /*
+     * Issue 3364 (https://issues.adblockplus.org/ticket/3364) introduced the
+     * feature to re-enabled element hiding.
+     *
+     * Nothing changes for Adblock Plus for Android, as `this.elemhideEnabled`
+     * is `false`, which results in an empty list being returned and converted
+     * into a `(String[])null` in AdblockPlus.java, which is the only place
+     * this function here is called from Adblock Plus for Android.
+     *
+     * If element hiding is enabled, then this function now first checks for
+     * possible whitelisting of either the document or element hiding for
+     * the given URL and returns an empty list if so. This is needed to
+     * ensure correct functioning of e.g. acceptable ads.
+     */
     if (!this.elemhideEnabled
         || this.isDocumentWhitelisted(url, referrerChainArray)
         || this.isElemhideWhitelisted(url, referrerChainArray))
     {
       return new ArrayList<String>();
     }
     return this.filterEngine.getElementHidingSelectors(url);
   }
 
   public void checkForUpdates()
   {
     this.filterEngine.forceUpdateCheck(this.updateCheckDoneCallback);
   }
 
   public void updateSubscriptionStatus(final String url)
   {
     final Subscription sub = this.filterEngine.getSubscription(url);
     if (sub != null)
     {
       Utils.updateSubscriptionStatus(this.context, sub);
     }
   }
 
   public FilterEngine getFilterEngine()
   {
     return this.filterEngine;
   }
 }