Issue 4399 - Add WebView inheritor with ad blocking

libadblockplus-android/src/org/adblockplus/libadblockplus/android/AdblockEngine.java

Index: libadblockplus-android/src/org/adblockplus/libadblockplus/android/AdblockEngine.java
diff --git a/libadblockplus-android/src/org/adblockplus/libadblockplus/android/AdblockEngine.java b/libadblockplus-android/src/org/adblockplus/libadblockplus/android/AdblockEngine.java
new file mode 100644
index 0000000000000000000000000000000000000000..b12740e6f1f358ef9723b7bbcbd0cee0e82a426f
--- /dev/null
+++ b/libadblockplus-android/src/org/adblockplus/libadblockplus/android/AdblockEngine.java
@@ -0,0 +1,313 @@
+/*
+ * This file is part of Adblock Plus <https://adblockplus.org/>,
+ * Copyright (C) 2006-2016 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
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package org.adblockplus.libadblockplus.android;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Locale;
+
+import org.adblockplus.libadblockplus.AppInfo;
+import org.adblockplus.libadblockplus.Filter;
+import org.adblockplus.libadblockplus.FilterChangeCallback;
+import org.adblockplus.libadblockplus.FilterEngine;
+import org.adblockplus.libadblockplus.FilterEngine.ContentType;
+import org.adblockplus.libadblockplus.JsEngine;
+import org.adblockplus.libadblockplus.LogSystem;
+import org.adblockplus.libadblockplus.ShowNotificationCallback;
+import org.adblockplus.libadblockplus.Subscription;
+import org.adblockplus.libadblockplus.UpdateAvailableCallback;
+import org.adblockplus.libadblockplus.UpdateCheckDoneCallback;
+
+import android.content.Context;
+import android.content.pm.PackageInfo;
+import android.content.pm.PackageManager.NameNotFoundException;
+import android.os.Build.VERSION;
+import android.util.Log;
+
+public final class AdblockEngine
+{
+  private static final String TAG = Utils.getTag(AdblockEngine.class);
+
+  private final Context context;
+
+  /*
+   * The fields below are volatile because:
+   *
+   * I encountered JNI related bugs/crashes caused by JNI backed Java objects. It seemed that under
+   * certain conditions the objects were optimized away which resulted in crashes when trying to
+   * release the object, sometimes even on access.
+   *
+   * The only solution that really worked was to declare the variables holding the references
+   * volatile, this seems to prevent the JNI from 'optimizing away' those objects (as a volatile
+   * variable might be changed at any time from any thread).
+   */
+  private volatile JsEngine jsEngine;
+  private volatile FilterEngine filterEngine;
+  private volatile LogSystem logSystem;
+  private volatile AndroidWebRequest webRequest;
+  private volatile UpdateAvailableCallback updateAvailableCallback;
+  private volatile UpdateCheckDoneCallback updateCheckDoneCallback;
+  private volatile FilterChangeCallback filterChangeCallback;
+  private volatile ShowNotificationCallback showNotificationCallback;
+  private final boolean elemhideEnabled;
+
+  private AdblockEngine(final Context context, final boolean enableElemhide)
+  {
+    this.context = context;
+    this.elemhideEnabled = enableElemhide;
+  }
+
+  public static AppInfo generateAppInfo(final Context context, boolean developmentBuild)
+  {
+    String version = "0";
+    try
+    {
+      final PackageInfo info = context.getPackageManager().getPackageInfo(context.getPackageName(), 0);
+      version = info.versionName;
+      if (developmentBuild)
+        version += "." + info.versionCode;
+    }
+    catch (final NameNotFoundException e)
+    {
+      Log.e(TAG, "Failed to get the application version number", e);
+    }
+    final String sdkVersion = String.valueOf(VERSION.SDK_INT);
+    final String locale = Locale.getDefault().toString().replace('_', '-');
+
+    return AppInfo.builder()
+        .setVersion(version)
+        .setApplicationVersion(sdkVersion)
+        .setLocale(locale)
+        .setDevelopmentBuild(developmentBuild)
+        .build();
+  }
+
+  public static AdblockEngine create(final Context context, final AppInfo appInfo, final String basePath)
+  {
+    return create(context, appInfo, basePath, false);
+  }
+
+  public static AdblockEngine create(final Context context, final AppInfo appInfo, final String basePath, boolean enableElemhide)
+  {
+    final AdblockEngine engine = new AdblockEngine(context, enableElemhide);
+
+    engine.jsEngine = new JsEngine(appInfo);
+    engine.jsEngine.setDefaultFileSystem(basePath);
+
+    engine.logSystem = new AndroidLogSystem();
+    engine.jsEngine.setLogSystem(engine.logSystem);
+
+    engine.webRequest = new AndroidWebRequest(enableElemhide);
+    engine.jsEngine.setWebRequest(engine.webRequest);
+
+    engine.filterEngine = new FilterEngine(engine.jsEngine);
+
+    engine.webRequest.updateSubscriptionURLs(engine.filterEngine);
+
+    return engine;
+  }
+
+  public void dispose()
+  {
+    // Safe disposing (just in case)
+    if (this.filterEngine != null)
+    {
+      this.filterEngine.dispose();
+      this.filterEngine = null;
+    }
+
+    if (this.jsEngine != null)
+    {
+      this.jsEngine.dispose();
+      this.jsEngine = null;
+    }
+
+    if (this.logSystem != null)
+    {
+      this.logSystem.dispose();
+      this.logSystem = null;
+    }
+
+    if (this.webRequest != null)
+    {
+      this.webRequest.dispose();
+      this.webRequest = null;
+    }
+
+    if (this.updateAvailableCallback != null)
+    {
+      this.updateAvailableCallback.dispose();
+      this.updateAvailableCallback = null;
+    }
+
+    if (this.updateCheckDoneCallback != null)
+    {
+      this.updateCheckDoneCallback.dispose();
+      this.updateCheckDoneCallback = null;
+    }
+
+    if (this.filterChangeCallback != null)
+    {
+      this.filterChangeCallback.dispose();
+      this.filterChangeCallback = null;
+    }
+
+    if (this.showNotificationCallback != null)
+    {
+      this.showNotificationCallback.dispose();
+      this.showNotificationCallback = null;
+    }
+  }
+
+  public boolean isFirstRun()
+  {
+    return this.filterEngine.isFirstRun();
+  }
+
+  public boolean isElemhideEnabled()
+  {
+    return this.elemhideEnabled;
+  }
+
+  public void setSubscription(final String url)
+  {
+    for (final Subscription s : this.filterEngine.getListedSubscriptions())
+    {
+      s.removeFromList();
+    }
+
+    final Subscription sub = this.filterEngine.getSubscription(url);
+    if (sub != null)
+    {
+      sub.addToList();
+    }
+  }
+
+  public void refreshSubscriptions()
+  {
+    for (final Subscription s : this.filterEngine.getListedSubscriptions())
+    {
+      s.updateFilters();
+    }
+  }
+
+  public boolean isAcceptableAdsEnabled()
+  {
+    final String url = this.filterEngine.getPref("subscriptions_exceptionsurl").toString();
+    List<Subscription> subscriptions = this.filterEngine.getListedSubscriptions();
+    for (Subscription eachSubscription : subscriptions)
+    {
+      if (eachSubscription.getProperty("url").toString().equals(url))
+      {
+        return true;
+      }
+    }
+    return false;
+  }
+
+  public void setAcceptableAdsEnabled(final boolean enabled)
+  {
+    final String url = this.filterEngine.getPref("subscriptions_exceptionsurl").toString();
+    final Subscription sub = this.filterEngine.getSubscription(url);
+    if (sub != null)
+    {
+      if (enabled)
+      {
+        sub.addToList();
+      }
+      else
+      {
+        sub.removeFromList();
+      }
+    }
+  }
+
+  public String getDocumentationLink()
+  {
+    return this.filterEngine.getPref("documentation_link").toString();
+  }
+
+  public boolean matches(final String fullUrl, final ContentType contentType, final String[] referrerChainArray)
+  {
+    final Filter filter = this.filterEngine.matches(fullUrl, contentType, referrerChainArray);
+
+    if (filter == null)
+    {
+      return false;
+    }
+
+    // hack: if there is no referrer, block only if filter is domain-specific
+    // (to re-enable in-app ads blocking, proposed on 12.11.2012 Monday meeting)
+    // (documentUrls contains the referrers on Android)
+    try
+    {
+      if (referrerChainArray.length == 0 && (filter.getProperty("text").toString()).contains("||"))
+      {
+        return false;
+      }
+    } catch (NullPointerException e) {
+    }
+
+    return filter.getType() != Filter.Type.EXCEPTION;
+  }
+
+  public boolean isDocumentWhitelisted(final String url, final String[] referrerChainArray)
+  {
+    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 domain, 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(domain);
+  }
+
+  public void checkForUpdates()
+  {
+    this.filterEngine.forceUpdateCheck(this.updateCheckDoneCallback);
+  }
+
+  public FilterEngine getFilterEngine()
+  {
+    return this.filterEngine;
+  }
+}