Made sure FilterEngine instances are always initialized

src/JsEngine.cpp

 /*
  * This file is part of Adblock Plus <http://adblockplus.org/>,
  * Copyright (C) 2006-2013 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 75 matching lines @@
 {
   const Context context(shared_from_this());
   const v8::TryCatch tryCatch;
   const v8::Handle<v8::Script> script = CompileScript(source, filename);
   CheckTryCatch(tryCatch);
   v8::Local<v8::Value> result = script->Run();
   CheckTryCatch(tryCatch);
   return JsValuePtr(new JsValue(shared_from_this(), result));
 }
 
+void AdblockPlus::JsEngine::SetEventCallback(const std::string& eventName,
+    AdblockPlus::JsEngine::EventCallback callback)
+{
+  eventCallbacks[eventName] = callback;
+}
+
+void AdblockPlus::JsEngine::RemoveEventCallback(const std::string& eventName)
+{
+  eventCallbacks.erase(eventName);
+}
+
+void AdblockPlus::JsEngine::TriggerEvent(const std::string& eventName)
+{
+  EventMap::iterator it = eventCallbacks.find(eventName);
+  if (it != eventCallbacks.end())
+    it->second();
+}
+
 void AdblockPlus::JsEngine::Gc()
 {
   while (!v8::V8::IdleNotification());
 }
 
 AdblockPlus::JsValuePtr AdblockPlus::JsEngine::NewValue(const std::string& val)
 {
   const Context context(shared_from_this());
   return JsValuePtr(new JsValue(shared_from_this(),
       v8::String::New(val.c_str(), val.length())));
@@ skipping 95 matching lines @@
     throw std::runtime_error("LogSystem cannot be null");
 
   logSystem = val;
 }
 
 AdblockPlus::JsEngine::Context::Context(const JsEnginePtr jsEngine)
     : locker(jsEngine->isolate), handleScope(),
       contextScope(jsEngine->context)
 {
 }