ListenerHolder.h

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// -*- C++ -*-
#ifndef RTM_UTIL_LISTENERHOLDER_H
#define RTM_UTIL_LISTENERHOLDER_H
 
#include <mutex>
 
#include <vector>
#include <utility>
 
namespace RTM
{
namespace util
{
  template <typename ListenerClass>
  class ListenerHolder
  {
  public:
    using Entry = std::pair<ListenerClass*, bool>;
    using EntryList = std::vector<Entry>;
    using EntryIterator = typename EntryList::iterator;
    ListenerHolder(ListenerHolder const&) = delete;
    ListenerHolder& operator=(ListenerHolder const&) = delete;
 
    ListenerHolder() = default;
 
    virtual ~ListenerHolder()
    {
      std::lock_guard<std::mutex> guard(m_mutex);
 
      for(auto & listener : m_listeners)
        {
          if (listener.second)
            {
              delete listener.first;
            }
        }
      m_listeners.clear();
    }
 
    virtual void addListener(ListenerClass* listener,
                     bool autoclean)
    {
      std::lock_guard<std::mutex> guard(m_mutex);
      m_listeners.emplace_back(listener, autoclean);
    }
 
    virtual void removeListener(ListenerClass* listener)
    {
      std::lock_guard<std::mutex> guard(m_mutex);
      EntryIterator it(m_listeners.begin());
 
      for (; it != m_listeners.end(); ++it)
        {
          if ((*it).first == listener)
            {
              if ((*it).second)
                {
                  delete (*it).first;
                }
              m_listeners.erase(it);
              return;
            }
        }
    }
 
  protected:
    std::mutex m_mutex;
 
    EntryList m_listeners;
  };
} // namespace util
} // namespace RTM
 
#define LISTENERHOLDER_CALLBACK(func, args)                           \
  do {                                                                \
    std::lock_guard<std::mutex> guard(m_mutex);                       \
    for (auto&& listener : m_listeners)                               \
      {                                                               \
        listener.first->func args;                                    \
      }                                                               \
  } while(0)
 
#endif  // RTM_UITL_LISTENERHOLDER_H