text: /************************************************************************
      created:    Tue Feb 28 2006
      author:     Paul D Turner <paul@cegui.org.uk>
  *************************************************************************/
  /***************************************************************************
   *   Copyright (C) 2004 - 2006 Paul D Turner & The CEGUI Development Team
   *
   *   Permission is hereby granted, free of charge, to any person obtaining
   *   a copy of this software and associated documentation files (the
   *   "Software"), to deal in the Software without restriction, including
   *   without limitation the rights to use, copy, modify, merge, publish,
   *   distribute, sublicense, and/or sell copies of the Software, and to
   *   permit persons to whom the Software is furnished to do so, subject to
   *   the following conditions:
   *
   *   The above copyright notice and this permission notice shall be
   *   included in all copies or substantial portions of the Software.
   *
   *   THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
   *   EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
   *   MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
   *   IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
   *   OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
   *   ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
   *   OTHER DEALINGS IN THE SOFTWARE.
   ***************************************************************************/
  #include "CEGUI/Event.h"
  #include "CEGUI/EventArgs.h"
  
  namespace CEGUI
  {
  
  //----------------------------------------------------------------------------//
  Event::Event(const String& name) :
      d_name(name)
  {
  }
  
  //----------------------------------------------------------------------------//
  Event::~Event()
  {
      for (std::pair<const Group, Connection>& groupAndSlot : d_slots)
      {
          groupAndSlot.second->d_event = nullptr;
          groupAndSlot.second->d_subscriber->cleanup();
      }
  
      d_slots.clear();
  }
  
  //----------------------------------------------------------------------------//
  Event::Connection Event::subscribe(const Event::Subscriber& slot)
  {
      return subscribe(static_cast<Group>(-1), slot);
  }
  
  //----------------------------------------------------------------------------//
  Event::Connection Event::subscribe(Event::Group group,
                                     const Event::Subscriber& slot)
  {
      Event::Connection c(new BoundSlot(group, slot, *this));
      d_slots.insert(std::pair<Group, Connection>(group, c));
      return c;
  }
  
  //----------------------------------------------------------------------------//
  void Event::operator()(EventArgs& args)
  {
      d_isBeingInvoked = true;
  
      // Execute all subscribers, updating the 'handled' state as we go.
      // Erase unsubscribed slots.
      const auto itLast = d_slots.cend();
      for (auto it = d_slots.begin(); it != itLast; )
      {
          // Hold a strong reference to prevent self-destruction
          Connection curr = it->second;
  
          // Call the handler
          if (curr && (*curr->d_subscriber)(args))
              ++args.handled;
  
          // Erase if unsubscribed
          if (!it->second)
              it = d_slots.erase(it);
          else
              ++it;
      }
  
      d_isBeingInvoked = false;
  }
  
  //----------------------------------------------------------------------------//
  void Event::unsubscribe(const BoundSlot& slot)
  {
      // Try to find the slot in our collection
      auto it = std::find_if(d_slots.begin(), d_slots.end(), [&slot](const std::pair<const Group, Connection>& groupAndSlot)
      {
          return (*groupAndSlot.second) == slot;
      });
  
      // Erase our reference to the slot, if we had one.
      // Delay erasing if we are in the middle of the invocation loop.
      if (it != d_slots.end())
      {
          if (d_isBeingInvoked)
              it->second = nullptr;
          else
              d_slots.erase(it);
      }
  }
  
  //----------------------------------------------------------------------------//
  
  }
  