pump.hpp

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/*
   Copyright (C) 2003 - 2016 by David White <[email protected]>
   Part of the Battle for Wesnoth Project http://www.wesnoth.org/

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.
   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY.

   See the COPYING file for more details.
*/

/**
 * @file
 * Define the game's event mechanism.
 *
 * Events might be units moving or fighting, or when victory or defeat occurs.
 * A scenario's configuration file will define actions to take when certain events occur.
 * This module is responsible for the processing of events.
 *
 * Note that game events have nothing to do with SDL events,
 * like mouse movement, keyboard events, etc.
 * See events.hpp for how they are handled.
 */

#ifndef GAME_EVENTS_PUMP_H_INCLUDED
#define GAME_EVENTS_PUMP_H_INCLUDED

#include "game_events/entity_location.hpp"
#include "game_events/handlers.hpp"

#include "config.hpp"

#include<string>
#include<sstream>

class game_display;
class vconfig;

namespace lg { class logger; }

namespace game_events
{
    struct queued_event {
        queued_event(const std::string& name, const entity_location& loc1,
                     const entity_location& loc2, const config& data)
            : name(name), loc1(loc1), loc2(loc2), data(data)
        {
            std::replace(this->name.begin(), this->name.end(), ' ',  '_');
        }

        std::string name;
        entity_location loc1;
        entity_location loc2;
        config data;
    };

    struct pump_impl;

    struct t_context;

    class manager;

    class t_pump {
        boost::scoped_ptr<pump_impl> impl_;
    public:
        t_pump(manager &);
        ~t_pump();
        /// Context: The general environment within which events are processed.
        /// Returns whether or not we believe WML might have changed something.
        bool context_mutated();
        /// Sets whether or not we believe WML might have changed something.
        void context_mutated(bool mutated);
        /// Returns whether or not we are skipping messages.
        bool context_skip_messages();
        /// Sets whether or not we are skipping messages.
        void context_skip_messages(bool skip);

        /// Helper function which determines whether a wml_message text can
        /// really be pushed into the wml_messages_stream, and does it.
        void put_wml_message(const std::string& logger, const std::string& message, bool in_chat);

        /**
         * Function to fire an event.
         *
         * Events may have up to two arguments, both of which must be locations.
         */
        bool fire(const std::string& event,
                  const entity_location& loc1=entity_location::null_entity,
                  const entity_location& loc2=entity_location::null_entity,
                  const config& data=config());

        void raise(const std::string& event,
                   const entity_location& loc1=entity_location::null_entity,
                   const entity_location& loc2=entity_location::null_entity,
                   const config& data=config());

        bool operator()();

        /**
         * Flushes WML messages and errors.
         */
        void flush_messages();

        /**
         * This function can be used to detect when no WML/Lua has been executed.
         */
        size_t wml_tracking();

    private:
        bool filter_event(const event_handler& handler, const queued_event& ev);

        bool process_event(handler_ptr& handler_p, const queued_event& ev);

        void fill_wml_messages_map(std::map<std::string, int>& msg_map, std::stringstream& source);

        void show_wml_messages(std::stringstream& source, const std::string & caption, bool to_cerr);

        void show_wml_errors();

        void show_wml_messages();

        void put_wml_message(lg::logger& logger, const std::string& prefix, const std::string& message, bool in_chat);
    };
}

#endif // GAME_EVENTS_PUMP_H_INCLUDED