StateMachine.cpp

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/**
 * \file      StateMachinge.cpp
 * \brief     State Machine Class Implementation
 * \authors   Michael Göttlicher
 * \copyright http://opensource.org/licenses/GPL-3.0
 * \remarks   Please use clangformat to format the code. See more code style on
 *            https://github.com/cpvrlab/SLProject4/wiki/SLProject-Coding-Style
 */
 
#include "StateMachine.h"
#include <sstream>
 
#define LOG_STATEMACHINE_WARN(...) Utils::log("StateMachine", __VA_ARGS__);
#define LOG_STATEMACHINE_INFO(...) Utils::log("StateMachine", __VA_ARGS__);
#define LOG_STATEMACHINE_DEBUG(...) Utils::log("StateMachine", __VA_ARGS__);
 
namespace sm
{
//-----------------------------------------------------------------------------
StateMachine::StateMachine(unsigned int initialStateId)
  : _currentStateId(initialStateId)
{
}
//-----------------------------------------------------------------------------
StateMachine::~StateMachine()
{
    for (auto it : _stateActions)
    {
        delete it.second;
    }
};
//-----------------------------------------------------------------------------
bool StateMachine::update()
{
    sm::EventData* data            = nullptr;
    bool           stateEntry      = false;
    bool           stateWasUpdated = false;
    // invoke state action for every valid event, but at least once
    while (!_events.empty())
    {
        Event* e = _events.front();
        _events.pop();
 
        unsigned int newState = e->getNewState(_currentStateId);
        data                  = e->getEventData();
 
        LOG_STATEMACHINE_DEBUG("Event %s received sent by %s",
                               e->name(),
                               e->senderInfo());
 
        if (newState != Event::EVENT_IGNORED)
        {
            if (_currentStateId != newState)
            {
                stateEntry = true;
                LOG_STATEMACHINE_DEBUG("State change: %s -> %s",
                                       getPrintableState(_currentStateId).c_str(),
                                       getPrintableState(newState).c_str());
 
                // inform old state that we will leave it soon
                auto itStateAction = _stateActions.find(_currentStateId);
                if (itStateAction != _stateActions.end())
                {
                    itStateAction->second->invokeStateAction(this,
                                                             data,
                                                             false,
                                                             true);
                }
                else
                {
                    std::stringstream ss;
                    ss << "You forgot to register state "
                       << getPrintableState(_currentStateId)
                       << "!";
                    Utils::exitMsg("StateMachine",
                                   ss.str().c_str(),
                                   __LINE__,
                                   __FILE__);
                }
 
                // update state
                _currentStateId = newState;
            }
            auto itStateAction = _stateActions.find(_currentStateId);
            if (itStateAction != _stateActions.end())
            {
                itStateAction->second->invokeStateAction(this,
                                                         data,
                                                         stateEntry,
                                                         false);
            }
            else
            {
                std::stringstream ss;
                ss << "You forgot to register state "
                   << getPrintableState(_currentStateId)
                   << "!";
                Utils::exitMsg("StateMachine",
                               ss.str().c_str(),
                               __LINE__,
                               __FILE__);
            }
            stateWasUpdated = true;
        }
        else
        {
            LOG_STATEMACHINE_DEBUG("Event %s ignored in state %s",
                                   e->name(),
                                   getPrintableState(_currentStateId).c_str());
        }
 
        delete e;
    }
 
    if (!stateWasUpdated)
        _stateActions[_currentStateId]->invokeStateAction(this, data, stateEntry, false);
 
    // ATTENTION: data ownership is not transferred to state
    delete data;
 
    return true;
}
//-----------------------------------------------------------------------------
}