repos/Callback_13/Callback_13.cpp

#include <array>
#include <vector>
#include <map>
#include <iostream>


/*
 *  https://stackoverflow.com/questions/2298242/callback-functions-in-c
 */

enum e_event_code {NONE, EVENT_PRESSED, EVENT_LONG_PRESSED, LV_EVENT_RELEASED, REDRAW };

class cEvents {
public:

    void* user_data = nullptr;
    void* param = nullptr;
    cEvents* prev = nullptr;

    enum e_event_code code;
    uint16_t x;
    uint16_t y;

    cEvents* event_get_code(cEvents* e) {
        std::cout << e->code << std::endl;
        return this;
    }

    bool event_send_code(cEvents* e) {
        return true;
    }
};


class cBaseClass {
    uint8_t age;
    enum { MALE, FEMALE, DIVERS } sex;
    virtual void init() {};
    virtual void run() {};
    virtual void update() {};

};


class myModel : public cBaseClass {
    const char* pClassName = "myModel"; 
};


void player_jump(cEvents& e) {

    std::cout << "player jump" << std::endl;
    std::cout << "x: " << e.x << " / y: " << e.y << std::endl;
    e.x = 36;
    e.y = 47;
};

void player_crouch(cEvents& e) {

    std::cout << "player crouch" << std::endl;
    std::cout << "x: " << e.x << " / y: " << e.y << std::endl;
}


class game_core : public cEvents
{
    // empty eventhandler (default)
    static void emptyEvent(cEvents& e) {
        std::cout << "empty event handler" << std::endl;
    }


public:
    std::array<void(*)(cEvents&), 6> actions;

    game_core() {
#if 0
        for (uint8_t i = 0; i < actions.size(); i++)
            actions[i] = &emptyEvent;
#else
        actions.fill(&emptyEvent);
#endif
    }
    // 
    void execEvent(cEvents& e)
    {
#if 0
        for (const auto act : actions)
         if (act) actions[e.code](e);
           // act (e);
#else
        if (actions[e.code]) actions[e.code](e);
#endif
    }

    // update keybind from menu
    void addEventCb(enum e_event_code key_id, void(*new_action)(cEvents&))
    {
        actions[key_id] = new_action;
    }

    // update keybind from menu
    void delEventCb(enum e_event_code key_id)
    {
        actions[key_id] = &emptyEvent;
    }

};


int main() {
    game_core gc;
    myModel mym;
    cEvents e;

    gc.addEventCb(REDRAW, &player_jump);
    gc.addEventCb(EVENT_PRESSED, &player_crouch);

    e.code = EVENT_PRESSED;
    e.x = 12;
    e.y = 24;
    gc.execEvent(e);

    e.code = REDRAW;
    e.x = 39;
    e.y = 41;
    gc.execEvent(e);

    gc.delEventCb(EVENT_PRESSED);

    e.code = EVENT_PRESSED;
    e.x = 39;
    e.y = 41;
    gc.execEvent(e); 

    return 0;
}