call_back.h

/* ScummVM - Graphic Adventure Engine
 *
 * ScummVM is the legal property of its developers, whose names
 * are too numerous to list here. Please refer to the COPYRIGHT
 * file distributed with this source distribution.
 *
 * 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 3 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; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#ifndef NUVIE_MISC_CALLBACK_H
#define NUVIE_MISC_CALLBACK_H

#include "ultima/nuvie/core/nuvie_defs.h"

namespace Ultima {
namespace Nuvie {

class CallBack;

// general messages
typedef enum {
    CB_TIMED,                /* timer fired (data=uint32:time) */

    ANIM_CB_DONE,            /* animation has finished */
    ANIM_CB_HIT,             /* animation hit a MapEntity (data=MapEntity) */
    ANIM_CB_HIT_WORLD,       /* animation hit some other tile on the map (data=MapCoord) */

    EFFECT_CB_COMPLETE,      /* effect has finished */

    CB_DATA_READY,           /* some data is ready to be retrieved (data=char)*/
    MSGSCROLL_CB_TEXT_READY, /* text is ready to be retrieved (data=Std::string)*/
    CB_INPUT_CANCELED        /* input canceled by user */
} CallbackMessage;


/* Classes inheriting this can send & receive callback messages.
 */
class CallBack {
protected:
    char *callback_user_data; // data set by Caller
    CallBack *callback_target; // Caller: default CallBack that message() sends to

public:
    CallBack()  {
        callback_user_data = nullptr;
        callback_target = nullptr;
    }
    virtual ~CallBack() { }

    // receive message
    virtual uint16 callback(uint16 msg, CallBack *caller, void *data = nullptr) {
        DEBUG(0, LEVEL_WARNING, "Unhandled callback. msg (%x)\n", msg);
        return 0;
    }
    // send message
    uint16 message(uint16 msg, void *msg_data = nullptr, void *my_data = nullptr) {
        if (my_data)
            set_user_data(my_data);
        callback_target->set_user_data(callback_user_data);

        return (callback_target->callback(msg, this, msg_data));
    }

    void set_user_data(void *user_data) {
        callback_user_data = (char *)user_data;
    }
    void set_target(CallBack *t) {
        callback_target = t;
    }
};

} // End of namespace Nuvie
} // End of namespace Ultima

#endif