selectable_item.hpp

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/*
    Copyright (C) 2007 - 2024
    by Mark de Wever <koraq@xs4all.nl>
    Part of the Battle for Wesnoth Project https://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.
*/
 
#pragma once
 
#include <functional>
#include <cassert>
 
namespace gui2
{
 
class widget;
 
/**
 * Small abstract helper class.
 *
 * Parts of the engine inherit this class so we can have generic
 * selectable items.
 */
class selectable_item
{
public:
    virtual ~selectable_item()
    {
    }
 
    /** Is the styled_widget selected? */
    virtual unsigned get_value() const = 0;
 
    /** Select the styled_widget. */
    virtual void set_value(unsigned value, bool fire_event = false) = 0;
 
    /** The number of states, that is 2 for normal buttons, 3 for tristate buttons. */
    virtual unsigned num_states() const = 0;
 
    bool get_value_bool() const
    {
        assert(num_states() == 2);
        return get_value() != 0;
    }
 
    void set_value_bool(bool value, bool fire_event = false)
    {
        assert(num_states() == 2);
        return set_value(value, fire_event);
    }
};
 
} // namespace gui2