observableproperty.h

/*
 * Copyright (C) 2016-2017 Pelagicore AB
 *
 * Permission to use, copy, modify, and/or distribute this software for
 * any purpose with or without fee is hereby granted, provided that the
 * above copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
 * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR
 * BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES
 * OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
 * WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION,
 * ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS
 * SOFTWARE.
 *
 * For further information see LICENSE
 */

#include <functional>
#include <vector>

template<typename Type>
class ObservableProperty
{
public:
    typedef std::function<void (const Type &)> Listener;

    ObservableProperty(Type &value) :
        m_value(value)
    {
    }

    void addListener(Listener listener)
    {
        m_listeners.push_back(listener);
    }

    operator const Type &() {
        return m_value;
    }

protected:
    std::vector<Listener> m_listeners;

private:
    const Type &m_value;

};

template<typename Type>
class ObservableWritableProperty :
    public ObservableProperty<Type>
{
public:
    ObservableWritableProperty(Type value) :
        ObservableProperty<Type>(m_value), m_value(value)
    {
    }

    ObservableWritableProperty() :
        ObservableProperty<Type>(m_value)
    {
    }

    void setValueNotify(Type value)
    {
        m_value = value;
        for (auto &listener : ObservableProperty<Type>::m_listeners) {
            listener(getValue());
        }
    }

    const Type &getValue() const
    {
        return m_value;
    }

    ObservableWritableProperty &operator=(const Type &type)
    {
        m_value = type;
        return *this;
    }


private:
    Type m_value;

};