text_field_delegate.hpp

// Copyright Take Vos 2021.
// Distributed under the Boost Software License, Version 1.0.
// (See accompanying file LICENSE_1_0.txt or copy at https://www.boost.org/LICENSE_1_0.txt)
 
#pragma once
 
#include <string>
#include <string_view>
#include <optional>
#include "../label.hpp"
 
namespace tt {
class text_field_widget;
 
class text_field_delegate {
public:
    using callback_ptr_type = std::shared_ptr<std::function<void()>>;
 
    virtual void init(text_field_widget const &sender) noexcept {}
    virtual void deinit(text_field_widget const &sender) noexcept {}
 
    virtual callback_ptr_type subscribe(text_field_widget &sender, callback_ptr_type const &callback_ptr) noexcept
    {
        return callback_ptr;
    }
 
    template<typename Callback>
    requires(std::is_invocable_v<Callback>) [[nodiscard]] callback_ptr_type
        subscribe(text_field_widget &sender, Callback &&callback) noexcept
    {
        return subscribe(sender, std::make_shared<std::function<void()>>(std::forward<Callback>(callback)));
    }
 
    virtual void unsubscribe(text_field_widget &sender, callback_ptr_type const &callback_ptr) noexcept
    {
    }
 
    virtual std::optional<label> validate(text_field_widget &sender, std::string_view text) noexcept
    {
        return {};
    }
 
    virtual std::string text(text_field_widget &sender) noexcept
    {
        return {};
    }
 
    virtual void set_text(text_field_widget &sender, std::string_view text) noexcept
    {
    }
};
 
} // namespace tt