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 <type_traits>
#include <concepts>
#include <memory>
#include "../l10n.hpp"
#include "../concepts.hpp"
 
namespace tt {
template<typename T>
class text_field_widget;
 
template<typename T>
class text_field_delegate {
public:
    using value_type = T;
    using sender_type = text_field_widget<value_type>;
 
    size_t text_width(sender_type &sender) const noexcept
    {
        return 20;
    }
 
    std::vector<std::string> suggestions(sender_type &sender) const noexcept
    {
        return {};
    }
 
    virtual std::string to_string(sender_type &sender, value_type const &value) noexcept
    {
        // XXX Need to pass the current local to format.
        return fmt::format("{}", value);
    }
 
    virtual std::optional<value_type> from_string(sender_type &sender, std::string_view text, l10n &error) noexcept
    {
        try {
            error = {};
            return tt::from_string<value_type>(text);
        } catch (parse_error) {
            error = l10n("Invalid character entered.");
            return {};
        }
    }
};
 
template<typename T>
inline std::shared_ptr<text_field_delegate<T>> text_field_delegate_default() noexcept
{
    static std::shared_ptr<text_field_delegate<T>> delegate = std::make_shared<text_field_delegate<T>>();
    return delegate;
}
 
} // namespace tt