tab_widget.hpp

// Copyright Take Vos 2020-2021.
// 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 "widget.hpp"
#include "grid_widget.hpp"
#include "tab_delegate.hpp"
#include "default_tab_delegate.hpp"
 
namespace tt {
 
class tab_widget final : public widget {
public:
    using super = widget;
    using delegate_type = tab_delegate;
 
    tab_widget(gui_window &window, widget *parent, std::weak_ptr<delegate_type> delegate) noexcept;
 
    template<typename Value>
    tab_widget(gui_window &window, widget *parent, Value &&value) noexcept
        requires(not std::is_convertible_v<Value, weak_or_unique_ptr<delegate_type>>) :
        tab_widget(window, parent, make_unique_default_tab_delegate(std::forward<Value>(value)))
    {
    }
 
    template<typename WidgetType, typename Key, typename... Args>
    WidgetType &make_widget(Key const &key, Args &&...args) noexcept
    {
        tt_axiom(is_gui_thread());
 
        if (auto delegate = _delegate.lock()) {
            delegate->add_tab(*this, static_cast<size_t>(key), std::size(_children));
        }
        auto &widget = super::make_widget<WidgetType>(std::forward<Args>(args)...);
        return widget;
    }
 
    void init() noexcept override;
    void deinit() noexcept override;
    [[nodiscard]] float margin() const noexcept override;
    [[nodiscard]] bool constrain(utc_nanoseconds display_time_point, bool need_reconstrain) noexcept override;
    [[nodiscard]] void layout(utc_nanoseconds display_time_point, bool need_layout) noexcept override;
    [[nodiscard]] widget const *find_next_widget(
        widget const *current_widget,
        keyboard_focus_group group,
        keyboard_focus_direction direction) const noexcept override;
private:
    weak_or_unique_ptr<delegate_type> _delegate;
    typename delegate_type::callback_ptr_type _delegate_callback;
 
    tab_widget(gui_window &window, widget *parent, weak_or_unique_ptr<delegate_type> delegate) noexcept;
    [[nodiscard]] auto find_selected_child() const noexcept;
    [[nodiscard]] auto find_selected_child() noexcept;
    [[nodiscard]] widget const &selected_child() const noexcept;
    void draw_child(draw_context context, utc_nanoseconds displayTimePoint, widget &child) noexcept;
};
 
} // namespace tt